The Zika news in the US and South America
Millions of Zika battling genetically modified (GM) mosquitoes are ready to be released in Florida, US, after the public vote of the November US elections was in favor of starting the test-trial in the area.
Since the summer of 2015, when the Zika virus first appeared in Brazil, it has continued to spread across the globe, most notably in South America, the Caribbean and Southeast Asia. The outbreak has also been confirmed in the USA, as of November 2nd 2016, there have been 4128 cases confirmed by Centre for Disease Control and Prevention, most of them in the State of Florida.
The Zika virus is transmitted by Aedes aegypti mosquito and is connected to the microcephaly in newborns, a condition marked by small head size that can lead to developmental problems and is frequently deadly. The GM mosquito OX513A, that will be released in Florida is carrying a self limiting gene which is preventing it’s offspring to survive. It was prepared at Oxitec, University of Oxford spin off. The reproduction of the OX513A mosquito is controlled by tetracycline repressible, lethal positive feedback system. The FDA has granted the approval for a field trial of mosquitoes to stop the spread of the Zika virus in August 2016, but the voter approval was needed to proceed. On the 8th of November, Florida Keys, US, voted to start the test trial and release GM Aedes aegypti into the wild. If the experiment is successful, it could be replicated on a larger scale.
Meanwhile, South American countries decided to combat yet another massive outbreak by a large scale approach: they will be releasing thousands of mosquitoes, infected with bacteria Wolbachia pipientis in Rio, Brazil and Medellin, Colombia. This bacterium plagues 60% of the insects worldwide, but naturally doesn’t infect Aedes aegypti. Wolbachia pipientis can hinder insect’s ability to transmit virus by obstructing the fertility of their host. The Australian test demonstrates, that this bacteria might infect more than 90% of local mosquitoes and reduce their population significantly. The process will take place over the next two years and will reach millions of people in the two cities.
Splice has already featured some other discoveries about Zika virus such as the first proof of the association between Zika virus and microcephaly, low-cost paper based test for Zika virus detection and effective vaccination against Zika.
By Urška Kotnik, MSc Student, University of Ljubljana