Trichinoza – Epidemiologia

Trichinoza
Epidemiologia

Trichinoza, wywoływana przez nicienie z rodzaju Trichinella, pozostaje istotnym problemem zdrowia publicznego i ekonomicznym w produkcji trzody chlewnej. Rocznie na świecie notuje się około 10 000 przypadków, ze wskaźnikiem śmiertelności około 0,2%. Choroba występuje globalnie, z największą częstością w Europie Wschodniej, Chinach, Ameryce Łacińskiej oraz wśród populacji spożywających surowe lub niedogotowane mięso, zwłaszcza dziczyznę (niedźwiedź, dzik). W USA liczba przypadków spadła z 393 rocznie w latach 1947-1951 do około 15 obecnie, z dominującym źródłem zakażeń mięsem dzikich zwierząt (44% przypadków związanych z mięsem niedźwiedzia). W UE/EOG w 2021 roku zgłoszono 79 przypadków, z najwyższym wskaźnikiem 0,42/100 000 mieszkańców w Bułgarii i Chorwacji. Epidemiologia uległa zmianie – obecnie dominują zakażenia związane z dziczyzną, a nie wieprzowiną handlową, co wymaga dostosowania strategii nadzoru i profilaktyki.

Epidemiologia – Trichinoza

Trichinoza (trichinelloza) jest chorobą pasożytniczą wywołaną przez nicienie z rodzaju Trichinella, która stanowi nie tylko zagrożenie dla zdrowia publicznego, ale również problem ekonomiczny w produkcji trzody chlewnej i bezpieczeństwie żywności¹. Na całym świecie szacuje się, że rocznie występuje około 10 000 przypadków zakażeń Trichinella u ludzi¹². Wskaźnik śmiertelności na świecie wynosi około 0,2%²³.

Globalne trendy epidemiologiczne

Dystrybucja geograficzna Trichinella jest bardzo szeroka – pasożyt występuje na wszystkich kontynentach poza Antarktydą¹. Czynniki kulturowe, takie jak tradycyjne potrawy oparte na surowym lub niedogotowanym mięsie, odgrywają istotną rolę w epidemiologii choroby¹. W wielu krajach europejskich, zwłaszcza w Europie Wschodniej, przemiany polityczne i gospodarcze doprowadziły do gwałtownego wzrostu częstości występowania Trichinella wśród stad świń domowych, przy czym wskaźnik zachorowalności osiągał w niektórych wioskach nawet 50% w latach 90¹.

Najwięcej przypadków zgłaszanych jest w Europie, szczególnie w Rumunii, byłym Związku Radzieckim i innych częściach Europy Środkowej. Inne kraje o wysokiej częstości występowania infekcji u ludzi to Chiny, Tajlandia, Meksyk, Argentyna i Boliwia¹. W Chinach odnotowano ponad 500 ognisk zakażeń Trichinella, które dotknęły 20 tysięcy osób (z około 200 zgonami)¹. W Chinach występowanie zakażeń jest szczególnie wysokie, ponieważ spożycie wieprzowiny jest tam najwyższe na świecie¹.

Sytuacja w Stanach Zjednoczonych

W Stanach Zjednoczonych dane z nadzoru epidemiologicznego wskazują na znaczny spadek liczby zgłaszanych przypadków trichinellozy od 1947 roku, kiedy rozpoczęto systematyczne gromadzenie danych¹². W latach 1947-1951 rocznie zgłaszano średnio 393 przypadki u ludzi, w tym 57 zgonów związanych z trichinellozą¹. Obecnie średnia liczba przypadków trichinellozy wynosi około 15 rocznie¹².

W latach 2008-2012 w Stanach Zjednoczonych zgłoszono łącznie 90 przypadków trichinellozy z 24 stanów i Dystryktu Kolumbii¹. Średnia roczna zachorowalność na trichinellozę w USA wynosiła 0,1 przypadku na 1 milion mieszkańców, z medianą 15 przypadków rocznie¹. W latach 2011-2015 odnotowano 80 przypadków w 24 stanach i Dystrykcie Kolumbii. Z tych przypadków 57 (71%) miało potwierdzone lub podejrzewane źródło, przy czym 25 przypadków (44%) było związanych z mięsem niedźwiedzia, 13 przypadków (23%) z mięsem dzika, a 9 przypadków (16%) z nieokreśloną wieprzowiną¹.

Sytuacja w Europie

W 2021 roku 29 krajów UE/EOG zgłosiło 79 przypadków trichinellozy, co stanowiło 32% spadek w porównaniu z rokiem 2020¹. Bułgaria i Chorwacja zgłosiły najwyższy wskaźnik powiadomień w UE/EOG wynoszący 0,42 przypadku na 100 000 mieszkańców i stanowiły 58% wszystkich zgłoszonych przypadków¹.

Europejskie Centrum Zapobiegania i Kontroli Chorób odnotowało 779 przypadków trichinellozy u ludzi w Unii Europejskiej w 2007 roku, głównie związanych z gospodarstwami i dzikimi zwierzętami¹. W Irlandii zgłoszono dwa powiązane ze sobą przypadki włośnicy w 2007 roku, a od tego czasu nie zgłoszono żadnych nowych przypadków¹.

W Europie, gdzie obowiązkowa kontrola wieprzowiny jest egzekwowana, większość przypadków trichinellozy jest związana z mięsem koni lub dzików. W przeciwieństwie do tego, w Ameryce Łacińskiej i Azji głównym źródłem zakażenia jest wieprzowina domowa, przy czym wskaźniki zakażenia Trichinella u świń w Chinach są zgłaszane nawet na poziomie 20%¹.

Zmiany w epidemiologii choroby

Na przestrzeni lat nastąpiła istotna zmiana w epidemiologii trichinellozy. Podczas gdy dawniej większość przypadków była związana z konsumpcją wieprzowiny z handlu detalicznego, obecnie przypadki częściej wiążą się z dziczyzną¹². Myśliwi i osoby spożywające mięso drapieżnych zwierząt łownych pozostają w grupie podwyższonego ryzyka, przy czym większość przypadków od mniej więcej lat 80. XX wieku występuje wśród osób, które spożywały lekko ugotowane dzikie zwierzęta, zwłaszcza niedźwiedzie i dziki¹.

W USA ryzyko zakażenia Trichinella związane z wieprzowiną handlową znacznie zmniejszyło się od lat 40. XX wieku¹. Zmiany w krajowej produkcji wieprzowiny i edukacja w zakresie zdrowia publicznego dotycząca bezpiecznego przygotowywania wieprzowiny przyczyniły się do zmniejszenia częstości występowania trichinellozy w Stanach Zjednoczonych; jednak spożywanie dziczyzny, takiej jak mięso niedźwiedzia, nadal stanowi ważne źródło zakażenia¹.

W Europie w ostatnich latach preferencje konsumentów dotyczące spożywania mięsa bez antybiotyków doprowadziły również do wzrostu liczby przypadków Trichinella¹.

Cykle transmisji Trichinella

Istnieją dwa główne cykle transmisji Trichinella: cykl domowy i dziki (sylwatyczny). Termin „cykl domowy” odnosi się do wzorca przenoszenia, w którym głównym ogniwem jest stado świń karmionych np. niedogotowanymi resztkami wieprzowiny, padliną, odpadami (tzw. świnie karmione odpadami) lub świnie mogą żywić się padliną, która nie zostaje szybko usunięta z gospodarstwa; transmisja może również stać się domowa poprzez zwierzęta synantropijne żyjące w pobliżu stada świń¹.

Trichinella jest przenoszona, gdy zwierzęta spożywają zainfekowane mięso innych zwierząt¹. Przetrwanie T. spiralis jest ułatwione przez szeroki zakres zwierząt, które służą jako żywiciele pośredni, przez długie przeżycie larw w włóknach mięśniowych oraz przez padlinożerną, kanibalistyczną naturę świń¹.

