An epidemiological study of dengue in Delhi, India

[Display omitted] •Targeting the index cases in different socio-economic groups of a community to evaluate the prospective dengue cases for proactive readiness of a resource limited health infrastructure.•Inclusion of asymptomatic dengue cases to ascertain the true burden of the disease load for better prevention and control.•Assessing the rate of secondary infections in a community for a possible prevention of developing Dengue Haemorrhagic Fever/ Dengue Shock Syndrome. Delhi, the capital of India, is an important metropolitan hub for major financial and sociocultural exchanges, offering challenging threats to current public health infrastructure. In recent past, an upsurge of dengue cases in Delhi posed a significant menace to the existing dengue control policies. To reform the control strategies and take timely intervention to prevent future epidemics, an epidemiological study on the proportion of both asymptomatic and symptomatic dengue infections in selected population was conducted. The aim of the study was to investigate and assess the epidemiology of dengue infection and to estimate the proportion of asymptomatic and symptomatic dengue infections in Delhi. In this study, around 50 confirmed dengue cases, a total of 2125 individuals as household and neighbourhood contacts, with or without dengue febrile illness, were finger pricked and serologically detected as dengue positive or negative using SD Duo Bioline Rapid Diagnostic Test (SD Inc, Korea) with NS1, IgM & IgG combo test, which detected dengue virus antigen and antibodies to dengue virus in human blood. Out of 2125 individuals, 768 (36.1%) individuals showed positive dengue test with past (25.5%), primary (1.88%) or secondary (8.8%) dengue infections. Higher percentage of IgG was found in age groups 15–24 years and 25–50 years (36% each). Infants (