Ugryzienie przez węża – Etiologia i przyczyny

Ugryzienie przez węża
Etiologia i przyczyny

Ugryzienia przez węże, będące ranami wywołanymi przez beznogie gady, stanowią poważny problem zdrowotny, szczególnie w krajach tropikalnych i subtropikalnych. Jad węży, będący złożoną mieszaniną białek i peptydów o działaniu enzymatycznym, wywołuje różnorodne efekty toksyczne, w tym hemotoksyczność (uszkodzenia układu krążenia, koagulopatia, krwawienia), neurotoksyczność (porażenie oddechowe) oraz cytotoksyczność (martwica tkanek). Hemotoksyny i neurotoksyny mogą współistnieć, co komplikuje obraz kliniczny. Koagulopatia wywołana jadem (VICC) różni się mechanizmem od klasycznego DIC i jest spowodowana aktywacją kaskady krzepnięcia przez enzymy podobne do trombiny. Czynniki ryzyka ciężkiego przebiegu obejmują m.in. gatunek i wiek węża, ilość wprowadzonego jadu, lokalizację ugryzienia, czas do podania antytoksyny oraz stan ogólny pacjenta. Wskaźniki złego rokowania to m.in. trombocytopenia, anemia i podwyższony poziom kinazy kreatynowej (CK). Ugryzienia przez żmijowate często prowadzą do poważnych powikłań, takich jak udar niedokrwienny i krwotok śródczaszkowy, a także ostre uszkodzenie nerek (do 32% przypadków). W USA rocznie odnotowuje się około 45 000 ugryzień, z czego 7 000-9 000 to ugryzienia jadowite, a śmiertelność jest niska (<12 zgonów rocznie). W Indiach natomiast śmiertelność jest znacznie wyższa, z około 50 000-60 000 zgonów rocznie.

Etiologia Ugryzienia przez węża

Rodzaje jadowitych węży i ich jad
Okoliczności i czynniki ryzyka ugryzień
Zjawisko „suchego ugryzienia”
Wpływ czynników klimatycznych i środowiskowych

Globalne znaczenie ugryzień przez węże

Czynniki socjoekonomiczne i dostęp do leczenia
Problemy z produkcją i dostępnością antytoksyn

Patofizjologia zatrucia jadem węża

Główne rodzaje toksyn w jadzie węży
Mechanizmy uszkodzenia tkanek
Efekty ogólnoustrojowe jadu węży
Specyfika działania toksyn różnych gatunków węży
Koagulopatia wywołana jadem węży

Czynniki wpływające na ciężkość ugryzienia i prognozy

Czynniki związane z wężem
Czynniki związane z ofiarą
Czynniki związane z ugryzieniem
Markery prognostyczne
Znaczenie czasu do leczenia
Długoterminowe efekty ugryzień

Epidemiologia ugryzień przez węże

Geograficzne występowanie ugryzień
Czynniki ryzyka dla populacji
Statystyki dla Stanów Zjednoczonych
Trendy czasowe i wpływ zmian klimatycznych

Przyczyny i konsekwencje ugryzień przez węże

Kolejne rozdziały

Etiologia Ugryzienia przez węża

Ugryzienie przez węża to rana spowodowana przez beznogie gady. Jad węża jest toksyczną substancją wytwarzaną w gruczołach ślinowych, która pomaga wężowi schwytać ofiarę, chronić się i trawić pokarm. Podczas ugryzienia wąż wprowadza jad przez swoje zęby (kły) do ciała ofiary ¹. Szacuje się, że 50-70% ugryzień przez jadowite węże skutkuje wprowadzeniem jadu do organizmu ofiary ².

Nie wszystkie węże są jadowite. Spośród około 3700 znanych gatunków węży na świecie, tylko około 15% jest uznawanych za niebezpieczne dla ludzi ¹². W Stanach Zjednoczonych jadowite węże stanowią około 20% wszystkich gatunków, a większość śmiertelnych przypadków ugryzień przypisuje się zachodnim i wschodnim grzechotnikom diamentowym ¹².

Rodzaje jadowitych węży i ich jad

Jadowite węże można podzielić na dwie główne rodziny: żmijowate (Viperidae), obejmujące węże grzechotnikowe (ang. pit vipers) oraz zdradnicowate (Elapidae), do których należą węże koralowe, kobry i mamby ¹².

Jad węży jest złożoną mieszaniną białek i peptydów o działaniu enzymatycznym, które mogą powodować różne efekty toksyczne ¹:

Jad żmijowatych jest zazwyczaj hemotoksyczny – atakuje układ krążenia, powoduje krwawienia lub zakłóca zdolność krwi do krzepnięcia ¹²
Jad zdradnicowatych jest głównie neurotoksyczny – zakłóca przewodnictwo nerwowe, powodując porażenie oddechowe ¹²
Niektóre jady mają również działanie cytotoksyczne – powodują zniszczenie tkanek i martwicę ¹²

Ważne jest zrozumienie, że działanie neurotoksyczne i hemotoksyczne nie wykluczają się wzajemnie. Na przykład grzechotniki mogą powodować zarówno krwawienia, jak i działać cytotoksycznie, niszcząc tkanki i powodując martwicę ¹.

Okoliczności i czynniki ryzyka ugryzień

Badania wskazują, że okoliczności ugryzień przez węże są różne, a czynniki ryzyka obejmują ¹²:

Płeć męska (91% ofiar ugryzień) ¹
Celowa interakcja z wężem (19-67% przypadków według różnych badań) ¹²
Spożycie alkoholu (zwiększa 27-krotnie prawdopodobieństwo konieczności podania antytoksyny i 31-krotnie ryzyko zgonu) ¹
Przebywanie w terenie zamieszkiwanym przez jadowite węże ¹
Posiadanie jadowitego węża jako zwierzęcia domowego ¹

Z danych North American Snakebite Registry (NASBR) wynika, że 100% ugryzień wynikających z celowej interakcji z wężem dotyczyło kończyn górnych ¹. W przypadku węży koralowych, większość ugryzień następuje po celowej interakcji z wężem ¹.

Zjawisko „suchego ugryzienia”

Suche ugryzienie (ang. dry bite) to ugryzienie, podczas którego wąż jadowity nie wprowadza jadu do organizmu ofiary. Charakteryzują się one śladami po kłach i zębach, ale brakiem wprowadzonego jadu ¹. Około 25-50% ugryzień przez żmijowate węże to ugryzienia suche ¹²³.

Czynniki wpływające na to, czy wąż wprowadzi jad podczas ugryzienia, obejmują ¹²:

Intencję węża – jeśli wąż jest w postawie obronnej, a nie aktywnie poluje, może wykonać suche ugryzienie jako ostrzeżenie, bez zużywania cennego jadu
Stan fizjologiczny węża, w tym wiek, zdrowie i status reprodukcyjny
Dojrzałość węża – dorosłe osobniki są bardziej oszczędne w używaniu jadu niż młode

Dorosłe węże często decydują o oszczędzaniu jadu, podczas gdy noworodki i młode węże zazwyczaj nie potrafią kontrolować dawkowania jadu i często opróżniają swoje gruczoły jadowe podczas ugryzień ¹.

Wpływ czynników klimatycznych i środowiskowych

Czynniki klimatyczne mają wpływ na częstotliwość ugryzień przez węże. Badania w stanie Georgia (USA) wykazały, że każdy stopień Celsjusza wzrostu temperatury dziennej wiąże się z około 6% wzrostem prawdopodobieństwa ugryzienia przez jadowitego węża ¹. Zmiany klimatu mogą prowadzić do geograficznego przesunięcia ryzyka ugryzień przez węże: na północ w Ameryce Północnej, na południe w Ameryce Południowej i Mozambiku, oraz zwiększenia częstości ugryzień na Sri Lance ¹.

Większość ugryzień przez węże występuje w sezonie wiosennym i letnim, gdy węże są bardziej aktywne ¹². W Indiach ugryzienia przez węże są częstsze latem i podczas pory monsunowej ¹.

Globalne znaczenie ugryzień przez węże

Ugryzienia przez węże stanowią istotny problem zdrowia publicznego na całym świecie, szczególnie w krajach tropikalnych i subtropikalnych ¹. Światowa Organizacja Zdrowia (WHO) sklasyfikowała ugryzienia przez węże jako zaniedbaną chorobę tropikalną (Neglected Tropical Disease) ¹².

Szacunki globalnej skali problemu wskazują, że rocznie dochodzi do ¹²³:

4,5-5,4 miliona ugryzień przez węże
1,8-2,7 miliona przypadków zatrucia jadem
81 000-138 000 zgonów
około 400 000 przypadków trwałego kalectwa (amputacje, trwała niepełnosprawność)

Najwyższa śmiertelność z powodu ugryzień przez węże występuje w Indiach, gdzie co roku dochodzi do około 50 000-60 000 zgonów, co stanowi około połowę wszystkich zgonów na świecie z tego powodu ¹². Analiza krzyżowa narażenia na jadowite węże i dostępności leczenia medycznego wykazała, że 93 miliony ludzi na całym świecie jest wysoce narażonych na śmierć z powodu ugryzienia przez węża ¹.

Czynniki socjoekonomiczne i dostęp do leczenia

Problem ugryzień przez węże dotyka nieproporcjonalnie biedniejsze społeczności, zwłaszcza w obszarach wiejskich krajów o niskim i średnim dochodzie ¹²:

Grupy najwyższego ryzyka obejmują pracowników rolnych, dzieci i społeczności wiejskie
Ofiary często mieszkają daleko od profesjonalnej opieki zdrowotnej – np. w północno-wschodniej Nigerii mediana odległości do najbliższej odpowiednio wyposażonej placówki zdrowotnej wynosi 80 km (około 12 godzin podróży)
Wysokie koszty antytoksyn często przekraczają możliwości finansowe ofiar
W wielu krajach afrykańskich ponad 50% urazów spowodowanych ugryzieniem węża nie jest odpowiednio leczonych

Ograniczony dostęp do wysokiej jakości antytoksyny jest największą przeszkodą w przeżyciu ugryzienia przez węża ¹. Słabości niektórych systemów regulacyjnych prowadzą do licencjonowania nieskutecznych lub niewłaściwych produktów, co w połączeniu ze złymi praktykami zakupowymi i nieefektywnymi strategiami dystrybucji dodatkowo utrudnia dostęp do antytoksyn ¹.

Problemy z produkcją i dostępnością antytoksyn

Dostępność skutecznych antytoksyn stanowi poważne wyzwanie na całym świecie ¹²:

Ze względu na niski popyt, wielu producentów zaprzestało produkcji antytoksyn
Cena niektórych antytoksyn drastycznie wzrosła w ciągu ostatnich 20 lat, czyniąc leczenie niedostępnym dla większości potrzebujących
W sytuacjach, gdy dane dotyczące zatruć jadem węży są niskiej jakości, trudno jest dokładnie określić zapotrzebowanie na antytoksyny
Większość ofiar ugryzień przez węże prawdopodobnie nigdy nie trafia do miejsc, gdzie mogłyby zostać policzone, więc liczba udokumentowanych ofiar lub rynek jest stosunkowo mały

Ograniczone finansowanie i zaniedbanie problemu na poziomie międzynarodowym dodatkowo utrudniają sytuację ¹. W 2019 roku WHO opublikowała strategię dotyczącą zapobiegania i kontroli zatruć jadem węży, której celem jest zmniejszenie o połowę liczby zgonów i przypadków niepełnosprawności spowodowanych ugryzieniami węży do 2030 roku ¹.

