OUTLINE #33
TRAVELLER’S DIARRHEA
Submitted by: Jane Hatashita RN
(519)883-2006 ext 5286
EPIDEMIOLOGY
· It is a syndrome characterized by a twofold increase in the frequency of unformed bowel movements
· Typically results in 4-5 loose or watery stools per day, with median duration of illness: 3 to 4 days.
· Traveler’s diarrhea (TD) is acquired through the ingestion of fecally contaminated food or water, or both.
· It is the most common medical problem affecting travelers to developing countries
· Associated symptoms: abdominal cramps, nausea, bloating, urgency fever, malaise
· Up to 50% of travelers from developed countries to developing countries can expect to have at least one episode of acute diarrhea during a 2 week stay.
· High risk destinations: Latin America, Africa, the Middle East, Asia
· Intermediate risk destinations: most of the southern European countries, and a few Caribbean islands.
ETIOLOGY
· Infectious agents are the primary cause of TD.
· Bacterial pathogens account for >80% of TD.
· Most commonly isolated organisms: Enterotoxigenic E. Coli (ETEC) which cause a watery diarrhea associated with cramps and a low-grade or no fever are the most common cause of TD. Other bacterial causes include: Salmonella, Shigellae (which cause up to 20% of TD acquired in developing countries), and Campylobacter jejuni. Vibrio parahaemolyticus is associated with ingestion of raw or poorly cooked seafood and has caused TD in passengers on Caribbean cruises and in people travelling in Asia.
· Parasites, although less frequently isolated, can also cause TD. These include: Giardia intestinalis (0-12%), Entamoeba histolytica (0-5%), Cryptosporidium parvum (2-5%), and Cyclospora cayetanensis (1-11%).
· Viruses can also cause TD, with Norwalk and rotavirus being the most common viral cause.
PREVENTION
· Prevention strategies for traveler’s diarrhea include:
Education about the ingestion of safe food and beverages
Use of chemoprophylaxis with antibiotics or antimotility therapy
Water purification
· Safer food choices include: food that has been recently and thoroughly cooked and still hot, pasteurized dairy products and fruit that is freshly peeled. Salad bars, raw vegetables and fruit that cannot be easily cleaned, as well as mayonnaise, hollandaise sauce, custards and mousses should be avoided. In the Caribbean and the South Pacific, Ciguatera poisoning may be a risk associated with ingestion of large reef fish.
· Safer beverage choices include: bottled and carbonated drinks (water &/or soda), hot beverages such as tea and coffee, bottled water, commercially prepared fruit juices, and alcoholic drinks without ice.
· Boiling water is the most effective method of purification. Chemical treatment can be achieved by adding iodine or chlorine to the water. Iodine is more effective and will kill bacteria and viruses but may not be effective for certain parasites. Portable water filters will provide varying degrees of protection.
· Chemoprophylaxis with bismuth subsalicylate (Pepto Bismol) has been shown to decrease the incidence of travelers’ diarrhea by 60% when taken four times daily. Bismuth subsalicylate should be avoided by persons with aspirin allergy, renal insufficiency, and gout, and by those taking anticoagulants, probenecid or methotrexate. Side effects may include temporary blackening of the tongue and stools, nausea, constipation and rarely, tinnitus. Caution should be exercised when using in children, and not for use in children <2years of age.
· Although resistance is significant, chemoprophylaxis with antibiotics, including trimethoprim/sulfamethoxazole and floroquinolones can decrease the incidence of travelers’ diarrhea by 52-95%.
· Prophylactic antibiotics or bismuth subsalicylate should only be considered for short-term travel to a maximum of 3 weeks in select high risk persons.
TREATMENT
· Anti- motility agents are widely recommended and used for treatment of travelers’ diarrhea. Loperimide (Imodium) is quite effective at reducing the duration and severity of mild to moderate diarrhea in adults and children >2 years of age. However, caution should be exercised in children due to an increased risk of toxic megacolon. Antimotility agents should not be used by people with high fever or blood in their stools.
· Antimicrobial treatment may be considered for those with moderate to severe diarrhea (>3 loose stools in an 8 hour period with or without nausea, vomiting, abdominal cramps, fever or blood in the stools).
· A floroquinolone is the antibiotic most likely to be effective. In Thailand, however, floroquinolone resistance among Campylobacter species is likely, and azithromycin is a more effective alternative.
· Floroquinolones are generally not indicated in children <16 years of age, however the benefits outweigh the risk for short term use. An alternative for children is azithromycin.
· Travelers should be advised to consult a physician if diarrhea does not respond to treatment, is severe and associated with fever, blood or mucus, or both in the stools.
· Fluid replacement is of primary importance in management of diarrhea illness, and especially important in children and the elderly in whom dehydration can occur rapidly and be life threatening. Dehydration should be managed with an oral re-hydration solution widely available in developing countries or a home made preparation .
References:
CDC Health Information for International Travel, 2001-2002
CCDR: CATMAT Statement on Traveler’s Diarrhea, March 15, 2001