The New Scientist reported on how a single mutation could make Zika virus more infectious and virulent.
Zika virus generally doesn't cause many symptoms in adults, but infection during pregnancy can result in microcephaly, a condition in which babies are born with a small head and possible brain damage.
Scientists at the La Jolla Institute for Immunology in California mimicked the virus's infection cycle by repeatedly switching the virus back and forth between mosquito and mouse cells, New Scientist reports. They also monitored the evolution of the virus in mice that had previously been exposed to dengue virus — which is part of the same virus family and is prevalent in the same regions as Zika — to see if Zika evolved differently than in mice that had not been previously infected with dengue.
They found that the same mutant form of Zika developed in mouse cells regardless of whether they had been exposed to dengue previously, suggesting that region of Zika's genome is a mutation hotspot. In addition, the scientists found that the mutated virus was more infectious and virulent when infecting pregnant mice, and replicated more easily in human fetal cells, New Scientist reported.
The La Jolla Institute's Sujan Shresta, corresponding author on the study that was published in Cell Reports, notes that the research doesn't prove that that a similar mutant virus would arise in the real world, but that the work allows infectious disease specialists to react more quickly if it does.