Patofizjologia zatrucia jadem węża

Jad węży to złożona mieszanina setek białek o różnorodnym działaniu toksycznym na organizm człowieka ¹. Skład jadu może różnić się nawet w obrębie tego samego gatunku i tego samego kraju, powodując różne efekty w organizmie i reagując różnie na tę samą antytoksynę ¹².

Główne rodzaje toksyn w jadzie węży

W jadzie węży można wyróżnić trzy główne rodzaje toksyn, które prowadzą do różnych uszkodzeń systemowych ¹:

Hemotoksyny – atakują układ krwionośny, powodując zaburzenia krzepnięcia, krwawienia i uszkodzenia naczyń krwionośnych ¹
Neurotoksyny – wpływają na układ nerwowy, blokując przewodnictwo nerwowo-mięśniowe i potencjalnie powodując paraliż oddechowy ¹
Cytotoksyny – powodują bezpośrednie uszkodzenie komórek i tkanek, prowadząc do martwicy ¹

Jad węży żmijowatych zawiera mieszaninę enzymów, które mogą powodować lokalne i ogólnoustrojowe efekty, w tym rabdomiolizę, zespół ciasnoty przedziałów powięziowych, koagulopatię, obrzęk płuc i hipotensję ¹.

Mechanizmy uszkodzenia tkanek

Toksyny powodujące uszkodzenie tkanek można podzielić na dwie główne grupy ¹:

Cytotoksyny – bezpośrednio wpływają na żywotność komórek
Enzymy degradujące macierz pozakomórkową – które dodatkowo mogą pośrednio wywoływać śmierć komórek

Metaloproteinazy jadu węży (SVMPs) obecne w jadzie żmijowatych mogą powodować uszkodzenia integralności naczyń krwionośnych i nadmierną stymulację układu krzepnięcia, prowadząc do niekontrolowanego krwawienia wewnętrznego, które może być śmiertelne ¹.

W przypadku ugryzień przez żmije najczęściej diagnozuje się udar niedokrwienny i krwotok śródczaszkowy, co prowadzi do zgonów ¹. Zarówno hemotoksyny, jak i neurotoksyny przyczyniają się do tych poważnych, śmiertelnych powikłań mózgowych ¹.

Efekty ogólnoustrojowe jadu węży

Zatrucie jadem węża może wpływać na niemal każdy układ organizmu ¹:

Układ krwionośny: koagulopatia, małopłytkowość, hipofibrygenemia, zespół podobny do rozsianego wykrzepiania wewnątrznaczyniowego (DIC) ¹²
Układ nerwowy: osłabienie mięśni, paraliż, zaburzenia czucia i koordynacji ¹
Nefrologia: ostre uszkodzenie nerek, z częstością występowania do 32% po ugryzieniach węży ¹
Układ oddechowy: ostry zespół niewydolności oddechowej (ARDS) ¹
Układ sercowo-naczyniowy: zaburzenia rytmu serca, hipotensja, wstrząs ¹

Mechanizm uszkodzenia nerek w zatruciu jadem węża jest zwykle wieloczynnikowy i wynika z bezpośredniej nefrotoksyczności jadu, zapaści krążeniowej, wewnątrznaczyniowej hemolizy z hemoglobinurią, rozległej martwicy mięśni powodującej mioglobinurię lub koagulopatii wywołanej jadem (VICC) ¹.

Specyfika działania toksyn różnych gatunków węży

Różne gatunki węży produkują jad o różnych właściwościach ¹²:

Rodzina kobr (Elapidae): ich jad może powodować neurotoksyczność, wpływając na mózg, serce, płuca lub inne części ciała. Zatrucie może okazać się śmiertelne w krótkim czasie, jeśli nie zostanie natychmiast leczone.
Żmijowate (Viperidae): ich jad jest ogólnie mniej toksyczny niż jad kobr, ale nadal może prowadzić do poważnych powikłań lub śmierci, jeśli nie zostanie odpowiednio leczony. Większość śmiertelnych powikłań spowodowanych ugryzieniami węży przypisuje się żmijom.
Grzechotniki (Crotalidae): ich jad może powodować poważne uszkodzenia tkanki wokół ugryzienia, a niektóre gatunki (jak grzechotnik z Mojave) mają również składniki neurotoksyczne ¹².

Jad węży koralowych wpływa na aktywność układu nerwowego, ale powoduje niewielkie uszkodzenia tkanki wokół ugryzienia ¹. Dominującymi objawami zatrucia jadem węża koralowego są objawy neurologiczne, z minimalnym obrzękiem i bólem lokalnym. Początek objawów może być opóźniony nawet o 18 godzin ¹.

Koagulopatia wywołana jadem węży

Koagulopatia wywołana jadem węży (Venom-Induced Coagulopathy, VICC) jest istotnym powikłaniem ugryzień przez żmijowate i stanowi odrębny mechanizm od rozsianego wykrzepiania wewnątrznaczyniowego (DIC) ¹:

Podczas gdy DIC powstaje z wieloczynnikowych mechanizmów prowadzących do odkładania fibryny, aktywacja krzepnięcia w VICC pochodzi głównie z prokoagulacyjnej toksyny węża, a nie ze szlaku czynnika tkankowego/czynnika VIIa, który jest zaangażowany w DIC.
Koagulopatia wywołana ugryzieniem węża jest wtórna do enzymu podobnego do trombiny, a nie prawdziwej trombiny, i w związku z tym nie jest hamowana przez antytrombinę III ¹.

Różne proteazy, enzymy esterazy aminokwasów i białka krwotoczne obecne w jadzie żmij mogą aktywować czynniki prokoagulacyjne i wywoływać zaburzenia kaskady krzepnięcia, w tym skazy krwotoczne i VICC ¹.

Czynniki wpływające na ciężkość ugryzienia i prognozy

Ciężkość ugryzienia przez węża i rokowanie zależą od wielu czynników ¹²:

Czynniki związane z wężem

Gatunek i wielkość węża – różne gatunki węży produkują jad o różnej toksyczności i składzie
Ilość wprowadzonego jadu – zależy od wieku węża, jego stanu fizjologicznego i intencji
Wiek węża – młode węże często nie potrafią kontrolować ilości wprowadzanego jadu i mogą wstrzyknąć więcej jadu niż dorosłe osobniki ¹

Czynniki związane z ofiarą

Wiek i ogólny stan zdrowia – dzieci i osoby starsze są bardziej narażone na ciężki przebieg zatrucia ¹
Masa ciała – osoby o mniejszej masie ciała (np. dzieci) mogą otrzymać większą dawkę jadu na kilogram masy ciała ¹
Choroby współistniejące – dłuższy pobyt w szpitalu obserwuje się u pacjentów z nadwagą, co może odzwierciedlać wolniejszy proces gojenia w przypadkach ugryzień przez węże z powodu chorób współistniejących ¹

Czynniki związane z ugryzieniem

Lokalizacja ugryzienia – ugryzienia w obszarach o bogatym unaczynieniu lub bliżej serca mogą powodować szybsze rozprzestrzenianie się jadu
Głębokość ugryzienia – głębsze ugryzienia mogą wprowadzić jad bezpośrednio do naczyń krwionośnych
Czas od ugryzienia do leczenia – skuteczność antytoksyny zależy od tego, jak szybko zostanie podana ¹

Markery prognostyczne

Niektóre parametry laboratoryjne mogą służyć jako wskaźniki złego rokowania w przypadku ugryzień przez węże ¹:

Niska liczba płytek krwi
Niski poziom hemoglobiny
Podwyższony poziom kinazy kreatynowej (CK)

W przypadku uszkodzenia nerek wywołanego jadem węża, martwica korowa nerek (ACN) i mikroangiopatia zakrzepowa (TMA) wiążą się z gorszym rokowaniem i zwykle prowadzą do schyłkowej niewydolności nerek i zależności od dializy w większości przypadków ¹.

Znaczenie czasu do leczenia

Czas od ugryzienia do podania antytoksyny (bite-to-needle time) jest kluczowym czynnikiem wpływającym na długość hospitalizacji i rokowanie ¹. Skuteczność antytoksyny zależy od tego, jak szybko zostanie podana – im wcześniej, tym lepszy efekt ¹.

Głównym problemem w przypadkach ugryzień przez węże jest utrata czasu podczas zgłaszania się, kierowania i transportu do odpowiedniej kliniki w celu leczenia ¹. Intensywne leczenie powinno być rozpoczęte jak najszybciej, ponieważ nieodwracalne skutki działania jadu zaczynają się natychmiast po ugryzieniu ¹.

Długoterminowe efekty ugryzień

Ciężkie zatrucie jadem węża może powodować znaczące długoterminowe efekty ¹²:

Obrzęk kończyn może utrzymywać się przez miesiące po ugryzieniu przez żmijowate
Uszkodzenia tkanek mogą prowadzić do trwałej niepełnosprawności, w tym amputacji kończyn
W niektórych przypadkach osoby stają się krytycznie chore i potrzebują miesięcy na powrót do zdrowia
Możliwe jest wystąpienie ciężkiego wstrząsu, który może prowadzić do udarów
W niektórych przypadkach ludzie tracą część jelit z powodu ograniczonego przepływu krwi, a inni zapadają na niewydolność nerek

W przeciwieństwie do ugryzień żmijowatych, ugryzienia przez węże z rodziny Elapidae (np. węże koralowe) zwykle nie powodują znaczących długoterminowych następstw u pacjentów, którzy przeżyją ¹.

Epidemiologia ugryzień przez węże

Ugryzienia przez węże stanowią istotny problem zdrowotny, szczególnie w Azji Południowej i Południowo-Wschodniej, Afryce Subsaharyjskiej i Ameryce Łacińskiej ¹.

Geograficzne występowanie ugryzień

Częstość występowania ugryzień przez węże różni się znacząco w zależności od regionu ¹²:

W Bangladeszu roczna częstość występowania ugryzień przez węże wynosi 623,4 na 100 000 osobolat (95% CI: 513,4-789,2)
Najwyższą częstość odnotowano w dystrykcie Barisal (2667,7), a najniższą w dystrykcie Sylhet (321,6)
W samym Bangladeszu szacuje się, że 589 919 osób jest kąsanych przez węże, a 6041 umiera z powodu ugryzień przez węże każdego roku

W Indiach około 94% zgonów z powodu ugryzień przez węży miało miejsce na obszarach wiejskich, a 77% zgonów nastąpiło poza szpitalem ¹. Około 1 na 270 osób w Indiach umiera z powodu ugryzień przez węże do 70 roku życia ¹.

Czynniki ryzyka dla populacji

Osoby najbardziej narażone na ugryzienia przez węże to ¹²³:

Mieszkańcy obszarów wiejskich
Pracownicy rolni i rybacy
Pasterze
Myśliwi
Osoby mieszkające w domach o słabej konstrukcji
Osoby bez łatwego dostępu do opieki zdrowotnej

Większość ofiar ugryzień przez węże (71%) doświadcza ugryzień w kończyny dolne ¹.

