Brazil plans to zap mosquitoes with radiation to halt spread of Zika virus

Authorities want to release sterilised males so that females lay inviable eggs, eradicating the Aedes mosquito that carries the virus blamed for surge in babies born with microcephaly

Mosquitoes genetically modified to pass on a 'kill switch' gene to offspring could stop the current zika outbreak Photo: CORBIS

By Reuters

12:01AM GMT 23 Feb 2016

Brazil is planning to fight the Zika virus by zapping millions of male mosquitoes with gamma rays to sterilise them and stop the spread of the virus linked to thousands of birth defects. 

Called an irradiator, the device has been used to control fruit flies on the Portuguese island of Madeira. The International Atomic Energy Agency said on Monday it will pay to ship the device to Juazeiro, in the northeastern state of Bahia, as soon as the Brazilian government issues an import permit. 

"It's a birth control method, the equivalent of family planning for humans," said Kostas Bourtzis, a molecular biologist with the IAEA's insect pest control laboratory. 

Brazil is scrambling to eradicate the Aedes mosquito that has caused an epidemic of dengue and more recently an outbreak of Zika, a virus associated with an alarming surge in cases of babies born with abnormally small heads. 

The new epidemic threatens to scare visitors away from the Rio 2016 Olympic Games in August. A Brazilian non-profit organisation called Moscamed will breed up to 12 million male mosquitoes a week and then sterilise them with the cobalt-60 irradiator, produced by Canadian company MDS Nordion, said Dr Bourtzis. 

The sterile males will be released into target areas to mate with wild females who will lay eggs that produce no offspring, he said during an IAEA meeting of mosquito control experts. 

Mothers pose with their babies who were born with microcephaly, at Pedro I hospital in Campina Grande in Brazil   Photo: REUTERS/Ricardo Moraes 

After an initial programme in a dozen towns near Juazeiro, the Brazilian government would have to decide on scaling up the sterile mosquito production with more funding for use in cities, where they would be released from the air, possibly from drones, said Dr Bourtzis. 

With no cure or vaccine available for Zika, which has spread to more than 30 countries, mostly in the Americas, the only way to contain the virus is to reduce the mosquito population. 

Brazilian researchers are also experimenting with radiation. The Fiocruz biomedical research institute has released 30,000 sterile mosquitoes on an island 217 miles off the coast of northeast Brazil. 

Another experiment under way in Brazil involves a mosquito genetically modified so their offspring die before reaching adulthood.

Much remains unknown about Zika, including whether the virus actually causes microcephaly. Brazil said it has confirmed more than 500 cases, and considers most of them to be related to Zika infections in the mothers. Brazil is investigating more than 3,900 additional suspected cases of microcephaly.