Traveler’s Diarrhea

Symptoms

Traveler’s diarrhea is usually defined as a diarrheal illness that occurs in travelers from industrialized countries during or after a visit to a high-risk area, such as Latin America, Africa, the Middle East, or Asia. It is the most common travel illness, affecting 20% to 60% of travelers. Depending on the pathogen and severity, occurrences include:

  • Watery or mucous-bloody diarrhea (in classic travel diarrhea ≥ 3 x daily unformed stools).

Accompanying symptoms such as:

  • Nausea, vomiting
  • Abdominal cramps
  • Painful bowel movements (tenesmus)
  • Fever, chills
  • Blood and mucus in the stool

Diarrhea usually occurs in the first 2 weeks after arrival. The average duration of illness is 3-4 days, the disease is usually self-limiting. It should be noted that, depending on the incubation period, symptoms may also appear 7-10 days after travel, especially if the length of stay is short.

Causes

Bacterial pathogens (enteropathogens) in approximately 80% of cases:

  • Approximately 50-60% of all cases are caused by , especially enterotoxin-producing (ETEC) and EAEC.
  • The second large group are the invasive bacterial pathogens: , and (about 10-15% of all cases); and other bacteria.
  • Also possible is poisoning by toxins formed in the food by the bacteria (eg , , ).
  • Other non-bacterial pathogens are protozoa (, , ) and viruses (rotavirus, norovirus).
  • Mixed infections
  • In many cases, no pathogen could be detected.

The main pathogens vary from region to region.

Transmission

Mostly via contaminated food, less commonly via water and ice.

Complications

The disease is usually self-limiting and rarely threatening. Nevertheless, complications are possible:

  • Disruption of personal or business activities (vacations, sports, appointments).
  • Dehydration is especially dangerous in children, infants and the elderly.
  • Long duration of illness from over a week to a month.
  • Chronic intestinal problems (e.g., triggering a gluten intolerance) and irritable bowel as a result
  • Other specific complications depending on the germ, e.g. liver abscess and meningitis in amebiasis.

Risk factors

  • Young age: children, adolescents, and young adults (up to 29 years). The reason is probably due to a weaker immune system in children and the adventurousness of younger people.
  • No travel to risk areas in the last 6 months.
  • Lack of care in the selection of food products
  • Individual predisposition and sensitivity
  • Season: more cases are observed in summer and during the rainy season

Travel destination:

  • High risk: Latin America, Africa, the Middle East and Asia.
  • Medium risk: southern Europe, China, Russia, some Caribbean islands.
  • Low risk: Canada, USA, Northern Europe, Australia, New Zealand.

Prevention

Behavioral and dietary recommendations can help prevent the disease. However, they are only partially effective and are not always followed by tourists:

  • Food should be heated as sufficiently as possible (> 70°C) before consumption.
  • Fruits should be peeled before consumption. Strawberries, grapes and tomatoes can not be sufficiently cleaned. Consumption of watermelons is not recommended, because sometimes additional water is injected. Fresh salads, cold sauces, desserts with cream, non-pasteurized dairy products and uncooked meat, poultry and fish should also be avoided.
  • Risky is also the consumption of food offered by street vendors.

Water and ice: see also: water disinfection.

  • Water should be boiled or consumed from closed bottles. Do not drink tap water.
  • Boil water for at least 1 minute and keep in a closed container.
  • Microfiltration
  • Chemical processing
  • Ice should be prepared from boiled water or water from a reliable source (eg, closed bottles).

Antibiotics: Antibiotics have proven to be very effective for prevention, since the majority of diarrheal diseases are caused by bacteria.However, they should not be routinely administered. The reasons for this are the undesirable effects, the possibility of resistance development, the imparting of a false sense of security, the cost and the lack of effect in viral and parasitic infections. The application, advantages and disadvantages should be explained in detail to the patients, even in the case of a therapeutic application. The two main reasons for preventive administration are an important job that must be completed within a short time or certain underlying diseases that would be aggravated by diarrhea (e.g., Crohn’s disease, ulcerative colitis).

Probiotics support the intestinal flora and can prevent traveler’s diarrhea. However, they are less effective than antibiotics or bismuth subsalicylate, but are usually very well tolerated:

  • Enterococcus SF 68
  • Lactobacillus
  • Saccharomyces boulardii

Vaccinations:

  • Some vaccines are on the market, for example, against cholera and LT-ETEC. Problem: many different possible causes.

Habituation (immunity):

  • During a prolonged stay (eg, study visit, prolonged military service) develops habituation. The disease rate approaches that of the local population.

Drug treatment

The disease is usually self-limiting and drug therapy is not essential. The focus is on fluid and electrolyte replacement through adequate fluid intake or special solutions: Oral rehydration solution:

  • Ready-made products according to WHO (ORS) or in an emergency self-prepared solutions.
  • Bouillon, broth, tea, light food such as bread, bananas, potatoes.
  • An alternative in a severe course are infusions

Antidiarrhoica act against diarrhea:

  • Loperamide is fast and well effective, but should not be taken when there is fever and blood in the stool, because of the risk of retaining germs in the intestine. Treatment should not last longer than 2 days.
  • Medicinal charcoal is an old and well-tolerated home remedy, but its effectiveness is controversial.

Probiotics are also used for treatment in addition to prevention. They support the intestinal flora and are well tolerated:

  • Enterococci SF 68
  • Lactobacillus
  • Saccharomyces boulardii

Antibiotics are used for accompanying symptoms such as fever or blood in the stool (dysentery) and shorten the duration of the disease. The effect is less rapid than with loperamide (after 2-3 days). Commonly used are:

Antibiotics should be prescribed by a doctor. Consider contraindications and adverse effects!

Things to know

  • Basic bismuth salicylate (Pepto Bismol, not commercially available in many countries) has shown good prophylactic efficacy in studies, but adverse effects must be expected (including black discoloration of the tongue and stool, tinnitus). The contraindications of salicylates must be observed.
  • Nitroimidazoles and paromomycin are used for therapy of amebiasis (see there).