U świń transmisja często następuje, gdy świnie zjadają zarażone Trichinella zwłoki świń, szczurów lub innych zwierząt. Transmisja występuje również, gdy nieugotowane odpady zawierające wieprzowinę lub inne resztki mięsa, które zawierają T. spiralis, są skarmiane świniami. Obgryzanie ogonów zakażonych świń i spożywanie larw w kale są innymi możliwymi źródłami ekspozycji¹.

Rezerwuary i żywiciele Trichinella

Trichinella jest szeroko rozpowszechniona w różnych gatunkach zwierząt. Trichinoza występuje powszechnie nie tylko u świń, ale także u psów, kotów, koni, szczurów i wielu dzikich zwierząt, w tym lisów, wilków, niedźwiedzi, niedźwiedzi polarnych, dzików, ssaków morskich w Arktyce, hien, szakali, lwów i lampartów¹. Żywicielami rezerwuarowymi są gryzonie, zwierzęta udomowione (np. psy, koty), szopy, oposy i skunks¹.

Dziki i niedźwiedzie stanowią ważne źródło zakażeń u ludzi. Godny uwagi wybuch w 2008 r. w Północnej Kalifornii dotknął 38 osób, które spożyły mięso czarnego niedźwiedzia zakażonego Trichinella murrelli, które wykryto również u szopów i kojotów¹. Spożycie kiełbasy z dzika w Hiszpanii doprowadziło do zakażeń ludzi T. britovi, a dziki zostały zidentyfikowane jako źródło zakażenia w różnych regionach śródziemnomorskich, w Azji Południowo-Wschodniej i na wyspach Pacyfiku¹.

Nadzór i raportowanie trichinellozy

Trichinelloza jest chorobą podlegającą obowiązkowi zgłaszania w wielu krajach, w tym w Stanach Zjednoczonych, Irlandii, Kanadzie i państwach członkowskich UE¹². Celem krajowego nadzoru jest oszacowanie zachorowalności na zakażenia, wykrywanie ognisk epidemii oraz kierowanie działaniami profilaktycznymi¹².

W Stanach Zjednoczonych przypadki trichinellozy są zgłaszane do CDC przez stanowe i lokalne departamenty zdrowia za pośrednictwem Krajowego Systemu Nadzoru Chorób Podlegających Zgłaszaniu (NNDSS)¹. Wszystkie zdiagnozowane przypadki trichinellozy muszą być zgłaszane do CDC i w latach 2008-2012 zgłoszono łącznie 90 przypadków¹.

Systemy nadzoru w różnych krajach

Wiele krajów ustanowiło systemy nadzoru i raportowania dla trichinellozy:

W Minnesocie trichinoza musi być zgłoszona do MDH (Minnesota Department of Health) w ciągu jednego dnia roboczego¹.
W Connecticut trichinelloza podlega zgłoszeniu przez lekarza pocztą w ciągu 12 godzin od rozpoznania lub silnego podejrzenia zarówno do Departamentu Zdrowia Publicznego (DPH), jak i lokalnego departamentu zdrowia (LHD)¹.
W stanie Waszyngton świadczeniodawcy opieki zdrowotnej i placówki opieki zdrowotnej muszą zgłaszać przypadki do lokalnej jurysdykcji zdrowotnej w ciągu 3 dni roboczych, laboratoria w ciągu 2 dni roboczych, a lokalne jurysdykcje zdrowotne do Departamentu Zdrowia Stanu Waszyngton w ciągu 7 dni od zakończenia dochodzenia w sprawie przypadku¹.
Kanadyjska Agencja Kontroli Żywności (CFIA) administruje programem kontroli Trichinella, który obejmuje nadzór, regulacje i testy¹.

Cele nadzoru epidemiologicznego

Nadzór nad trichinellozą służy kilku celom:

Identyfikacji źródeł przenoszenia (np. skażonego mięsa) i zapobieganiu dalszemu przenoszeniu z takich źródeł¹.
Edukacji osób narażonych na temat objawów choroby, ułatwiając wczesne rozpoznanie¹.
Edukacji ludzi na temat sposobów zmniejszenia ryzyka zakażenia¹.
Monitorowaniu i kontroli w celu zapobiegania wybuchom epidemii¹.

Generalnie trudno jest uzyskać krajowe dane dotyczące częstości występowania trichinellozy, ponieważ wiele ognisk choroby jest uważanych za niewielkie, zwykle dlatego, że odnoszą się do konkretnej partii mięsa lub jakiegoś nietypowego zdarzenia¹.

Programy kontroli i przepisy regulacyjne

Komisja Europejska wdrożyła nowe rozporządzenie, rozporządzenie nr 2075/2005, ustanawiające szczegółowe zasady kontroli urzędowych Trichinella w mięsie w celu poprawy bezpieczeństwa żywności dla europejskich konsumentów¹. Opisany mechanizm certyfikacji Trichinella pozwala na ustanowienie procesu zapewniającego bezpieczeństwo świń w zakresie Trichinella, a ostatecznie produktów spożywczych pochodzących od świń na poziomie produkcji¹.

W Stanach Zjednoczonych Kongres uchwalił Federal Swine Health Protection Act, ograniczający wykorzystanie niegotowanych odpadów jako paszy dla świń, i stworzył dobrowolny Program Certyfikacji Stad Trichinae. Program Certyfikacji Stad Trichinae jest dobrowolnym programem bezpieczeństwa wieprzowiny przed ubojem, który zapewnia dokumentację praktyk zarządzania trzodą chlewną w celu zminimalizowania narażenia na Trichinella¹.

Programy kontroli w różnych krajach

W Stanach Zjednoczonych skuteczne programy kontroli niemal wyeliminowały chorobę u większości świń domowych, ale świnie hodowane na zewnątrz w bliskim kontakcie z gryzoniami i innymi dzikimi zwierzętami mają zwiększone ryzyko zakażenia Trichinella¹. Amerykański Departament Rolnictwa ogłosił, że naukowcy z Agricultural Research Service (ARS) udokumentowali brak zakażeń Trichinella, pasożytem, który kiedyś stanowił poważne zagrożenie dla bezpieczeństwa żywności w komercyjnych dostawach wieprzowiny¹.

Dane z nadzoru potwierdzają twierdzenie, że amerykański program PQA+ skutecznie łagodzi ryzyko zakażenia Trichinella u świń. Wytyczne PQA+ i szczegóły wdrażania są zgodne z zaleceniami dotyczącymi kontrolowanego zarządzania opisanymi przez Światową Organizację Zdrowia Zwierząt i wytycznymi Międzynarodowej Komisji ds. Trichinellozy¹.

W Kanadzie CFIA prowadzi dwa bieżące programy nadzoru na statystycznie reprezentatywnej populacji kanadyjskich świń. Co roku testuje się około 18 000 ubitych świń, a co trzy do pięciu lat testuje się 16 000 loch. Ma to na celu zapewnienie, że nie doszło do wprowadzenia choroby do populacji świń domowych oraz zademonstrowanie krajom importującym, że kanadyjskie stado świń komercyjnych jest wolne od Trichinella¹.

Metody kontroli i testowania

Do technik stosowanych w nadzorze należy badanie trichinoskopowe mięśni (często mięśni przepony), które mogą zawierać larwy T. spiralis. W tym teście mięsień jest homogenizowany i enzymatycznie trawiony w celu uwolnienia larw z cyst dla efektywnej wizualizacji przez technika. Dostępny jest również test immunoenzymatyczny ELISA i PCR. Certyfikacja produkcji wolnej od Trichinella w USA opiera się obecnie na teście ELISA¹.

