Evaluation of the effectiveness of a behavioural intervention on Dengue prevention for house holders living in the Colombo Municipal Council area based on larval indicesand disease incidence

Abstract

In the absence of a vaccine or a specific treatment the prevention of dengue aims at reducing the density of the vectors, Aedes aegypti and Aealbopicil/S. Behavioural interventions carried out in other countries have shown a high impact on reduction of Ae. larval indices. The present study aimed to develop, implement and evaluate a behavioural intervention for dengue prevention. In order to achieve these objectives, a community based intervention trial was carried out in the Colombo Municipal Council The study consisted of three stages. In stage one a pre intervention survey gathered baseline data. The behavioural intervention was developed and implemented in stage two. Stage three evaluated the impact of the intervention. Five hundred households, each from the intervention and control areas were selected using multistage sampling technique and GIS technology. The study was conducted in ten randomly selected Municipal wards and included 20 study clusters of 50 households each. The participation rate was high in both the intervention (93.2 percent ) and control groups (93.0 percent ). Information on socio-demographic characteristics, environmental factors, knowledge, attitudes, practices, behavioural , larval parameters and disease incidence at the baseline were assessed. All the data collecting instruments were pre tested and showed good test re-test reliability. Both groups were similar in respect of sociodemographic and economic characteristics. Environmental risk factors \\-lthin the clusters and in the neighbourhood were similar. At the baseline, respondents in both groups were similar in knowledge. Awareness of vector bionomics was relatively low compared to the knowledge on dengue infection and prevention. The two groups were also similar in their attitudes