Summary

Dengue is a mosquito borne diseases which has emerged as a key public health challenge in Sri Lanka. During last two decades dengue incidence had increased with regular epidemics. Vector control and entomological surveillance are essential components of dengue control programme which helps in early warning and epidemic forecasting.
However, currently practicing entomological surveillance based on larval surveys are inadequate for epidemic forecasting. Furthermore, there are gaps in vector bionomic studies, currently practicing vector control intervention and availability of novel tools. Proposed research will optimize a rapid colourimetric reverse transcription loop mediated isothermal amplification (RT-LAMP) for differential detection of dengue virus serotypes in adult Aedes mosquitoes.
In the collaborative pilot study of World Mosquito Programme (WMP) and National Dengue Control Unit (NDCU), Ministry of Health, Wolbachia-infected Aedes aegypti adult mosquitoes will be released as a novel method to reduce dengue burden. The indices measured in WMP project will be prevalence of Wolbachia in Ae. aegypti population in addition to monitoring dengue cases in intervention/study sites. NDCU as the national agency will thus monitor virus
prevalence using RT-LAMP method and density distribution and bionomics of both vectors, Ae. aegypti and Ae.
albopictus in intervention/study areas since Aedes albopictus also contribute to local dengue outbreaks. Proposed study will thus be complementary to WMP project. On completion, entomological information gathered and RT LAMP used will provide surveillance mechanisms for long-term strategy for Dengue control. Moreover, Sri Lankan population will benefit by reducing dengue burden and by saving human hours and resources for economic
development of the country.

Objectives

General objective
To optimize the colourimetric reverse transcription loop-mediated isothermal amplification (RT LAMP) for the differential detection of dengue virus serotypes in Aedes mosquitoes and use as a novel surveillance tool in dengue control

Specific objectives
1. To optimize the colourimetric RT-LAMP assay for the detection of dengue virus in infected
Aedes mosquitoes
2. To further optimize this colourimetric RT-LAMP assay for differential detection of dengue virus
serotypes in vector Aedes mosquitoes
3. To assess the prevalence of dengue virus in Wolbachia infected/uninfected Aedes mosquitoes,
pre-, during- and post-intervention periods (in relation the release of Wolbachia-infected Aedes
aegypti to the interventions areas)
4. To assess the vector bionomics (number and the place of indoor resting Aedes mosquitoes,
male:female ratios of indoor resting mosquitoes, proportion of blood-fed mosquitoes) during the
study period in the two intervention and in the control area

Major Equipment Facilitated by Grant