W UE wszystkie zwierzęta podatne na Trichinella przeznaczone do spożycia przez ludzi muszą być badane na obecność tych pasożytów metodą sztucznego trawienia, chyba że świnie pochodzą z kontrolowanych warunków hodowli¹. W większości rzeźni przepony świń są rutynowo badane w celu wykrycia zakażeń Trichinella¹.

Testy serologiczne mogą być stosowane do monitorowania zakażenia w stadach świń, ale nie wykryją wszystkich zakażonych zwierząt¹. Koszty ekonomiczne wykrywania włośnicy mogą stanowić dodatkowe obciążenie. W 1998 r. szacunkowy globalny koszt wynosił 3,00 USD za świnię na wykrycie pasożyta¹.

Profilaktyka trichinellozy

Zapobieganie trichinellozie u ludzi opiera się na trzech głównych podejściach:

Edukacji konsumentów na temat ryzyka spożywania surowego lub półsurowego mięsa i produktów mięsnych zarówno od zwierząt domowych (np. świń, koni i psów), jak i sylwatycznych (np. dzików, niedźwiedzi, morsów, pum, borsuków, lisów, szakali, pancerników, krokodyli i waranów), które mogą być nosicielami pasożytów Trichinella, jeśli nie są odpowiednio badane na obecność larw Trichinella podczas kontroli mięsa;
Hodowli świń (najważniejszego źródła zakażenia Trichinella dla ludzi) w nowoczesnych, uprzemysłowionych, krytych chlewniach pod ścisłą kontrolą weterynaryjną i stosowaniu certyfikowanej paszy;
Kontroli wszystkich podatnych zwierząt (zarówno domowych, jak i sylwatycznych) standardową metodą sztucznego trawienia podczas uboju lub po polowaniu¹.

Zalecenia dotyczące bezpiecznego przygotowania mięsa

Dokładne gotowanie całego mięsa, niezależnie od źródła, przed spożyciem jest najlepszym sposobem zapobiegania zakażeniu Trichinella i wieloma innymi patogenami przenoszonymi przez żywność¹. Zaleca się:

Dokładne gotowanie (do co najmniej 77°C) całej świeżej wieprzowiny i produktów wieprzowych¹.
Zamrażanie zainfekowanego mięsa w temperaturze -25°C przez 10 dni lub dłużej również zabije pasożyta; jednak niektóre szczepy odporne na zimno, występujące w niektórych zwierzętach arktycznych, nie mogą być w ten sposób zabite¹.
Aby zapobiec zanieczyszczeniu krzyżowemu niezakażonego mięsa zakażonym mięsem, zdecydowanie zaleca się regularne czyszczenie i dezynfekowanie sprzętu używanego do przetwarzania mięsa, zwłaszcza młynków¹.

Przemysł spożywczy, przy bardzo ściśle kontrolowanych warunkach, może próbować niszczyć trichiny poprzez peklowanie i wędzenie, marynowanie, zamrażanie lub gotowanie i puszkowanie. Międzynarodowa Komisja ds. Trichinellozy (ICT) uważa napromieniowanie za skuteczną metodę zmniejszania liczby larw w mięsie do poziomów bezpiecznych dla spożycia przez ludzi¹.

Edukacja i świadomość publiczna

Chociaż częstość występowania trichinellozy znacznie spadła od 1947 roku, ciągłe identyfikowanie przypadków trichinellozy związanych z konsumpcją komercyjnej wieprzowiny, zakażeń ze źródeł sylwatycznych, takich jak mięso niedźwiedzia, oraz zgłaszane historie spożywania surowego lub niedogotowanego mięsa wskazują na ciągłą potrzebę edukacji publicznej na temat trichinellozy¹.

Ogniska choroby są częstsze na obszarach wiejskich, gdzie ludzie jedzą surową lub niedogotowaną wieprzowinę i/lub dzikie zwierzęta. Wskazuje to na potrzebę programów edukacji zdrowotnej w celu zapobiegania i kontrolowania trichinellozy jak najszybciej na obszarach wysokiego ryzyka¹.

Podróżni do regionów, w których powszechna jest hodowla świń w małych gospodarstwach, powinni zachować ostrożność w odniesieniu do produktów wieprzowych i unikać spożywania kiełbasy wieprzowej¹. Podczas konsultacji przedpodróżnych należy doradzić podróżnym o możliwym ryzyku ze strony konserwowanych produktów wieprzowych, które zostały wyprodukowane lokalnie na obszarach endemicznych dla Trichinella¹.

Wyzwania w kontroli trichinellozy

Mimo znacznego spadku globalnej zachorowalności na trichinellozę, ogniska nadal występują często, szczególnie w krajach rozwijających się¹. Międzynarodowy przepływ przetworzonych składników żywności wprowadził nowe wyzwania dla wysiłków kontrolnych¹.

Można oczekiwać, że Trichinella będzie rozprzestrzeniać się jeszcze bardziej z powodu nielegalnego importu mięsa z krajów bez odpowiednich służb weterynaryjnych i systemów zdrowia publicznego, co skutkuje brakiem odpowiedniej inspekcji mięsa przed eksportem¹.

W niektórych częściach Europy Wschodniej Światowa Organizacja Zdrowia donosi, że niektóre stada świń mają wskaźniki zakażenia włośnicą powyżej 50%, z odpowiednio dużą liczbą zakażeń u ludzi¹.

Specyficznym wyzwaniem jest również rosnąca popularność dziczyzny. Wiele pytań pozostaje bez odpowiedzi na temat ryzyka związanego ze spożywaniem mięsa dzikich zwierząt, biorąc pod uwagę ich status ważnych rezerwuarów Trichinella sp. w środowisku¹. Społeczeństwo, urzędnicy ds. dzikiej przyrody i myśliwi wyrazili zaniepokojenie brakiem informacji o ryzyku zakażenia od mięsa dzikich zwierząt¹.

Wyzwania na obszarach chronionej przyrody

Obszary chronionej przyrody stanowią wyjątkowe wyzwanie dla kontroli Trichinella. Większy Park Narodowy Krugera (GKNP) w Republice Południowej Afryki reprezentuje obszar chroniony, gdzie obfitość gatunków sylwatycznych zapewnia zarówno przetrwanie, jak i transmisję Trichinella spp.¹ Jednak sytuacja w Parku Narodowym Krugera nie jest wyjątkowa i podobnie optymalne warunki można przewidywać w innych chronionych obszarach krajowych w Afryce Subsaharyjskiej, takich jak Serengeti (Tanzania), Kafue (Zambia), Hwange (Zimbabwe) i Gorongosa (Mozambik)¹.

Ogromny rozmiar i ograniczona ingerencja człowieka w połączeniu z bogactwem gatunków na chronionym obszarze GKNP stwarzają doskonałe warunki do ustalenia i utrzymania krążenia Trichinella spp. na tym obszarze¹.

Pomimo różnorodnego zakresu żywicieli i faktu, że Republika Południowej Afryki ma najwyższy zgłaszany wskaźnik występowania Trichinella w Afryce Subsaharyjskiej, do tej pory nie zgłoszono żadnych przypadków u ludzi z RPA¹.

Potrzeba dalszych badań i nadzoru

Wiedza na temat epidemiologii, zakresu żywicieli i transmisji zakażeń Trichinella spp. w różnych strefach ekologicznych w południowej Afryce, w tym na obszarach styku dzikiej przyrody i człowieka, jest ograniczona¹. Anegdotyczny charakter niektórych przedstawionych danych potwierdza potrzebę bardziej intensywnego nadzoru epidemiologicznego w parkach narodowych i obszarach chronionych dzikiej przyrody w pozostałej części Afryki Subsaharyjskiej w celu odkrycia epidemiologii zakażeń Trichinella na tych unikalnych i zróżnicowanych chronionych krajobrazach¹.