Statystyki dla Stanów Zjednoczonych

W Stanach Zjednoczonych rocznie zgłasza się około ¹²³:

45 000 ugryzień przez węże
7000-9000 ugryzień przez węże jadowite (prawie wszystkie to ugryzienia przez węże grzechotnikowe)
Mniej niż 12 zgonów rocznie

Zatrucie jadem występuje w około 75% ugryzień przez jadowite węże w USA ¹. Większość śmiertelnych zatruć dotyczy pacjentów płci męskiej, którzy celowo manipulowali wężem; etanol był czynnikiem przyczyniającym się do wielu zatruć ¹.

Przypuszczalnie 95% zgonów spowodowanych ugryzieniami węży w Stanach Zjednoczonych przypisuje się zachodnim i wschodnim grzechotnikom diamentowym ¹².

Trendy czasowe i wpływ zmian klimatycznych

Wskaźniki zgonów z powodu ugryzień przez węże zmniejszyły się w skali krajowej w Indiach, a bezwzględne ryzyko zgonu z powodu ugryzienia przez węża do 70 roku życia spadło z 0,4% do 0,37% między 2001 a 2014 rokiem ¹.

W ostatnich latach w Stanach Zjednoczonych zaobserwowano wzrost częstości ugryzień przez węże, przy czym stany takie jak Teksas odnotowują ponad 50% wzrost liczby zgłoszeń związanych z wężami do ośrodków kontroli zatruć ¹.

Oczekuje się, że zmiany klimatyczne wpłyną na epidemiologię ugryzień przez węże, powodując geograficzne przesunięcie ryzyka – na północ w Ameryce Północnej i na południe w Ameryce Południowej i Mozambiku – oraz wzrost częstości ugryzień na Sri Lance ¹.

Przyczyny i konsekwencje ugryzień przez węże

Ugryzienia przez węże nadal stanowią istotne zagrożenie dla zdrowia publicznego na całym świecie, szczególnie w regionach tropikalnych i subtropikalnych. Etiologia ugryzień przez węże jest złożona i zależy od wielu czynników, w tym gatunku węża, okoliczności ugryzienia, ilości wprowadzonego jadu oraz charakterystyki ofiary ¹.

Jad węży jest kompleksową mieszaniną białek o działaniu enzymatycznym, które mogą powodować różnorodne efekty toksyczne, od lokalnych uszkodzeń tkanek po zagrażające życiu zaburzenia systemowe ¹. Główne typy toksyn w jadzie węży – hemotoksyny, neurotoksyny i cytotoksyny – powodują różne obrazy kliniczne zatrucia, które wymagają specyficznego podejścia terapeutycznego ¹.

Skuteczne leczenie ugryzień przez węże, zwłaszcza podanie odpowiedniej antytoksyny, jest kluczowe dla poprawy rokowania pacjentów ¹. Jednak ograniczony dostęp do wysokiej jakości antytoksyn, szczególnie w obszarach wiejskich krajów rozwijających się, stanowi istotną barierę dla skutecznego leczenia ¹.

Zrozumienie etiologii ugryzień przez węże, mechanizmów działania jadu oraz czynników wpływających na ciężkość zatrucia jest kluczowe dla opracowania skutecznych strategii prewencji i leczenia, które mogą zmniejszyć globalny ciężar tej zaniedbanej choroby tropikalnej ¹.

Kolejne rozdziały

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Wybierz kolejny rozdział z menu poniżej, aby otworzyć nową podstronę kompedium wiedzy i uzyskać szczegółowe informację o leku, substancji lub chorobie.

