Australasian Science: Australia's authority on science since 1938

Mosquitoes Engineered to Resist Zika Virus

CSIRO scientists have helped to develop a strain of mosquitoes that do not spread the devastating Zika virus, which caused more than 4000 cases of serious birth defects in 2015 and is still a risk to millions of people.

Aedes aegypti mosquitoes normally pick up the Zika virus when they feed on the blood of an infected person, and can then spread the virus to the next person they bite. “Our study found the mosquitoes with an anti-Zika gene were unable to pick up Zika when they fed, so they were incapable of spreading the virus to anybody else,” said Dr Prasad Paradkar of CSIRO, who co-authored the paper published in PNAS (

The researchers injected a synthetic anti-Zika gene into mosquito embryos along with a red-eye gene to differentiate them from normal mosquitoes. Once the mosquitoes were adults, the anti-Zika gene prevented them from picking up the virus when they fed.

Zika has spread to 86 countries, but is not currently present in Australia. However, Aedes aegypti is the biggest transmitter of the virus and is established in northern Queensland and the Torres Strait.

“People in 86 countries across Africa, the Americas, Asia and the Pacific are at risk of Zika,” Paradkar said. “With increased globalisation and international travel, the virus is capable of making it to Australian shores some day. Infection during pregnancy can cause life-threatening complications to a foetus or newborn baby, including birth defects such as microcephaly.”

The mosquitoes were engineered at the University of California San Diego and were tested in the quarantined insectary at the Australian Animal Health Laboratory in Geelong, CSIRO’s national biocontainment facility that allows scientific research into the most dangerous infectious agents in the world.