Novel approach to fighting malaria
“Wolbachia is an interesting bacterium that seems perfectly suited for mosquito control. However, there were strong doubts that it could ever be used against field Anopheles populations,” said Flaminia Catteruccia, associate professor of immunology and infectious diseases at Harvard School of Public Health (HSPH) and at the University of Perugia, Italy. “We were thrilled when we identified infections in natural mosquito population.
Anopheles mosquitoes are the deadliest animal on the planet. They are responsible for transmitting malaria, which causes more than 600,000 deaths each year and puts half of the world’s population at risk for diseases. Wolbachia infections spread rapidly through wild insect populations by inducing a reproductive phenomenon called cytoplasm incompatibility (CI), and 66% of arthropod species are infected.
However, it was commonly thought that Anopheles mosquitoes were not natural hosts for Wolbachia infections, and attempts to identify infections in these mosquitoes in the field had failed.
A study that screened 221 mosquitos from a village in Burkina Faso for both the malaria parasite and for Wolbachia, found malaria in 12 of the insects and Wolbachia in 116 of them. Only one of the latter insects also tested positive for malaria, suggesting that the bacteria is somehow preventing malaria parasites from establishing themselves when Wolbachia is present.
The researchers say they can now investigate whether this strain shares properties with other Wolbachia strains, which could make control strategies possible by inducing CI and reducing Plasmodium (the parasite that causes malaria) numbers in Anopheles mosquitoes in the field. “If successful, exploiting Wolbachia infections in malaria mosquitoes could reduce the burden of the disease globally,” said co-author Elena Levashina, from the Max Planck Institute for Infection Biology, Berlin.
