Clinical features

Majority of travellers diarrhoea episodes are generally short-lived and self-limiting (mean duration 4 days). The onset of diarrhoea is usually early in the trip (peak on third day).

• bacterial and viral agents
  • incubation period is around 6–48 hours
  • symptoms range from mild cramps and urgent loose stools to severe abdominal pain, fever, vomiting, and bloody diarrhea (in norovirus, vomiting may be more prominent)
  • untreated bacterial diarrhoea lasts 3–5 days while viral diarrhoea resolves in 2–3 days
• protozoal diarrhoea,
  • incubation period is around 1-2 weeks (rarely present in the first few weeks of travel with the exception of Cyclospora cayetanensis, which can present quickly in areas of high risk.)
  • generally has a more gradual onset of low-grade symptoms, with 2–5 loose stools per day.
  • persist for weeks to months if not treated (1)

In general four clinical syndromes can be seen in enteric infection of travellers.

• acute gastroenteritis (10%)
  • consider Noroviruses, preformed toxins of Staphylococcus aureus or Bacillus cereus
  • vomiting is the predominant feature
  • incubation period for viral gastroentritis is more than 14 hours while for the intoxications, the incubation period is 2–7 h, often less than 4 h.
• acute watery diarrhoea (80%)]
  • consider all agents, including ETEC, EAEC, Shigella, Salmonella, noroviruses
  • patients present with acute watery diarrhoea with abdominal pain and cramps
• dysentric diarrhoea (1-9%)
  • consider Shigella, Campylobacter, less commonly Salmonella spp, non-cholera Vibrios and Aeromonas spp
  • presents with bloody stools, often with associated fever,
• persistent diarrhoea and post infectious irritable bowel syndrome
  • persistent diarrhoea (2–10%)
    • diarrhoea lasting two weeks or longer
    • consider Giarda, Cryptosporidium, E. histolytica, Microsporidium, Cyclospora etc
    • commonly seen in persons living close to the locals including peace corps volunteers and medical missionaries.
  • post infectious irritable bowel syndrome (5–10%)
    • caused by invasive/inflammatory bacteria in a genetically susceptible host which appears to unmask an underlying propensity or worsen the pre-existent condition
    • risk factors include - severity of bout of acute diarrhoea, virulence properties of the infecting organism, age <60 years and female gender
    • pateints have chronic gastrointestinal illness with abdominal pain and discomfort associated with change in stool form resembling irritable bowel syndrome (2)

Reference:

• (1) Centers for Disease Control and Prevention (CDC) 2013. Yellow Book. Chapter 2 - For the Record: A History of the Definition & Management of Travelers’ Diarrhea
• (2) DuPont HL. Systematic review: the epidemiology and clinical features of travellers' diarrhoea. Aliment Pharmacol Ther. 2009;30(3):187-96