Epidemiology of travelers' diarrhea in Thailand

Abstract

Background: Current data on risk of travelers' diarrhea (TD) among visitors to Thailand largely comes from US military personnel, Peace Corps volunteers, or expatriates. We performed a 14-month systematic study of the incidence rate and characteristics of TD and a smaller study of etiology of the disease among visitors to Phuket and Chiang Mai.

Methods: One randomly selected day each week from August 2005 until October 2006, data were collected from foreign tourists departing from airports serving Phuket and Chiang Mai. A separate subgroup of subjects with TD acquired in Phuket were invited to submit a stool sample for enteropathogens.

Results: Based on 22,401 completed questionnaires, the attack rate for TD was highest among residents from Australia or New Zealand (16%), while those from the United States and Europe had attack rates of 7% to 8%. Independent risk factors for the development of TD were eating outside the hotel and eating meat. In contrast, a history of drinking tap water and consuming ice cream were protective. In 56 subjects studied for etiology, Aeromonas spp were found in 8 subjects (14%), enterotoxigenic Escherichia coli (ETEC) or Vibrio spp each was found in 7 (13%) with O1 V. cholera (cholera) seen in one, mixed pathogens were found in 3 (5%), with no pathogen being detected in 33 (59%).

Conclusions: Phuket and Chiang Mai should not be considered high-risk destinations for development of TD among US and European travelers to Thailand. In the study, Aeromonas, ETEC, and Vibrio spp were the most frequent enteropathogens identified.