Biegunka podróżnych – Patofizjologia i mechanizm

Biegunka podróżnych
Patofizjologia i mechanizm

Biegunka podróżnych jest najczęściej wywoływana przez bakterie, zwłaszcza enterotoksyczną Escherichia coli (ETEC), odpowiedzialną za 30-50% przypadków, która powoduje sekrecyjną biegunkę poprzez produkcję toksyn termolabilnej (LT) i termostabilnej (ST). Mechanizm patofizjologiczny obejmuje zarówno nieinwazyjne zaburzenia absorpcji i hipersekrecję wody i elektrolitów, jak i inwazyjne uszkodzenie błony śluzowej jelita przez patogeny takie jak Campylobacter, Shigella czy Salmonella, które mogą wywoływać biegunkę z krwią i gorączką. Droga zakażenia jest pokarmowo-kałowa, a czynniki ryzyka to m.in. pierwsza podróż do regionów o niskich standardach sanitarnych, stosowanie leków zmniejszających kwasowość żołądka oraz immunosupresja. Wirusy (norowirusy, rotawirusy) i pasożyty (Giardia lamblia, Cryptosporidium) stanowią mniejszy odsetek etiologii, ale mogą powodować przewlekłe i trudne do leczenia objawy. Najważniejszym powikłaniem jest odwodnienie i zaburzenia elektrolitowe, a także ryzyko rozwoju poinfekcyjnego zespołu jelita drażliwego (PI-IBS), którego ryzyko wzrasta pięciokrotnie po przebytym zakażeniu.

Patogeneza biegunki podróżnych

Drogi transmisji

Czynniki etiologiczne i ich mechanizmy działania

Bakteryjne czynniki etiologiczne
Wirusowe czynniki etiologiczne
Pasożytnicze czynniki etiologiczne

Czynniki ryzyka i mechanizmy modulujące
Konsekwencje patofizjologiczne
Implikacje terapeutyczne wynikające z patogenezy
Nowe kierunki badawcze w patogenezie biegunki podróżnych
Wnioski

Kolejne rozdziały

Patogeneza biegunki podróżnych

Biegunka podróżnych to częsta dolegliwość przewodu pokarmowego, która dotyka osoby podróżujące, szczególnie do regionów o niższych standardach sanitarnych. Charakteryzuje się występowaniem luźnych lub wodnistych stolców, często z towarzyszącymi objawami jak skurcze brzucha, nudności czy wymioty. Patogeneza tej choroby jest złożona i zależy od czynnika wywołującego zakażenie, przy czym najczęstszymi patogenami są bakterie, rzadziej wirusy i pasożyty.¹²

Patofizjologię biegunki podróżnych można podzielić na dwa główne mechanizmy: nieinfekcyjny (nieinwazyjny) oraz infekcyjny (inwazyjny). Droga nieinfekcyjna prowadzi do zmniejszenia zdolności absorpcyjnych błony śluzowej jelita, co skutkuje zwiększonym wydzielaniem treści do światła przewodu pokarmowego. Z kolei droga infekcyjna powoduje uszkodzenie błony śluzowej jelita poprzez uwalnianie cytotoksyn lub bezpośrednią inwazję patogenów, co również prowadzi do zmniejszenia absorpcji i zwiększenia częstości wypróżnień.¹³

Drogi transmisji

Podstawową drogą zakażenia w biegunce podróżnych jest droga pokarmowo-kałowa. Do zakażenia dochodzi najczęściej poprzez spożycie zanieczyszczonej żywności lub wody zawierającej patogeny pochodzące z kału ludzkiego lub zwierzęcego. Osoby podróżujące są szczególnie narażone ze względu na brak wcześniejszej ekspozycji na lokalne patogeny i brak wykształconej odporności, w przeciwieństwie do miejscowej ludności, która często nabywa odporność poprzez wielokrotne ekspozycje na lokalne drobnoustroje.⁴²

Najczęstszymi źródłami zakażenia są:⁵⁶

Zanieczyszczona woda pitna
Lód wykonany z nieczystej wody
Surowe lub niedogotowane potrawy
Niepasteryzowane produkty mleczne
Owoce myte w zanieczyszczonej wodzie
Żywność przygotowywana w niehigienicznych warunkach

Czynniki etiologiczne i ich mechanizmy działania

W epidemiologii biegunki podróżnych dominują czynniki bakteryjne, które odpowiadają za około 80-90% wszystkich przypadków. Wirusy i pasożyty stanowią mniejszy odsetek, choć mogą prowadzić do bardziej długotrwałych objawów.⁷⁸

Bakteryjne czynniki etiologiczne

Najczęstszym bakteryjnym czynnikiem etiologicznym biegunki podróżnych jest enterotoksyczna Escherichia coli (ETEC), która odpowiada za około 30-50% wszystkich przypadków. Inne często izolowane bakterie obejmują Campylobacter jejuni, Shigella spp., Salmonella spp., enteroagregacyjny szczep E. coli (EAEC) oraz enterpatogenny E. coli (EPEC).⁹⁹¹⁰

Enterotoksyczna Escherichia coli (ETEC)

ETEC stanowi najważniejszy patogen wywołujący biegunkę podróżnych. Bakteria ta kolonizuje jelito cienkie za pomocą specyficznych fimbrii adhezyjnych (CFA I i CFA II), które przyczepiają się do receptorów na enterocytach proksymalnej części jelita cienkiego. Po kolonizacji ETEC produkuje enterotoksyny, które są głównym czynnikiem wirulencji.¹¹¹²

ETEC wytwarza dwa rodzaje enterotoksyn:

Toksyna termolabilna (LT) – strukturalnie i funkcjonalnie podobna do toksyny cholery. Składa się z podjednostek A i B, gdzie podjednostka B wiąże się ze specyficznymi receptorami gangliozydowymi (GM1) na komórkach nabłonka jelita cienkiego, umożliwiając wniknięcie podjednostki A do wnętrza komórki. Tam aktywuje cyklazę adenylanową, co prowadzi do zwiększonej produkcji cAMP. Podwyższony poziom cAMP powoduje hipersekrecję wody i elektrolitów do światła jelita oraz hamuje reabsorpcję sodu, co klinicznie objawia się wodnistą biegunką.¹¹¹³¹²
Toksyna termostabilna (ST) – wiąże się z receptorami glikoproteinowymi i stymuluje cyklazę guanylanową, co prowadzi do zwiększonej produkcji cGMP, a w konsekwencji do hipersekrecji wody i elektrolitów. Efektem jest wodnista biegunka sekrecyjna.¹¹¹⁴

W wielu szczepach ETEC plazmidy niosą zarówno geny kodujące enterotoksyny, jak i czynniki kolonizacji, co zwiększa ich wirulencję. Produkcja enterotoksyn jest ograniczona do określonych serotypów O: O6, O8, O15, O25, O63, O78, O148 i O159.¹¹

Inne bakterie diarrheagenic

Campylobacter, Shigella i Salmonella są przykładami bakterii inwazyjnych, które powodują biegunkę poprzez bezpośrednią inwazję śluzówki jelita lub uwolnienie cytotoksyn. Prowadzą one do niszczenia nabłonka jelitowego, co skutkuje upośledzeniem wchłaniania i zapaleniem, a klinicznie może objawiać się biegunką z domieszką krwi i śluzu oraz gorączką.¹⁴¹⁵

