Genetically Modified Mosquitoes to Fight Zika?
The goal: Sterile males would mate with females that carry the germ suspected of causing birth defects
By Dennis Thompson
TUESDAY, Feb. 16, 2016 (HealthDay News) -- As the Zika virus continues to spread fear and potentially devastating health problems throughout Latin America and the Caribbean, scientists are weighing the use of a controversial weapon -- genetically modified mosquitoes.
The mosquito-borne Zika virus is thought -- but not proven -- to be behind an epidemic of birth defects that leave newborns with very small heads and potential brain damage.
The spread of the birth defects, called microcephaly, prompted the World Health Organization (WHO) last week to call the Zika outbreak a global emergency.
The U.S. Centers for Disease Control and Prevention has said it does not expect the Zika virus to become widespread in the United States. But the CDC is recommending that pregnant women avoid those regions of Central and South America and the Caribbean where Zika virus has been identified and officials have described it as spreading "explosively."
Next week, WHO's director general, Dr. Margaret Chan, will travel to Brazil -- the epicenter of the microcephaly epidemic -- to discuss the outbreak with the country's health minister and other officials, the Associated Press reported. It's believed there have been more than 4,100 suspected or confirmed cases of microcephaly in Brazil.
The WHO said in a statement Tuesday that advisers to the United Nations-affiliated agency have recommended further field tests of genetically modified mosquitoes. Sterile male mosquitoes were released in the Cayman Islands to fight dengue fever, to mate with wild Aedes aegypti female mosquitoes. That type of mosquito carries both the Zika and dengue viruses, the WHO said.
Another technique being developed "involves the mass release of male insects that have been sterilized by low doses of radiation. When sterile males mate, the female's eggs are not viable, and the insect population dies out," the WHO said in the statement. This technique has worked in the past to control "agriculturally important insect pests," the agency added.
Also under consideration, according to WHO: a "promising biological method of control [that] uses male mosquitoes carrying the naturally occurring Wolbachia bacteria, which are found in 60 percent of common insects, including butterflies and fruit flies. These bacteria do not infect humans or other mammals. When females mate with males carrying the bacteria, the eggs do not hatch, thus suppressing mosquito populations."