PRACTICE RECOMMENDATIONS
1. Recommend antibiotic chemoprophylaxis for travelers at high risk for travelers’ diarrhea (TD) and those at high risk for complications. It is also appropriate for travelers who have an inflexible itinerary. B
2. Recommend bismuth subsalicylate chemoprophylaxis for travelers at high risk for TD who are willing to comply with the regimen and want to avoid antibiotic prophylaxis. B
3. Advise travelers to initiate self-treatment for TD with a fluoroquinolone (or azithromycin, if in South or Southeast Asia) at the onset of diarrhea if it is bloody or accompanied by fever. A
NOTE: This practice recommendation in the print version of this article stated that travelers should also take loperamide; however, both the Centers for Disease Control and Prevention and the Infectious Diseases Society of America advise against the use of loperamide by travelers with fever or bloody diarrhea [corrected August 27, 2013].
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
A 40-year-old female patient, a childhood immigrant from India, is seeking advice regarding her upcoming 2-week trip to Mumbai. She is taking her 2 children, ages 16 years and 16 months, to visit their grandparents for the first time. She has made this trip alone a few times and has invariably experienced short bouts of self-limited diarrheal illness. She wonders what she might do to prevent travelers’ diarrhea. Her only medical problem is rheumatoid arthritis, which has been well controlled with methotrexate. Her children are healthy. What would you recommend?
Recommendations regarding travelers’ diarrhea (TD) address prevention and management. Prevention encompasses advice about personal behaviors and the use of chemoprophylaxis (antimicrobial and non-antimicrobial) and vaccinations. Since international travelers are known to treat themselves for diarrheal illnesses during their trips,1 recommendations regarding management should assume self-treatment and include the use of both antibiotics and non-antibiotic remedies. Pretravel recommendations will of course be most effective if they account for the individual’s risk for TD.
Innate patient susceptibility, destination, and dietary choices determine TD risk
TD is generally defined as the passage of 3 of more loose stools in a 24-hour period, with associated symptoms of enteric infection—eg, fever, nausea, vomiting, or abdominal cramping. Defined in this manner, TD is thought to occur in 60% to 70% of individuals who travel from developed countries to less-developed countries.2,4 Risk of TD is influenced both by intrinsic personal factors and by factors specific to the trip.
Personal risk factorsIndividual variation in susceptibility to TD might result from a genetic predisposition arising from single nucleotide polymorphisms governing various inflammatory marker proteins.5 A history of multiple episodes of TD, especially if fellow travelers were spared, can suggest this kind of individual susceptibility. Other factors that increase vulnerability to TD are immunodeficiency, achlorhydric states such as atrophic gastritis, and chronic use of proton pump inhibitors.6,7 However, the trip itself is much more important in assessing risk for TD.
Trip-related risk factors
The destination. The most salient risk factor for TD is the geographic destination. Regions of the world can be divided into TD risk strata:2
- Very high: South Asia
- High: South America, Sub-Saharan Africa
- Medium: Central America, Mexico, Caribbean, Middle East, North Africa, Southeast Asia, Oceania
- Low: Europe, North America (excluding Mexico), Australasia, Northeast Asia.
Particularly notable countries, in descending order of risk, are Nepal, India, Myanmar, Bolivia, Sri Lanka, Ecuador, Peru, Kenya, and Guatemala.2
Dietary choices. Additionally, since travelers acquire TD by ingesting food or beverages contaminated with pathogenic fecal microbes, dietary behaviors during the trip affect their susceptibility. At least risk are business travelers and tourists who confine their activities to more affluent settings in which food and beverages are prepared and stored hygienically.1,4,8,9 At greater risk are travelers who immerse themselves in local culture, visiting locations that are more impoverished and not as well equipped with sanitation systems, especially if their stay is at least 2 to 3 weeks.1,4,8,9
Also, the older a traveler is, the lower his or her risk of TD.1,9 An exception to this might be infants whose diet consists solely of breast milk or formula prepared under sanitary conditions.
Mandates and options for preventing TD
Emphasize food and beverage precautions
It might be reasonable to expect that travelers who are circumspect about their food and beverage choices on trips will be able to avoid TD. Indeed, this is the basis for the aphorism, “Boil it, peel it, or forget it.” Guidelines routinely recommend that travelers restrict their selection of foods to those that have been well cooked and are served while still very hot, and to fruits and vegetables that they peel themselves. Likewise, they should drink only beverages that have been boiled or are in sealed bottles or under carbonation and served without ice.10-12 Many travelers might find these recommendations too restrictive to follow faithfully. Moreover, studies suggest it may not be possible for even the most assiduous traveler to fully avoid the risk of TD.13,14 The hygienic characteristics of the travel destination may be more determinative, as illustrated by the successful reduction of TD rates in Jamaica by improving sanitation in tourist resorts.15