148 Infectious Disease and Foreign Travel Emergencies
Gastrointestinal Tract Infection
2 Otherwise, discharge the patient with advice to avoid preparing food for
others and to use their own knife, fork, spoon, cup and plate (assuming the
patient could have hepatitis A or E).
3 Advise the patient to avoid alcohol and cigarettes.
4 Give the patient a referral letter to medical outpatients or to their general
practitioner (GP) for definitive diagnosis and follow-up.GASTROINTESTINAL TRACT INFECTION
DIAGNOSIS
1 The commonest manifestation is sudden acute diarrhoea, often with
vomiting.
2 Causes of infectious diarrhoea include:
(i) Toxin-related diarrhoea from staphylococcal food poisoning
which has a precipitate onset in hours, as does Bacillus cereus
enterotoxin from rice, in which vomiting and abdominal cramps
predominate.
(ii) Viral diarrhoea from the rotavirus in very young children and
Norwalk-like viruses in older children and adults, with an
incubation period of 1–2 days, sometimes occurring in outbreaks
of non-bloody diarrhoea.
(iii) Salmonella with an incubation period of 6–72 h and Shigella
infections with an incubation period of 1–3 days result in fever,
malaise, diarrhoea (which may be blood-stained), vomiting and
abdominal pain.
(iv) Campylobacter infection has an incubation period of 2–5
days and presents with colicky abdominal pain, which may
precede the onset of diarrhoea, that is watery and offensive, and
sometimes blood-stained.
(v) Giardiasis has an incubation period of 3–25 days and causes
explosive watery diarrhoea, which often persists for weeks.
Chronic infection may eventually cause malabsorption with
steatorrhoea. Ask about travel to Russia or North America,
and contact with children in day care who have had recent
diarrhoea.
(vi) Amoebiasis may also cause a chronic, recurring diarrhoea, with
stools containing blood and mucus. Ask about travel to Africa,
Asia or Latin America.