Recently, thousands of mosquitoes infected with the Wolbachia bacteria were released in the Florida Keys in hopes of a new approach to control the disease-carrying female of the mosquito species Aedes aegypti. The female Aedes aegypti mosquito transmits the Zika virus, Dengue fever, and Chikungunya, a disease with painful symptoms and no treatment or vaccine, and is endemic in Asia and Africa.
According to the Florida Keys Mosquito Control District, 20,000 male Aedes aegypti mosquitoes were released on Stock Island Tuesday for a field trial that will last 12 weeks. The mosquitoes, which do not bite, have been manually infected with a naturally occurring bacteria called Wolbachia.
This bacteria is found in the cells of many insects, but not mosquitoes, so the bacteria must be manually injected into the mosquitoes in a lab before being released. As explained by the Florida Keys Mosquito Control District, when these infected male mosquitoes mate with the female Aedes aehypti mosquitoes, the eggs she produce won’t hatch, rendering her unable to properly reproduce. The desire effect of the experiment will be a reduced or eliminated population of the females of this mosquito species and the viruses they spread, including Zika virus.
Zika is a very large concern to pregnant women, and those hoping to become pregnant, because it can have devastating consequences for babies born to mothers who were infected while pregnant. One in 10 Zika-infected mothers had babies with related birth defects in the United States last year, according to the US Centers for Disease Control and Prevention.
“A successful trial with the Wolbachia-infected mosquitoes could mean the availability of a new tool in the fight against the Aedes aegypti mosquito for not only our District, but for Mosquito Control Districts around the country,” said Andrea Leal, executive director for the Florida Keys Mosquito Control District.
These Wolbachia-infected mosquitoes will be released twice a week at 20 different spots in the designated area for the trial. While the male mosquitoes don’t bite, “increases of mosquito activity will be most noticeable immediately following the releases,” the mosquito control office warned.
Outside of the United States, the first Wolbachia-infected mosquitos were released into the suburbs of Cairns, Australia, in 2011, and quickly spread into the wild; replacing the diseased population quickly with the new, disease-free one, and replicating quickly into following generations. According to the research group Eliminate Dengue, testing so far shows the helpful bacteria remain. Additional field trials are underway in Indonesia, Vietnam, Colombia and Brazil.
But the Florida officials haven’t put all of their hope in this one project, and are also trying to move forward with a trial of genetically modified mosquitoes from British company Oxitec. OX513A is a male Aedes aegypti mosquito that is genetically engineered to pass along a lethal gene to their female counterparts that makes the offspring die.