Five cases of malaria spread by mosquitoes have been detected in the United States in recent months. It’s the first time there’s been local spread of the disease in the country in 20 years.
Four of the cases were reported in Florida and one in Texas, according to a June 26 health alert issued by the U.S. Centers for Disease Control and Prevention (CDC). The agency said the people who were diagnosed received treatment and “are improving.”
But some social media users claim these recent malaria cases are connected to a Bill Gates-funded mosquito project in Florida. VERIFY viewer Zachary messaged our team to ask if these claims are true.
THE QUESTION
Is a mosquito project linked to Bill Gates responsible for recent malaria cases in the U.S.?
THE SOURCES
THE ANSWER
No, a mosquito project linked to Bill Gates is not responsible for recent malaria cases in the U.S.
WHAT WE FOUND
Bill Gates and a mosquito project that exclusively works with non-biting genetically modified male mosquitoes in the Florida Keys are not responsible for recent malaria cases in the U.S.
The CDC says malaria is caused by a parasite that spreads through the bite of an infected female Anopheles mosquito. In June 2023, four people in Sarasota County, Florida, and one person in Cameron County, Texas, contracted the disease after they were bitten by an infected female Anopheles mosquito, according to the CDC, Florida Department of Health and the Texas Department of State Health Services.
On its website, the Bill & Melinda Gates Foundation says that malaria eradication is one of the organization’s top priorities. For nearly two decades, it has devoted resources to fighting malaria in low- and middle-income countries. One of the foundation’s partners is Oxitec, a UK-based biotechnology company that develops genetically modified insects that safely and sustainably control pests that spread disease, damage crops and harm livestock across the globe.
In 2021, Oxitec partnered with the Florida Keys Mosquito Control District (FKMCD) to evaluate the effectiveness of the company’s genetically modified mosquitoes to control invasive, disease-spreading Aedes aegypti mosquitoes in the Florida Keys.
The genetically modified mosquitoes used in the Florida Keys Mosquito project are male, cannot bite people and do not pose a risk to humans or the environment, according to the company. They are produced to specifically combat invasive female Aedes aegypti mosquitoes that spread disease to humans. Aedes aegypti mosquitoes carry dengue fever, chikungunya, Zika fever and yellow fever — not malaria.
“Oxitec has only worked in the Florida Keys — not in Texas or any other part of the U.S., and only with the Aedes aegypti. This species does not carry malaria. As malaria is transmitted through infected Anopheles mosquitoes, it is scientifically impossible for Oxitec's Aedes aegypti to carry malaria. There is no interbreeding between species,” Oxitec spokesperson Joshua Van Raalte told VERIFY.
“Malaria in Florida is transmitted through infected Anopheles mosquitoes, and Oxitec does not carry out malaria work in the U.S.,” Van Raalte said. “There is absolutely no truth to these claims.”
More from VERIFY: Yes, genetically modified mosquitoes do exist, but they don’t bite and aren’t harmful to humans
This project, which is called The Florida Keys Mosquito Control District (FKMCD) - Oxitec Mosquito Project, is also not funded by the Bill & Melinda Gates Foundation. Instead, it is fully funded by Oxitec.
“The Bill and Melinda Gates Foundation does fund some of our other work on other mosquito species,” Nathan Rose, Ph.D., Oxitec’s Head of Malaria Programs told VERIFY in 2021. “They are funding us to work on two different species that transmit malaria, one in Africa, one in the Caribbean, but that has nothing to do with the work that's happening in Florida.”
VERIFY found documentation on the Bill & Melinda Gates Foundation website that shows the nonprofit organization has funded several Oxitec agricultural development and malaria-related projects in Africa since 2018, but none in the U.S.
“The claim linking the Bill & Melinda Gates Foundation’s work on malaria to the cases reported in Florida and Texas is false. The foundation does not fund any work involving mosquito release in the United States,” a Bill & Melinda Gates Foundation spokesperson said in an email.
Genetically modified mosquitoes are mass-produced in a laboratory to carry two types of genes: A self-limiting gene that prevents female mosquito offspring from surviving to adulthood and a fluorescent marker gene that glows under a special red light, according to the CDC. This allows researchers to identify genetically modified mosquitoes in the wild.
“Oxitec’s self-limiting gene allows the release of male-only adult mosquitoes into the environment which mate with invasive females,” the mosquito project explains on its website. “With sustained releases of self-limiting male mosquitoes, the number of females in the population declines, and the target invasive population declines.”
Oxitec was invited to do the project in the Florida Keys because the area has had a couple of outbreaks of Dengue fever in the last few years. It began its third season in spring 2023. The project has received full approval from the U.S. Environmental Protection Agency (EPA) and the Florida Department of Agriculture and Consumer Services.
There have been 11 outbreaks involving malaria from mosquitoes in the U.S. since 1992. The last one occurred in 2003 in Palm Beach County, Florida, where eight cases were reported.
Before the COVID-19 pandemic, the CDC said about 2,000 U.S. cases of malaria were diagnosed each year — the vast majority in travelers coming from countries where malaria commonly spreads.
The Associated Press contributed to this report.
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