Shigella produkuje toksynę Shiga, która hamuje syntezę białek w komórkach gospodarza, prowadząc do ich śmierci. Bakteria może również rozprzestrzeniać się wewnątrzkomórkowo poprzez procesy polimeryzacji aktyny.¹⁵

Inne bakterie, jak Vibrio cholerae, wywołują biegunkę poprzez produkcję toksyny cholery, która działa podobnie do toksyny LT, powodując masywną sekrecję wody i elektrolitów do światła jelita.¹³¹⁶

Wirusowe czynniki etiologiczne

Wirusy odpowiadają za mniejszy odsetek przypadków biegunki podróżnych u dorosłych (około 10-20%), ale mogą być odpowiedzialne za nawet 70% przypadków u niemowląt i dzieci. Najczęściej izolowane wirusy to norowirusy i rotawirusy.¹⁷¹⁸

Mechanizm biegunki wirusowej nie jest tak dobrze poznany jak bakteryjnej, ale wiadomo, że wirusy mogą uszkadzać komórki nabłonka jelita, prowadząc do zaburzenia wchłaniania i wydzielania. Norowirusy wykorzystują domeny P2 do wiązania i HBGA do przyłączania się do komórki gospodarza.¹⁵¹⁹

Biegunka wywołana przez wirusy jest zazwyczaj samolimitująca i nie reaguje na antybiotykoterapię.¹⁷

Pasożytnicze czynniki etiologiczne

Pasożyty stanowią około 10% przyczyn biegunki podróżnych, a zakażenia pasożytnicze rozwijają się wolniej i manifestują objawami później niż bakteryjne czy wirusowe. Najczęstsze pasożyty to Giardia lamblia, Cryptosporidium i Cyclospora cayetanensis.⁷¹⁷

Giardia przyczepia się do nabłonka jelitowego za pomocą tarczy przyczepnej i rozmnaża się przez podział binarny. Crypto-sporidium przechodzi przez proces ekscystacji w jelicie cienkim i migruje do jelita grubego. Pasożyty są zazwyczaj minimalnie inwazyjne, powodując powierzchowne zapalenie błony śluzowej.¹⁵²⁰

Zakażenia pasożytnicze mogą prowadzić do przewlekłej biegunki, która nie reaguje na standardową antybiotykoterapię i wymaga specyficznego leczenia przeciwpasożytniczego.²¹

Czynniki ryzyka i mechanizmy modulujące

Istnieje wiele czynników, które mogą wpływać na ryzyko zachorowania na biegunkę podróżnych oraz na jej przebieg:²²²³¹⁰

Pierwsza podróż lub rozmieszczenie – osoby podróżujące po raz pierwszy do danego regionu są bardziej narażone z powodu braku wcześniejszej ekspozycji na lokalne patogeny
Podróż do krajów rozwijających się – szczególnie regiony o niskich standardach sanitarnych i higienicznych
Młodszy wiek – młodzi dorośli są bardziej skłonni do podejmowania ryzykownych zachowań dietetycznych
Przyjmowanie leków zmniejszających kwasowość żołądka – takich jak inhibitory pompy protonowej, leki blokujące receptor H2 czy leki zobojętniające, które zmniejszają naturalną barierę ochronną kwasu żołądkowego
Osłabiony układ odpornościowy – osoby z immunosupresją są bardziej podatne na zakażenie i cięższy przebieg choroby
Przewlekłe choroby przewodu pokarmowego – jak zespół jelita drażliwego czy nieswoiste zapalenia jelit zwiększają ryzyko

Warto zauważyć, że miejscowa ludność regionów endemicznych często nie choruje, ponieważ ich organizmy wytworzyły odporność na lokalne patogeny w wyniku wielokrotnej ekspozycji od wczesnego dzieciństwa.⁴²⁴

Konsekwencje patofizjologiczne

Biegunka podróżnych może prowadzić do szeregu konsekwencji patofizjologicznych, spośród których najważniejsze to:²²²⁵

Odwodnienie – najbardziej powszechne powikłanie, wynikające z utraty płynów i elektrolitów, szczególnie niebezpieczne u dzieci i osób starszych
Zaburzenia elektrolitowe – utrata sodu, potasu, chlorków może prowadzić do zaburzeń homeostazy organizmu
Wtórna nietolerancja laktozy – uszkodzenie nabłonka jelitowego może prowadzić do czasowej niezdolności trawienia laktozy
Poinfekcyjny zespół jelita drażliwego (PI-IBS) – przewlekłe dolegliwości jelitowe mogące utrzymywać się po ustąpieniu ostrej fazy zakażenia
Zaostrzenie istniejących chorób przewodu pokarmowego – jak nieswoiste zapalenia jelit

Badania wykazały, że ryzyko rozwoju poinfekcyjnego zespołu jelita drażliwego jest 5 razy wyższe u podróżnych, którzy przebyli biegunkę podróżnych, w porównaniu do tych, którzy nie zachorowali podczas podróży.¹⁸²⁶

Implikacje terapeutyczne wynikające z patogenezy

Zrozumienie patogenezy biegunki podróżnych ma kluczowe znaczenie dla odpowiedniego leczenia. W zależności od mechanizmu działania patogenu i ciężkości objawów, stosuje się różne podejścia terapeutyczne:²⁷²⁸

Nawodnienie – podstawą leczenia jest uzupełnianie utraconych płynów i elektrolitów, szczególnie w przypadku biegunki sekrecyjnej. Doustne płyny nawadniające są zazwyczaj wystarczające, ale w ciężkich przypadkach może być konieczne nawodnienie dożylne.²⁹

Leki przeciwbiegunkowe – takie jak loperamid (Imodium) mogą zmniejszyć częstość wypróżnień poprzez spowolnienie perystaltyki jelitowej, co daje więcej czasu na wchłanianie płynów. Należy jednak pamiętać, że mogą one przedłużać infekcję w przypadku niektórych patogenów inwazyjnych, dlatego są przeciwwskazane przy gorączce lub krwawej biegunce.³⁰³¹

Antybiotyki – są skuteczne w skracaniu czasu trwania biegunki o około 1-2 dni w przypadkach wywołanych przez bakterie wrażliwe na dany antybiotyk. Wybór antybiotyku zależy od prawdopodobieństwa obecności organizmu inwazyjnego oraz wzorców oporności na antybiotyki, które różnią się w zależności od regionu geograficznego.⁷⁹

Fluorochinolony (np. ciprofloksacyna) są często stosowane u dorosłych
Azytromycyna jest preferowana u dzieci i w regionach z wysoką opornością na fluorochinolony
Rifaksymina jest skuteczna głównie przeciwko ETEC i EAEC, ale jej skuteczność przeciwko bakteriom inwazyjnym nie została ustalona

Substancje antysekrecyjne – takie jak subsalicylan bizmutu (BSS) wykazują działanie przeciwbakteryjne i antysekrecyjne, zmniejszając ryzyko biegunki podróżnych o około 50% w badaniach profilaktycznych.²⁷³²

Leki przeciwpasożytnicze – w przypadku stwierdzenia zakażenia pasożytniczego stosuje się specyficzne leki przeciwpasożytnicze, których wybór zależy od rodzaju patogenu.²³³³