Materiały źródłowe

#1 Snake Bites: Treatment & Prevention
https://my.clevelandclinic.org/health/diseases/15647-snake-bites
A snake bite is a wound caused by a legless reptile. Snakes are both venomous and nonvenomous. Venom is toxic to humans and can be life-threatening. […] A snake bite can cause an injury and, in some cases, it can be life-threatening. […] Venom is a poisonous substance that a snake makes to help it capture prey, protect itself and digest food. If a snake is venomous, it injects venom through its teeth (fangs) into whatever it bites. […] Yes, snake bites are dangerous. Some types of snake bites are more serious than others: […] Venomous bites: These are dangerous and often life-threatening. They occur when a snake injects venom into your body during a bite. […] An estimated 50% to 70% of venomous snake bites result in envenoming (injecting venom into someone or something) or poisoning.
#1 Epidemiology of snakebites – Wikipedia
https://en.wikipedia.org/wiki/Epidemiology_of_snakebites
Most snakebites are caused by non-venomous snakes. Of the roughly 3,700 known species of snake found worldwide, only 15% are considered dangerous to humans. […] However, some estimates put the number at 1.2 to 5.5 million snakebites, 421,000 envenomings, resulting in perhaps 20,000 deaths, but the actual number of deaths may be as high as 94,000. […] An analysis cross-referencing exposure to venomous snakes and accessibility of medical treatment identified that 93 million people worldwide are highly vulnerable to dying from snakebite. […] Available evidence on the effect of climate change on the epidemiology of snakebite is limited but it is expected that there will be a geographic shift in risk of snakebite: northwards in North America and southwards in South America and in Mozambique, and increase in incidence of bite in Sri Lanka.
#1 Snakebite – Wikipedia
https://en.wikipedia.org/wiki/Snakebite
A snakebite is an injury caused by the bite of a snake, especially a venomous snake. A common sign of a bite from a venomous snake is the presence of two puncture wounds from the animal’s fangs. Sometimes venom injection from the bite may occur. This may result in redness, swelling, and severe pain at the area, which may take up to an hour to appear. The venom may cause bleeding, kidney failure, a severe allergic reaction, tissue death around the bite, or breathing problems. Bites may result in the loss of a limb or other chronic problems or even death. […] The type of snake that most often delivers serious bites depends on the region of the world. In Africa, it is mambas, Egyptian cobras, puff adders, and carpet vipers. In the Middle East, it is carpet vipers and elapids. In Latin America, it is snakes of the Bothrops and Crotalus types, the latter including rattlesnakes. In North America, rattlesnakes are the primary concern, and up to 95% of all snakebite-related deaths in the United States are attributed to the western and eastern diamondback rattlesnakes.
#1 Snakebite – Special Pet Topics – Merck Veterinary Manual
https://www.merckvetmanual.com/special-pet-topics/poisoning/snakebite
Venomous snakes fall into two families: 1) the Elapidae, which include the cobra, mamba, and coral snakes; and 2) the Cortalidae, which include the true vipers (for example, puff adder, Russells viper, and the common European adder) and the pit vipers (for example, rattlesnakes, cottonmouth moccasin, copperhead, and fer-de-lance). Pit vipers and coral snakes are found in North America. […] Crotalid venom is typically toxic to the blood, killing cells and preventing normal clotting. The venom of some crotalid species, for example, the Mojave rattlesnake, also affects the nervous system. […] A venomous snakebite is a true emergency. Rapid examination and appropriate treatment by a veterinarian are paramount. […] Many bites do not result in venom being injected, or are made by nonpoisonous snakes.
#1 Snakebites – Injuries; Poisoning – Merck Manual Professional Edition
https://www.merckmanuals.com/professional/injuries-poisoning/bites-and-stings/snakebites
There are about 3000 snake species throughout the world, and only approximately 15% worldwide and 20% in the United States are dangerous to humans because of venom or toxic salivary secretions. […] Approximately 45,000 snakebites are reported each year to poison centers in the United States (of which 7000 to 8000 are venomous and cause approximately 5 deaths). Rattlesnakes account for the majority of snakebites and almost all deaths. Copperheads and, to a lesser extent, cottonmouths account for most other venomous bites. […] Most fatal envenomations occur in male patients who have deliberately handled the snake; ethanol was a contributing factor in many of the envenomations. […] Outside the United States, fatal snakebites are much more common, accounting for 100,000 deaths yearly. […] Snake venoms are complex substances, chiefly proteins, with enzymatic activity. Although enzymes play an important role, the lethal properties of venom are caused by certain smaller polypeptides.
#1 What happens when youâre bitten by a venomous snake? | Natural History Museum
https://www.nhm.ac.uk/discover/what-does-snake-venom-do-to-you.html
Snakebite can kill over 100,000 people each year and is considered one of the worlds deadliest neglected health issues. […] Venom is thought to have evolved independently at least 100 times. […] Almost all snakes evolved venom to help them hunt but some will also use it defend themselves. […] Two groups of venomous snakes are particularly well known: vipers and elapids. Broadly speaking, the venoms in these two groups do different things to a bite victim. […] Vipers have venoms that are generally haemotoxic. This means they attack the circulatory system. They can cause bleeding or interfere with the bloods ability to clot. […] Elapid venom is typically neurotoxic. This means that it interferes with the transmission of nerve impulses. It generally has an immobilising effect, either making a victims body turn rigid or become limp.
#1 Tissue damaging toxins in snake venoms: mechanisms of action, pathophysiology and treatment strategies | Communications Biology
https://www.nature.com/articles/s42003-024-06019-6
Snakebite envenoming is an important public health issue responsible for mortality and severe morbidity. Where mortality is mainly caused by venom toxins that induce cardiovascular disturbances, neurotoxicity, and acute kidney injury, morbidity is caused by toxins that directly or indirectly destroy cells and degrade the extracellular matrix. […] Tissue-damaging effects are the leading cause of snakebite morbidity, including life-long disabilities such as permanent muscle tissue loss, contractures, hypertrophic scars, chronic ulceration, chronic renal disease, ocular damage and other debilitating pathologies. […] Despite these morbidity rates, considerably less research has been performed on the tissue-damaging effects than on the neurotoxic and haemotoxic effects of venoms. […] Toxins with tissue-damaging capabilities can be broadly divided into two main groups based on the way they affect cells (and thus tissues). These include (a) cytotoxins, defined as toxins that are truly cytotoxic by directly affecting the viability of cells and (b) extracellular matrix (ECM) degrading enzymes, which, in addition to this action, may be indirectly cytotoxic, meaning that cell death occurs as a secondary effect and not by directly damaging the cells.
#1 What happens when youâre bitten by a venomous snake? | Natural History Museum
https://www.nhm.ac.uk/discover/what-does-snake-venom-do-to-you.html
Neurotoxicity and haemotoxicity are not the only effects venoms can have, nor are they mutually exclusive. […] Rattlesnakes can cause horrible bleeding, but their venom is also cytotoxic. This means its tissue destructive and can cause wounds and necrosis. […] With the damage these toxins can do to the integrity of blood vessels and their over-stimulation of the clotting system, SVMPs can result in uncontrollable internal bleeding that is ultimately fatal. […] A bite from a venomous snake isnt always deadly for people. The effects of some species bites can be quite mild. […] The boomslangs potent venom makes it one of the members of Colubridae that causes some of the worst bites in humans. […] Venoms have very complex chemical structures. This is one of the reasons there isnt a universal antivenom that could cure all venomous bites.
#1 Snakebite: Background, Pathophysiology, Etiology
https://emedicine.medscape.com/article/168828-overview
A previous study suggested that most people become envenomated because they are intentionally interacting with the snake. However, data from the North American Snakebite Registry (NASBR), a subregistry of the American College of Medical Toxicology’s Toxicology Investigators Consortium (ToxIC), demonstrated that only 19% of the bites reported between 2013 and 2015 were the result of intentional interaction. Males accounted for 91% of the bite victims, and 100% of bites that resulted from intentional interaction involved the upper extremity. Among US snakes, coral snakes are unique in that most bites do follow intentional interaction with the snake. […] It is a common misconception that most snakebite victims are under the influence of intoxicating substances when they are envenomated. In a study of snakebite reports to the American Association of Poison Control Centers (AAPCC; now America’s Poison Centers), only 608 (0.7%) of 92,751 snakebites were associated with concomitant drug or alcohol use. However, those who used alcohol were 27 times as likely to receive antivenom and 31 times as likely to die from the envenomation compared to those who had not consumed ethanol.
#1 Snake Toxicity – StatPearls – NCBI Bookshelf
https://www.ncbi.nlm.nih.gov/books/NBK557565/
Venomous snakebites generally occur when venomous snakes (most commonly pit vipers) are cornered or startled by humans. Increased interest in warm weather outdoor activities like hiking, backpacking, and fishing, as well as the increasing number of venomous snakes being kept as pets, has increased the number of venomous snakebites in recent decades. Many snakebites do not result in envenomation, although it is initially quite difficult to distinguish between an envenomated and non-envenomated bite. […] In the United States, greater than 95% of snakebites are caused by the Crotalidae („pit viper”) family of snakes, so named because of heat-sensitive „pits” between the eyes and the nostrils used to sense their prey. […] Risk factors for snake bites include male sex, handling or disturbing a snake, and owning a venomous snake.
#1 Dry Bite in Snakes: Causes, Implications, and Management – EcoFriendly Coffee
https://ecofriendlycoffee.org/dry-bite-in-snakes-causes-implications-and-management/
The World Health Organization (WHO) estimates that about 5 million snakebites occur each year, resulting in up to 2.7 million envenomingâs. […] In India, around 90% of snakebites are caused by the âbig fourâ among the crawlers â common krait, Indian cobra, Russellâs viper and saw scaled viper. […] About 50% of snakebite cases can be dry bites. They are characterized by fang and tooth marks and the absence of injected venom. […] Understanding the mechanisms and significance of dry bites offers valuable insights into snake behavior, venom utilization, and the delicate balance between survival strategies and ecological dynamics in snake habitats. […] Several factors can influence whether a snake delivers a dry bite. One factor is the snakeâs intent. If the snake is in a defensive posture rather than actively hunting, it may deliver a dry bite as a warning to deter potential threats without expending valuable venom.
#1 Snakebites – Injuries and Poisoning – Merck Manual Consumer Version
https://www.merckmanuals.com/home/injuries-and-poisoning/bites-and-stings/snakebites
Venomous snakes in the United States include pit vipers (rattlesnakes, copperheads, and cottonmouths) and coral snakes. […] Severe venom injection (envenomation) can cause damage to the bitten extremity, bleeding, and vital organ damage. […] In about 25% of all pit viper bites, venom is not injected. […] The venom of rattlesnakes and other pit vipers damages tissue around the bite. Venom may cause changes in blood cells, prevent blood from clotting, and damage blood vessels, causing them to leak. These changes can lead to internal bleeding and to heart, respiratory, and kidney failure. […] The venom of coral snakes affects nervous system activity but causes little damage to tissue around the bite. […] Envenomation is recognized by the development of characteristic symptoms. […] Venom antidote (antivenom) is the most important part of treatment if venom was injected and symptoms indicate a serious bite. Antivenom contains antibodies that neutralize venoms toxic effects.
#1 Dry Bite in Snakes: Causes, Implications, and Management – EcoFriendly Coffee
https://ecofriendlycoffee.org/dry-bite-in-snakes-causes-implications-and-management/
Furthermore, the physiological state of the snake, including its age, health, and reproductive status, can affect venom production and delivery. […] Adults are thought to be far more judicious than juveniles and will therefore more often deliver a dry bite if they perceive that they are under threat, which usually provides them with enough time to escape. […] This intentional decision to conserve venom can occur in one of two ways: […] While adults exhibit this strategic venom conservation behavior, neonates and juvenile snakes typically lack the ability to control venom metering and often empty their venom glands during bites. […] Dry bites have significant implications for both the snake and the victim. For the snake, delivering a dry bite allows it to conserve venom for hunting and self-defense, ensuring its survival in its natural habitat.
#1 Warmer weather makes venomous snake bites more likely, especially in spring – AGU Newsroom
https://news.agu.org/press-release/warmer-weather-makes-venomous-snake-bites-more-likely-especially-in-spring/
