Estimated prevalence of dengue viremia in Puerto Rican blood donations, 1995 through 2010

BACKGROUND: Dengue virus (DENV) nucleic acid amplification testing of blood donations during epidemics in endemic locations, including Puerto Rico, has suggested possible sizable transfusion transmission risk. Estimates of the long‐term prevalence of DENV viremic donations will help evaluate the potential magnitude of this risk in Puerto Rico. STUDY DESIGN AND METHODS: Estimates of the prevalence of DENV viremia in the Puerto Rican population at large from 1995 through 2010 were derived from dengue case reports and their onset dates obtained from islandwide surveillance, estimates of case underreporting, and extant data on the duration of DENV viremia and the unapparent‐to‐apparent dengue infection ratio. Under the assumptions that viremia prevalence in blood donors was similar to that of the population at large and that symptomatic persons do not donate, statistical resampling methods were used to estimate the prevalence of dengue viremia in blood donations. RESULTS: Over the 16‐year period, the maximum and mean daily prevalences of dengue viremia (per 10,000) in blood donations in Puerto Rico were estimated at 45.0 (95% confidence interval [CI], 36.5‐55.4) and 7.0 (95% CI, 3.9‐10.1), respectively. Prevalence varied considerably by season and year. CONCLUSION: These data suggest a substantial prevalence of DENV viremia in Puerto Rican blood donations, particularly during outbreaks.