Scientists modifying mosquitoes to prevent dengue

Oxitec Ltd., a U.K. biotechnology start-up company, wants to begin tests in the United States to genetically modify mosquitoes carrying dengue fever to make their offspring self-destruct.

The company has released the genetically modified mosquitoes in the Cayman Islands, Brazil and Malaysia, though a proposed trial in Key West has had resistance from communities opposing genetic modification. With no vaccine or drugs to prevent or treat dengue, the approach could be an effective option to limit infections, Bloomberg reports.

"It is a promising technology," James Logan, a lecturer at the London School of Hygiene and Tropical Medicine, said, according to Bloomberg. "If you stop us being bitten, you stop the disease from being transmitted."

Luke Alphey, the chief scientist of Oxitec, uses a technique in which scientists insert one copy of an altered gene into a mosquito. The modification causes the insects to produce excess amounts of a cell-disrupting protein unless they receive an antibiotic. Male mosquitoes with the gene are released into the wild, reproduce with females and die prior to adulthood.

"The lethal gene is something that will kill the offspring when it's inherited," Alphey said, according to Bloomberg.

Oxitec's efforts are part of a major worldwide efforts to reduce the spread of dengue.

Dengue is endemic in more than 100 countries and has started to show up in the continental United States. More than 100 million people are affected by dengue worldwide, which can cause severe flu-like symptoms, fatal bleeding and intense pain.

While the genetically modified mosquitoes have shown promise, there are concerns that after multiple generations the bugs would impact the ecosystem.

"We're concerned GM mosquitoes could survive and breed to produce further generations," Helen Wallace, the executive director of GeneWatch UK, said, according to Bloomberg. "The mosquitoes would become part of a complicated ecosystem that might respond in ways that could be bad for health."