In Georgia, a snake hotspot in the United States, for each degree a day heats up, the odds of getting bitten by a venomous snake increase by nearly 6%. […] Climate change is not only making Georgia hotter but also increasing the likelihood of snake bite, according to a new study. Every degree Celsius of daily temperature increase corresponds with about a 6% increase in snake bites, researchers found. […] Venomous snake bites are classified by the World Health Organization (WHO) as a high-priority neglected tropical disease. […] The occurrence of venomous snake bites was associated with increased maximum daily air temperatures, the researchers found. […] The specific findings only relate to Georgia, but they highlight a pressing need for similar studies to be done in other parts of the world with different climate regimes and snake species.
#1 Self-Assessment Questions – Course #94111: Pit Viper Snakebite Assessment and Treatment – NetCE
https://www.netce.com/studypoints.php?courseid=2541&printable=yes&page=printquestions
By far, most bites to humans occur in the spring and summer. […] Approximately one-third of all bites are non-accidental; that is, the patient was purposefully handling or playing with a venomous snake. […] Most of these deaths can be attributed to complications of the injury, errors in management, or other factors not directly related to snake venom. […] The venom of rattlesnakes is responsible for more deaths, more hospitalizations, and more injuries than the venom of any other animal in North America. […] The eastern diamondback rattlesnake accounts for the majority of deaths from snakebite in the United States. […] Envenomation by the massasauga (Sistrurus catenatus) in general causes edema that is far less severe than with crotalid bites, although it may sometimes be marked in an untreated case.
#1
https://www.scientificdiscovery.dev/p/14-how-many-people-die-from-snakebites
Around 1 in 270 people in India die from snakebites by the age of 70. […] In total, around 50,000 to 60,000 people in India die from snakebites each year. […] Deaths from snakebites are highly spatially concentrated. […] Because snakebite deaths are caused by snakes and poverty together. […] People who die from snakebites tend to live in poor rural parts of these areas, often work in farms, and lack access to hospitals, doctors and treatment. […] In India, snakebite deaths happen more often in summers and during monsoon seasons. […] In India, around 94% of snakebite deaths occurred in rural areas, and 77% occurred out of hospital. […] People who died from snakebites in these areas didn’t just lack access to the cure they also lacked their deaths being counted. […] Snakebite death rates declined nationwide as well, and the absolute risk of dying from snakebite in India by the age of 70 declined from 0.4% to 0.37% between 2001 and 2014. […] The WHO now estimates that a total of 4.5 to 5.4 million people get bitten by snakes per year; that 1.8 to 2.7 million people develop illness from it, and that 81,000 to 138,000 die from its complications worldwide each year.
#1 Snakebite – Wikipedia
https://en.wikipedia.org/wiki/Snakebite
The World Health Organization says snakebites are a „neglected public health issue in many tropical and subtropical countries,” and in 2017, the WHO categorized snakebite envenomation as a Neglected Tropical Disease (Category A). The WHO also estimates that between 4.5 and 5.4 million people are bitten each year, and of those figures, 40-50% develop some kind of clinical illness as a result. Furthermore, the death toll from such an injury could range between 80,000 and 130,000 people per year.
#1
https://www.who.int/news-room/fact-sheets/detail/snakebite-envenoming
An estimated 5.4 million people worldwide are bitten by snakes each year with 1.8 to 2.7 million cases of envenomings. […] Bites by venomous snakes can cause paralysis that may prevent breathing, bleeding disorders that can lead to a fatal haemorrhage, irreversible kidney failure and tissue damage that can cause permanent disability and limb amputation. […] Bites by venomous snakes can cause acute medical emergencies involving severe paralysis that may prevent breathing, cause bleeding disorders that can lead to fatal haemorrhage, cause irreversible kidney failure and severe local tissue destruction that can cause permanent disability and limb amputation. […] Most deaths and serious consequences of snake bites are entirely preventable by making safe and effective antivenoms more widely available and accessible.
#1 Snakebite: Seven bites of inequity | Doctors Without Borders – USA
https://www.doctorswithoutborders.org/latest/snakebite-seven-bites-inequity
About 100,000 people die every year from snakebite, and many more are disabled or disfigured. […] Snakebite claims 138,000 lives a year and leaves many with life-changing injuries. […] For snakebite to have an impact, you need to encounter a snake, but with no protective equipment. […] Living far from professional health care or people who know and understand snakes and their behaviors, people in rural communities are often left to their own devices to cope by themselves. […] In northeastern Nigeria, the median distance to reach the nearest equipped health facility is 50 miles12 hours on average. […] Most of the victimschildren and agricultural and mining workers from rural areas in low- and middle-income countriesare often the poorest of the poor, and simply cant afford to pay out of pocket for expensive treatments.
#1 Snakebite | MSF UK
https://msf.org.uk/issues/snakebite
Snakebite is a hidden health crisis that kills more than 100,000 people a year. […] Although the exact number of global snakebites is unknown, estimates put the number of people bitten by venomous species at 2.7 million a year. […] Of these, some 400,000 will require an amputation or be left with another type of permanent disability. […] Most people bitten by snakes live in tropical or subtropical countries where venomous species are endemic. […] Those most at risk include agricultural workers, children and rural communities. […] Limited access to quality antivenom is the biggest obstacle to surviving a snakebite. […] The high cost of antivenom is a major barrier to people accessing treatment. […] In May 2019, MSF welcomed the release of a long-awaited WHO strategy on the prevention and control of snakebite envenoming, which commits to halving the number of snakebite deaths and cases of disability by 2030.
#1
https://www.who.int/news-room/fact-sheets/detail/snakebite-envenoming
In situations where data on snakebite envenoming are poor, it is difficult to accurately determine the need for antivenoms. […] The weaknesses in some regulatory systems that leads to licensing of ineffective or incorrect products is sometimes coupled to poor procurement practices and inefficient distribution strategies, further hindering access to antivenoms and creating shortages of safe, affordable and effective products. […] Given low demand, several manufacturers have ceased production, and the price of some antivenom products have dramatically increased in the last 20 years, making treatment unaffordable for the majority of those who need it. […] Many believe that unless strong and decisive action is taken quickly, antivenom supply failure is imminent in Africa and in some countries in Asia.
#1 Snakebite: Seven bites of inequity | Doctors Without Borders – USA
https://www.doctorswithoutborders.org/latest/snakebite-seven-bites-inequity
At an international level, snakebite has long been ignored. […] The WHO Global Strategy against snakebite envenoming, which contains, among other things, an ambitious plan to roll out effective antivenoms in Africa, is still grossly underfunded and the few funding programsfor instance that undertaken by the Wellcome Trustwill end soon with no identified new donors to take over. […] Snakebite victimsfarmers, miners, or fishing workerswork in industries that provide us with food, materials, and other essentials.
#1
https://www.bbc.com/news/health-34214029
Snake venom is deadly, with as many as 100,000 people worldwide dying each year from snake bites. […] Snake venom is made up of several hundred proteins which all have a slightly different toxic effect on the human body. […] But, on the whole, there are two main ways snakes make us suffer – by attacking the circulatory system (ie. the blood) and/or the nervous system. […] Haemotoxic venom goes for the bloodstream. […] Neurotoxic venom tends to act more quickly, attacking the nervous system and stopping nerve signals getting through to the muscles. […] Around the area of the bite, necrosis can set in. […] Each year, up to five million people worldwide are estimated to be bitten by snakes. […] But the numbers could be even larger – because many of the worst-affected countries don’t keep data on snakebites and research into this problem is scarce.
#1
https://www.bbc.com/news/health-34214029
Snake venom is produced in glands at the back of the snake’s head and it comes out through the tips of its fangs. […] The venom produced by the snake’s ancient ancestor was relatively simple. But research suggests that it has diversified over time and now venoms are more complex and more toxic than ever before. […] Venoms can vary, even within snake species and within the same country, causing different effects on the body and responding differently to the same anti-venom.
#1 Cerebral Complications of Snakebite Envenoming: Case Studies
https://www.mdpi.com/2072-6651/14/7/436
There are an estimated 5.4 million snakebite cases every year. People with snakebite envenoming suffer from severe complications, or even death. […] Snake venoms are complex mixtures of enzymes, lipids, nucleotides, and carbohydrates. There are three main toxins in snake venom, including hemotoxins, neurotoxins, and cytotoxins, which lead to systematic damage, including cerebral complications. Among the complications, cerebral hemorrhage, ischemic stroke, cerebral infarction, and secondary inflammation frequently occur after viper envenomings due to hemotoxic enzymes such as snake-venom metalloproteinases (SVMPs), coagulant enzymes, and proteolytic enzyme toxicity. Without appropriate treatment, these compounds cause severe irreversible brain edema and fatality. […] In cases of viper bites, most patients were diagnosed with ischemic stroke and intracranial hemorrhage, leading to six deaths.
#1 Snakebites – Injuries; Poisoning – Merck Manual Professional Edition
https://www.merckmanuals.com/professional/injuries-poisoning/bites-and-stings/snakebites
The complex venom of most North American pit vipers has local effects as well as systemic effects such as coagulopathy. […] Venom alters capillary membrane permeability, causing extravasation of electrolytes, albumin, and red blood cells through vessel walls into the envenomated site. […] The venom of most North American pit vipers causes very minor changes in neuromuscular conduction, except for Mojave and eastern diamondback rattlesnake venom, which may cause serious neurologic deficits. […] Coral snakes are the most common elapids found in the United States. Other elapids include cobras and mambas. Venom of these snakes contains primarily neurotoxic components, which cause a presynaptic neuromuscular blockade, potentially causing respiratory paralysis. […] Symptoms and signs of envenomation may be local, systemic, or a combination, depending on degree of envenomation and species of snake.
#1 Snake bites – Symptoms, Causes, Images, and Treatment Options
https://www.epocrates.com/online/diseases/945/snake-bites
Snakebites in the US usually occur during intentional snake exposures, such as snake handling, snake hunts, and aggravating snakes in the wild. […] Crotalinae (pit viper) envenomation may cause significant local and systemic effects including rhabdomyolysis, compartment syndrome, coagulopathy, pulmonary edema, and hypotension. […] Crotalinae antivenom (Crotalidae polyvalent immune Fab) should be administered in Crotalinae envenomations with worsening local toxicity or systemic symptoms.
#1 Cerebral Complications of Snakebite Envenoming: Case Studies
https://www.mdpi.com/2072-6651/14/7/436
This indicates that AV treatment is the key to survival after a venomous snakebite. […] We then discuss the potential underlying molecular mechanisms that cause these complications. […] Cerebral infarctions and hemorrhages are the main causes leading to fatal cases of viper bite. Both hemotoxins and neurotoxins contribute to those severe lethal brain complications. […] To reduce accidental bites, always wearing shoes and pants while walking could be a strategy for preventing viper snakebites.
#1 Self-Assessment Questions – Course #94111: Pit Viper Snakebite Assessment and Treatment – NetCE
https://www.netce.com/studypoints.php?courseid=2541&printable=yes&page=printquestions
Pit viper envenomation can rise to the level of a complex poisoning, affecting every organ system, resulting in coagulopathy and hemoconcentration (early) followed by a decrease in erythrocytes (anemia), thrombocytopenia, hematuria, proteinuria, hematemesis, melena, hemoptysis, epistaxis, and hypotension. […] The impact of the venom on the blood coagulation cascade, coupled with the possibility of hypovolemic shock resulting from leakage of intravascular fluid into the tissues, constitutes the greatest threat to the victim. […] Pit viper venom does not cross the blood brain barrier and thus does not affect the brain directly. […] The presence of mental status changes suggests a comorbidity, prescription or recreational drug use, or the possibility of a cerebral bleed as a result of coagulopathy.
#1 Snakebites – Injuries; Poisoning – Merck Manual Professional Edition
https://www.merckmanuals.com/professional/injuries-poisoning/bites-and-stings/snakebites
Approximately 25% of pit viper bites are dry (venom is not deposited), and no systemic symptoms or signs develop. […] Systemic manifestations of envenomation can include nausea, vomiting, diarrhea, diaphoresis, anxiety, confusion, spontaneous bleeding, fever, chest pain, difficulty breathing, paresthesias, hypotension, and shock. […] Rattlesnake envenomations may induce various coagulation abnormalities, including thrombocytopenia, prolongation of prothrombin time (PT, measured by the INR [international normalized ratio]) or activated partial thromboplastin time (PTT), hypofibrinogenemia, elevated fibrin degradation products, or a combination of these findings, causing a disseminated intravascular coagulation (DIC)-like syndrome. […] Severity of envenomation depends on the following: size and species of the snake (rattlesnakes cottonmouths copperheads), amount of venom injected per bite, number of bites, location and depth of the bite, age, size, and health of the patient, time elapsed before treatment, patients susceptibility (response) to the venom.
#1
