Tuberculosis (TB) is one of the most common infectious diseases in the world. The World Health Organization (WHO) estimates over 9 million new cases and nearly 2 million deaths attributable to TB each year.1
Many regions with the highest burden of TB disease also continue to report a rise in the incidence of drug-resistant TB.2
Interest among US medical trainees for on-site health experiences in the developing world has grown in recent years. A recent survey of pediatric residency programs found that more than half offered a global health elective, an increase from 25% reporting similar programs 10 years earlier.3,4
In a 2009 survey of medical students conducted by the Association of American Medical Colleges, 30% of students indicated participation in a global health experience on an elective or volunteer basis during medical school.5
Recognition of this interest in global health has prompted many medical educators and researchers to establish formal opportunities for trainees to gain experience in health care facilities in the developing world.
Trainees in these settings may experience increased risk of exposure to infectious diseases such as TB, malaria, and HIV. While universal precautions and appropriate prophylactic medications can significantly reduce the risk of acquiring HIV and malaria, adequate infection control measures to minimize the spread of airborne pathogens such as TB are lacking in many health care facilities in the developing world. Reports of US Peace Corps volunteers and long-term (>3 months) Dutch travelers to areas of TB endemicity demonstrate that the incidence of TB infection and disease is higher than in the travelers’ country of origin.6,7
Furthermore, the risk of exposure to highly drug-resistant TB in many of these settings [especially in locations where nosocomial spread of multidrug (MDR) and extensively (XDR) drug-resistant TB has been documented8
] heightens the urgency for measures to prevent transmission.
The Indiana University Kenya medical exchange program (now AMPATH Consortium Medical Exchange Program) was established in 1990 between Indiana University School of Medicine (Indiana) and Moi University Faculty of Health Sciences (now renamed Moi University School of Medicine) in Eldoret, Kenya. The history and philosophical underpinnings of this relationship have been described previously.9
Over the past 20 years, the partnership has grown to include a number of North American academic partners and a variety of care, teaching, and research initiatives. The medical exchange program facilitates the travel of over 300 individuals to Eldoret annually. Eldoret is located within Uasin Gishu District where a TB intensified case-finding program screened over 36,000 individuals in the community from 2005–2009 and revealed an average acid-fast bacillus (AFB) smear positivity rate of 12% among those with a positive symptom screen (unpublished data). The Moi Teaching and Referral Hospital is a District Referral hospital with a catchment population of 13 million. The hospital has crowded, shared, open-air wards where multiple patients often share beds. Infection control efforts include: placement of TB suspects and smear-positive patients near windows and encouraging cough hygiene, opening of windows during ward rounds, and early diagnosis and initiation of treatment through an intensified case finding strategy. There are no isolation facilities for TB patients; personal respirators are not routinely available. The medical exchange program is “family friendly;” it is not uncommon for spouses and children to accompany program participants to Kenya. Many spouses and children volunteer in various affiliated programs such as the hospital pediatric education center and local orphanages.
Guidelines exist for management of TB risk among travelers from low burden countries who are visiting TB-endemic areas.10–12
These include recommendations for pre- and post-travel testing for TB infection, counseling travelers to avoid exposure to known TB patients in crowded environments, and consideration of BCG vaccination in selected populations. Guidelines vary slightly in identification of which individuals are at increased risk and suggest that the specific location visited, duration of stay, and in-country activities should all be considered as important variables. The US Center for Disease Control and Prevention's Health Information for International Travel
suggests that a subset of travelers anticipating “prolonged or routine exposure to TB (hospitals, prisons, homeless shelters) or those who plan an extended stay over a period of years in an endemic country” should be advised to have pre- and post-travel TB skin testing (TST), including a two-step TST or interferon gamma release assay (IGRA) prior to departure.11
The Public Health Agency of Canada suggests a similar strategy for travelers visiting high-incidence countries for 3 months or longer, and for travelers engaged in health care work in such countries.12
The particular emphasis on screening of health care workers is justified by the higher risk of TB exposure in health care settings in the developing world, and the implications for US and Canadian hospitals if trainees and health care workers develop active TB upon return. 13
We evaluated the risk of TB infection among travelers participating in an academic, international medical exchange program. Improved knowledge defining high-risk individuals and activities will aid the development of guidelines for TB screening, pre/post-travel education, and risk reduction.