Dengue fever remains a significant public health concern in endemic regions. This study examines the occurrence of primary and secondary dengue infections in South Andaman over a 5-year period (2018-22), mainly focusing on demographic and environmental factors influencing transmission. A total of 14 783 individuals with suspected dengue were tested using NS1 Antigen ELISA, IgM, and IgG antibody assays. Data on age, gender, location (urban vs. rural), household exposure, and clinical symptoms were analysed to identify patterns and risk factors related to dengue infections. Primary dengue infections were found in 6.6% of cases, while 2.5% had secondary infections, and 5.5% showed signs of past infections. Higher infection rates were observed among males and individuals aged 16-30 years, followed by those of <15 years. Urban areas reported higher rates of both primary and secondary infections compared to rural areas. Household exposure to dengue cases significantly influenced infection rates. Respiratory symptoms were also strongly linked to dengue infections. This study identifies key demographic and urban-rural risks for dengue in South Andaman. Our results dictate the need for targeted vaccination in the age group of <15 years, as per WHO criteria, intensified urban vector control, and preventive household interventions to effectively reduce the disease burden in this endemic region.
Murugesan et al. (Thu,) studied this question.