https://journals.lww.com/annals-of-medicine-and-surgery/fulltext/2024/01000/neurological_and_neuro_ophthalmological.61.aspx
Snakebites, a major health concern in developing countries, affect rural farming communities. Venom, primarily neurotoxin, injected during a snake bite disrupts the nervous system, causing symptoms like muscle weakness, paralysis, altered sensation, and coordination issues. […] When neurotoxin enters the body by a snake bite, it causes neurological symptoms like muscle weakness, paralysis, altered sensation, and coordination issues. It can also impact the visual system, resulting in neuro-ophthalmological manifestations such as blurred vision, double vision, drooping eyelids, and vision loss. […] Understanding patterns of neurological manifestations contributes valuable insights for the comprehensive management of snakebite. […] Ptosis is a prevalent neurological symptom in various snakebites, often accompanied by respiratory paralysis, limb weakness, dysphasia, and visual disturbances in certain cases. Notably, improvements are observed after ASV treatment, with almost no residual manifestations.
#1 The kidney histopathological spectrum of patients with kidney injury following snakebite envenomation in India: scoping review of five decades | BMC Nephrology | Full Text
https://bmcnephrol.biomedcentral.com/articles/10.1186/s12882-024-03508-y
Snakebite is a public health problem leading to about 58,000 deaths every year in India. Kidney injury subsequent to snakebite envenomation is common with a reported prevalence of up to 32%. […] Acute kidney injury (AKI) after snakebite envenomation is an important cause of mortality and morbidity. The incidence of AKI after snakebite envenomation as a cause of community-acquired AKI has been reported to be as high as 26% in some Indian studies. […] AKI after snakebite envenomation may be associated with snake venom-induced injury mostly due to hemotoxic or myotoxic snakes of the Viperidae, Atractaspidae, Elapidae, and Colubridae families. […] In India Daboia russelii and Echis carinatus are common snake species known to cause AKI. […] The mechanism of kidney injury in snakebite envenomation is usually multifactorial, it is an interplay of various cytokines, vasoactive substances like endothelin, and other immune mediators. It can be attributed to numerous reasons such as direct nephrotoxicity of the venom, circulatory collapse, intravascular hemolysis with hemoglobinuria, extensive myonecrosis causing myoglobinuria, or Venom-Induced Coagulopathy (VICC).
#1 Vasculotoxic snake bite induced multi-organ dysfunction- A case report
https://apjmt.mums.ac.ir/article_18232.html
There are numerous mechanisms responsible for cerebral haemorrhage following snake bite, among which venom-induced consumptive coagulopathy (VICC) and hemorrhagin-induced direct endothelial injury are the most important causes. […] The initiation of acute respiratory distress syndrome (ARDS) after being bitten by a snake is an unusual occurrence that has received insufficient attention in the medical literature. […] A small proportion of patients bitten by venomous snakes, primarily vipers, develop acute kidney injury (AKI). […] Acute tubular necrosis due to persistent hypotension, acute diffuse interstitial nephritis, and extra capillary proliferative glomerulonephritis, myoglobinuria, and rhabdomyolysis due to DIC are some of the important causative factors. […] Mortality in snake bite induced AKI is 120%. […] Despite early and timely management with ASV and blood products, our patient developed significant multi-organ dysfunction due to snake envenomation.
#1 Snake Bite Causes, Symptoms, Diagnosis and Treatment – Cura4U
https://cura4u.com/conditions/snake-bite
There are many different types of snakes, but two types of venomous snakes are most common. The first one is the cobra family. There are around 300 different cobra family species, including coral snakes, mambas, kraits, and sea snakes. Their venomous fangs are short in size and located at the front of the upper jaw. Once they bite someone, their venom can cause neurotoxicity. It can affect your brain, heart, lungs, or other parts of your body. If immediate treatment is not given, it can prove fatal in a short time. […] The second most common type of venomous snakes is vipers. They can be seen in different regions of the United States. There are around 200 species of vipers, including rattlesnakes, cottonmouths, copperheads, etc. They have long fangs that are retractable when not in use. The bite from a viper snake is comparatively less toxic than a cobra snake, but it can still lead to severe complications or can be fatal if not addressed on time. […] Majority of the snake bites that result in fatal complications have been reported to be caused by vipers. […] However, untreated snakebites, especially from a venomous snake, can lead to fatal complications.
#1 Snakebite in Animals: A Brief Refresher
https://www.dvm360.com/view/snakebite-in-animals-a-brief-refresher
The predominant signs of coral snake envenomation are neurologic, with minimal local swelling and pain. The onset of signs may be delayed for up to 18 hours. Signs include tetraparesis, weakness, ataxia, muscle fasciculations, tachypnea, shallow breathing, altered (quiet) mental state, hemolysis, anemia, and hemoglobinuria. Death, when it occurs, is usually caused by respiratory paralysis. […] Severe crotalid envenomation can cause significant long-term effects secondary to tissue necrosis; limb edema may persist for months. Elapid bites usually do not cause significant long-term sequelae in patients that survive.
#1 The kidney histopathological spectrum of patients with kidney injury following snakebite envenomation in India: scoping review of five decades | BMC Nephrology | Full Text
https://bmcnephrol.biomedcentral.com/articles/10.1186/s12882-024-03508-y
Various proteases, amino acid esterase enzymes, and hemorrhagic proteins present in viperine snake venom can activate procoagulant factors and induce coagulation cascade abnormalities including bleeding diathesis and VICC. […] Pigment-induced nephropathy was seen in the cases complicated with intravascular hemolysis leading to hemoglobinuria. It was particularly more common in viper and crotalid snakebites whereas sea snakes were categorically myotoxic. […] The pathogenesis of VICC distinguishes itself from Disseminated Intravascular Coagulation (DIC). While DIC arises from multifaceted mechanisms culminating in fibrin deposition, VICCs coagulation activation originates primarily from a snake procoagulant toxin, not the tissue factor/factor VIIa pathway implicated in DIC. […] The infiltration of various cells such as lymphocytes, monocytes, eosinophils, basophils, and mast cells in the interstitium in cases of ATN was hypothesized to be either a consequence of some immunologically mediated reaction to antigens released from necrotic renal tubules or due to homocytotropic antibody-mediated reaction.
#1 Snake Bites – Cancer Therapy Advisor
https://www.cancertherapyadvisor.com/home/decision-support-in-medicine/pediatrics/snake-bites/
A majority of snake bites are the result of intentional interaction and frequently involve alcohol. […] In general, snake venom composition can vary significantly from snake to snake and is dependent on a host of factors, some of which include snake age, geographic location, and diet. […] Crotalinae (pit vipers) The complex composition of the venom consists of varying proteins or enzymes that work to cause muscle necrosis, cell lysis, and/or increase cell permeability. […] Induced coagulopathy by snake bite envenomation is secondary to thrombin-like enzyme not true thrombin and thus is not inhibited by antithrombin III.
#1
https://www.saem.org/about-saem/academies-interest-groups-affiliates2/cdem/for-students/online-education/m4-curriculum/group-m4-environmental/snake-bites
Viperidae snakes, also known as pit vipers, are identified by their heat-sensing pit organs, fangs, triangular head, and elliptical pupils. The fangs are connected to venom sacs that inject venom. Rattlesnakes account for 65% of Viperidae bites; copperheads are responsible for 25%. The remaining 10% are from water moccasins. […] Elapidae Venom has various toxins which produce systemic neurotoxicity. Coral snake envenomation may present with serious systemic toxicity with little findings at the actual site of envenomation due to the venoms lack of cytotoxicity. The neurologic abnormalities may include weakness, numbness, fasciculations, tremor, diplopia, bulbar palsies with slurred speech, dysphagia and respiratory paralysis (immediate cause of death). […] Because children have smaller body mass, smaller limbs, and less subcutaneous tissue, they can potentially receive more venom per kilogram body weight and therefore have more clinical severity than adults.
#1 Factors Affecting Prognosis in Patients with Snakebite – Eurasian Journal of Emergency Medicine
https://eajem.com/articles/factors-affecting-prognosis-in-patients-with-snakebite/doi/eajem.galenos.2020.69885
The long hospitalisation durations in overweight patients may reflect a slower healing process in snakebite cases due to co-morbidities. […] The long durations of hospitalisation in patients with low platelets, low haemoglobin and elevated CK may lead to interpretation of these markers as poor prognostic indicators.
#1 Snakebites – Injuries and Poisoning – Merck Manual Consumer Version
https://www.merckmanuals.com/home/injuries-and-poisoning/bites-and-stings/snakebites
The effectiveness of antivenom depends on how soon it is given. Antivenom is more effective when it is given within a short time after a snakebite. […] Prognosis depends on the persons age and overall health and on the location and venom content of the bite. Almost everyone bitten by a venomous snake survives if treated early with appropriate amounts of antivenom.
#1 The kidney histopathological spectrum of patients with kidney injury following snakebite envenomation in India: scoping review of five decades | BMC Nephrology | Full Text
https://bmcnephrol.biomedcentral.com/articles/10.1186/s12882-024-03508-y
Vasculotoxic effects and complement activation by the snake venom probably via alternate pathways (based on the C3 without immunoglobulin deposition on the arterial wall) are plausible mechanisms for the pathogenesis of these vascular lesions. […] Kidney biopsies during the initial week are usually not feasible and pose a high risk due to coagulation abnormalities and thrombocytopenia. This is a deterrent in establishing a correlation between structural and functional findings in the kidneys. […] ACN and TMA lesions impart worse prognosis and usually progress to ESKD and dialysis-dependent stages in most cases.
#1 Factors Affecting Prognosis in Patients with Snakebite – Eurasian Journal of Emergency Medicine
https://eajem.com/articles/factors-affecting-prognosis-in-patients-with-snakebite/doi/eajem.galenos.2020.69885
Aim: This study aimed to determine the factors influencing hospitalization durations and discharge status of patients with snakebite, starting from pre-hospital care in the field. […] As it is throughout the whole world, snakebite is an important cause of morbidity and mortality in Turkey. The estimated number of snakebite victims is 421,000, resulting in 20,000 deaths worldwide. […] The species Macrovipera lebetina and Vipera barani comprise most snakes in our region of Turkey. These species toxins cause serious local tissue toxicity due to consumption coagulopathy. […] The major problem we realised in snakebite cases was the time loss during applying, referral and transportation to the adequate clinic for treatment. […] The association between shorter bite-to-needle times and shorter hospitalisation durations shows the importance of early administration of antivenom.
#1 Snakebite – Special Pet Topics – Merck Veterinary Manual
https://www.merckvetmanual.com/special-pet-topics/poisoning/snakebite
Intensive treatment should be started as soon as possible because irreversible effects of venom begin immediately after the bite. […] Antivenin is highly beneficial because its action is the only direct and specific mechanism for neutralizing snake venom. […] Animals bitten by coral snakes or other elapids may be treated with supportive care as needed and antivenom, if available.
#1 Snakebites worldwide: Clinical manifestations and diagnosis – UpToDate
https://www.uptodate.com/contents/snakebites-worldwide-clinical-manifestations-and-diagnosis
Snakebites account for significant morbidity and mortality worldwide, especially in South and Southeast Asia, sub-Saharan Africa, and Latin America. Venomous snakes are widely distributed around the world and clinical effects from envenomation can overlap to a great degree even among different classes of snakes. […] This topic will discuss the clinical manifestations and diagnosis of snakebite worldwide.
#1 Annual Incidence of Snake Bite in Rural Bangladesh | PLOS Neglected Tropical Diseases
https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0000860
Snake bite is a neglected public health problem in the world and one of the major causes of mortality and morbidity in many areas, particularly in the rural tropics. […] The estimated incidence density of snake bite is 623.4 / 100,000 person years (95% C I 513.4789.2 /100,000 person years). […] Incidence density of snake bite in rural Bangladesh is substantially higher than previously estimated. […] Snake bite particularly in the rural tropics is a major cause of mortality and morbidity, and it has a significant impact on human health and economy through treatment related expenditure and loss of productivity. […] The true incidence of snake bite in rural Bangladesh is largely unknown. […] The majority of the victims (71%) received snake bites in lower extremities. […] The majority of the victims (71%) received snake bites in lower extremities.
#1 Snake Bite
https://mobile.fpnotebook.com/ER/Derm/SnkBt.htm
Total: 45,000 Snake Bites in U.S. per year […] Venomous bites: 8000 to 9000 in U.S. per year (almost all are Pit Viper bites) […] Deaths from Snake Bite in U.S.: 12 or less per year […] Envenomation occurs in 75% of U.S. poisonous Snake Bites […] Incidence: 1.8 to 2.7 Million Snake Bites/year worldwide (50% are venomous) […] Roughly 81,000 to 138,000 deaths per year worldwide from Snake Bites […] Roughly 300,000 amputations per year worldwide from Snake Bites […] 95% of deaths (esp. Diamondback) […] Neurotoxic effects may present with findings similar to Botulism […] Venom alters Coagulation Factors (via Thrombin-like Glycoproteins) resulting in consumptive Coagulopathy […] Venom contains a Neurotoxin (primarily affecting Acetylcholine receptors) […] Results in paralysis […] Generalized symptoms may be delayed 1-8 hours (local effects may have onset in first 15 min) […] Systemic complications (develop over time after initial visual effects) […] Delayed Thrombocytopenia (antivenin-refractory) may occur.
