The Zika virus was first reported in 1947. For many decades it received scant attention, apart from studies in schools of tropical medicine. Now it is the subject of international attention, particularly in relation to Brazil where the viral infection has been linked with babies being born with abnormally small heads and brain defects, a condition called microcephaly. To date, 1.5 million people in Brazil have become infected. Another factor driving current discussion is the spread northwards.
Zika is not, in general, the most deadly virus faced by humankind. Malaria kills thousands each year, for instance. It can, however, be unpleasant for some who come in contact with it and endure its symptoms. Symptoms only appear in one out of four people and here the disease is played out as a rash and slight fever. Symptoms dissipate in around seven days. The primary risk is to pregnant women, and here the condition can be very serious to the unborn child.
One problem in dealing with the disease is the inaccuracy of laboratory diagnosis. This has led researchers like Matthew Aliota (UW-Madison School of Veterinary Medicine) to seek better test methods (as outlined in his paper in the journal Emerging Infectious Diseases, titled “Detection of Autochthonous Zika Virus Transmission in Sincelejo, Colombia.”)
Another tranche of research is focused on tackling the disease vectors — the mosquito. Here genetically modified mosquitoes are being considered, as Digital Journal reported in January 2015. The idea is to release Aedes aegypti mosquitoes, with altered genomes, “manufactured” by a company called Oxitec. However, this remains an untried and possibly hard-to-control option.
The process of modifying the insects involves a method called “gene drive.” This consists of inserting modified genes into an organism. In the case, the modified mosquito will be incapable of carrying the Zika virus. The idea is that the modified mosquitoes will out-breed the Zika carrying insects, with the net result that the species at large is altered. Not all scientists are keen on this concept, for it could lead to the elimination of an entire species and could have ecological consequences, such as cross-species gene transfer. Moreover, there is no internationally agreed regulatory framework to track the release of the modified mosquitoes.
Here scientists from the Max Planck Institute in Germany have criticized the science behind the modified mosquito releases. Here the respected body writes there are “deficits in the scientific quality of regulatory documents and a general absence of accurate experimental descriptions available before releases start.” These fears are worth considering. The rush to deal with Zika is worthy; but is genetic modification in this form the best solution?
A alternative approach involves harnessing genetic sequencing technology to track the evolution of the virus (as was done with Ebola.) Here the Pasteur Institute, in French Guiana, has completed the first genomic sequencing of the Zika virus. It is hoped this will provide clues about the behavior of the virus and point to a means to control it.