Epidemiology and trends of dengue fever cases- a 4 year study in a tertiary care centre of north Delhi

Background: Dengue an important emerging mosquito-borne disease worldwide, is transmitted primarily by the bite of Aedes aegypti mosquito. In recent times, there has been a surge in number of dengue cases creating a burden on the already stressed health infrastructure. Objectives: This study was done to assess & analyze the trend of the disease progression over the years along with the epidemiological features in patients admitted to Hindu Rao hospital situated in North Delhi. Method: Blood samples from patients suspected of having dengue infection, attending medicine, pediatrics, fever clinics of Hindu Rao hospital were collected and tested for dengue specific IgM antibodies and NS1 antigen positivity. Results: In this study, conducted over a period of 4 yrs (2015-2018), a total of 17,499 samples were tested from suspected dengue infection cases. Out of 9968 samples tested for dengue specific IgM antibody, 1711 (17.17%) were positive and out of 7531 samples tested for NS1 antigen, 580 (7.70%) were positive. Conclusion: An increase in detection of dengue cases was observed in 2017 & 2018 in comparison to 2015 & 2016.The increase in case detection may be attributed to active health campaigns generating awareness among general public and availability of prompt diagnostic facilities. The increase may also be indicative of infection by a possible new serotype.