Mosquito Screening

The Monash Centre for Biospectroscopy is collaborating with the Eliminate Dengue program, part of the Institute of Vector-Borne Diseases based at Monash University.

The following text is an excerpt from Eliminate Dengue’s summary of their research (see more at www.eliminatedengue.com/our-research):

Our approach uses natural bacteria called Wolbachia. Wolbachia occur naturally in up to 60% of all insect species, but not the Aedes aegypti mosquito.

We have successfully transferred Wolbachia from other insects into Aedes aegypti mosquitoes and have shown that when Wolbachia is present in the mosquito it reduces the mosquito’s ability to transmit dengue.

Our hope is to seed wild mosquito populations with Wolbachia in areas where dengue is endemic. We do this through controlled releases of Wolbachia mosquitoes that then breed with the wild mosquitoes. Our prediction is that if Wolbachia can establish in the wild mosquito population in a local area then there would be reduced transmission of dengue between people.

We have been conducting trials of our approach in dengue-affected communities since 2011, which have shown we can deploy the method and that it sustains itself. Ongoing small-scale trials in Australia, Vietnam, Indonesia, Brazil and Colombia as well as initial laboratory studies in India are helping us refine our methods.

We are now developing the method for low-cost, large-scale application across urban areas. Our first city-wide trial began in 2014 in northern Australia and we hope to undertake further large-scale trials starting in 2016.

Over the next few years, we also plan to evaluate the impact of our approach by directly measuring the reduction in dengue during large-scale trials. To determine the most suitable locations for measuring impact, we will first spend 1-2 years monitoring potential sites.

In the course of this large-scale rollout, Eliminate Dengue researchers need an accurate, cheap, and quick method for screening mosquitoes for the presence of Wolbachia.  Up until now, a genetic test has been used.  While this is highly accurate, the time-scale and cost factors make it an impediment to city-wide implementation of the program.  Even a saving of a few cents per sample makes a big difference when scaled up.

We have been working on a new ATR-FTIR-based method for detecting Wolbachia in adult mosquitoes, along with other research-relevant characteristics. This method uses a library of spectra and multivariate statistics to classify mosquitoes as infected and uninfected.  Our first paper in this area has been accepted pending minor revisions.

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Main staff involved: Dale Christensen, Aazam Khoshmanesh, David Perez-Guaita, Bayden Wood