Prevalence of dengue virus infection in US travelers who have lived in or traveled to dengue-endemic countries

Abstract

Background Dengue virus (DENV) infections may occur in travelers. Objectives To determine prevalence of anti-DENV IgG antibody in travelers who lived in or visited dengue-endemic countries and to describe risk factors and characteristics associated with infection and subsequent anti-DENV IgG antibody presence. Methods Participants were enrolled from travel clinics of the Boston Area Travel Medicine Network from August 2008 through June 2009. Demographic information, trip duration, travel history, and a blood sample were collected. Serum samples were tested for anti-DENV IgG antibody by indirect IgG enzyme-linked immunosorbent assay (ELISA), and antibody-mediated virus neutralization by plaque reduction neutralization test (PRNT) for anti-DENV IgG antibody-positive and selected negative samples. Participants were stratified into group 1: born in dengue-endemic countries; group 2: born in nonendemic countries but lived continuously for ≥1 year in a dengue-endemic country; group 3: born in nonendemic countries and traveled to a dengue-endemic country for ≥2 weeks but <1 year. Results Six hundred travelers were enrolled. Anti-DENV IgG antibody was identified in 113 (19%) when tested by ELISA (51% in group 1, 40% in group 2, and 6.9% in group 3) and in 71 (12%) by PRNT (42% primary monotypic and 58% heterotypic reactive responses). Sensitivity and specificity of the ELISA based on PRNT results were 85% to 100% and 79% to 94%, assuming up to 15% misclassification of ELISA negative results. Presence of anti-DENV IgG antibody by ELISA was associated with years lived in dengue-endemic countries and birthplace in the Caribbean for group 1, receipt of Japanese encephalitis vaccine in group 3, and self-reported history of dengue in all three groups. Conclusions Nineteen percent of participants who were born, lived in, or traveled to dengue-endemic countries had anti-DENV IgG antibody by ELISA; 12% had antibodies by PRNT, 85% of whom had no history of dengue. Presence of DENV antibodies was associated with years lived in dengue-endemic countries and self-reported history of dengue. © 2013 International Society of Travel Medicine.