If you’re skeptical that some “cures” for diseases transmitted by insects and ticks could be worse than the diseases themselves, say hello to the innovative breakthrough that involves implanting the naturally-occurring Wolbachia bacterium into mosquitoes to help stop the spread of Dengue Fever.
What is Wolbachia?
Wolbachia is a genus of bacteria found exclusively in arthropods (insects, spiders, etc) and nematode worms. The bacteria affects somewhere between 25-70% of all known insect species. The bacteria does not always harm insect hosts. In fact, some species cannot even reproduce unless they are colonized by Wolbachia.
However, in the case of some mosquitoes, Wolbachia can decrease the mosquito’s ability to transmit a disease virus.
Killing a Dengue Fever without Shooting the Messenger
Dengue fever is a disease transmitted by mosquitoes, in this case mostly by the Yellow Fever Mosquito, Aedes aegypti. Scientists found that introducing Wolbachia bacteria into female mosquitoes greatly decreased their ability to transmit the Dengue virus.
Releasing these mosquitoes into wild populations results in more Wolbachia-infected mosquitoes over time. Eventually, no additional releases are necessary. This strategy largely stops the need for toxic pesticides to kill mosquitoes. Thus, mosquitoes continue to be a part of the natural food chain, and there are no GMOs (genetically modified organisms) involved.
A Proven Concept?
Dengue fever cases plaqued the city of Townsville in Queensland, Australia, until the World Mosquito Program took action. School children in the city of 187,000 helped release the infected mosquitoes, dating back seven years. There have been no cases of dengue fever in Townsville over the last four years.
The cost came to $15 (Australian) per person in the city, but hopefully this cost can be reduced as the process for breeding and dispersing the mosquitoes becomes more streamlined.
What about Other Diseases?
Scientists are already trying this out on other diseases, namely the Zika virus, in Rio de Janeiro, Brazil. It is more challenging there, if only because of the greater number of jurisdictions that have to give approval before the scientists can proceed. Scientists are keenly aware of the possibility that the positive results in Australia may not be easily duplicated.