A 24-year-old patient presents to the Emergency Department with watery diarrhoea. He returned from
holiday in Tanzania yesterday. Which of the following pathogens is the most likely to be responsible
for this presentation?
Enterotoxigenic E. coli
All the listed options are potential causative organisms of an acute watery diarrhoeal illness.
Worldwide, enterotoxigenic E. coli (ETEC) is the most common cause of diarrhoea in travellers.
There is, however, geographical variation - Campylobacter is more common in travellers in South East
Diarrhoea in cholera is classically painless, ‘rice-water’, stool. While cholera is seen worldwide, it is
less common as a cause of diarrhoea in travellers.
Diarrhoea in acute giardiasis is classically foul-smelling and fatty, and associated with abdominal
cramps and bloating. The incubation period for acute infection is one to two weeks.
Non-typhoidal Salmonellae are another common cause of diarrhoea worldwide. They are the most
common cause of food-borne disease in the United States. The incubation period is up to three days.