WHO: Countries Must Fight Zika Virus at Its Source

Mosquito control is key

Countries coping with the Zika virus crisis should consider new ways to fight disease-carrying mosquitoes, including testing the release of genetically modified insects and bacteria that stop their eggs from hatching, the World Health Organization (WHO) has announced.

“Given the magnitude of the Zika crisis, WHO encourages affected countries and their partners to boost the use of both old and new approaches to mosquito control as the most immediate line of defense,” it said in a Reuters report.

The WHO also emphasized the potential of releasing sterile irradiated male mosquitoes, a technique that has been developed at the United Nations’ Geneva-based International Atomic Energy Agency (IAEA).

The Zika virus, which is now spreading across the Americas, is transmitted primarily by the Aedes aegypti mosquito, which the IAEA has described as an “opportunistic and tenacious menace.” Mosquitos are also the source of dengue, chikungunya, and yellow fever.

Many scientists believe that the Zika virus could be linked to microcephaly (abnormally small heads) in newborns and with Guillain-Barre syndrome, a serious neurological disorder, in adults.

“If these presumed associations are confirmed, the human and social consequences for the over 30 countries with recently detected Zika outbreaks will be staggering,” WHO observed.

While spraying with insecticide may be helpful, WHO experts also recommend evaluating newer tools, including a genetically modified prototype mosquito developed by Oxitec, the British subsidiary of Intrexon. The male mosquitoes are modified so that their offspring will die before reaching adulthood and being able to reproduce. The WHO said its Vector Control Advisory Group recommended further field trials of the technique after promising tests in the Cayman Islands.

Another anti-Zika option involves the mass release of male insects that have been sterilized by low doses of radiation, which the IAEA has already used to control agricultural insect pests, Reuter says.

Another approach uses Wolbachia bacteria, which do not infect humans but prevent the eggs of infected female mosquitos from hatching. Mosquitoes carrying Wolbachia have already been released to reduce dengue, and the WHO has announced that large-scale field trials would soon be initiated against Zika-carrying mosquitos.

Source: Reuters; February 16, 2016.