Warto zaznaczyć, że rutynowe stosowanie antybiotyków w profilaktyce biegunki podróżnych budzi kontrowersje ze względu na ryzyko rozwoju oporności bakterii oraz zaburzenia naturalnej mikroflory jelitowej.²⁷²¹⁵

Nowe kierunki badawcze w patogenezie biegunki podróżnych

Badania nad patogenezą biegunki podróżnych nadal się rozwijają, a nowe odkrycia mogą prowadzić do innowacyjnych metod profilaktyki i leczenia:³⁴²¹

Zrozumienie struktury fimbrii bakteryjnych – badania nad mechanizmem przyczepiania się fimbrii bakteryjnych ETEC do komórek jelita mogą prowadzić do opracowania nowych leków, które zakłócałyby ten proces. Badacze odkryli, że fimbrie ETEC skręcają się i rozwijają, co pozwala bakteriom utrzymać się przy śluzówce jelita pomimo sił fizjologicznych dążących do ich usunięcia.³⁴³⁵

Biopreparaty terapeutyczne – wykorzystanie mikroorganizmów, które hamują infekcję patogenami, może stanowić alternatywę dla antybiotyków. Badania nad probiotykami i prebiotykami w kontekście biegunki podróżnych mogą otworzyć nowe możliwości profilaktyki.²¹

Immunoprofilaktyka – prace nad szczepionkami doustnymi przeciwko najczęstszym patogenom biegunki podróżnych, szczególnie ETEC, są obiecującym kierunkiem badań. Zrozumienie struktury antygenowej patogenów może pomóc w opracowaniu skutecznych szczepionek.²¹³⁵

Metagenomika – wykorzystanie sekwencjonowania metagenomicznego do identyfikacji nowych patogenów i sygnatur patogennych w próbkach kału od pacjentów z biegunką podróżnych, u których nie zidentyfikowano znanego patogenu. Może to prowadzić do odkrycia nowych czynników etiologicznych i lepszego zrozumienia choroby.²⁶

Peptyd histamina-5 – badania nad składnikiem śliny, peptydem histamina-5, który może zakłócać funkcję fimbrii bakteryjnych i zmniejszać wiązanie bakterii wywołujących biegunkę do komórek, mogą prowadzić do nowych terapii.³⁶

Te nowe kierunki badawcze mają potencjał do zrewolucjonizowania podejścia do biegunki podróżnych, umożliwiając bardziej skuteczną profilaktykę i leczenie przy jednoczesnym zmniejszeniu ryzyka rozwoju oporności na antybiotyki.¹⁰³⁶

Wnioski

Patogeneza biegunki podróżnych jest złożonym procesem, który zależy od wielu czynników, w tym rodzaju patogenu, mechanizmu jego działania oraz czynników związanych z gospodarzem. Większość przypadków wywoływana jest przez bakterie, szczególnie enterotoksyczną E. coli, która powoduje sekrecyjną biegunkę poprzez produkcję toksyn LT i ST. Inne patogeny, jak bakterie inwazyjne, wirusy czy pasożyty, również przyczyniają się do obrazu klinicznego choroby poprzez różne mechanizmy uszkadzające błonę śluzową jelita.¹¹³¹⁴

Zrozumienie tych mechanizmów jest kluczowe dla opracowania skutecznych strategii profilaktycznych i terapeutycznych. Aktualnie leczenie opiera się głównie na nawodnieniu, lekach przeciwbiegunkowych i w wybranych przypadkach antybiotykoterapii. Nowe badania nad patogenezą biegunki podróżnych mogą prowadzić do opracowania innowacyjnych metod leczenia, takich jak leki zakłócające przyleganie bakterii do śluzówki jelita czy szczepionki przeciwko najczęstszym patogenom.³⁴³⁶

Mimo postępów w zrozumieniu patogenezy biegunki podróżnych, nadal istnieje potrzeba dalszych badań, szczególnie w kontekście odkrywania nieznanych dotąd patogenów oraz badania długoterminowych konsekwencji zakażenia, takich jak poinfekcyjny zespół jelita drażliwego. Bardziej kompleksowe zrozumienie mechanizmów choroby może prowadzić do lepszych metod zapobiegania i leczenia, zmniejszając obciążenie zdrowotne i ekonomiczne związane z biegunką podróżnych.²⁶¹⁸

Kolejne rozdziały

Zapraszamy do dalszego czytania naszego leksykonu.

