Scientists say they have created mosquitoes resistant to the dengue virus, which might eventually help control the spread of the disease in humans.
A worldwide problem
The team at Johns Hopkins Bloomberg School of Public Health in Baltimore genetically modified Aedes aegypti mosquitoes to boost their natural ability to fight infection by the virus.
Mosquitoes get infected when they feed on someone who has the disease. Then they pass dengue to healthy people by biting them.
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Each year, dengue sickens about 96 million people worldwide. The virus kills more than 20,000 people, mostly children, the researchers said.
"If you can replace a natural population of dengue-transmitting mosquitoes with genetically modified ones that are resistant to virus, you can stop disease transmission. This is a first step toward that goal," said study leader George Dimopoulos, a professor of molecular microbiology and immunology at Hopkins.
The genetic modifications significantly increased the mosquitoes' resistance to dengue. But the changes didn't boost the mosquitoes' defences against Zika or chikungunya viruses.
More research and testing needed
"This finding, although disappointing, teaches us something about the mosquito's immune system and how it deals with different viruses. It will guide us on how to make mosquitoes resistant to multiple types of viruses," Dimopoulos said in a Hopkins news release.
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He and his team said more research and testing is needed before these dengue-resistant mosquitoes are introduced into the wild, a process they said could take a decade or more.
Forty percent of the world's population live in areas where they are at risk for dengue infection, the study authors said. The virus is most common in Southeast Asia and the western Pacific islands. But dengue infections have been increasing in Latin America and the Caribbean.
The research was published in the journal PLOS Neglected Tropical Diseases.
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