Odkrycie enigmatycznej epidemiologii tych potencjalnie odzwierzęcych gatunków z rodzaju Trichinella jest ważne z perspektywy zdrowia publicznego, ponieważ pomaga w ustaleniu nie tylko potencjalnego ryzyka zakażenia u ludzi, ale ostatecznie właściwych środków kontroli i zapobiegania¹.

Innym obszarem badań jest ocena ryzyka dla myśliwych i innych konsumentów mięsa dzikich zwierząt w zakresie Trichinella, biorąc pod uwagę różne scenariusze działań zdrowia publicznego¹.

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Materiały źródłowe

#1 Epidemiology, Diagnosis, Treatment, and Control of Trichinellosis
https://pmc.ncbi.nlm.nih.gov/articles/PMC2620635/
Throughout much of the world, Trichinella spp. are found to be the causative agents of human trichinellosis, a disease that not only is a public health hazard by affecting human patients but also represents an economic problem in porcine animal production and food safety. […] Due to political and economic changes, recent increases in prevalence and incidence have been observed in many former eastern European countries. […] The European Commission has implemented a new regulation, regulation no. 2075/2005, laying down specific rules for the official controls of Trichinella in meat in order to improve food safety for European consumers. […] The described Trichinella certification mechanism allows the establishment of a process for ensuring the Trichinella safety of swine and, ultimately, food products derived from swine at the production level.
#1
https://www.who.int/publications/i/item/WHO-UCN-NTD-VVE-2021.7
Trichinellosis (trichinosis) is a zoonosis, caused by roundworms of the genus Trichinella. […] About 10,000 human infections occur annually worldwide. Cultural factors such as traditional dishes based on raw or undercooked meat or meat-derived products play an important role in the epidemiology of the disease.
#1 Trichinosis | 5-Minute Pediatric Consult
https://peds.unboundmedicine.com/pedscentral/view/5-Minute-Pediatric-Consult/617715/4/Trichinosis
Historically, most U.S. infections are due to Trichinella spiralis in commercial pork. […] Currently, more U.S. infections are associated with wild game meat (especially bear) or through spillover to domestic animals. […] Trichinella parasites found in animals from all continents except Antartica. […] Occasional grouped outbreaks (e.g., families and communities with common exposure). […] Reservoir hosts include rodents, domesticated animals (e.g., dogs, cats), raccoons, opossums, and skunks.
#1 Epidemiology, Diagnosis, Treatment, and Control of Trichinellosis
https://pmc.ncbi.nlm.nih.gov/articles/PMC2620635/
The term domestic cycle refers to the transmission pattern where the focus is on a swine herd being fed, e.g., uncooked pork scraps, carrion, garbage (i.e., garbage-fed pigs), or the pigs can feed on carcasses that are not promptly removed from the farm; transmission can also become domestic via synanthropic animals living near the swine herd. […] In several countries of Central-Eastern Europe, the transient breakdown of governmental veterinary services and state farms accompanied by economic problems and war have resulted in sharp increases in the incidence of Trichinella infection among domestic pig herds, with prevalence rates reaching 50% in some villages in the 1990s. […] In Canada, the United States, and most European Union countries, Trichinella infection in domestic animals has virtually disappeared, although sporadic foci do occur.
#1 Trichinellosis – UpToDate
https://www.uptodate.com/contents/trichinellosis/print
Trichinellosis occurs worldwide (figure 1). The prevalence of Trichinella infection is unknown, and there is significant underreporting of cases. A thorough literature review from 1986 to 2009 revealed 65,818 cases of trichinellosis and 42 deaths reported from 41 countries. Most cases were reported in Europe, especially Romania, the former Soviet Union, and other parts of Central Europe. Other countries with high prevalences of human infection are China, Thailand, Mexico, Argentina, and Bolivia. […] There are 9 species and at least 13 genotypes of Trichinella. Trichinellae are divided into those that encapsulate in host muscle tissue of mammals only and those that do not encapsulate and infect mammals, birds (one species), or reptiles (two species). All recognized species and genotypes can infect humans, but there are seven species of Trichinella that have been implicated in human disease.
#1 Azthena logo with the word Azthena
https://www.news-medical.net/health/Trichinellosis-Epidemiology.aspx
The global distribution of certain Trichinella species, coupled with a diversity of hosts and various cultural eating habits that involves raw or undercooked meat, represents a pivotal factor favoring human infection in industrialized and developing countries alike. […] The prevalence of swine trichinellosis and the rates of human trichinellosis are peaking in developing countries and regions, with pork still being the predominant source of infection (even though wild animal meat is increasing as a globally significant source). […] Generally, it is difficult to obtain national prevalence data for trichinellosis, as many outbreaks are considered small in scale usually because they relate to a particular batch of meat or some unusual event. […] In China, over 500 outbreaks of Trichinella infection have been documented that affected 20 thousand people (with approximately 200 deaths). […] It can be expected that Trichinella will spread even further due to the illegal importation of meat from countries without adequate veterinary services and public health systems, resulting in lack of proper meat inspection prior to export.
#1 Trichinella spiralis Infection – StatPearls – NCBI Bookshelf
https://www.ncbi.nlm.nih.gov/books/NBK538511/
Trichinellosis occurs worldwide, and estimates are that about 10000 cases occur each year. […] Cases usually tend to occur in clusters among groups of people who have consumed infected meat from a common animal. […] Per the Centers for Disease Control and Prevention around 400 cases of trichinellosis were reported every year in the 1940s, but now the number of reported cases has dropped significantly and has been around 20 cases every year from 2008 to 2010. […] The highest number of cases appear to be in China where pig consumption is the highest in the world. […] In recent years, consumer preference for eating antibiotic-free meat has also led to an increase in Trichinella in Europe.
#1 Trichinosis (Trichinellosis): Background, Pathophysiology, Epidemiology
https://emedicine.medscape.com/article/230490-overview
National surveillance data indicate a significant decline in reported trichinosis cases in the United States since 1947, the inaugural year of systematic data collection. Between 2011 and 2015, there were 80 reported cases across 24 states and the District of Columbia. Of these cases, 57 (71%) had a confirmed or suspected source, with 25 cases (44%) linked to bear meat, 13 cases (23%) to wild boar meat, and 9 cases (16%) linked to unspecified pork. […] Hunters and individuals consuming carnivorous game remain at heightened risk, with the majority of cases since approximately the 1980s occurring among those who ingested lightly cooked wild game, particularly bear and wild boar. […] The prevalence of infected domestic swine in the United States is approximately 0.001%; however, an autopsy study revealed a 4% incidence of historical infections.
#1 Trichinella spiralis – Wikipedia
https://en.wikipedia.org/wiki/Trichinella_spiralis
Trichinosis (trichinellosis) is a disease caused by tissue-dwelling roundworms of the species Trichinella spiralis. In the United States, the national trichinellosis surveillance system has documented a steady decline in the reported incidence of this disease. During 1947 to 1951, a median of 393 human cases was reported annually, including 57 trichinellosis-related deaths. During 1997-2001, the incidence in the US decreased to a median of 12 cases annually, with no reported deaths. The decrease was largely due to improved compliance with standards and regulations by commercial pork producers. […] In the United States, Congress passed the Federal Swine Health Protection Act, restricting the use of uncooked garbage as feed stock for pigs, and creating a voluntary Trichinae Herd Certification Program. The Trichinae Herd Certification Program is a voluntary pre-slaughter pork safety program that provides documentation of swine management practices to minimize Trichinella exposure.
#1
https://brokenarrowranch.com/blogs/wild-and-pure/trichinosis-how-common-is-the-disease
Trichinosis is a disease of man and other animals caused by a tiny parasitic worm, most commonly Trichinella spiralis. […] Now the disease is much less common with an average of 15 cases per year reported to the CDC from 2008 – 2012. […] All diagnosed cases of trichinosis are required to be reported to the CDC and there were 90 cases total reported from 2008 – 2012. […] Wild boar meat was the source of only 6 of those cases. Domesticated pork products infected 10 people – more than wild boar! […] Surveillance of feral swine for Trichinella spp. and Toxoplasmagondii in the USA and host-related factors associated with infection. […] Trichinellosis Surveillance – United States, 2008-2012.
