Cumulative Incidence of Travelers' Diarrhea Among Long-Term Foreign Travelers in Thailand

Status: Ongoing and Recruiting
Study period: May 2025 – April 2026
Lead investigator: Dr.  Narissara Techavachara
Site: Thai Travel Clinic, Hospital for Tropical Diseases, Faculty of Tropical Medicine, Mahidol University
Ethics: Approved by the Ethical Committee of the Faculty of Tropical Medicine, Mahidol University
Language: English

Travelers’ diarrhea (TD) is one of the most common health issues among travelers visiting lower-income regions worldwide. It is often anticipated by travelers and frequently discussed during pretravel consultations, but definitive prevention of TD through vaccine, medication, or behavioral changes remains elusive. The knowledge gap exists upon the incidence of TD among long-term travelers, including expatriates.

This research aims to determine the cumulative incidence of travelers’ diarrhea in long-term foreign travelers in Thailand.

You may participate in this research if you are

1. Non-SEA foreign travelers visiting Thailand, with the intention to travel abroad for > 1 month
2. Age 18 years old and above
3. Travelers who have been traveling for less than 6 months (from the date of enrollment)
4. Travelers visiting the study sites between the study period
5. Signed informed consent
6. Able to read and understand the questionnaire(English/Chinese/Japanese/Korean)

If you agree to participate in this study, and sign the Informed Consent Form, the researcher will ask you to complete an initial paper-based questionnaire providing your general information, contact details, past medical history and trip details upon enrollment. Depending on the status of your trip, you will be asked to complete another set of questionnaires, which can be either/or both:

1. 1. Paper-based, retrospective questionnaire on the date of enrollment
   2. Online-based, prospective questionnaire: a Jotform link will be sent to your email (default) or WhatsApp (optional) once a month

The principle investigator of this research is Dr. Narissara Techavachara.
If interested, please contact: Tel (+66)23069145 or Email narissara@thaitravelclinic.com