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

Materiały źródłowe

#1 Travelers Diarrhea – StatPearls – NCBI Bookshelf
https://www.ncbi.nlm.nih.gov/books/NBK459348/
Traveler’s diarrhea is most commonly spread by fecal-oral transmission of the causative organism, typically through consumption of contaminated food or water. […] The pathophysiology for travelers diarrhea differs by a causative agent but can be split into non-inflammatory or inflammatory pathways. Non-inflammatory agents cause a decrease in the absorptive abilities of the intestinal mucosa, thereby increasing the output of the gastrointestinal (GI) tract. Inflammatory agents on the other hand cause destruction of the intestinal mucosa either through cytotoxin release or direct invasion of the mucosa. The loss of mucosa surface again results in a decrease of absorption with a resultant increase in bowel movements.
#2 Travelersâ Diarrhea | Yellow Book | CDC
https://www.cdc.gov/yellow-book/hcp/preparing-international-travelers/travelers-diarrhea.html
Travelers’ diarrhea (TD) is a clinical syndrome that can result from a variety of intestinal pathogens. Bacteria are the predominant enteropathogens and are thought to account for 75%90% of cases. […] The use of multiplex molecular diagnostic assays has suggested that the contribution of viruses to the overall burden of TD disease is underestimated. Infections with protozoal pathogens are slower to manifest symptoms and collectively account for approximately 10% of diagnoses, predominantly in longer-term travelers. […] Bacteria are the most common cause of TD. Overall, the most common pathogens identified are diarrheagenic Escherichia coli (most prominently enterotoxigenic E. coli, but also including enteroaggregative E. coli and enteropathogenic E. coli), followed by Campylobacter jejuni, Shigella spp., and Salmonella spp.
#3 Travelerâs Diarrhea
https://www.salixmedical.com/therapeutic-areas/travelers-diarrhea/
TD generally occurs via non-inflammatory or inflammatory pathways. […] Non-inflammatory agents decrease absorption in the intestinal mucosa, increasing the output of the GI tract. Inflammatory agents cause destruction of the intestinal mucosa through cytotoxin release or direct invasion. The loss of mucosal surface also results in decreased absorption in the mucosa and increased bowel movements.
#4 Traveler’s diarrhea – Symptoms and causes – Mayo Clinic
https://www.mayoclinic.org/diseases-conditions/travelers-diarrhea/symptoms-causes/syc-20352182
Traveler’s diarrhea is a digestive tract disorder that commonly causes loose stools and stomach cramps. It’s caused by eating contaminated food or drinking contaminated water. […] It’s possible that traveler’s diarrhea may stem from the stress of traveling or a change in diet. But usually infectious agents such as bacteria, viruses or parasites are to blame. You typically develop traveler’s diarrhea after ingesting food or water contaminated with organisms from feces. […] So why aren’t natives of high-risk countries affected in the same way? Often their bodies have become used to the bacteria and have developed immunity to them.
#5 Travelers’ Diarrhea – Traveler Summary – TripPrep.com
https://tripprep.com/library/travelers-diarrhea
Travelers’ diarrhea (TD), the most common health problem for travelers, is an intestinal infection affecting up to 70% of travelers going to developing countries. […] TD is caused primarily by bacteria (uncommonly by parasites or viruses) acquired through consumption of contaminated food or beverages. […] Poor sanitation, the presence of stool in the environment, and the absence of safe restaurant practices lead to risk of diarrhea from eating a variety of foods contaminated by fecal organisms, especially bacteria. […] Individuals at high risk for TD or adverse consequences include young adults (prone to risk-taking behavior and often on limited budgets); persons with compromised immunity, inflammatory bowel disease, or diabetes; and those taking medicines (e.g., omeprazole) that decrease gastric acidity.
#5 Travelers’ Diarrhea – Traveler Summary – TripPrep.com
https://tripprep.com/library/travelers-diarrhea
TD caused by bacteria typically presents with abrupt onset of uncomfortable, crampy diarrhea and may be accompanied by nausea or vomiting and, less commonly, fever. […] Persistent diarrhea, recurrent diarrhea, and other chronic gastrointestinal discomfort (e.g., bloating, gas, constipation) may occur as a result of TD. […] The use of antibiotics can turn a 3- or 4-day illness into a 1-day illness. However, antibiotic use for TD increases the intestinal carriage of antibiotic-resistant bacteria in returning travelers, especially in South Asia where 80% of travelers treated with antibiotics acquired resistant bacteria.
#6 Traveller’s diarrhoea | Better Health Channel
https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/travellers-diarrhoea
Micro-organisms that can cause travellers diarrhoea include: […] Bacteria Escherichia coli (E. coli), primarily enterotoxigenic strains (ETEC). This is one of the most common bacterial causes of travellers diarrhoea. Other bacterial causes of travellers diarrhoea include Campylobacter jejuni, Salmonella species and Shigella species. These infections are usually associated with severe abdominal pains and fever […] Viruses some estimates suggest that around one in three cases of travellers diarrhoea is caused by or associated with a viral infection, particularly norovirus and rotavirus […] Unknown causes a cause can’t be found in approximately one-fifth to half of all cases of travellers diarrhoea. It is thought that diarrhoea may be the gastrointestinal system’s response to unfamiliar micro-organisms.
#7 Travelersâ Diarrhea | Yellow Book | CDC
https://wwwnc.cdc.gov/travel/yellowbook/2024/preparing/travelers-diarrhea
Travelers’ diarrhea (TD) is a clinical syndrome that can result from a variety of intestinal pathogens. Bacteria are the predominant enteropathogens and are thought to account for 75%90% of cases. […] The use of multiplex molecular diagnostic assays has suggested that the contribution of viruses to the overall burden of TD disease is underestimated. Infections with protozoal pathogens are slower to manifest symptoms and collectively account for approximately 10% of diagnoses, predominantly in longer-term travelers. […] Bacteria are the most common cause of TD. Overall, the most common pathogens identified are diarrheagenic Escherichia coli (most prominently enterotoxigenic E. coli, but also including enteroaggregative E. coli and enteropathogenic E. coli), followed by Campylobacter jejuni, Shigella spp., and Salmonella spp.
#7 Travelersâ Diarrhea | Yellow Book | CDC
https://wwwnc.cdc.gov/travel/yellowbook/2024/preparing/travelers-diarrhea
The incubation period between exposure and clinical presentation can provide clues to etiology. Toxin-mediated illness, for example, generally causes symptoms within a few hours. By contrast, illnesses caused by bacterial and viral pathogens have incubation periods of 696 hours. […] An acute (less than 2 weeks) bout of TD can lead to persistent enteric symptoms, even in the absence of continued infection. This presentation is commonly referred to as post-infectious irritable bowel syndrome. […] Prophylactic antibiotics afford no protection against nonbacterial pathogens and can remove normally protective microflora from the bowel, increasing the risk for acquisition of resistant bacterial pathogens. […] Antibiotics are effective in reducing the duration of diarrhea by approximately 12 days in cases caused by bacterial pathogens susceptible to the antibiotic prescribed. However, concerns about the adverse consequences of using antibiotics to treat TD remain.
#8 Approach to Treatment and Prevention of Travelerâs Diarrhea
https://www.uspharmacist.com/article/approach-to-treatment-and-prevention-of-travelers-diarrhea
Travelers diarrhea (TD) is the most common ailment affecting persons from industrialized countries who visit developing areas. […] Bacterial pathogens are thought to account for 80% to 90% of TD. The most causative organism is enterotoxigenic Escherichia coli, followed by Campylobacter jejuni, Shigella species, and Salmonella species. Some bacteria release toxins that bind to the intestinal wall and cause diarrhea, while others damage the intestine merely by their presence. […] In most cases, TD is acquired primarily through the consumption of contaminated food or water.
