Dengue in Peace Corps Volunteers, 2000-14.

Abstract

Dengue is an arboviral disease estimated to cause 50-100 million infections each year in >100 tropical and subtropical countries. Urbanization, human population growth and expanded global travel have resulted in an increase in the incidence of dengue worldwide. International travellers to areas with endemic dengue are at risk of contracting dengue and US Peace Corps Volunteers are one specific group of long-term travellers who are exposed to environments where dengue can be contracted. Cases of dengue among Peace Corps Volunteers, defined as clinically apparent infections with laboratory-confirmation by a positive NS1 antigen test, demonstration of IgM antibodies or by a 4-fold increase in IgG antibodies, between 1 January 2000 and 31 December 2014, reported to the Peace Corps’ Epidemiologic Surveillance System were analyzed. Overall there were 1448 cases of dengue reported among Volunteers, with an incidence rate of 1.12 cases per 1000 Volunteer-months (95% CI 1.06-1.17). The highest rate of dengue among Volunteers was reported in the Caribbean region, with a rate of 5.51 cases per 1000 Volunteer-months (95% CI 4.97-6.10), followed by the East Asia/South Asia region (3.34, 95% CI 2.96-3.75) and Central America (2.55, 95% CI 2.32-2.79). The rate of dengue peaked in 2007, 2010 and 2013. Each peak year was followed by a trough year. Globally, there appears to be a 3-year cyclical pattern of dengue incidence among Volunteers, with differences by region. Dengue continues to be a priority health issue for travellers to endemic areas, and enhanced surveillance of dengue among international travellers may result in improved patient education and prevention efforts.