Traveler’s Diarrhea in Jamaica

Abstract & Commentary

Synopsis: The overall attack rate for diarrhea in travelers to Jamaica was 23.6%. Less than 3% of travelers avoided all potentially high-risk food and beverages. The most frequently detected pathogens were enterotoxigenic Escherichia coli, Rotavirus, and Salmonella species.

Source: Steffen R, et al. JAMA 1999;281:811-817.

A two-armed, cross-sectional survey was conducted between March 1996 and May 1997 to determine the epidemiology, etiology, and impact of traveler’s diarrhea (TD) in Jamaica. The first part of the study was a survey of travelers leaving from Montego Bay’s Sangster International Airport, analyzing the epidemiology, economic features, and impact of TD on the travelers’ well-being. Data were collected from travelers who filled in the questionnaires while waiting in the departure area. The second part of the study consisted of stool collections from patients with diarrhea who volunteered for evaluation of the etiology of TD. Ten large hotels participated by encouraging their guests with TD to visit the nurse’s station.

A total of 30,532 questionnaires were collected. The questionnaires elicited information on pretravel health advice and economic features (such as expenses for prophylaxis, TD therapy, and cost of stay) as well as food/ beverage consumption and quality of life.

Stool samples were analyzed for bacterial pathogens including Escherichia coli, Salmonella spp., Shigella spp., Campylobacter jejuni, Yersinia enterocolitica, Vibrio spp., Aeromonas spp., and Plesiomonas shigelloides. Detection of protozoa was done using enzyme-linked immunosorbent assay (Giardia lamblia, Entamoeba histolytica, and Cryptosporidium parvum) as well as stains for Microsporidia and Cyclospora. Virology studies were performed specifically for rotavirus and adenovirus.

In this study, classic TD was defined as passage of three or more unformed stools per 24 hours, with at least one accompanying symptom (nausea, vomiting, abdominal cramps or pain, fever, blood in stools). Moderate TD was passage of 1-2 unformed stools, with at least one additional symptom or more unformed stools without additional symptoms. Mild TD was passage of 1-2 unformed stools without additional symptoms.

The attack rate for diarrhea was 23.6% overall, with 11.7% having classically defined TD, 8.3% moderate TD, and 3.6% mild TD. TD attack rates significantly decreased with age but did not differ between the sexes. All TD attack rates increased with duration of stay until day 14 but then decreased. Residents of northern countries and honeymooners showed higher classic and moderate TD attack rates. A recent stay in another developing country was associated with a lower attack rate. Patients with underlying medical conditions had no increased severity of disease. The visitors who stayed with friends and/or family had a lower total TD rate, whereas tourists with full board had a higher probability of diarrhea. There was seasonal variation with the TD rate dropping to 15% in the winter months. The onset of TD occurred around day 4. Almost half the patients with classic TD were incapacitated, and the mean duration of incapacitation for all TD patients was 11.6 hours. A total of 6.6% of the travelers experiencing TD consulted medical professionals. Travel health advice had no effect on the incidence of TD.

Details of the airport survey showed that less than 3% reported having avoided all potentially contaminated food and drinks. Ninety-five percent of travelers had ice cubes in their drinks and 90% ate salads, 80% consumed dairy products and tap water, and more than 55% ate ice cream, hamburgers, and incompletely cooked chicken, lobster, or shrimp. Travelers aged 36-55 were slightly more negligent with respect to potentially contaminated food and beverage items compared with other age groups. There was no significant risk associated with eating food from street vendors. Two percent of all travelers used prophylactic medication against TD; most often, these were Americans using bismuth subsalicylate.

A total of 322 volunteers participated in the hotel survey. The pathogen detection rate was 31.7%. Enterotoxigenic E. coli (ETEC) was the most frequently diagnosed pathogen. C. jejuni was only detected during the winter. Viruses were also predominant in the winter.

The economic analyses revealed that per stay (mean duration, 7.7 days), the estimated cost for medication, medical treatment, and missed activities was US $116.50/patient or US $27.50/traveler to Jamaica.

Comment by Lin H. Chen, MD

Diarrhea is the most common health problem encountered by travelers visiting developing countries. Prior reports have shown the incidence to be 20-60%, and destination is a significant determinant of diarrhea risk.1 The diarrhea rate of 23.6% from the current survey puts Jamaica in the range of intermediate-to-moderate risk.

The study made several important observations, confirming some prior findings:2-4 1) There was no significant difference in diarrhea attack rates between the sexes; 2) Diarrhea risk decreased with age; 3) Residency in areas with high attack rates or recent travel to those areas was associated with lower TD attack rates; 4) Travelers on full board plans appeared to have an increased risk for diarrhea, possibly associated with buffets; and 5) ETEC was the most frequently identified pathogen.

Some interesting differences emerged in comparison with other studies. First, incapacitation lasted about 12 hours, which was shorter than other reports of 3.6 days.1,3-5 Second, the pathogen detection rate of 31.7% was lower than other studies.2-4 There was a higher than usual rate for rotavirus (9.2%) in the current study. Also, there was a marked seasonal variation for the diarrhea attack rate in Jamaica.

The lack of dietary discipline was notable, even in people who had received pretravel advice. Clearly, there is need for additional ways to prevent TD. Improved hygienic conditions at the destination would be desirable. A killed oral ETEC vaccine is undergoing clinical evaluations and appears safe and immunogenic.6 When this vaccine becomes available, it should contribute greatly to reducing TD. A rotavirus vaccine has been licensed by the FDA to prevent gastroenteritis among infants and children,7 and this may also help to reduce TD rate. (Dr. Chen is Clinical Instructor, Harvard Medical School and Travel/Tropical Medicine Clinic, Lahey Hitchcock Medical Center.)

References

    1. Steffen R, et al. JAMA 1983;249:1176-1180.

    2. Black RE. Rev Infect Dis 1990;12(suppl 1):s73-79.

    3. Passaro DJ, Parsonnet J. Curr Clin Top Infect Dis 1998;18:217-236.

    4. Okhuysen PC, Ericsson CD. Med Clin North Am 1992; 76:1357-1373.

    5. Beecham III HJ, et al. Am J Trop Med Hyg 1997;57: 699-701.

    6. Savarino SJ, et al. J Infect Dis 1999;179:107-114.

    7. CDC. MMWR Morb Mortal Wkly Rep 1999;48:12-16.

Traveler’s diarrhea:

    a. affects men and women equally.
    b. occurs less frequently in visitors from a developing country.
    c. attack rates decrease with age.
    d. is caused by ETEC more frequently than other identifiable pathogens.
    e. All of the above