An Epidemiological Study on Investigation of Vector Indices and Migration Pattern of Aedes Mosquito in a Dengue Outbreak in an Urban Habitat in North 24 Parganas District of West Bengal

Background: Investigation of Dengue outbreaks play a big role to ascertain the behaviour and migration pattern of Aedes mosquito. Entomological investigation is based largely on larval indices. However, there is weak association between these indices and viral transmission, because these threshold indices also differ from place to places. It is recommended to find an area-specific re-evaluation of the utility of larval indices. Materials and Methods: This study aimed at to study the migration pattern of infected Aedes mosquito and relationship of vector indices with occurrence of outbreak. This is a observational study on investigation of a dengue outbreak in an urban habitat in a North 24 Parganas of West Bengal. The period of study was done in August and September 2021. Data was collected by house-to-house team of the municipality and subsequently analysed by District entomologists. House Index, Container Index, Bratue Index and Pupal Index are considered as study variables. Diagram was drawn on Microsoft office power point for illustration of movement of focus of outbreak with time. Results: House Index was observed to be highest just before the upsurge of the cases. It is found to be most sensitive index among all larval indices. Container Index did not reflect any change during the outbreak. Breatue Index did not collaborate with the occurrence of outbreak. Pupal Index is also found to be as sensitive as House Index. Conclusions: Diagrammatic presentation based on vector indices may guide the public health personnel to predict the cluster formation of Dengue outbreak in advance.