Engineers apply imaging technology to help in the fight against malaria

Researchers at Warwick University’s School of Engineering are using the technology to image thousands of mosquitoes to help develop better netting against the malaria-spreading insect.

Warwick University engineers - David Towers, Natalia Angarita and Catherine Towers - are helping entomologists at the Liverpool School of Tropical Medicine explore the best insecticide treatment and physical design of the protection for sleeping people in areas where mosquitoes are a problem.

Their work is part of AvecNet, a €12m research project funded by an FP7 grant.

The entomologists at the Liverpool School of Tropical Medicine are carrying out their latest experiments in a swamp in Tanzania that is home to a population of mosquitoes where some are resistant to insecticide and others are not.

They have built a hut at this site mimicking the typical housing and sleeping arrangements for local people. They need to experiment at night when people are at greatest risk of being bitten by anopheles gambiae mosquitoes, which is  the species responsible for transmission of the malaria parasite that is the most dangerous to humans.

When observing mosquitoes an their interaction with insecticide treated barriers such as netting, researchers have previously relied on recording the insect’s final landing location, which does not give a full picture of how they approach and handle the protective barriers.

To help overcome this limitation, the Warwick University engineers devised a method that would capture a vast amount of data on the behaviour of the tiny mosquitoes.

Using a modified back lighting technique the insects have been imaged throughout a 2.0 × 2.4 × 1.0 metre volume using illumination in the near infrared. This is a wavelength that is not perceived by mosquitoes so it does not change their natural behaviour. Two cameras are positioned so each captures images at a rate of 50 per second. For every hour of operation 360,000 images are captured, each taken at 4 million pixels, or 1.4 TerraBytes (TB) in total size.

Until now there was no software capable of analysing such a large number of high-resolution images, so it had to be specially written by the Warwick Engineers and it has now been used to process over 50 TB of data so far.

“There is a lot of interest in the analysis of so-called ‘big data’ – here we have the added complexity of capturing information from the field with everything powered from petrol fuelled generators and we need very robust algorithms to be tolerant of the natural variability in behaviour exhibited by wild mosquitoes,’ said Prof David Towers, an engineering researcher at Warwick University.

A report - Infrared video tracking of Anopheles gambiae at insecticide treated bed nets reveals rapid decisive impact after brief localised net contact – has been published in Nature Scientific Reports.

Indications show that the mosquitoes do not realise a net is treated before they touch it and future research will build on these findings.