Entomological investigation during dengue outbreak in Kudus and Jepara Districts, Central Java, Indonesia

Abstract

Background: Between January to July 2014, dengue outbreak occurred in Kudus and Jepara Districts, Central Java Province. We conducted an entomological investigation of the dengue vectors in 6 selected villages with the most impact on the outbreak. Aims: This study aimed to investigate the risk factor of dengue transmission based on entomology data and to identifies the most appropriate vector control measure. Methods and materials: Larvae collection was conducted in 6 selected endemic villages using the single larvae method. The survey used a cross-sectional method. We used Breteau Indices (BI) and Density Figure (DI) to assess the risk transmission. The resistance assay was carried out using the WHO standard impregnated paper. The Odd Ratio test was carried out to determine the risk factor of potential breeding places. Results: The dengue risk transmission in this study varies between low, medium, and high, with an average BI rate above 5 and DI between 2-7. The main breeding places were water tanks in bathrooms. There was no difference in risk between covered and uncovered containers becoming breeding sites, and varied risk between drained and non-drained containers. Aedes aegypti from all villages were resistant against all insecticides classes. Conclusion: Outbreaks occurred in all villages, although the risk of transmission was low. Due to the resistance to insecticides, vector control approaches should be introduced, such as mechanical and bio-insecticide methods. It is necessary to develop alternative entomological parameters to predict risk transmission more accurately.