A study on the prevalence of Dengue fever in Kelambakkam in comparison to an earlier study

Abstract

Introduction: Dengue is a mosquito borne viral fever, which is prevalent in India. A one year study was conducted from July 2014 to June 2015, to determine the prevalence of Dengue infection in patients with clinically suspected Dengue fever at Chettinad Hospital and Research institute, Kelambakkam, a suburb of Chennai. Materials and Methods: The samples were tested for Dengue NS1antigen, IgM antibodies and IgG antibodies using the ELISA Methodology. 1231samples were tested during this period. Results: Total positive cases were 474(38.5%). 299 samples were collected from adult males and 65 from pediatric males. 86 samples were collected from adult females and 25 from pediatric females. In males, dengue prevalence rate was higher (76.8%) than females (23.2%).Total positive cases for IgM was 215(45.6%) and for IgG was 203(43%). 284(76.8%) were positive for NS1 antigen. About 43(12%) cases were positive for both IgM and IgG antibodies and NS1 antigen. An increase in the prevalence of dengue was recorded during the months of June, July, August, September, and October. This increase in prevalence was due to the onset of the monsoon season in Tamil Nadu when the vector Aedes aegypti occurs in large numbers.50.6%of the positive cases had thrombocytopenia and 11.6% had leucopenia. Total IgM positivity has increased from 5.04% to 45.6% and total IgG positivity has increased from 14.2% to 43%, as when compared to our previous study. Key words: pyrexia, dengue, prevalence, ELISA, Leucopenia, thrombocytopenia