A Study on Larval Indices of Aedes and Risk for Dengue Outbreak in a Rural Area of Thrissur District, Kerala

Abstract

Background: Mosquitoes are one of the deadliest animals in the world. Their ability to carry and spread disease to humans’ cause millions of deaths every year. Knowledge regarding the bionomics of mosquito is utmost important for developing control measures. Dengue is one of the most important and fastest re-emerging arboviral diseases, with 2.5 billion people living in areas of risk. The larval indices are easy to assess and gives the mosquito density. Objective: This study was done to calculate standardized larval indices over a period of 5 months, to determine the major breeding sources for mosquitoes, to study the seasonal trends in larval indices in a rural residential area under Kaiparambu Panchayat of Thrissur district, Kerala. Methods: A cross sectional study was conducted over a period of 5 months (June-October) in the houses under ARCH (Amala Rural Community health) programme of Amala Institute of Medical Sciences- Kaiparambu panchayat of Thrissur district. A house to house survey was done and every water holding container-indoor and outdoor were counted, searched for larval presence, collected and assessed. Each Larvae collected was examined and species identified. Descriptive statistics was done manually to quantify the percentage of positive containers obtained. Result: A total of 581 houses were surveyed, 223 had larval presence. The entomological indices were respectively accounted as Container Index=29.03; House Index=49.1; Breteau Index=80.3 in June and CI=19.8; HI=32.6; BI=34.7 in October. There was seasonal variation in the indices. The commonest species of mosquito identified was Aedes albopictus. Conclusion: The area has high risk for mosquito borne disease outbreaks, with seasonal variations and rainfall patterns. With adequate preventive measures, it can be avoided. How to cite this article:Anna SP, Vincent J, Saju CR, Rafi MM. A Study on Larval Indices of Aedes and Risk for Dengue Outbreak in a Rural Area of Thrissur District, Kerala. J Commun Dis 2020; 52(1): 1-6. DOI: https://doi.org/10.24321/0019.5138.202001