Dengue infection: its prevalence with seasonal variations

Abstract

Background: Dengue fever is emerging arbo-viral acute febrile illness, which is endemic in India. Continuous surveillance of dengue fever is important for the proper and timely institution of vector control measures. With this study we made an attempt to know seasonal variation of incidence of dengue infection and correlation between thrombocytopenia and leucopenia in dengue positive cases. Apart from dengue serological markers platelet count and leucocyte count are also important in proper management of dengue infected cases. Methods: This study was conducted in department of Microbiology Al-ameen medical college Vijaypur from January 2014-december 2015. Serum samples were collected from patients suspected with dengue fever and dengue serology was done using immunocrhomatographic card test, along with this platelet count and total count was done by automation. Results: Of 284 samples received 58 (20.42%) samples were positive for one or more parameters of dengue. 27(46.55%) samples were positive for only NS1, 4(6.89%) were positive for only IgM, 14(24.13%) were positive for only IgG. Remaining 13 were positive for more than one serological markers. 36.26% of dengue positive cases had thrombocytopenia whereas only 4.28% of dengue negative cases had thrombocytopenia. 55.17% of dengue positive cases had leucopenia whereas only 12.38% of dengue negative cases had leucopenia. The increase incidence of cases coincides with the mason and post monsoon season. Conclusion: Incidence of dengue infection was higher in monsoon and post Manson period. Thrombocytopenia and leucopenia provide high suspicion of dengue infection, mainly where dengue serological tests are not available. Keywords: Dengue fever, NS1 antigen, IgM antibody, Seasonal, Platelet count