#1 Trichinellosis Surveillance — United States, 2008–2012
https://www.cdc.gov/mmwr/preview/mmwrhtml/ss6401a1.htm
Trichinellosis surveillance has documented a steady decline in the reported incidence of the disease in the United States. […] The purpose of national surveillance is to estimate incidence of infection, detect outbreaks, and guide prevention efforts. […] During 2008-2012, a total of 90 cases of trichinellosis were reported to CDC from 24 states and the District of Columbia. […] The mean annual incidence of trichinellosis in the United States was 0.1 cases per 1 million population, with a median of 15 cases per year. […] The risk for Trichinella infection associated with commercial pork has decreased substantially in the United States since the 1940s. […] Changes in domestic pork production and public health education regarding the safe preparation of pork have contributed to the reduction in the incidence of trichinellosis in the United States; however, consumption of wild game meat such as bear continues to be an important source of infection.
#1 Trichinellosis – Annual Epidemiological Report for 2021
https://www.ecdc.europa.eu/en/publications-data/trichinellosis-annual-epidemiological-report-2021
In 2021, 29 EU/EEA countries reported 79 cases of trichinellosis which represented a 32% decrease compared with 2020. […] In 2021, Bulgaria and Croatia reported the highest notification rate in the EU/EEA at 0.42 cases per 100 000 population and accounted for 58% of all cases reported. […] Consumption of undercooked meat from pigs raised under non-controlled (non-confined/free-range) housing conditions or hunted wild boar constitutes the highest risk for acquiring Trichinella infection in the EU/EEA.
#1 Trichinosis (Trichinellosis): Background, Pathophysiology, Epidemiology
https://emedicine.medscape.com/article/230490-overview
A notable outbreak in 2008 in Northern California involved 38 individuals who consumed black bear infected with Trichinella murrelli, which also has been detected in raccoons and coyotes. […] In Europe, where mandatory pork inspection is enforced, the majority of trichinosis cases are associated with horse or wild boar meat. In contrast, domestic pork is the primary source of infection in Latin America and Asia, with Trichinella infection rates in swine in China reported as high as 20%. […] Increased rates of trichinosis have been observed in former Eastern European countries, such as Romania and Hungary, attributed to political changes and evolving regional dietary practices. […] The European Centre for Disease Prevention and Control reported 779 human cases of trichinosis in the European Union in 2007, predominantly linked to farm and wild animal sources.
#1 Trichinellosis – Health Protection Surveillance Centre
https://www.hpsc.ie/a-z/zoonotic/trichinellosis/
Trichinellosis is a notifiable disease in Ireland. […] Two linked cases of trichinosis were reported in Ireland in 2007. […] No cases of trichinellosis have been notified in Ireland since 2007.
#1 Trichinellosis Surveillance — United States, 2008–2012
https://www.cdc.gov/mmwr/preview/mmwrhtml/ss6401a1.htm
This report presents data on trichinellosis cases in the United States reported to CDC from state and local health departments through the National Notifiable Disease Surveillance System (NNDSS) during 2008-2012. […] The number of reported trichinellosis cases has decreased since 1947. […] The decline in incidence of trichinellosis is a result of decreased prevalence of Trichinella in commercial pork products. […] Although the incidence of trichinellosis has decreased substantially since 1947, the continued identification of trichinellosis cases related to commercial pork consumption, infections from sylvatic sources such as bear meat, and the reported histories of consumption of raw or undercooked meat indicate the continuing need for public education about trichinellosis.
#1 Trichinellosis (Trichinosis) | Texas DSHS
https://www.dshs.texas.gov/notifiable-conditions/zoonosis-control/zoonosis-control-diseases-and-conditions/trichinellosis-trichinosis
Trichinosis is a common infection worldwide. […] Trichinosis is not only common in swine but also be found in dogs, cats, horses, rats, and in many wild animals, including fox, wolf, bear, polar bear, wild boar, marine mammals in the Arctic, hyena, jackal, lion, and leopard. […] In the United States, infection was once very common; however, infection is now relatively rare. […] The number of cases has decreased because of legislation prohibiting the feeding of raw meat garbage to hogs, commercial and home freezing of pork, and the public awareness of the danger of eating raw or undercooked pork products. […] Cases are less commonly associated with pork products and more often associated with eating raw or undercooked wild game meats. […] The worm is spread when animals ingest infected animal flesh.
#1 Trichinellosis | Iowa State University
https://vetmed.iastate.edu/vdpam/about/focus-areas/swine/swine-disease-manual/index-diseases/trichinellosis
Survival of T. spiralis is promoted by the wide range of animals that serve as intermediate hosts, by the long survival of larvae in muscle fibers, and by the scavenging, cannibalistic nature of pigs. […] In swine, transmission often occurs when pigs scavenge trichinella-infected carcasses of swine, rats or other animals. Transmission also occurs when uncooked garbage containing pork or other meat scraps that harbor T. spiralis are fed to pigs. Tail-biting of infected pigs and ingestion of larvae in feces are other possible sources of exposure. […] The prevalence in the US swine population is low (0.007% in 2000) and usually no special effort is made to detect T. spiralis in slaughtered swine. In many countries, techniques used for surveillance include trichinoscopic examination of muscle (often diaphragm muscle) likely to contain T. spiralis larvae. In this test, the muscle is homogenized and enzymatically digested in order to release the larvae from their cysts for efficient visualization by the technician. An enzyme-linked immunosorbent assay (ELISA) test and PCR are also available. Trichinella-free production certification in the US currently relies on an ELISA test. […] In the US, an educational program that places emphasis on thorough cooking of pork has been reasonably successful in minimizing the incidence of human infection. Also, there are regulations that govern the way ready-to-eat pork products must be processed to ensure destruction of T. spiralis.
#1 Trichinosis (Trichinellosis): Background, Pathophysiology, Epidemiology
https://emedicine.medscape.com/article/230490-overview
Despite a substantial decline in the global incidence of trichinosis, outbreaks continue to occur frequently, particularly in developing nations. […] An estimated 10,000 cases are reported annually, with a mortality rate of approximately 0.2%. […] The international movement of processed food ingredients has introduced new challenges for control efforts. […] Travelers to regions with prevalent small-farm pig raising should exercise caution regarding pork products and avoid consuming any pork sausage. […] An outbreak in Turkey was attributed to a producer who incorporated pork from unverified sources into beef meatballs. […] Consumption of wild boar sausage in Spain has resulted in human infections with T britovi, and wild boar have been identified as a source of infection in various Mediterranean regions, Southeast Asia, and Pacific Islands. […] This comprehensive overview underscores the clinical significance of trichinosis and highlights the importance of dietary and travel history in patients presenting with gastroenteritis, particularly when accompanied by eosinophilia or palpebral edema.
#1 Reporting Trichinosis (Trichinella spiralis) – MN Dept. of Health
https://www.health.state.mn.us/diseases/trichinosis/report.html
Trichinosis (Trichinella spiralis) must be reported to MDH within one working day. […] Health care practitioners (health care facilities, medical laboratories, and in certain circumstances veterinarians and veterinary medical laboratories) are required to report disease to the Minnesota Department of Health (MDH) under Minnesota state law. […] Unless previously reported, every licensed health care provider who provides care to any patient who has, is suspected of having, or has died from a reportable disease is required to report. […] Any person in charge of any institution, school, child care facility, or camp is also required to report disease to MDH. […] Infectious Disease Reporting Find out which infectious diseases must be reported by law in Minnesota, who is required to report diseases, how each disease can be reported, and download the appropriate forms.
#1 EEIP RIDRM Trichinellosis