#1 Five common snakebite myths, debunked – SERB PharmaceuticalsClose Close
https://serb.com/insights/five-common-snakebite-myths-debunked/
Snakebites are on the rise this year, with states like Texas seeing a more than 50% increase in snake-related calls to their poison control centers. […] Studies have shown that confining the venom to an extremity where the bite occurred actually causes more damage to that area â without providing any benefit to the victim overall. […] Sucking the venom out can cause the poison to spread to the mouth, and the extractor pumps found in snake kits wonât do any better: a study found that one of the most common extractor pumps extracted bloody fluid but virtually no venom. […] While that may be true in other parts of the world, 98% of venomous snakebites in the US are from the North American pit viper, including copperheads, cottonmouths, and rattlesnakes. […] While itâs true that most copperhead bites are not fatal, that doesnât mean theyâre harmless. People have died from such bites (and not just those who have an allergic reaction). Whatâs more, a randomized, double-blind, placebo-controlled study in copperhead envenomation showed prompt treatment results in faster recovery of limb function.
#2 Snake Bites: Treatment & Prevention
https://my.clevelandclinic.org/health/diseases/15647-snake-bites
A snake bite is a wound caused by a legless reptile. Snakes are both venomous and nonvenomous. Venom is toxic to humans and can be life-threatening. […] A snake bite can cause an injury and, in some cases, it can be life-threatening. […] Venom is a poisonous substance that a snake makes to help it capture prey, protect itself and digest food. If a snake is venomous, it injects venom through its teeth (fangs) into whatever it bites. […] Yes, snake bites are dangerous. Some types of snake bites are more serious than others: […] Venomous bites: These are dangerous and often life-threatening. They occur when a snake injects venom into your body during a bite. […] An estimated 50% to 70% of venomous snake bites result in envenoming (injecting venom into someone or something) or poisoning.
#2 Snakebites – Injuries; Poisoning – Merck Manual Professional Edition
https://www.merckmanuals.com/professional/injuries-poisoning/bites-and-stings/snakebites
There are about 3000 snake species throughout the world, and only approximately 15% worldwide and 20% in the United States are dangerous to humans because of venom or toxic salivary secretions. […] Approximately 45,000 snakebites are reported each year to poison centers in the United States (of which 7000 to 8000 are venomous and cause approximately 5 deaths). Rattlesnakes account for the majority of snakebites and almost all deaths. Copperheads and, to a lesser extent, cottonmouths account for most other venomous bites. […] Most fatal envenomations occur in male patients who have deliberately handled the snake; ethanol was a contributing factor in many of the envenomations. […] Outside the United States, fatal snakebites are much more common, accounting for 100,000 deaths yearly. […] Snake venoms are complex substances, chiefly proteins, with enzymatic activity. Although enzymes play an important role, the lethal properties of venom are caused by certain smaller polypeptides.
#2 What happens when youâre bitten by a venomous snake? | Natural History Museum
https://www.nhm.ac.uk/discover/what-does-snake-venom-do-to-you.html
Snakebite can kill over 100,000 people each year and is considered one of the worlds deadliest neglected health issues. […] Venom is thought to have evolved independently at least 100 times. […] Almost all snakes evolved venom to help them hunt but some will also use it defend themselves. […] Two groups of venomous snakes are particularly well known: vipers and elapids. Broadly speaking, the venoms in these two groups do different things to a bite victim. […] Vipers have venoms that are generally haemotoxic. This means they attack the circulatory system. They can cause bleeding or interfere with the bloods ability to clot. […] Elapid venom is typically neurotoxic. This means that it interferes with the transmission of nerve impulses. It generally has an immobilising effect, either making a victims body turn rigid or become limp.
#2
https://www.bbc.com/news/health-34214029
Snake venom is deadly, with as many as 100,000 people worldwide dying each year from snake bites. […] Snake venom is made up of several hundred proteins which all have a slightly different toxic effect on the human body. […] But, on the whole, there are two main ways snakes make us suffer – by attacking the circulatory system (ie. the blood) and/or the nervous system. […] Haemotoxic venom goes for the bloodstream. […] Neurotoxic venom tends to act more quickly, attacking the nervous system and stopping nerve signals getting through to the muscles. […] Around the area of the bite, necrosis can set in. […] Each year, up to five million people worldwide are estimated to be bitten by snakes. […] But the numbers could be even larger – because many of the worst-affected countries don’t keep data on snakebites and research into this problem is scarce.
#2 What happens when youâre bitten by a venomous snake? | Natural History Museum
https://www.nhm.ac.uk/discover/what-does-snake-venom-do-to-you.html
Neurotoxicity and haemotoxicity are not the only effects venoms can have, nor are they mutually exclusive. […] Rattlesnakes can cause horrible bleeding, but their venom is also cytotoxic. This means its tissue destructive and can cause wounds and necrosis. […] With the damage these toxins can do to the integrity of blood vessels and their over-stimulation of the clotting system, SVMPs can result in uncontrollable internal bleeding that is ultimately fatal. […] A bite from a venomous snake isnt always deadly for people. The effects of some species bites can be quite mild. […] The boomslangs potent venom makes it one of the members of Colubridae that causes some of the worst bites in humans. […] Venoms have very complex chemical structures. This is one of the reasons there isnt a universal antivenom that could cure all venomous bites.
#2 Snake Toxicity – StatPearls – NCBI Bookshelf
https://www.ncbi.nlm.nih.gov/books/NBK557565/
Venomous snakebites generally occur when venomous snakes (most commonly pit vipers) are cornered or startled by humans. Increased interest in warm weather outdoor activities like hiking, backpacking, and fishing, as well as the increasing number of venomous snakes being kept as pets, has increased the number of venomous snakebites in recent decades. Many snakebites do not result in envenomation, although it is initially quite difficult to distinguish between an envenomated and non-envenomated bite. […] In the United States, greater than 95% of snakebites are caused by the Crotalidae („pit viper”) family of snakes, so named because of heat-sensitive „pits” between the eyes and the nostrils used to sense their prey. […] Risk factors for snake bites include male sex, handling or disturbing a snake, and owning a venomous snake.
#2 Snakebite injuries: contributing factors and intentionality of exposure – PubMed
https://pubmed.ncbi.nlm.nih.gov/11990155/
The objective was to study the intent of exposure to snakes and other factors contributing to snakebite injuries in order to develop prevention strategies. […] Sixty-seven percent (20/30) of all bites resulted from intentional exposures to snakes: professional snake handlers (7), snake hunts (8), and playing with (aggravating) snakes in the wild (5). […] I concluded that the majority of snakebite injuries resulted from intentional exposures to snakes in which a variety of factors such as the use of alcohol and lack of protective equipment likely played a role.
#2 Snakebites – Injuries; Poisoning – Merck Manual Professional Edition
https://www.merckmanuals.com/professional/injuries-poisoning/bites-and-stings/snakebites
Approximately 25% of pit viper bites are dry (venom is not deposited), and no systemic symptoms or signs develop. […] Systemic manifestations of envenomation can include nausea, vomiting, diarrhea, diaphoresis, anxiety, confusion, spontaneous bleeding, fever, chest pain, difficulty breathing, paresthesias, hypotension, and shock. […] Rattlesnake envenomations may induce various coagulation abnormalities, including thrombocytopenia, prolongation of prothrombin time (PT, measured by the INR [international normalized ratio]) or activated partial thromboplastin time (PTT), hypofibrinogenemia, elevated fibrin degradation products, or a combination of these findings, causing a disseminated intravascular coagulation (DIC)-like syndrome. […] Severity of envenomation depends on the following: size and species of the snake (rattlesnakes cottonmouths copperheads), amount of venom injected per bite, number of bites, location and depth of the bite, age, size, and health of the patient, time elapsed before treatment, patients susceptibility (response) to the venom.
#2 Dry Bite in Snakes: Causes, Implications, and Management – EcoFriendly Coffee
https://ecofriendlycoffee.org/dry-bite-in-snakes-causes-implications-and-management/
Furthermore, the physiological state of the snake, including its age, health, and reproductive status, can affect venom production and delivery. […] Adults are thought to be far more judicious than juveniles and will therefore more often deliver a dry bite if they perceive that they are under threat, which usually provides them with enough time to escape. […] This intentional decision to conserve venom can occur in one of two ways: […] While adults exhibit this strategic venom conservation behavior, neonates and juvenile snakes typically lack the ability to control venom metering and often empty their venom glands during bites. […] Dry bites have significant implications for both the snake and the victim. For the snake, delivering a dry bite allows it to conserve venom for hunting and self-defense, ensuring its survival in its natural habitat.
#2 Bites and stings â first aid | Better Health Channel
https://www.betterhealth.vic.gov.au/health/healthyliving/bites-and-stings-first-aid
Seek medical attention following any snake bite. […] Australia has nearly 200 snake species (around 25 are potentially dangerous). Their most active seasons are in the warmer months during spring and summer. […] Some venomous snakes in Victoria to watch out for include: tiger snake (most common cause of snake envenoming in Victoria), copperhead snake, red-bellied black snake, Common or Eastern brown snake. […] Signs of a snake bite are not always visible. In some cases, a person may not even feel a snake biting them. […] Symptoms may not be obvious for an hour or more after being bitten. It is important to act quickly if you suspect someone has had a snake bite. […] Depending on the type of snake, signs and symptoms may include: immediate or delayed pain at the bite site, swelling, bruising or local bleeding, bite marks (usually on a limb) that may vary from obvious puncture wounds to scratches that may be almost invisible, swollen and tender glands in the groin or armpit of the bitten limb, faintness, dizziness, nausea and vomiting, headache, abdominal pain, oozing of blood from the bite site or gums, double or blurred vision, drooping eyelids, difficulty in speaking or swallowing, limb weakness or paralysis, difficulty in breathing, occasionally, initial collapse or confusion followed by partial or complete recovery.
#2 Snake bites are now a global health priority, says WHO
https://www.bbc.com/news/world-asia-india-44253586
Snake bites are now a „global health priority” according to a new resolution passed by the World Health Organization (WHO) on Friday. […] The WHO says complications linked to attacks make the phenomenon one of the most neglected of tropical diseases. […] According to the World Health Organization (WHO), around five million snake bites occur each year, although venom is only injected in just over half of cases. […] From blindness to amputations, hundreds of thousands of people are left with permanent disability after being attacked by snakes. The WHO describes such cases as among the most neglected tropical diseases. […] Poor, rural populations are at particular risk from snake bites, as they often lack access to antidotes or may turn to traditional treatments in the absence of modern medical facilities.
#2 Snakebite – Wikipedia
https://en.wikipedia.org/wiki/Snakebite
The World Health Organization says snakebites are a „neglected public health issue in many tropical and subtropical countries,” and in 2017, the WHO categorized snakebite envenomation as a Neglected Tropical Disease (Category A). The WHO also estimates that between 4.5 and 5.4 million people are bitten each year, and of those figures, 40-50% develop some kind of clinical illness as a result. Furthermore, the death toll from such an injury could range between 80,000 and 130,000 people per year.
#2 Epidemiology of snakebites – Wikipedia
https://en.wikipedia.org/wiki/Epidemiology_of_snakebites
In sub-Saharan Africa, over 50% of snakebite injuries are not appropriately treated. […] In many sub-Saharan countries, poor availability of expensive antivenom contributes to morbidity, and snakebites continue to remain a neglected health problem. […] According to the most conservative estimates, at least 81,000 snake envenomings and 11,000 fatalities occur in India each year, making it the most heavily affected country in the world. […] The black mamba, in particular, is among the most venomous snakes in the world and one of the most aggressive. […] Although antivenom saves many lives, mortality due to black mamba envenomation is still at 14%, even with antivenom treatment. […] The variability of these estimates is indicative of the difficulty in accurately assessing snakebite morbidity and mortality.
#2 Snakebite | MSF UK
https://msf.org.uk/issues/snakebite
