A study on mosquito density in rural Kerala before and after floods

Abstract

Background: Mosquito borne diseases are a major public health problem in Kerala. Mosquito density assessed by larval surveys is easier and quicker to perform. The larval indices are an important practical predictor of outbreaks of mosquito borne disease and are valuable in taking preventive measures. This study is done to calculate standardized larval indices namely house index, container index and Breteau index and to identify the major breeding sources of mosquitoes in the residential environment in a rural of Thrissur, Kerala.Methods: A cross-sectional study selecting 80 houses from 1 wards of Konnikara village under Thrikkur Panchayath under the field practice area of rural training centre, Amala Institute of Medical Sciences Thrissur. Every water holding container indoors and outdoors was counted and searched for larval presence and noted on a pretested format.Results: In this study, 80 houses were surveyed in 2 days initially in June and in September. All the entomological indices were found to be above the critical level in the initial survey in June. House index=36% container index=44%; Breteau index=143% showing high chances for outbreaks of mosquito borne diseases. In September though the indices were very low house index 1.25% container index 2.77% and Breteau index.Conclusions: The area is prone for mosquito borne disease outbreaks like dengue fever and after interventions the vector indices and potential risks came down.