https://portal.ct.gov/DPH/Epidemiology-and-Emerging-Infections/EEIP-RIDRM-Trichinellosis
Trichinellosis is physician reportable by mail within 12 hours of recognition or strong suspicion to both the Connecticut Department of Public Health (DPH) and the local health department (LHD). […] If a cluster/outbreak is identified, the LHD will work with the DPH to implement control measures. […] The DPH will contact the testing laboratory and the patients physician to confirm the diagnosis of trichinosis; interview the patient to collect food history during incubation period (5 45 days before symptom onset); specifically inquire about consumption of pork and pork products, other high-risk foods such as wild game meat and dried jerky, and methods of preparation; assess other household members and persons who have eaten suspected meat (if any) for evidence of infection; confiscate any remaining suspect food and consult with CDC about testing.
#1 Trichinosis | Washington State Department of Health
https://doh.wa.gov/public-health-provider-resources/notifiable-conditions/trichinosis
To identify sources of transmission (e.g., contaminated meat) and to prevent further transmission from such sources […] To educate exposed persons about signs and symptoms of disease, thereby facilitating early diagnosis […] To educate people about how to reduce their risk of infection. […] Health care providers and health care facilities: notifiable to local health jurisdiction within 3 business days […] Laboratories: notifiable to local health jurisdiction within 2 business days; submission on request specimen associated with positive result, within 2 business days. […] Local health jurisdictions: notifiable to the Washington State Department of Health (DOH) Communicable Disease Epidemiology (CDE) within 7 days of case investigation completion or summary information required within 21 days.
#1 Trichinellosis – Fact Sheet – inspection.canada.ca
http://inspection.canada.ca/en/animal-health/terrestrial-animals/diseases/reportable/trichinellosis/fact-sheet
Provincial abattoirs must report suspected cases for Canadian Food Inspection Agency (CFIA) follow-up. […] The CFIA administers a Trichinella control program which includes surveillance, regulation and testing. […] The CFIA conducts two ongoing surveillance programs on a statistically representative population of Canadian swine. Approximately 18,000 slaughtered swine are tested annually and every three to five years, 16,000 sows are tested. This is done to ensure that there has been no introduction of disease to the domestic swine population and to demonstrate to importing countries that Canada’s commercial swine herd is Trichinella-free. […] Trichinellosis is a reportable disease under the Health of Animals Act. This means that all suspected cases must be reported to the CFIA for immediate investigation by inspectors.
#1 Trichinellosis (Trichinosis) – FL Health CHARTS – Florida Department of Health
https://www.flhealthcharts.gov/ChartsDashboards/rdPage.aspx?rdReport=NonVitalIndNoGrp.Dataviewer&cid=8643
Trichinellosis is monitored to prevent and control outbreaks. […] This disease became reportable prior to 1992. Counts and rates include confirmed and probable cases of Trichinellosis (Trichinosis). […] Data presented here are from Merlin, Florida’s web-based reportable disease surveillance system. Note that any data prior to 1992 are not maintained in Merlin and should be interpreted with caution. […] Reports for reportable disease data are produced weekly, monthly, and annually. To access these reports, visit Surveillance Publications. More detailed information on interpreting data can be found in the introduction section of the annual reports. For questions, please contact the Bureau of Epidemiology at (850) 245-4401.
#1 Trichinellosis (Trichinosis) – Epidemiology
https://www.vdh.virginia.gov/epidemiology/epidemiology-fact-sheets/trichinellosis-trichinosis/
People who eat raw or undercooked meat from animals infected with the Trichinella worm are at higher risk for developing trichinellosis. […] Successful control programs in the United States have nearly eliminated the disease in most domestic pigs, but pigs raised outdoors in close contact with rodents and other wildlife have an increased chance of acquiring Trichinella infection. […] Infection used to be more common and was usually caused by ingestion of undercooked pork. Infection is now relatively rare. The number of cases decreased beginning in the mid-20th century because of legislation prohibiting the feeding of raw-meat garbage to hogs, commercial and home freezing of pork, and the public awareness of the danger of eating raw or undercooked pork products. Current cases are less commonly associated with pork products and more often associated with eating raw or undercooked wild game meats.
#1 USDA Research Documents Absence of Trichinella Infection in Commercial Pigs : USDA ARS
https://www.ars.usda.gov/news-events/news/research-news/2024/usda-research-documents-absence-of-trichinella-infection-in-commercial-pigs/
The U.S. Department of Agriculture today announced that Agricultural Research Service (ARS) scientists have documented the absence of infection by Trichinella, a parasite that once posed a major food safety risk in the commercial pork supply. […] These results are consistent with international food safety guidelines for Trichinella to be considered a negligible risk for public health. […] The surveillance data support the assertion that the U.S. PQA+ program effectively mitigates risk for Trichinella infection in pigs, said Dr. Benjamin Rosenthal, Research Leader of the ARS Animal Parasitic Disease Laboratory. […] PQA+ guidelines and implementation details follow those for controlled management described by the World Organization for Animal Health and guidelines of the International Commission on Trichinellosis.
#1 Trichinellosis in Animals – Generalized Conditions – Merck Veterinary Manual
https://www.merckvetmanual.com/generalized-conditions/trichinellosis/trichinellosis-in-animals
Trichinellosis is an important human public health risk globally. […] The number of human cases has greatly declined in the past 50 years in part because of the move to modern production facilities (reduced confinement) that decreases or eliminates exposure of domestic pigs to wild rodents and other wildlife. […] Inspection of meat for viable trichinae at the time of slaughter (by means of digestion methods) is effective to prevent human infection in many countries. […] In the EU, all Trichinella-susceptible animals intended for human consumption must be tested for these parasites by artificial digestion testing unless pigs are from controlled housing conditions. […] In North America, the assumption is that pork may be infected; therefore, those products labeled ready to eat must be processed by adequate heating, freezing, or curing to kill larvae before marketing. […] Serology (ELISA) testing can be used to monitor the infection in pig herds but will not detect all infected animals.
#1 Trichinella spiralis – Wikipedia
https://en.wikipedia.org/wiki/Trichinella_spiralis
It was reported in 2005 that the prevalence of human infections from Trichinella spiralis was low in the United States, despite nonexistent meat inspection with respect to trichinella. This was due to strict enforcement of the regulations applying to large meat production facilities: most cases have been from raw or undercooked meat from game animals. […] Also reported in 2005, the rate of infection from Trichinella spiralis was significantly higher in people living in parts of Europe, Asia, and Southeast Asia than in the United States. However, EU nations employ several strategies for detecting meat infected with Trichinella spiralis. […] In most abattoirs, the diaphragms of pigs are routinely sampled to detect Trichinella infections. […] The economic cost of detecting trichinosis can be another cost burden. In 1998, a rough global cost estimate was $3.00 per pig to detect the parasite.
#1 Epidemiology, Diagnosis, Treatment, and Control of Trichinellosis
https://pmc.ncbi.nlm.nih.gov/articles/PMC2620635/
The prevention of trichinellosis in humans is based on three main approaches: (i) education of the consumer about the risk of consumption of raw or semiraw meat and meat products from both domestic (e.g., pigs, horses, and dogs) and sylvatic (e.g., wild boars, bears, walruses, cougars, badgers, foxes, jackals, armadillos, crocodiles, and monitor lizards) animals that can be carriers of Trichinella parasites if they are not properly tested for Trichinella larvae upon meat inspection; (ii) farming of pigs (the most important source of Trichinella infection for humans) in modern, industrialized, indoor pigsties under strict veterinary control and use of certified feedstuff; and (iii) control of all susceptible animals (both domestic and sylvatic) by a standardized artificial digestion method at slaughtering or after hunting. […] Conclusively, there is ample evidence that trichinellosis in humans can be monitored and controlled to some extent with a rigorous reporting and testing system, an option that requires a good interaction between the public health sector and the corresponding veterinary sector.