Snakebite is a hidden health crisis that kills more than 100,000 people a year. […] Although the exact number of global snakebites is unknown, estimates put the number of people bitten by venomous species at 2.7 million a year. […] Of these, some 400,000 will require an amputation or be left with another type of permanent disability. […] Most people bitten by snakes live in tropical or subtropical countries where venomous species are endemic. […] Those most at risk include agricultural workers, children and rural communities. […] Limited access to quality antivenom is the biggest obstacle to surviving a snakebite. […] The high cost of antivenom is a major barrier to people accessing treatment. […] In May 2019, MSF welcomed the release of a long-awaited WHO strategy on the prevention and control of snakebite envenoming, which commits to halving the number of snakebite deaths and cases of disability by 2030.
#2 Snakebite: Seven bites of inequity | Doctors Without Borders – USA
https://www.doctorswithoutborders.org/latest/snakebite-seven-bites-inequity
Since the large majority of snakebite victims probably never make it to the place where they will be counted, the number of documented victims or market is rather small. […] In short there is very little money to be made by pharmaceutical companies. […] Though the estimates remain uncertain, since the large majority of snakebite victims probably never make it to the place where they will be counted, the number of documented victims or market is rather small, particularly as different products are required for different snake venoms, splintering the market. […] When a person cant afford the cost of medicine, and certainly not a treatment that costs more than your monthly salary, you would expect governments to step in and reduce the out-of-pocket cost to individuals. […] In most European countries, even if you are poor and living in a rural area, you would be able to access treatment of some kind or other.
#2 Snake Bites – Cancer Therapy Advisor
https://www.cancertherapyadvisor.com/home/decision-support-in-medicine/pediatrics/snake-bites/
A majority of snake bites are the result of intentional interaction and frequently involve alcohol. […] In general, snake venom composition can vary significantly from snake to snake and is dependent on a host of factors, some of which include snake age, geographic location, and diet. […] Crotalinae (pit vipers) The complex composition of the venom consists of varying proteins or enzymes that work to cause muscle necrosis, cell lysis, and/or increase cell permeability. […] Induced coagulopathy by snake bite envenomation is secondary to thrombin-like enzyme not true thrombin and thus is not inhibited by antithrombin III.
#2 Snake Bites – Cancer Therapy Advisor
https://www.cancertherapyadvisor.com/home/decision-support-in-medicine/pediatrics/snake-bites/
Crotalinae (Pit vipers: Rattlesnakes, copperheads, cottonmouths/water moccasins) […] Pit viper venom can affect nearly every system of the body, but it is most notable for local tissue effects as well as hematologic abnormalities. […] Hematologic effects include coagulopathy, thrombocytopenia, and hypofibrinogenemia which has also been referred to as venom-induced consumption coagulopathy. […] Coral snake bites elicit predominantly neurotoxic effects with very little local injury. […] The latest comprehensive data on the incidence of snake bites in the United States was published in 1966 and reported approximately 45,000 snake bites annually, with 8,000 of those from venomous snakes. […] The majority of indigenous venomous snakes in the United States are of the family Viperidae and subfamily Crotalinae (rattlesnakes, copperheads, cottonmouths) and account for greater than 95% of the venomous snake bites.
#2 Snakebites – Injuries; Poisoning – Merck Manual Professional Edition
https://www.merckmanuals.com/professional/injuries-poisoning/bites-and-stings/snakebites
The complex venom of most North American pit vipers has local effects as well as systemic effects such as coagulopathy. […] Venom alters capillary membrane permeability, causing extravasation of electrolytes, albumin, and red blood cells through vessel walls into the envenomated site. […] The venom of most North American pit vipers causes very minor changes in neuromuscular conduction, except for Mojave and eastern diamondback rattlesnake venom, which may cause serious neurologic deficits. […] Coral snakes are the most common elapids found in the United States. Other elapids include cobras and mambas. Venom of these snakes contains primarily neurotoxic components, which cause a presynaptic neuromuscular blockade, potentially causing respiratory paralysis. […] Symptoms and signs of envenomation may be local, systemic, or a combination, depending on degree of envenomation and species of snake.
#2 Snakebite in Animals: A Brief Refresher
https://www.dvm360.com/view/snakebite-in-animals-a-brief-refresher
Each year, 7000 to 8000 people and an estimated 150,000 dogs and cats in the United States are bitten by venomous snakes. Venomous snakes native to North America belong to 2 groups: crotalids and elapids. Crotalid bites occur much more often than elapid bites. Fatalities are more common in dogs than in other animals, occurring in an estimated 1% to 30% of cases. Mortality after snakebite is low in cattle and horses because of their size, although bites to the head can result in swelling that leads to asphyxiation and death. Not all bites result in envenomation, however. Many are dry bites, with little or no venom delivered. […] The venom of Mojave, timber, and canebrake rattlesnakes is primarily neurotoxic. Envenomation causes neurologic signs such as muscle fasciculations. It is possible for an animal to die from neurotoxic crotalid venom without showing any local tissue reaction.
#2 Snakebites – Injuries and Poisoning – Merck Manual Consumer Version
https://www.merckmanuals.com/home/injuries-and-poisoning/bites-and-stings/snakebites
The effectiveness of antivenom depends on how soon it is given. Antivenom is more effective when it is given within a short time after a snakebite. […] Prognosis depends on the persons age and overall health and on the location and venom content of the bite. Almost everyone bitten by a venomous snake survives if treated early with appropriate amounts of antivenom.
#2 Rattlesnake Bite: Symptoms, Treatment, and Recovery Timeline
https://www.healthline.com/health/rattlesnake-bite
Rattlesnake bites are a medical emergency and can be fatal if left untreated. […] The venom from the majority of rattlesnake bites will damage tissue and affect your circulatory system by destroying skin tissues and blood cells and by causing you to hemorrhage internally. Most rattlesnake venom is composed mainly of hemotoxic elements. […] If the bite is left untreated, your bodily functions will break down over a period of 2 or 3 days and the bite may result in severe organ damage or death. […] In recent years, the long-term side effects from rattlesnake bites seem to have increased in severity, though there has been very little research into why this may be. […] In some cases, people have become critically ill and taken months to recover following a rattlesnake bite. […] Its possible to go into severe shock, which can lead to strokes. […] In some instances, people have lost a portion of their intestines due to restricted blood flow, and others have gone into kidney failure. These are side effects that were rarely seen in previous years.
#2 Annual Incidence of Snake Bite in Rural Bangladesh | PLOS Neglected Tropical Diseases
https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0000860
The estimated incidence density of snake bite is 623.4/ 100,000 person years (95% CI: 513.4789.2/100,000 person years). […] The highest incidence was found for Barisal division (2667.7) and the lowest for Sylhet division (321.6). […] The findings suggest that an annual incidence density of snake bite is 623.4 per 100,000 person-years, which may be as high as 789.2 per 100,000 person-years. […] An estimated 589,919 individuals are bitten by snakes and 6041 die from snake bites every year in rural Bangladesh. […] This incidence is much higher than the previously estimated incidence.
#2 Snakebite: Seven bites of inequity | Doctors Without Borders – USA
https://www.doctorswithoutborders.org/latest/snakebite-seven-bites-inequity
About 100,000 people die every year from snakebite, and many more are disabled or disfigured. […] Snakebite claims 138,000 lives a year and leaves many with life-changing injuries. […] For snakebite to have an impact, you need to encounter a snake, but with no protective equipment. […] Living far from professional health care or people who know and understand snakes and their behaviors, people in rural communities are often left to their own devices to cope by themselves. […] In northeastern Nigeria, the median distance to reach the nearest equipped health facility is 50 miles12 hours on average. […] Most of the victimschildren and agricultural and mining workers from rural areas in low- and middle-income countriesare often the poorest of the poor, and simply cant afford to pay out of pocket for expensive treatments.
#2 Snake Bite
https://mobile.fpnotebook.com/ER/Derm/SnkBt.htm
Total: 45,000 Snake Bites in U.S. per year […] Venomous bites: 8000 to 9000 in U.S. per year (almost all are Pit Viper bites) […] Deaths from Snake Bite in U.S.: 12 or less per year […] Envenomation occurs in 75% of U.S. poisonous Snake Bites […] Incidence: 1.8 to 2.7 Million Snake Bites/year worldwide (50% are venomous) […] Roughly 81,000 to 138,000 deaths per year worldwide from Snake Bites […] Roughly 300,000 amputations per year worldwide from Snake Bites […] 95% of deaths (esp. Diamondback) […] Neurotoxic effects may present with findings similar to Botulism […] Venom alters Coagulation Factors (via Thrombin-like Glycoproteins) resulting in consumptive Coagulopathy […] Venom contains a Neurotoxin (primarily affecting Acetylcholine receptors) […] Results in paralysis […] Generalized symptoms may be delayed 1-8 hours (local effects may have onset in first 15 min) […] Systemic complications (develop over time after initial visual effects) […] Delayed Thrombocytopenia (antivenin-refractory) may occur.
#3 Dry Bite in Snakes: Causes, Implications, and Management – EcoFriendly Coffee
https://ecofriendlycoffee.org/dry-bite-in-snakes-causes-implications-and-management/
The World Health Organization (WHO) estimates that about 5 million snakebites occur each year, resulting in up to 2.7 million envenomingâs. […] In India, around 90% of snakebites are caused by the âbig fourâ among the crawlers â common krait, Indian cobra, Russellâs viper and saw scaled viper. […] About 50% of snakebite cases can be dry bites. They are characterized by fang and tooth marks and the absence of injected venom. […] Understanding the mechanisms and significance of dry bites offers valuable insights into snake behavior, venom utilization, and the delicate balance between survival strategies and ecological dynamics in snake habitats. […] Several factors can influence whether a snake delivers a dry bite. One factor is the snakeâs intent. If the snake is in a defensive posture rather than actively hunting, it may deliver a dry bite as a warning to deter potential threats without expending valuable venom.
#3
https://www.scientificdiscovery.dev/p/14-how-many-people-die-from-snakebites
Around 1 in 270 people in India die from snakebites by the age of 70. […] In total, around 50,000 to 60,000 people in India die from snakebites each year. […] Deaths from snakebites are highly spatially concentrated. […] Because snakebite deaths are caused by snakes and poverty together. […] People who die from snakebites tend to live in poor rural parts of these areas, often work in farms, and lack access to hospitals, doctors and treatment. […] In India, snakebite deaths happen more often in summers and during monsoon seasons. […] In India, around 94% of snakebite deaths occurred in rural areas, and 77% occurred out of hospital. […] People who died from snakebites in these areas didn’t just lack access to the cure they also lacked their deaths being counted. […] Snakebite death rates declined nationwide as well, and the absolute risk of dying from snakebite in India by the age of 70 declined from 0.4% to 0.37% between 2001 and 2014. […] The WHO now estimates that a total of 4.5 to 5.4 million people get bitten by snakes per year; that 1.8 to 2.7 million people develop illness from it, and that 81,000 to 138,000 die from its complications worldwide each year.
#3 Snake Bite: Keep Aside the Fear and Trauma
https://emccochin.com/snake-bite-keep-aside-the-fear-and-trauma
Snakebite sounds and is life-threatening. Approximately, 4.5â5.4 million people get bitten by snakes annually. Out of this, 1.8â2.7 million develop clinical illness and 81,000 to 138,000 die from complications. […] Most people living in rural areas are susceptible to snake bites. From herders, rural agricultural workers and fishermen to hunters and people living in poorly constructed houses are in this category. People who do not have easy access to healthcare suffer from fatalities. […] Most of the bites by poisonous snakes are treated with immediate medical attention and effective anti snake venom. It is advisable not to panic and create stress. […] Not all snakebites are poisonous and not all venom cause deaths. […] The severity of the bite depends on the nature of the wound, the place of the bite and the age and overall health conditions of the patients.
#3 Snake Bites – Cancer Therapy Advisor
https://www.cancertherapyadvisor.com/home/decision-support-in-medicine/pediatrics/snake-bites/
Crotalinae (Pit vipers: Rattlesnakes, copperheads, cottonmouths/water moccasins) […] Pit viper venom can affect nearly every system of the body, but it is most notable for local tissue effects as well as hematologic abnormalities. […] Hematologic effects include coagulopathy, thrombocytopenia, and hypofibrinogenemia which has also been referred to as venom-induced consumption coagulopathy. […] Coral snake bites elicit predominantly neurotoxic effects with very little local injury. […] The latest comprehensive data on the incidence of snake bites in the United States was published in 1966 and reported approximately 45,000 snake bites annually, with 8,000 of those from venomous snakes. […] The majority of indigenous venomous snakes in the United States are of the family Viperidae and subfamily Crotalinae (rattlesnakes, copperheads, cottonmouths) and account for greater than 95% of the venomous snake bites.