#9 Travelerâs Diarrhea | AAFP
https://www.aafp.org/pubs/afp/issues/2005/0601/p2095.html
Acute diarrhea affects millions of persons who travel to developing countries each year. Food and water contaminated with fecal matter are the main sources of infection. Bacteria such as enterotoxigenic Escherichia coli, enteroaggregative E. coli, Campylobacter, Salmonella, and Shigella are common causes of travelers diarrhea. […] In contrast to the largely viral etiology of gastroenteritis in the United States, diarrhea acquired in developing countries is caused mainly by bacteria. Enterotoxigenic Escherichia coli is the pathogen most frequently isolated, but other types of E. coli such as enteroaggregative E. coli have been recognized as common causes of travelers diarrhea. […] The prevalence of specific organisms varies with travel destination. Available data suggest that E. coli is the predominant cause of travelers diarrhea in Latin America, the Caribbean, and Africa, while invasive pathogens are relatively uncommon. Enterotoxigenic E. coli and enteroaggregative E. coli may be responsible for up to 71 percent of cases of travelers diarrhea in Mexico.
#9 Travelerâs Diarrhea | AAFP
https://www.aafp.org/pubs/afp/issues/2005/0601/p2095.html
Food poisoning is part of the differential diagnosis of travelers diarrhea. Gastroenteritis from preformed toxins (e.g., Staphylococcus aureus, Bacillus cereus) is characterized by a short incubation period (one to six hours), and symptoms typically resolve within 24 hours. […] Counseling travelers about food precautions does not eliminate the risk of travelers diarrhea, and nonantibiotic prophylaxis requires frequent dosing to achieve only a modest reduction in risk. […] Antibiotic selection is based on the likelihood that an invasive organism is present and on antibiotic resistance patterns. These factors are determined largely by travel destination. […] Therapy that involves an antibiotic with loperamide (Imodium) often limits symptoms to one day. Loperamide has antimotility and antisecretory effects and is taken as two 2mg tablets after the first loose stool, followed by one tablet after each subsequent loose stool (maximum of 8 mg in 24 hours for two days). […] Dehydration is the main complication of travelers diarrhea, especially in children and older adults.
#10 Travelersâ diarrhea: update on the incidence, etiology and risk in military and similar populations â 1990-2005 versus 2005â2015, does a decade make a difference? | Tropical Diseases, Travel Medicine and Vaccines | Full Text
https://tdtmvjournal.biomedcentral.com/articles/10.1186/s40794-018-0077-1
Consistent with estimates from our prior systematic review, diarrheagenic E. coli (particularly ETEC and EAEC) and Campylobacter remained the most common pathogens causing TD in aggregate. […] This finding likely reflects the heterogeneity of study designs. […] While we did not find a difference in duration of symptoms between treated and untreated travelers, within the group of travelers who received treatment, data on time to last unformed stool (TLUS) demonstrates that subjects administered a combination of loperamide plus antibiotic reported more rapid recovery than those using only antibiotics, with a difference of almost 20h. […] Despite this relative short duration of symptoms, there remains a significant burden of morbidity due to more severe cases, with a high rate of individuals being incapacitated as a result of their illness or requiring IV rehydration.
#10 Travelersâ diarrhea: update on the incidence, etiology and risk in military and similar populations â 1990-2005 versus 2005â2015, does a decade make a difference? | Tropical Diseases, Travel Medicine and Vaccines | Full Text
https://tdtmvjournal.biomedcentral.com/articles/10.1186/s40794-018-0077-1
Travelers diarrhea remains a prevalent illness impacting individuals visiting developing countries, however most studies have focused on this disease in the context of short term travel. […] Sixty-two percent of tested cases were due to bacterial pathogens, with enterotoxigenic E. coli (ETEC), enteroaggregative E. coli (EAEC), and Campylobacter predominating, and significant regional variability. […] The risks for developing acute TD are similar between military and non-military long-term travelers, with first time travel or deployment, travel or deployment to developing nations, younger age, and lack of dietary discretion being common risk factors. […] We found that in those studies where evaluation for specific infectious etiologies was performed, a majority of subjects had at least one pathogen identified, a finding consistent with other reviews that have reported pathogen recovery ranging from 50 to 94% of TD cases.
#10 Travelersâ diarrhea: update on the incidence, etiology and risk in military and similar populations â 1990-2005 versus 2005â2015, does a decade make a difference? | Tropical Diseases, Travel Medicine and Vaccines | Full Text
https://tdtmvjournal.biomedcentral.com/articles/10.1186/s40794-018-0077-1
Diarrheagenic E. coli (ETEC and EAEC, particularly), Campylobacter, and Shigella species remain significant diarrheal pathogens globally, with some variations in prevalence geographically. […] Lastly, because diarrheal disease remains frequent in this population, the high incidence of cases not seeking care remains high, and the associated morbidity of disease can be significant, diarrheal disease should be considered an important health threat and be investigated further with further well-designed studies, including those focused on timely and effective treatment strategies and preventative measures including behavioral or hygiene interventions and vaccine development.
#11 Travellers Diarrhea: Microbiology notes of Sridhar Rao P.N
https://www.microrao.com/micronotes/travellers_diarrhea.htm
Infection is acquired by ingestion of food or water contaminated with ETEC. […] The bacteria colonize the GI tract by means of a fimbrial adhesin (CFA I and CFA II). These fimbrial adhesins adhere to specific receptors on enterocytes of the proximal small intestine. The symptoms of diarrhoea are due to ETEC strains produce enterotoxins. Enterotoxins produced by ETEC include the LT (heat-labile) toxin and or the ST (heat-stable) toxin, the genes for which may occur on the same or separate plasmids. LTs are similar to cholera toxin in structure and mode of action. Like cholera toxin, LTs are holotoxin consisting of A subunit and B subunit. The B subunit of LTs binds to specific ganglioside receptors (GM1) on the epithelial cells of small intestine and facilitates the entry of A subunit where it activates adenylate cyclase. Stimulation of adenylate cyclase causes an increased production of cAMP, which leads to hypersecretion of water and electrolytes into the lumen and inhibition of sodium reasborption. LT are divided into two antigenic types LT-I and LT-II. While LT-I is plasmid encoded, LT-II is chromosomally encoded. STs are of two types, ST-I and ST-II. Following colonization, the cells produce ST-I, which binds to glycoprotein receptor and stimulates guanylate cyclase. This results in increased production of cGMP that is followed by hypersecretion of water and electrolytes. The mechanism of ST-II is independent of cGMP activation and has not been found on strains affecting humans. In several strains, the plasmids carry genes for both enterotoxin and colonization factor production. The enterotoxin production is limited to following O serotypes: O6, O8, O15, O25, O63, O78, O148 and O159.
#12 Enterotoxigenic Escherichia coli (ETEC) as the Cause of Travelerâs Diarrhea
http://article.sapub.org/10.5923.j.ajmms.20140405.03.html
Traveler’s diarrhea is one of the most common gastrointestinal illnesses among the travelers all over the world. […] The underlying mechanism of bacterial diarrhea discussed includes the pathway in how ETEC causes diarrhea which is through intestinal colonization, followed by elaboration of diarrhegenic enterotoxin. […] Pathogenesis of ETEC bacteria invasion involves two steps which are intestinal colonization, followed by elaboration of diarrheagenic enterotoxins. […] First ETEC must colonize the small intestine to cause disease. Then, the pilli liaise attaches to specific receptors on villous enterocytes. […] When the colonization is complete, the bacteria produces toxins which causes the diarrhea. […] ETEC identified to produce two types of enterotoxins which are heat-labile toxin (LT) and heat stable toxin (ST).
