Domestic and environmental factors of chikungunya-affected families in Thiruvananthapuram (Rural) district of Kerala, India

Background: The world is experiencing a pandemic of chikungunya which has swept across Indian Ocean and the Indian subcontinent. Kerala the southernmost state of India was affected by the chikungunya epidemic twice, first in 2006 and then in 2007. Kerala has got geography and climate which are highly favorable for the breeding of Aedes albopictus, the suspected vector. Aim: The aim of the study was to highlight the various domestic and environmental factors of the families affected by chikungunya in 2007 in Thiruvananthapuram district (rural) of Kerala. Settings and design: This is a cross-sectional survey conducted in Thiruvananthapuram (rural) district during November 2007. Materials and Methods : Samples were selected from field area under three Primary Health Centers. These areas represent the three terrains of the district namely the highland, midland, and lowland. The sample size was estimated to be 134 houses from each study area. The field area of health workers was selected as clusters and six subcenters from each primary health center were randomly selected (lot method). Results and Conclusions: The proportion of population affected by chikungunya fever is 39.9% (38.9-40.9%). The investigators observed water holding containers in the peri-domestic area of 95.6% of the houses. According to regression (binary logistic) analysis, the area of residence [adjusted odds ratio (OR) = 8.01 (6.06-14.60)], residing in a non-remote area [adjusted OR=0.25 (0.16-0.38)], perceived mosquito menace [adjusted OR=3.07 (2.31-4.64)], and containers/tires outside the house [adjusted OR=5.61 (2.74-27.58)] were the independent predictors of the occurrence of chikungunya in households.