#1 Whatâs New
https://www.cdph.ca.gov/Programs/CID/DCDC/Pages/Trichinellosis-Trichinosis.aspx
Trichinellosis is a parasitic disease of humans and animals. The trichinellosis worm Trichinella spiralis is found most commonly in pigs, but it can infect a wide range of carnivorous animals including bears, rodents, foxes, badgers, wolves, cats, and dogs. […] In the United States, humans are most commonly infected by eating raw or undercooked meat from wild pigs or bears. […] Trichinellosis is not spread from person to person, but many people can become infected at the same time if they eat undercooked meat from the same infected animal. […] Thoroughly cooking all meats, regardless of source, before eating is the best way to prevent infection with Trichinella and many other food-borne pathogens.
#1 Trichinellosis (Trichinosis) | Texas DSHS
https://www.dshs.texas.gov/notifiable-conditions/zoonosis-control/zoonosis-control-diseases-and-conditions/trichinellosis-trichinosis
Anyone who eats undercooked meat of infected animals can develop trichinosis. […] Thoroughly cook (to at least 170F) all fresh pork and pork products. […] Freezing infected meats at -13 F for 10 days or longer will also kill the parasite; however, some cold resistant strains found in some Arctic wildlife cannot be killed this way. […] Diagnosis of trichinosis in man is often difficult because symptoms usually don’t occur until about a week after the infected meat is eaten; the clinical signs of the disease may be absent in the early stages and those noted in the later stages often simulate other diseases. […] Trichinosis is diagnosed by a blood test or by a biopsy of the muscle to identify the parasite. […] Since trichinellosis is found worldwide, the traveler should observe the indicated precautions when eating meat.
#1 How can we help you?
https://www.thepigsite.com/articles/the-cause-of-trichinosis-and-its-prevention-through-safe-food-handling-practices
Trichinosis is an infection caused by roundworms in the genus Trichinella, with infection resulting entirely from food sources. […] According to the most recent data from the Centers for Disease Control and Prevention (CDC), there were 72 reported cases of trichinosis for the years 19972001. […] The United States Department of Agriculture (USDA) is responsible for verifying the wholesomeness of meats sold in the United States. […] However, trichinae are not typically discovered during USDA inspection due to their microscopic size, so no pork sold in the US should be assumed to be safe from trichinae. […] To prevent cross-contamination of uninfected meat with infected meat, it is highly recommended that the equipment used to process meat, particularly grinders, be regularly cleaned and sanitised.
#1 How can we help you?
https://www.thepigsite.com/articles/the-cause-of-trichinosis-and-its-prevention-through-safe-food-handling-practices
Performed under very carefully controlled conditions, the food industry may attempt to destroy trichinae through curing and smoking, pickling, freezing, or cooking and canning. […] The ICT considers irradiation to be an effective method for reducing larvae in meat to levels safe for human consumption.
#1 Trichinosis: Epidemiology in Thailand
https://www.wjgnet.com/1007-9327/full/v12/i40/6440.htm
Trichinosis is one of the most common food-borne parasitic zoonoses in Thailand and many outbreaks are reported each year. […] The annual epidemiological surveillance reports of the Bureau of Epidemiology, Department of Disease Control, Ministry of Public Health, Thailand, show that trichinosis cases increased from 61 in 1997 to 351 in 1998. […] The outbreaks were more common in the northern areas, especially in rural areas where people ate raw or under-cooked pork and/or wild animals. This indicates the need for health education programs to prevent and control trichinosis as soon as possible in the high-risk areas. […] The epidemiological surveillance reports of trichinosis have been conducted almost every year and data investigation reveals that the outbreaks have occurred predominantly in rural areas.
#1 LSHTM LSHTM Research Online
https://researchonline.lshtm.ac.uk/15047/
An outbreak of trichinellosis that occurred in the United Kingdom is described. […] During pre-travel counselling, travellers should be advised about possible risk from cured pork products which have been produced locally in Trichinella endemic areas.
#1 Trichinosis – Wikipedia
https://en.wikipedia.org/wiki/Trichinosis
Between 2002 and 2007, 11 trichinosis cases were reported to the CDC each year on average in the United States, and 2008â10 averaged 20 cases per year; these were mostly the result of consuming undercooked game (sylvatic transmission) or home-reared pigs (domestic transmission). […] Trichinosis is common in developing countries where meat fed to pigs is raw or undercooked, but infections also arise in developed countries in Europe where raw or undercooked pork, wild boar, and horse meat may be consumed as delicacies. […] In parts of Eastern Europe, the World Health Organization reports, some swine herds have trichinosis infection rates above 50%, with correspondingly large numbers of human infections.
#1 Hunter Food Safety in California: Evaluating Risk of Trichinellosis from Consumption of Wildlife Meat | National Agricultural Library
https://www.nal.usda.gov/research-tools/food-safety-research-projects/hunter-food-safety-california-evaluating-risk
Human food borne outbreaks associated with the consumption of wildlife meat infected with disease-causing parasites such as Trichinella continue to occur due to a lack of contemporary data and decreased public awareness. […] Many questions remain about the risks associated with the consumption of wildlife meat given their status as important ant reservoirs of Trichinella sp. in the environment. […] The results of this study will help to gain an understanding of the contemporary epidemiology and current public awareness of Trichinella and thus 1) supply information and educational workshops and lay publications to inform the public whether or not Trichinella is a key risk for consumption of wildlife meat; 2) provide California agencies with the data and analyses necessary to better monitor, control and prevent the agricultural and public health aspects of the parasite; 3) adapt newly-published state-of the art RT-PCR Trichinella-detection techniques for use at UC Davis and share them with diagnostic labs including the California Animal Health and Food Safety (CAHFS) Laboratory System for use in Trichinella surveillance; 4) develop epidemiologic models to assess risks to hunters and other wildlife meat consumers of Trichinella given various public health action scenarios.
#1 Hunter Food Safety in California: Evaluating Risk of Trichinellosis from Consumption of Wildlife Meat | National Agricultural Library
https://www.nal.usda.gov/research-tools/food-safety-research-projects/hunter-food-safety-california-evaluating-risk
The public, wildlife officials, and hunters have expressed concern over lack of information for risk of infection from wildlife meat. […] Our goal is to investigate the overall prevalence of Trichinella in free-ranging black bears and wild pigs in California. […] The results of this study will help to gain an understanding of the contemporary epidemiology of Trichinella and thus 1) supply information to inform the public whether or not Trichinella is a key risk for consumption of wildlife meat; and 2) provide California agencies with the data and analyses necessary to better monitor and control the agricultural and public health aspects of the parasite.
#1 Epidemiology and hypothetical transmission cycles of Trichinella infections in the Greater Kruger National Park of South Africa: an example of host-parasite interactions in an environment with minimal human interactions | Parasite
https://www.parasite-journal.org/articles/parasite/full_html/2020/01/parasite200010/parasite200010.html
Despite the diverse host range and the fact that South Africa has the highest reported prevalence of Trichinella in sub-Saharan Africa, no human cases have been reported from South Africa to date. […] Trichinella spp. infection is notifiable and listed in the Terrestrial Animal Health Code of the World Organization for Animal Health. […] The GKNP of South Africa represents a protected area where the abundance of sylvatic host species ensures both Trichinella spp. survival and transmission. […] However, the situation in the KNP is not unique and similarly optimal conditions may be expected in other national protected areas in sub-Saharan Africa such as the Serengeti (Tanzania), Kafue (Zambia), Hwange (Zimbabwe) and Gorongosa (Mozambique). […] In this study, we reviewed published information on Trichinella infection in wildlife in the GKNP of South Africa from 1964 to 2019 and based on the results, the authors constructed complete hypothetical transmission cycles for the three taxa known to circulate in the GKNP.
