Two years ago, researchers infected mosquitoes with bacteria and released them into parts of an Indonesian city. In areas where such mosquitoes were deployed. dengue incidence was 77% lower than in areas where they were not.
How can mosquitoes bring down dengue?
- The key to this is a bacterium, Wolbachia, which occurs naturally in some species of insects. While such insects include some mosquitoes, Wolbachia does not occur naturally in Aedes aegypti, the mosquito species that spreads dengue and other diseases such as chikungunya, Zika and yellow fever.
- In 2008, the Australian-based research group World Mosquito Program (WMP) discovered that Aedes aegypti mosquitoes can no longer spread dengue when they are carrying Wolbachia, This is because the dengue virus struggles to replicate inside the mosquito when these bacteria are present.
- Therefore, once you release mosquitoes carrying the Wolbachia bacteria, they will interbreed with the local wild mosquitoes. Over time, several generations of mosquitoes will be carrying Wolbachia naturally. A stage will eventually be reached when those carrying Wolbachia represent a large proportion of the local mosquito population, so that a bite is less likely to transmit the virus to humans.