On Friday, Verily started releasing sterile mosquitoes in California. The company, formerly known as Google Life Sciences, released the bacteria-infected male mosquitoes to kick off its Debug Fresno campaign. The campaign backed by Verily and MosquitoMate is an effort to get the county freed of Aedes aegypti mosquitoes, carriers of the Zika Virus.
In October last year Verily announced the launch of the Debug Project, which aims to reduce the global health impacts that disease-carrying mosquitoes inflict on thousands of people worldwide.
With the Debug Fresno initiative, the company’s first field study in the United States, Verily seeks to test a potential mosquito control method using sterile insect technique, the bacteria-infected male mosquitoes. The company is working alongside MosquitoMate and Fresco County’s Consolidated Mosquito Abatement District in this project.
Google’s Verily will release 1 million sterile male mosquitoes every 20 weeks
The Debug Fresno project released yesterday 1 million mosquitoes and will do so every 20 weeks. By releasing them, Verily expects to eradicate the mosquito population of Aedes aegypti, an invasive mosquito that can spread Zika, dengue, and chikungunya.
Mosquitoes kill more people around the world than every other animal combined, said Verily when it kicked off the Debug Project last year. Before they started the initiative, they talked with experts from around the world and decided the best approach to deal with the disease-spreading insects was through the sterile insect technique.
“The idea is to release sterile insects to mate with wild ones,” said Linus Upson, Verily VP of engineering, in a blog post on October 2016. “No offspring result from these matings. So if enough sterile insects are released, they can reduce, or even locally eliminate, the wild population.”
The technology was developed in the 1950s to fight a livestock pest called the New World screwworm. Currently, the technique is also used in California to control Mediterranean fruit flies. Experts believe the sterile insect technique is far better than chemicals to stop disease-spreading insects, as insects only mate with others of their species.
For the Debug Fresno project, Verily treated 1 million male mosquitoes with Wolbachia, a naturally occurring bacteria, said Verily. They released the sterile mosquitoes in two Fresno neighborhoods each approximately 300 acres in size. Kathleen Parkes, a Verily spokesperson, told The Verge that the first 1 million mosquitoes would be ultimately released by next week.
Sterile insect technique guarantees no more mosquito hatchings
Last year, Fresno’s Consolidated Mosquito Abatement District and Mosquito Mate led the first-ever U.S. release of sterile male Aedes aegypti mosquitoes treated with Wolbachia in Fresno County.
The Wolbachia bacteria naturally infects many mosquitoes, but not Fresno’s. These infections would allow for released mosquitoes to be sterile to any female that doesn’t have the Wolbachia infection. Verily noted the male mosquitoes don’t bite (the females do), so the Fresno community doesn’t have to worry about getting bit by a new horde of mosquitoes.
Entomologist Stephen Dobson at the University of Kentucky, told The Verge the way Wolbachia works is a “lock-and-key” system for mosquito reproduction. Stephen Dobson is also part of MosquitoMate, which was the company that provided Google’s Verily with their breeding stock of Wolbachia-infected females, to breed the sterile male mosquitoes.
As Fresno’s female mosquitoes aren’t infected with the Wolbachia bacteria, they don’t have the “key” to unlock the male’s Wolbachia-modified gene, thus making it impossible for these mosquitoes to hatch fertile eggs.
When MosquitoMate and CMAD released the first batch of mosquitoes last year, the Environmental Protection agency determine the pilot experiment wasn’t risky for the human population, and the company renewed the permit to continue and expand the initiative.
Zika can be spread through mosquito bites or by having sex with someone infected
Debug Fresno represents a 25 fold increase in mosquito release efforts than the pilot release of 2016. According to Verily, their software algorithms and on-the-ground release devices will allow them to distribute the sterile male mosquitoes throughout Fresno County.
“We believe that these advancements could have a meaningful impact on what is traditionally a very labor-intense process and could reduce the number of biting Aedes aegypti in Fresno County,” said Jacob Crawford, a scientist at Verily, in a press release issued on Friday.
According to the Centers for Disease Control and Prevention, Zika-carrying mosquitoes can bite anyone at any time of the day. The CDC says that people carrying the virus can spread it through sex. The disease can be particularly dangerous for pregnant women, as Zika is linked to congenital disabilities, such as microcephaly.
The CDC recommends that pregnant women shouldn’t travel to areas with risk of Zika. People with Zika can also spread it through mosquito bites –if a mosquito bites that person and then bites someone else- or through sex, so the CDC also suggests that people use condoms at all times during sex.