#1 Epidemiology and hypothetical transmission cycles of Trichinella infections in the Greater Kruger National Park of South Africa: an example of host-parasite interactions in an environment with minimal human interactions | Parasite
https://www.parasite-journal.org/articles/parasite/full_html/2020/01/parasite200010/parasite200010.html
Unravelling the enigmatic epidemiology of these potentially zoonotic species from the genus Trichinella is important from a public health perspective as it aids in establishing not only the potential risk for human infection, but ultimately proper control and prevention measures. […] Results from passive surveillance in the GKNP further revealed that T. zimbabwensis has the highest prevalence in crocodiles and carnivores, of three species known to circulate in South Africa. […] This would certainly suggest the general knowledge and perceptions of interspecies predation and scavenging to be incomplete. […] The vast size and limited human interference combined with the species richness within the protected area of the GKNP provide an excellent setting for the establishment and maintenance of the Trichinella spp. known to circulate in the area. […] As such, the information presented here cannot, by any means, be considered complete but should rather be viewed as ongoing which undoubtedly will require future update as new evidence is presented.
#1 Epidemiology and hypothetical transmission cycles of Trichinella infections in the Greater Kruger National Park of South Africa: an example of host-parasite interactions in an environment with minimal human interactions | Parasite
https://www.parasite-journal.org/articles/parasite/full_html/2020/01/parasite200010/parasite200010.html
Knowledge on the epidemiology, host range and transmission of Trichinella spp. infections in different ecological zones in southern Africa including areas of wildlife-human interface is limited. […] Of recent, there have been reports of Trichinella infections in several wildlife species within the Greater Kruger National Park (GKNP) of South Africa, which has prompted the revision and update of published hypothetical transmission cycles including the hypothetical options based previously on the biology and feeding behaviour of wildlife hosts confined to the GKNP. […] We presume that the formulated sylvatic cycles may be extrapolated to similar national parks and wildlife protected areas in sub-Saharan Africa where the same host and parasite species are known to occur. […] The anecdotal nature of some of the presented data confirms the need for more intense epidemiological surveillance in national parks and wildlife protected areas in the rest of sub-Saharan Africa to unravel the epidemiology of Trichinella infections in these unique and diverse protected landscapes.
#2 Trichinosis (Trichinellosis): Background, Pathophysiology, Epidemiology
https://emedicine.medscape.com/article/230490-overview
Despite a substantial decline in the global incidence of trichinosis, outbreaks continue to occur frequently, particularly in developing nations. […] An estimated 10,000 cases are reported annually, with a mortality rate of approximately 0.2%. […] The international movement of processed food ingredients has introduced new challenges for control efforts. […] Travelers to regions with prevalent small-farm pig raising should exercise caution regarding pork products and avoid consuming any pork sausage. […] An outbreak in Turkey was attributed to a producer who incorporated pork from unverified sources into beef meatballs. […] Consumption of wild boar sausage in Spain has resulted in human infections with T britovi, and wild boar have been identified as a source of infection in various Mediterranean regions, Southeast Asia, and Pacific Islands. […] This comprehensive overview underscores the clinical significance of trichinosis and highlights the importance of dietary and travel history in patients presenting with gastroenteritis, particularly when accompanied by eosinophilia or palpebral edema.
#2 Trichinellosis Surveillance — United States, 1997–2001
https://diuwinlog.com/mmwr/preview/mmwrhtml/ss5206a1.htm
Trichinellosis is a parasitic disease caused by tissue-dwelling roundworms of the species Trichinella spiralis. […] The national trichinellosis surveillance system has documented a steady decline in the reported incidence of this disease, as well as a change in its epidemiology. […] The purpose of the surveillance system is to determine the incidence of trichinellosis, to maintain awareness of the disease, to monitor epidemiologic changes, to identify outbreaks, to guide prevention efforts, and to measure the effectiveness of those efforts. […] In the United States, the national trichinellosis surveillance system has documented a steady decline in the reported incidence of this disease. […] This report presents data for 1997–2001 on trichinellosis and describes the changing epidemiology of this disease.
#2 Trichinosis epidemiology and demographics – wikidoc
https://www.wikidoc.org/index.php/Trichinosis_epidemiology_and_demographics
Worldwide, an estimated 10,000 cases of trichinosis occur every year. […] During 2008-2012, a total of 90 cases of trichinosis were reported in the USA. […] In the USA, the average of trichinosis is approximately 15 cases per year. […] The mortality rate of trichinosis is approximately 0.2% worldwide. […] Trichinosis most commonly affects individuals 30 to 39 years of age. […] Men are more commonly affected with trichinosis than women. […] In the US and EU, the overall incidence of trichinosis is low given the improved pig-raising practices in the pork industry, commercial and home freezing of pork, and public awareness of the danger of eating raw or undercooked meat products. […] Trichinosis is common in developing countries where meat fed to pigs is either raw or undercooked. […] Incidence data from developing countries are limited.
#2 Trichinellosis (Trichinosis) – Epidemiology
https://www.vdh.virginia.gov/epidemiology/epidemiology-fact-sheets/trichinellosis-trichinosis/
People who eat raw or undercooked meat from animals infected with the Trichinella worm are at higher risk for developing trichinellosis. […] Successful control programs in the United States have nearly eliminated the disease in most domestic pigs, but pigs raised outdoors in close contact with rodents and other wildlife have an increased chance of acquiring Trichinella infection. […] Infection used to be more common and was usually caused by ingestion of undercooked pork. Infection is now relatively rare. The number of cases decreased beginning in the mid-20th century because of legislation prohibiting the feeding of raw-meat garbage to hogs, commercial and home freezing of pork, and the public awareness of the danger of eating raw or undercooked pork products. Current cases are less commonly associated with pork products and more often associated with eating raw or undercooked wild game meats.
#2 Reporting Trichinosis (Trichinella spiralis) – MN Dept. of Health
https://www.health.state.mn.us/diseases/trichinosis/report.html
Trichinosis (Trichinella spiralis) must be reported to MDH within one working day. […] Health care practitioners (health care facilities, medical laboratories, and in certain circumstances veterinarians and veterinary medical laboratories) are required to report disease to the Minnesota Department of Health (MDH) under Minnesota state law. […] Unless previously reported, every licensed health care provider who provides care to any patient who has, is suspected of having, or has died from a reportable disease is required to report. […] Any person in charge of any institution, school, child care facility, or camp is also required to report disease to MDH. […] Infectious Disease Reporting Find out which infectious diseases must be reported by law in Minnesota, who is required to report diseases, how each disease can be reported, and download the appropriate forms.
#3 Trichinosis epidemiology and demographics – wikidoc
https://www.wikidoc.org/index.php/Trichinosis_epidemiology_and_demographics
Worldwide, an estimated 10,000 cases of trichinosis occur every year. […] During 2008-2012, a total of 90 cases of trichinosis were reported in the USA. […] In the USA, the average of trichinosis is approximately 15 cases per year. […] The mortality rate of trichinosis is approximately 0.2% worldwide. […] Trichinosis most commonly affects individuals 30 to 39 years of age. […] Men are more commonly affected with trichinosis than women. […] In the US and EU, the overall incidence of trichinosis is low given the improved pig-raising practices in the pork industry, commercial and home freezing of pork, and public awareness of the danger of eating raw or undercooked meat products. […] Trichinosis is common in developing countries where meat fed to pigs is either raw or undercooked. […] Incidence data from developing countries are limited.