Healthy wildlife, healthy people
Mosquitoes as auxiliary troops in disease prevention
As well as possessing a lot of knowledge, scientists have a great deal of imagination. It takes a special way of looking at things to look at a mosquito and see a flying injection needle with a predictable value for the outbreak of diseases, for instance. This seemingly far-fetched idea was formulated by associate professor Sander Koenraadt and his team at Wageningen University & Research (WUR), who started working on it after they accidently discovering a way to catch mosquitoes that had recently bitten someone.
WHY THIS RESEARCH?
Large-scale outbreaks of infectious diseases constitute a major risk to the human population in vulnerable regions. Monitoring and prevention are important for timely prevention.
Using the blood that mosquitoes carry after a bite to check the health of the human population in a region, and, where necessary, act in time to prevent diseases from spreading.
“We have been successfully capturing hungry mosquitoes with odour-baited traps,” Koenraadt says. “That finding was successfully tested in Kenya as a way of keeping malaria mosquitos away from people. But hardly any of the mosquitoes caught this way carry blood. Mosquitoes that have recently been on someone’s skin are not sensitive to the odours that we use – or, at least, they have not been until now. We recently made a new odour mixture by fermenting molasses, which is very attractive to blood-carrying mosquitoes. It seems to be a coincidence, but it is a very valuable one.”
‘We can use drops of blood from mosquitoes to chart human health’
Amsterdam UMC, International Centre of Insect Physiology and Ecology (Kenya), Biogents AG (Germany), National Center for Vector Entomology (UZH; Switzerland)
Rift Valley, Kenya
Mosquitoes often play a role in the spread of diseases. Photo: Shutterstock
How can catching those mosquitoes make such a difference? “The answer is in bio-nanotechnology,” Koenraadt explains. “There is work within this discipline at WUR on the development of chips that allow diagnostic tests with a small, handy device. If we combine that with our ability to catch the right mosquitoes at the right time, a world of possibilities opens up. Imagine: we catch mosquitoes in our traps in a village or a neighbourhood and then analyse the drops of blood they are carrying. If we catch enough mosquitoes, we can see exactly which diseases affect the people in the area. Such an early warning signal could enable us to either provide medications or start new prevention programmes in time. This could save lives on a large scale in Africa, for instance.”
FLYING INJECTION NEEDLES
Koenraadt’s project aims to combine knowledge on mosquito biology and ecology with high-tech applications, with an initial focus on developing a prototype of the analysis equipment. “We already have the odour mixtures to attract the mosquitoes and now have to be able to work effectively with the collected blood. The analysis has to be fast to get a sort of ‘snapshot’ of the health of the people in an entire area. And that brings with it another challenge: we can use the mosquitoes only if they have just bitten someone.
Left: Checking an odour-baited trap.
Right: A trap specifically developed to catch mosquitoes that carry blood. Photos: Sander Koenraadt
“It takes mosquitoes three to four days to digest blood, after which the viruses and bacteria we are looking for disappear too. In other words, we have to catch mosquitoes within 24 hours of feeding so our lab is studying how to make the odour-baited traps especially attractive to that category. We are becoming more and more efficient at using our flying injection needles. That is what I enjoy about this project: using the possibilities that nature give us to monitor and, where necessary, improve people’s health. It is a great example of how WUR bundles knowledge from a range of domains and uses it in very concrete solutions with the potential to help millions of people.”
DR SANDER KOENRAADT
Associate Professor One Health Entomology, Wageningen University & Research
Biological control, Ecology, Insect pathology, Acarology, Medical entomology, Malaria, Vector-borne diseases
Photo: Gea Hogeveen