#12 Enterotoxigenic Escherichia coli (ETEC) as the Cause of Travelerâs Diarrhea
http://article.sapub.org/10.5923.j.ajmms.20140405.03.html
The heat-labile toxin (LT) activates adenylyl cyclase in a manner analogous to cholera toxin. […] The heat-stable toxin (ST) activates guanylylcyclase activity. […] There are two steps involved in the pathogenesis of ETEC: intestinal colonization, followed by elaboration of diarrheagenic enterotoxins. […] The bacteria gain entry to the small intestinal lumen through ingestion of contaminated food.
#13 Travelersâ Diarrhea: A Clinical Review
https://pmc.ncbi.nlm.nih.gov/articles/PMC6751351/
Travelers diarrhea may be caused by increased secretion and/or decreased absorption of fluid and electrolytes across the intestinal epithelium. […] Pathogens that can lead to secretory diarrhea include, ETEC, Vibrio cholera and rotavirus. […] Infection by these pathogens leads to the secretion of neurotransmitters (e.g., 5-hydroxytryptamine) from enteroendocrine cells and activation of afferent neurons that stimulate submucosal secretomotor neurons resulting in an outpouring of electrolytes and fluid into the intestinal lumen. […] Activation of adenylate cyclase and elevation of intracellular cAMP in the enterocytes mediated by the bacterial toxins may account for the pathogenesis of secretory diarrhea. […] The majority of cholera is caused by the cholera toxin-producing V. cholerae strains of 01 and 0139 serogroups.
#14 Travelersâ Diarrhea: A Clinical Review
https://pmc.ncbi.nlm.nih.gov/articles/PMC6751351/
ETEC can produce a heat-labile enterotoxin (LT), a heat-stable enterotoxin (ST), or both enterotoxins (LT/ST). […] Approximately two-thirds of ETEC produce LT, which is functionally and structurally similar to cholera toxin. […] The enterotoxins produced by ETEC are responsible for ETEC’s virulence. […] Other virulence factors include adhesion properties and colonization factors. […] Impaired absorption of fluid and electrolytes with resultant diarrhea may result from the direct invasion of the intestinal mucosa or the destruction of enterocytes by the cytolytic toxins released by the pathogens. […] Examples of these pathogens include Salmonella spp, Shigella spp, Campylobacter spp, Yersinia enterocolitica, and ETEC.
#15 Traveler’s diarrhea pathophysiology – wikidoc
https://www.wikidoc.org/index.php/Traveler%27s_diarrhea_pathophysiology
The transmission and pathogenesis of traveler’s diarrhea is dependent on the infectious agent. The pathogenesis and mechanism of infection depends on the infectious agent. In E. coli traveler’s diarrhea (most common), the organism secretes 2 endotoxins, heat-labile toxin (LT) and heat-stable toxin (ST), to induce clinical manifestations. […] Enterotoxin-mediated: secretion of heat-labile toxin (LT) and heat-stable toxin (ST). […] Enterotoxin-mediated: secretion of Cholera-like enterotoxin. […] Enterotoxin-mediated: secretion of Shiga toxin. […] Invasion of macrophages and induction of cellular apoptosis. […] Intracellular spread by actin polymerization processes (rocket propulsion). […] High inoculum sufficient for infection (inactivated by gastric acid). […] Vi capsule endotoxin prevents opsonization and lysis.
#15 Traveler’s diarrhea pathophysiology – wikidoc
https://www.wikidoc.org/index.php/Traveler%27s_diarrhea_pathophysiology
Virus uses P2 subdomain for binding and HBGA for attachment on host cell. […] Poorly understood pathogenesis. […] Attaches to the epithelium by a ventral adhesive disc, and reproduces via binary fission. […] Excystation in the small intestine and migration to the large intestine. […] Minimally invasive, surface-level mucosal inflammation.
#16 Epidemiology and etiology of Travelerâs diarrhea in Bangkok, Thailand, a case-control study | Tropical Diseases, Travel Medicine and Vaccines | Full Text
https://tdtmvjournal.biomedcentral.com/articles/10.1186/s40794-019-0085-9
Travelers diarrhea (TD) is a common health problem among visitors from developed to developing countries. Although global and regional estimates of pathogen distribution are available, the etiology of diarrhea among non-military travelers to Thailand is largely unknown. […] Etiology of TD in Thailand is mainly of bacterial origin. Plesiomonas, Vibrio, and norovirus are underappreciated diarrheagenic pathogens. In our study, the origin of the traveler plays an important role in diarrhea etiology. Understanding variations in TD severity and etiology among travelers from different regions warrants further study. […] Our findings suggest that Plesiomonas, Vibrio, Campylobacter, and norovirus are important pathogens causing acute diarrhea among travelers and expatriates to Bangkok.
#17 Travelers’ diarrhea – Wikipedia
https://en.wikipedia.org/wiki/Travelers%27_diarrhea
While viruses are associated with less than 20% of adult cases of travelers’ diarrhea, they may be responsible for nearly 70% of cases in infants and children. Diarrhea due to viral agents is unaffected by antibiotic therapy, but is usually self-limited. Protozoans such as Giardia lamblia, Cryptosporidium and Cyclospora cayetanensis can also cause diarrhea. Pathogens commonly implicated in travelers’ diarrhea appear in the table in this section.
#18 New Developments in Travelerâs Diarrhea â Gastroenterology & Hepatology
https://www.gastroenterologyandhepatology.net/archives/february-2011/new-developments-in-travelers-diarrhea/
Although not part of normal human gut flora, strains of Arcobacter, including the normally nonpathogenic species A. cryaerophilus and the diarrheagenic A. butzleri, appear to cause TD. […] Enterotoxigenic Bacteroides fragilis (ETBF) has recently been identified as a cause of diarrhea associated with colonic inflammation that is accompanied by watery diarrhea and fecal inflammatory products such as interleukin (IL)-8, tumor necrosis factors, and lactoferrin. […] Noroviruses appear to be the third most important cause of TD, behind ETEC and EAEC. […] The definition of classic TD is passage of at least 3 unformed stools per day plus 1 or more signs or symptoms of an enteric infection, such as nausea, vomiting, fever, abdominal pain, cramps, fecal urgency, dysentery, or tenesmus. […] Some patients develop chronic complications from TD. […] The risk of developing PI-IBS is 5 times higher in returning travelers who had TD than travelers who did not develop diarrhea during their trip. […] Pathogen- and geographic-based approaches to TD treatment should be encouraged.
#19 Alterations in the Human gut Microbiome Associated with Travelers’ Diarrhea | National Agricultural Library
https://www.nal.usda.gov/research-tools/food-safety-research-projects/alterations-human-gut-microbiome-associated-travelers
Alterations in the GI microbiota have been correlated to diseases such as obesity and irritable bowel syndrome. Secretory diarrhea exhibits alterations on the GI community, and up to 60% of people traveling from developed to developing countries acquire a form of secretory diarrhea know as travelers’ diarrhea (TD). Enterotoxigenic E. coli (ETEC) and Norovirus (NV) are the leading cause of bacterial and viral TD, respectively. ETEC expresses two toxins, heat labile toxin (LT) and heat stable toxin (ST), which ultimately lead to secretory diarrhea. […] The mechanism of noroviral diarrhea is not well understood. […] Presumably, TD causes a shift in bacterial GI communities; however, this has not been studied. […] This proposal outlines the necessary first steps in understanding how TD affects the gut microbiome. Results from my research could potentially lead to development of preventative treatments and novel therapeutics against TD.
#20
https://link.springer.com/article/10.1007/s11908-003-0067-x
