- In an effort to stop the spread of Zika virus, the World Health Organization is calling on affected countries to implement measures to better control their mosquito populations.
- Both conventional and newer control methods should be used against to fight the Aedes aegypti mosquito, which shares habitat with more than half of the world’s population, the WHO said Tuesday.
- To date, Zika outbreaks have hit more than 30 countries, and cases contracted elsewhere have been confirmed in the U.S.
Because this mosquito is so aggressive and opportunistic, the WHO said the first line of defense should be elimination of breeding sites. New control techniques, such as a genetically modified prototype mosquito, may be more effective than fogging, which is recommended for emergency situations and most effective around dawn and dusk.
Early tests of the mosquito in the Cayman Islands show a significant drop in the Aedes aegypti population, WHO said, adding more studies are needed to assess its impact in slowing spread of Zika virus. Other options include the mass release of sterilized male mosquitos and release of mosquitoes infected with Wolbachia bacteria, which is harmless to humans and animals, but prevents the females' eggs from hatching.
A “container breeder,” Aedes aegypti can breed in even the smallest amounts of water, and eggs can survive for more than a year in dry conditions, hatching as soon as they contact water. However, outside of sub-Saharan Africa, few developing countries have well-funded, dedicated mosquito control programs.
Zika is suspected of causing a spike in microcephaly, a rare congenital brain defect, in babies born to women infected with the virus. It has also been associated with an increase in cases of Guillain-Barré syndrome.