Public health officials are warning pregnant women to avoid being bitten by mosquitoes that might be carrying the Zika virus. They are concerned that the recent steep rise in cases of microcephaly in Brazil is linked to the virus. The number of cases in Brazil of this severe birth defect has increased from 150 in 2014 to nearly 4,000 in 2015. The overall rate is now around 1 in 1,000 births, but in some regions one to two percent of babies are born with the malady.
The Zika virus, like the chikungunya and West Nile viruses, originated in Africa and are now being chiefly spread by the Aedes aegypti mosquito. Until recently, Zika virus infections had been regarded as relatively mild causing joint pain and fever. Besides the association with microcephaly, Zika is also suspected of boosting the incidence of the paralyzing Guillain-Barre syndrome.
Producing a vaccine would likely take three to five years, assuming that pharmaceutical companies could be persauded to undertake the effort. Vaccines rarely yield profits and expose companies to our dysfunctional liability system.
But there is another promising way to control Zika—control the mosquitoes that carry it and other diseases like dengue, malaria, chikungunya and West Nile virus. The biotechnology company Oxitec has created male Aedes aegypti mosquitoes that have been genetically modified to pass along a gene that is lethal to their larval progeny. In fact, Oxitec has already shown considerable success in a pilot program in Brazil in which engineered autocidal mosquitoes reduced the local population of the Aedes aegypti mosquitoes by more than 80 percent. Given this record, the city of Piracicaba is now contracting with the company to release their GMO mosquitoes to help reduce Zika virus infections.
Oxitec is seeking to conduct a trial using its mosquitoes in Key West, but that proposal has been opposed by anti-biotech activists. It will be interesting to see how long that opposition lasts if there is a sustained outbreak of Zika virus there.
But even more promisingly, Oxitec's vector-control technology could be superseded by mosquitoes that have been gene-edited to resist infection by disease organisms in the first place. Last fall, researchers at the University of Missouri reported a proof of concept experiment in which they used the fantastic CRISPR gene-editing technique to create Aedes aegypti mosquitoes that would pass along disease resistance genes to all of their progeny.
The horrible consequences of a Zika virus outbreak here might be enough for the public to sweep aside anti-biotech misinformation and embrace the GMO mosquito solution to disease contol.