A three year retrospective study on the increasing trend in seroprevalence of dengue infection from southern Odisha, India

BACKGROUND & OBJECTIVES: In Odisha, several cases of dengue virus infection were detected for the first time in 2010, the importance of dengue as a serious mosquito-borne viral infection was felt only in 2011 with the reporting of many more positive cases. This retrospective three year study was done to find out the seroprevalence of dengue IgM antibody and to know the predominant serotype of dengue virus among the patients suspected to have dengue virus infection in a tertiary care hospital in southern Odisha, India. METHODS: Blood samples from clinically suspected dengue cases admitted in the Medicine and Paediatrics departments of a tertiary care hospital were collected. These were processed for detection of dengue specific IgM antibody, carried out by the ELISA method. Dengue IgM antibody positive serum samples were tested for serotypic identification. RESULTS: Of the 5102 samples tested, 1074 (21.05 %) were positive for dengue IgM. Maximum numbers of cases were found in 2012. Majority (47.86 %) of cases were detected in the month of September. The most common affected age group was 11 to 20 yr. DENV1 and DENV2 were the detected serotypes. INTERPRETATION & CONCLUSIONS: Rapid increase in the dengue cases in 2012 became a public health concern as majority of cases were affecting the young adolescents. Most of the cases were reported in post-monsoon period indicating a need for acceleration of vector control programmes prior to arrival of monsoon.