High Seroprevalence of Dengue Virus Infection in Blood Donors From Delhi: A Single Centre Study

Introduction: The risk of transfusion transmitted dengue has been increasingly recognized. Blood donors in an endemic area like Delhi may serve as a potential vehicle for transmission of the infection. Moreover, prevalence of infection in them would be representative of the true picture of dengue in a population. Aim: To determine the prevalence of dengue virus infection in blood donors in a tertiary care centre. Materials and Methods: A total of 200 blood donors were recruited in the study after obtaining informed consent in the Institute of Liver and Biliary Sciences, New Delhi in July and August 2012. Data regarding clinical and demographic characteristics was collected using a preformed questionnaire. Blood samples obtained were subjected to anti-dengue IgM and IgG ELISA as well as semi-nested Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) for dengue RNA. Results: Of the study subjects, most were men (97%) with a median age of 28 years (range 19–51 years). Anti-dengue IgG was positive in 116 cases (58%) while IgM was seen in 27cases (13.5%). Of them, in 25 (12.5%) cases both IgG and IgM were positive, while only two (1%) cases tested positive for IgM alone. None of the blood donors were found to be viremic on screening using Nested RT-PCR. A clear increase of IgG seroprevalence with age was evident. No difference in the seroprevalence rates in urban vs. rural areas was seen. Conclusion: High seroprevalence of dengue infection was seen in healthy asymptomatic blood donors. Though evidence of acute infection was found in some, none were found to be viremic. Larger studies are required to quantify the risk and provide strong evidence for policies to be made.