Dengue Infection - prevalence and seasonal variation among patients attending a tertiary care hospital at Chamarajanagar, Karnataka

Abstract

Introduction: Dengue fever is an emerging acute febrile illness caused by arboviruses and presenting with wide spectrum of clinical manifestations ranging from self-limiting asymptomatic infection to severe fatal infection like Dengue hemorrhagic shock with unpredictable outcome. It is endemic in India and in recent years it is appearing in the form of epidemics especially during rainy season. Objectives To determine seroprevalence of dengue virus among clinically suspected cases. To determine the seasonal variation of dengue infection in the study setting. To study the demographic profile of dengue positive patients. Materials and Methods: A cross sectional study was done at a tertiary care hospital, Chamarajanagar using secondary data which were maintained in the microbiology laboratory registers, for clinically suspected dengue patients reported to the hospital from January- December 2017. Prevalence was estimated by analyzing data for the results of both NS1antigen and IgM antibody by ELISA tests and any variations in disease reporting by gender, age and season were assessed. Statistical analysis was done using WHO Epi info software version 3.5.4. Results:A total of 2213 serum samples were analyzed during the study period. Out of which 475 samples (21.46%) were found positive for dengue infection either by NS1 or IgM ELISA. The proportion of dengue cases was higher in monsoon season with maximum rate of positivity in August (55.37%). Paediatric population was the most common affected group (30.33%). Conclusion:The present study confirms that dengue is mainly a disease of rainy season and also identifies certain vulnerable groups for effective planning of interventions. Keywords: Dengue, IgM, NS1, Seasonal variation