Tuberculosis risk in US Peace Corps Volunteers, 1996 to 2005

With the popularity of international travel increasing, more travelers in endemic areas may increase their risk of tuberculosis (TB). We analyzed Peace Corps data to assess the risk of TB in long-term travelers from the United States.

We analyzed purified protein derivative (PPD) conversion and acute TB case data from the Peace Corps Epidemiological Surveillance System as well as postservice claims data. We calculated the risk of PPD conversion and active TB in all countries with Peace Corps Volunteers between 1996 and 2005 and compared these risks with other published data.

The overall incidence rates for positive PPD conversions and active TB cases are 1.283 and 0.057 per 1,000 Volunteer-months, respectively. The Africa region had the highest PPD conversion rate of 1.467 conversions per 1,000 Volunteer-months as well as the highest active TB rate of 0.089 cases per 1,000 Volunteer-months. Per-country incidence rates for PPD conversions and active TB cases ranged widely from 0.000 to 5.514 cases and 0.000 to 2.126 cases per 1,000 Volunteer-months, respectively. In countries identified as "high risk," there were 1.436 cases of PPD conversions and 0.084 cases of active TB per 1,000 Volunteer-months.

Peace Corps Volunteers have significantly higher rates of TB when compared to the average US population but much lower than those reported for travelers to highly endemic countries. Volunteers assigned to highly endemic countries still have a lower risk compared to other travelers to those same countries. Keeping in mind that Peace Corps Volunteers are a unique population, these data may be useful in providing medical advice to long-term travelers.