Travel is a risk factor for acquiring infection with a sporeforming protozoa: Cryptosopridium, Cyclospora, Microsporidia, and Isospora. […] Very mild infections may be underdiagnosed and may cause typical travelers diarrhea. […] If immune status is normal and the disease is mild, symptomatic therapy may suffice. Effective treatment is available for Cyclospora, Microsporidia, and Isospora. […] This experienced investigator in Cryptosporidium infection reviews the evidence that parasites cause travelers diarrhea. All four of the sporeforming protozoa are reviewed. […] Cryptosporidium was the cause of 3% of acute diarrhea in travelers to Mexico in this prospective study of 127 US adult travelers. […] Using light microscopy and PCR, nine cases of persistent diarrhea in returned travelers were found to be associated with Microsporidia infection. […] This study showed that if water supplies are excluded, the major risk factors for sporadic Cryptosporidium infection are swimming in public pools and contact with a person with diarrhea. Travel is a strong risk, but it was excluded because the source of water cannot be controlled for.
#21 Prevention and Treatment of Traveler’s Diarrhea | AAFP
https://www.aafp.org/pubs/afp/issues/1999/0701/p119.html
Common pathogens in traveler’s diarrhea include enterotoxigenic Escherichia coli, Campylobacter, Shigella, Salmonella, Yersinia and many other species. […] Enterotoxigenic Escherichia coli is the chief pathogen, accounting for 40 to 50 percent of cases. […] All of these agents are efficiently spread by the fecal-oral route and, in some cases, such as Shigella infections, a minute inoculum (as few as 10 to 100 organisms) is all that is necessary to produce disease. […] Traveler’s diarrhea is fundamentally a sanitation failure, leading to bacterial contamination of food and water. […] The three major protozoal causes of traveler’s diarrhea are Entamoeba histolytica, Giardia duodenalis and Cryptosporidium parvum. […] Diarrheal disease caused by these organisms is notable for its longer duration and failure to respond to routine antibiotic therapy.
#21 Prevention and Treatment of Traveler’s Diarrhea | AAFP
https://www.aafp.org/pubs/afp/issues/1999/0701/p119.html
Even with the emphasis now placed on pre-cautionary measures to prevent traveler’s diarrhea rather than drug prophylaxis, the treatment of traveler’s diarrhea will be increasingly hampered by antibiotic resistance. […] Some respite may be provided by the most recently developed fluoroquinolones and azithromycin, but eventually a new approach will be necessary. […] One future option might be nonabsorbable antimicrobial drugs such as bicozamycin, furazolidone, aztreonam and rifaximin, which have already shown some benefit in the treatment of traveler’s diarrhea. […] Use of biotherapeutic agents made of microorganisms that suppress pathogenic infection is another option. […] Immunoprophylaxis by means of oral vaccines may become a third alternative to systemic antibiotics.
#22 Travelerâs Diarrhea: What It Is, Treatment & Antibiotics
https://my.clevelandclinic.org/health/diseases/7315-travelers-diarrhea
Travelers diarrhea is contagious. In travelers diarrhea, germs from your gastrointestinal tract can spread through tiny particles of poop or vomit that linger on surfaces. […] The most common risk factor is consuming contaminated food and drinks. But certain groups of people have more risk than others, including: Young adults, People with weak immune systems, People with underlying chronic gastrointestinal diseases. […] Dehydration is the most common complication, and severe dehydration can be a serious medical condition. Less frequently, travelers diarrhea may trigger an underlying gastrointestinal disease. For example, you may develop post-infectious irritable bowel syndrome (PI-IBS). If you have a genetic tendency for inflammatory bowel disease, having travelers diarrhea may lead to your first IBD symptoms. Severe travelers diarrhea from a bacterial infection may cause symptoms like blood or mucus in your poop and fever.
#23 Travelerâs Diarrhea – Digestive Disorders – Merck Manual Consumer Version
https://www.merckmanuals.com/home/digestive-disorders/gastroenteritis/traveler-s-diarrhea
Travelers diarrhea can be caused by bacteria, parasites, or viruses. […] The organisms are usually acquired from food or water, especially in countries where the water supply may be inadequately treated. […] Travelers diarrhea occurs when people are exposed to bacteria, viruses, or, less commonly, parasites to which they have had little exposure and thus no immunity. […] The bacteria Escherichia coli (E. coli) is the organism most likely to cause travelers diarrhea, particularly the types of E. coli that produce certain toxins, and viruses such as norovirus, which has been a particular problem on some cruise ships. […] People who take medications that decrease stomach acid (such as antacids, H2 blockers, and proton pump inhibitors) are at risk of developing a more severe illness. […] Antibiotics are not necessary for mild traveler’s diarrhea. […] However, if diarrhea is more severe (3 or more loose stools over 8 hours), antibiotics are often given. […] Antiparasitic medications are given if a parasite is identified in the stool.
#24 Can You Protect Your Tummy From Traveler’s Diarrhea? : Goats and Soda : NPR
https://www.npr.org/sections/goatsandsoda/2015/08/06/429356591/can-you-protect-your-tummy-from-travelers-diarrhea
Long-term trekkers and expats will eventually build up immunity to diarrhea-causing bacteria. But it takes years, not weeks or months. […] Young children in developing countries are frequently exposed to diarrhea-causing E. coli and thus build up immunity to these strains during the first few years of life. […] The major source of traveler’s diarrhea is contaminated food and water at restaurants, Shlim says. […] The problem is usually poor hygiene in restaurants’ kitchens, Shlim says. […] But there is one strategy that seems to work, Shlim and Connor say: high temperature. […] One concern with travelers using antibiotics is the rise of drug-resistant bacteria around the world. Some studies have suggested that travelers may exacerbate the problem. […] Another concern about using antibiotics on vacation is that the drugs disrupt a healthy microbiome.
#25 Traveller’s Diarrhoea | Symptoms, Treatments and Prevention
https://patient.info/travel-and-vaccinations/travellers-diarrhoea-leaflet
Most people with traveller’s diarrhoea do not need treatment with antibiotic medicines. However, sometimes antibiotic treatment is advised. This may be because a specific germ (microbe) has been identified after testing of your stool (faeces) sample. […] Most people have mild illness and complications of traveller’s diarrhoea are rare. However, if complications do occur, they can include: Salt (electrolyte) imbalance and dehydration. This is the most common complication. It occurs if the salts and water that are lost in your stools (faeces), or when you are sick (vomit), are not replaced by you drinking adequate fluids. […] Severe dehydration can lead to a drop in your blood pressure. This can cause reduced blood flow to your vital organs. If dehydration is not treated, your kidneys may be damaged. […] Lactose intolerance can sometimes occur for a period of time after traveller’s diarrhoea. It is known as 'secondary’ or 'acquired’ lactose intolerance. Your gut (intestinal) lining can be damaged by the episode of diarrhoea.
#26 New Pathogen Discovery in Travelersâ Diarrhea by Metagenomic Sequencing | J. Craig Venter Institute
https://www.jcvi.org/research/new-pathogen-discovery-travelers%E2%80%99-diarrhea-metagenomic-sequencing
Diarrheal disease affects one billion people per year worldwide, yet 80% of these cases are of unknown etiology. […] Bouts of travelers diarrhea can predispose to development of post-infectious irritable bowel disease (IBD). […] Pathogen negative TD remains an enigma, although this may not be surprising since only a few percent of the bacteria, in or on the human body, have been cultivated, and many of the organisms within the human gut are obligate anaerobes. […] The failure to associate a pathogen with cases of TD is also be due to non-specific virulence gene assays that yield false negatives and the result of limited assays directed against known viruses and parasites. […] We are leveraging the power of deep metagenomic sequencing of DNAs isolated from pathogen negative stool samples from TD subjects to identify pathogens and pathogen signatures that could lead to hypothesis-based microbiological and clinical investigations into the etiological nature of unidentified pathogen travelers diarrhea. […] The database contains genes, microbial genomes and other features predicted to be associated with diarrheal agents and will be an ongoing resource for data mining for new diarrheal agents.
#27 Travelersâ Diarrhea | Yellow Book | CDC
