Does Zika kill?

Think of the Zika virus and you’re likely to picture those sobering photos of infants with tiny heads—microcephaly caused when their brain development was thrown off in utero after mothers were infected. But this mosquito-borne virus may cause worse harm: fetal death.

In a case study in PLoS Neglected Tropical Diseases, Yale professor Albert Ko and a team of Brazilian researchers describe a pregnant Brazilian woman whose fetus stopped growing, though the mother recalled no recent illness. Ultrasound revealed not only microcephaly, but also fluid buildup throughout the body, an effect that had not been previously described. Soon, the fetus died. The team isolated Zika RNA. “This was a warning sign for us,” says Ko, chair of the epidemiology of microbial diseases department at the School of Public Health. 

Since 1995, the school has run an urban infectious-disease research program in Salvador, and many of its Brazilian and Yale-affiliated trainees and alumni are among those fighting the epidemic. Ko, who has been named to the 23-person Zika Task Force of the Global Virus Network, is helping to coordinate a research and clinical team that is racing to set up mother-baby surveillance, search for risk factors, and map the scope of the disease, which has spread to dozens of countries and territories. What we know about Zika so far, Ko says, “is the tip of the iceberg.”