Dengue scenario: Chennai perspective-a six-year study (2009-2014).

Dengue is a public health problem with an increasing global incidence and geographic distribution in almost all tropical and subtropical countries, with a transition from epidemic to endemic occurrence. In this study, we report a six-year analysis (2009-2014) performed at the Department of Virology, King Institute of Preventive Medicine, Chennai, Tamil Nadu, India. Our data confirm earlier findings that dengue is highly endemic in Chennai. In the present study, 10,099 serum samples from suspected dengue cases were tested for IgM ELISA (NIV Capture) and IgG Panbio ELISA (Australia). Of these suspected cases 6,798 and 3,301 were pediatric and adult cases, respectively, and 1,927 (19.08 %) were confirmed serologically as dengue. Of these, 1,752 (25.7 %) and 175 (5.3 %) were pediatric and adult cases, respectively. The aim of this study was to highlight the occurrence of DHF and DSS, mainly among the pediatric population, in which the infection causes higher mortality and morbidity. The overall positivity was higher in the pediatric group than in the adults. Detection of both IgM and IgG positivity will be useful for monitoring infection rates, the disease spectrum, and the prevalence of the different serotypes, which will give us insight about the circulating serotypes and pathogenicity. These data will be valuable for providing an early warning to predict an impending epidemic leading to major clinical manifestations of DHF and DSS.