Dengue Sero-surveillance in Delhi: A Community-Based Study

Background: IgG ELISA is useful as an epidemiological tool when used to establish sero-prevalence. Extensive background information is required before selecting sites for dengue vaccine trials like types of dengue virus that are causing disease, preferably over a number of years, sero-prevalence of dengue IgG antibodies, prevalence of each serotype, rates of infection, specific mortality, etc. Aims and Objectives • To study the prevalence of dengue IgG antibodies in the serum of adults in urban slums of Delhi • To study the knowledge, attitude and the practice of study subjects about the prevention of mosquito breeding and dengue fever Methodology: This cross-sectional study was conducted from January 2013 to December 2013 in two urban slums of Delhi, Balmiki Basti and Delhi Gate. All adults aged 20 years and above were included in the study irrespective of sex and previous history of dengue. Knowledge, attitude and practices against mosquito breeding were also taken through predesigned, pretested questionnaires. Results: A total of 49(20.5%) adults from Balmiki Basti and 190 from Delhi Gate were enrolled in the study. Mean IgG dengue OD levels of the study subjects was 1.62±0.568. Of the total, 86% were positive for dengue IgG positivity while 13% negative and 1% equivocal. Of all participants, 214(89.9%) were aware of mode of dengue transmission while 25(10.1%) were not. Majority of the participants 137(57.3%) used liquid vaporizers for prevention of mosquito bites. Discussion: The current study reported that 85.4% of the healthy population in urban slums of Delhi is seropositive for dengue IgG, which indicates the unprecedented extent of exposure to dengue virus. It is 7.8% higher than the study conducted in Delhi in 1998(77.6%). It coincides with the rising trend of dengue cases every year in Delhi, making it an endemic region now.