Traveler’s Diarrhea

Traveler’s diarrhea affects 30 to 70% of travelers over 2 weeks, depending on the location and time of year. It may be caused by any of several bacteria, viruses, or, less commonly, parasites (1).

The most common cause of traveler's diarrhea is

• Enterotoxigenic Escherichia coli (E. coli)

E. coli is common in the water supplies of areas that lack adequate purification. Infection is common among people traveling to low-resource countries. Campylobacter jejuni, Shigella, Salmonella and enteroaggregative E. coli are also common causes (1).

Norovirus gastroenteritis has been a particular problem on some cruise ships (2).

Both food and water can be the source of infection. Travelers who avoid drinking local water may still become infected by brushing their teeth with an improperly rinsed toothbrush, drinking bottled drinks with ice made from local water, or eating food that is improperly handled or washed with local water. People taking medications that decrease stomach acid (antacids, H2 blockers, and proton pump inhibitors) are at risk of more severe illness.

Nausea, vomiting, hyperactive bowel sounds, abdominal cramps, and diarrhea begin 12 to 72 hours after ingesting contaminated food or water. Severity is variable. Some people develop fever and myalgias. Diarrhea is rarely bloody.

Most cases are mild and self-limited, although dehydration can occur, especially in warm climates.

• Clinical evaluation

Specific diagnostic measures are usually not necessary. However, fever, severe abdominal pain, and bloody diarrhea suggest more serious disease and should prompt immediate evaluation.

• Fluid replacement

• Sometimes antidiarrheal (antimotility) medications

• Antibiotics (eg, ciprofloxacin, azithromycin) for moderate to severe diarrhea

The mainstay of treatment of traveler's diarrhea is fluid replacement and an antidiarrheal medication such as loperamide. The dosage of loperamide for children < 12 years of age is weight-based. An alternative for adults is diphenoxylate/atropine.. The dosage of loperamide for children diphenoxylate/atropine.

Antidiarrheal medications should not be used in adults with suspected C. difficile or E. coli O157:H7 infection (eg, with recent antibiotic use, bloody diarrhea, heme-positive stool, or diarrhea with fever) or in children, particularly those < 2 years. Iodochlorhydroxyquin should not be used because it may cause neurologic damage.

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. For adults, recommended oral antibiotics include ciprofloxacin or levofloxacin, although fluoroquinolone resistance continues to increase in some areas, particularly in 3 loose stools over 8 hours), antibiotics are given, especially if vomiting, abdominal cramps, fever, or bloody stools are present. For adults, recommended oral antibiotics include ciprofloxacin or levofloxacin, although fluoroquinolone resistance continues to increase in some areas, particularly inCampylobacter infections. Alternatives include azithromycin or rifaximin. For pregnant patients and children, azithromycin is preferred (infections. Alternatives include azithromycin or rifaximin. For pregnant patients and children, azithromycin is preferred (1).

Travelers should dine at restaurants with a reputation for safety and avoid foods and beverages from street vendors. They should consume only cooked foods that are still steaming hot, fruit that can be peeled, and carbonated beverages without ice served in sealed bottles (bottles of noncarbonated beverages can contain tap water added by unscrupulous vendors); uncooked vegetables (particularly including salsa left out on the table) should be avoided. Buffets and fast food restaurants pose an increased risk. Washing food with tap water can contaminate it.

Some patients may require prophylaxis if they have underlying medical conditions that make them particularly susceptible to the consequences of traveler’s diarrhea. This includes patients with immunocompromise including inflammatory bowel disease or HIV infection, recipients of organ transplants, and patients with severe cardiovascular or kidney disease. The nonabsorbable antibiotic rifaximin can be used for prophylaxis in these patients. Fluoroquinolones are not recommended for prophylaxis due to adverse effects, including tendon rupture and peripheral neuropathy. Some travelers may consider the nonantibiotic bismuth subsalicylate as an alternative for prophylaxis (Some patients may require prophylaxis if they have underlying medical conditions that make them particularly susceptible to the consequences of traveler’s diarrhea. This includes patients with immunocompromise including inflammatory bowel disease or HIV infection, recipients of organ transplants, and patients with severe cardiovascular or kidney disease. The nonabsorbable antibiotic rifaximin can be used for prophylaxis in these patients. Fluoroquinolones are not recommended for prophylaxis due to adverse effects, including tendon rupture and peripheral neuropathy. Some travelers may consider the nonantibiotic bismuth subsalicylate as an alternative for prophylaxis (1).

The following English-language resources may be useful. Please note that The Manual is not responsible for the content of these resources.

1. Centers for Disease Control and Prevention: Preparing international travelers for travelers’ diarrhea

2. Expert panel: Guidelines for the prevention and treatment of travelers' diarrhea (2017)