Zika Virus Infections and Fetal Damage

We're learning more about the effect of a Zika virus infection on an unborn fetus every week. Two new reports strengthen the link between Zika virus infection during pregnancy and an increased risk of birth defects, most notably microcephaly. One ongoing study is following pregnant women in Brazil who were infected with the Zika virus during pregnancy. Forty-two of the women agreed to have regular ultrasounds to study the progression of the fetus. Among those 42 women, the fetus has already died or appears to suffer from serious birth defects in 12 of the women. Only 8 of the women have given birth so far, and in all cases the ultrasound diagnoses were accurate. The study will continue until all of the women have given birth, but the preliminary results are pretty dismal; a 29% rate of fetal death or significant fetal problems.

In a second laboratory-based study, researchers showed that the Zika virus appears to attack and kill human neural progenitor cells that will ultimately form the cortex of the brain. In this study, the researchers cultured various fetal cells and then exposed them to the Zika virus. The cultured neural progenitor cells were infected and killed by the virus, whereas several other types of cultured fetal cells were not.

There is no vaccine yet for the Zika virus. Although research into Zika vaccines is underway, it is likely to be several years before one is available. And because this is the first major outbreak of the virus, there are almost no women who are currently immune to the virus by virtue of a previous exposure. The clock is ticking.