https://www.cdc.gov/yellow-book/hcp/preparing-international-travelers/travelers-diarrhea.html
The primary agent studied for prevention of TD, other than antibiotics, is bismuth subsalicylate (BSS). Studies from Mexico have shown that this agent reduces the incidence of TD by approximately 50%. […] Prophylactic antibiotics afford no protection against nonbacterial pathogens and can remove normally protective microflora from the bowel, increasing the risk for acquisition of resistant bacterial pathogens. […] Antibiotics are effective in reducing the duration of diarrhea by approximately 12 days in cases caused by bacterial pathogens susceptible to the antibiotic prescribed. However, concerns about the adverse consequences of using antibiotics to treat TD remain.
#28 Travelerâs Diarrhea – Gastrointestinal Disorders – Merck Manual Professional Edition
https://www.merckmanuals.com/professional/gastrointestinal-disorders/gastroenteritis/traveler-s-diarrhea
Specific diagnostic measures are usually not necessary. […] However, fever, severe abdominal pain, and bloody diarrhea suggest more serious disease and should prompt immediate evaluation. […] The mainstay of treatment of traveler’s diarrhea is fluid replacement and an antidiarrheal medication such as loperamide. […] Generally, antibiotics are not necessary for mild diarrhea. […] However, in patients with moderate to severe diarrhea (3 loose stools over 8 hours), antibiotics are given, especially if vomiting, abdominal cramps, fever, or bloody stools are present. […] Traveler’s diarrhea is usually caused by enterotoxigenic E. coli, but viruses, parasites, and other bacteria may be involved. […] Diagnosis is clinical and testing is not usually needed unless bloody diarrhea, fever, or abdominal pain is present.
#29 Traveler’s Diarrhea
https://www.massgeneral.org/condition/travelers-diarrhea
Traveler’s diarrhea occurs within 10 days of travel to a location or an area with poor public hygiene. It’s the most common illness in travelers. […] Its caused by drinking water or eating food that has bacteria, viruses, or parasites. Most traveler’s diarrhea is from bacteria. Diarrhea from viruses and parasites is less common. […] Traveler’s diarrhea often goes away in a few days. Often the only treatment is replacing fluids. […] Dehydration from diarrhea can be serious. You need to replace body fluid that has been lost.
#30 Travelerâs Diarrhea – Gastrointestinal Disorders – Merck Manual Professional Edition
https://www.merckmanuals.com/professional/gastrointestinal-disorders/gastroenteritis/traveler-s-diarrhea
Treatment is fluid replacement and usually an antidiarrheal medication such as loperamide; however, antidiarrheal medications are contraindicated in patients with fever or bloody stools and in children. […] Patients with more severe traveler’s diarrhea are given antibiotics a fluoroquinolone for adults and azithromycin for children. […] Prevention is the best measure and involves careful selection of foods and beverages; prophylactic antibiotics are not routinely used except for patients with immunocompromise.
#31 FAQ about travelers’ diarrhea
https://www.thaitravelclinic.com/Knowledge/faq-about-travelers-diarrhea.html
Antimotility agents (e.g. loperamide) can reduce diarrhea by slowing the bowel movement. Since diarrhea is the body’s defense mechanism to get rid of the pathogen from the gastrointestinal tract, therefore antimotility agents may reduce the clearance of the pathogen and lead to systemic toxicity in the patient. However, these agents may be useful in reducing diarrhea while traveling. […] Taking antibiotics to prevent diarrhea is not recommended. Routine antimicrobial prophylaxis increases the risk for adverse reactions to the travelers and may increase resistance to the organism. […] Travelers’ diarrhea is caused by a pathogen in unclean food or drink. Here are some useful tips.
#32 Diarrhea – Knowledge @ AMBOSS
https://www.amboss.com/us/knowledge/diarrhea/
Traveler’s diarrhea is defined as 3 unformed stools with at least one additional enteric symptom occurring after recent travel. […] Enterotoxigenic E. coli (ETEC) is the most common cause of traveler’s diarrhea globally. […] For most destinations: ciprofloxacin (off label) OR rifaximin. […] Antibiotic treatment is not recommended in patients with mild traveler’s diarrhea. […] Bismuth subsalicylate is an antidiarrheal agent used to treat traveler’s diarrhea (caused by enterotoxigenic Escherichia coli).
#33 Travelerâs Diarrhea: Treatment, Antibiotic, and Prevention
https://www.healthline.com/health/travelers-diarrhea
Travelers diarrhea is a digestive tract disorder. It consists of abdominal cramps and diarrhea thats most often caused by consuming food or water that the body isnt familiar with. […] It can be caused by bacteria, viruses, or parasites. […] The most common complication of travelers diarrhea is dehydration. This can be very serious. Dehydration can easily occur when the diarrhea causes the body to lose fluids at a faster rate than they can take them in. […] Travelers diarrhea caused by a parasitic infection typically needs to be treated with medications, or the infection could become more severe. Parasitic infections can cause: […] If you have a bacterial infection, theyll prescribe antibiotics like doxycycline (Acticlate) or ciproflaxin (Cipro). […] If you have parasites, your doctor will prescribe oral antiparasitic drugs. The exact prescription will depend on the type of parasite infection you have. You’ll likely need to take several rounds of the parasitic drug to ensure the infection is completely out of your system.
#34 Hereâs the Scoop on PoopâTravelerâs Diarrhea Could Soon Be Washed Away | The Brink | Boston University
https://www.bu.edu/articles/2023/better-treatments-for-travelers-diarrhea/
Travelers diarrhea, the most common travel-related illness, is a gastrointestinal infection commonly caused by bacteria from contaminated food or water. […] Bacteria called Enterotoxigenic Escherichia coli (ETEC) which cause the largest number of recorded cases of childhood diarrhea and travelers diarrhea, according to the World Health Organization use long, thin filaments called pili to bind to cells in the gut, allowing an infection to start. […] They found that pili stick together by winding and unwinding themselves, giving scientists a better understanding of how the bacteria stays attached and causes an infection. […] By learning the structure of the pili, we are figuring out how to disrupt them, and have bacteria get washed away instead of causing disease, says Esther Bullitt. […] Unwinding and rewinding of pili reduces the force at the site of binding, and allows the bacteria to stay attached.
#35 Structure of Bacteria Responsible for Traveler’s Diarrhea Identified | Chobanian & Avedisian School of Medicine
https://www.bumc.bu.edu/camed/2009/06/10/structure-of-bacteria-responsible-for-travelers-diarrhea-identified/
ETEC uses surface pili or fimbriae to attach to host intestinal epithelia, an early, vital step in diarrhea pathogenesis. […] These fibers are essential for initiation of infection in the intestines by ETEC. […] According to the researchers, this study elucidates the mechanics of assembly of the fimbriae helical fibers as they exit the bacterium through a pore on the bacterial surface. […] Because of this, the antibodies produced against ETEC during one episode of infection are often not protective against later infections by other strains, she added. […] The structural findings reported here have bearing on research to help guide vaccine development.
#36 Hereâs the Scoop on PoopâTravelerâs Diarrhea Could Soon Be Washed Away | The Brink | Boston University
https://www.bu.edu/articles/2023/better-treatments-for-travelers-diarrhea/
Because pili are critical for bacteria to cause disease, finding a way to prevent pili from unwinding and rewinding can be used in the future to prevent diarrheal disease, Bullitt says. […] Currently, Bullitt is looking at how a component of saliva, a peptide called histatin-5, disrupts the function of pili, and reduces binding of the diarrhea-causing bacteria to cells. […] Therapeutics that disrupt pili and allow bacteria to be washed away have advantages over current antibiotics, as physical removal would not lead to the evolution of resistant strains and only the pathogens would be targeted, while leaving the good bacteria of the microbiome intact, she says.