Evaluation of Thrombocytopenia in Dengue Infection Along with Seasonal Variation in Rural Melmaruvathur

Introduction: Dengue is one of the most prevalent mosquito borne arboviral infection in India. Seventy percent of the 96 million apparent infections occur in Asia, in which India is making upto one third of the total. Despite considerable efforts to control the mosquito populations, dengue fever has emerged, spread and established itself rapidly. The most serious manifestations of the infection are Dengue Hemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS). Objectives: Evaluation of thrombocytopenia in dengue infection along with seasonal variation. Material and Methods: The present study was conducted retrospectively for a period of two years in Melmaruvathur from January 2011 to December 2012. Blood samples were collected from 1,464 patients experiencing febrile illness, clinically consistent with dengue infection. Serological confirmation of dengue infection and evaluation of platelet counts was done in all the serologically positive cases. Results: A total of 1,464 fever cases were admitted during the study period and among them, 107 (7.3%) were found to be seropositive for dengue. A majority, 41 (38.3%) of the dengue cases was noted in the age group of 15-30 years, followed by less than 15 years of age and the mean age of the seropositive cases was 29.78 15.3 years. Among the dengue cases, 62.6% were males and 37.4 % were females. A statistically significant association (p<0.05) was found between the age groups and severity of thrombocytopenia, between severity of thrombocytopenia and clinical presentation of dengue infections. A significantly higher number of serologically positive cases were noted, when compared to serologically negative cases in the post monsoon period. Conclusion: This retrospective study highlighted significant dengue infection during seasonal variation. The median age of dengue patients has decreased and younger patients may be more susceptible.