Yale study looks at how Zika can infect a fetus

Alice Vitoria Gomes Bezerra, 7-months-old, who has microcephaly, is held by her mother Nadja on May 29, 2016 in Recife, Brazil. Microcephaly is a birth defect linked to the Zika virus where infants are born with abnormally small heads. A new study out of Yale Medical School gives insight into how the mosquito-borne Zika virus can be transmitted to a fetus by a pregnant woman. less Alice Vitoria Gomes Bezerra, 7-months-old, who has microcephaly, is held by her mother Nadja on May 29, 2016 in Recife, Brazil. Microcephaly is a birth defect linked to the Zika virus where infants are born ... more Photo: Mario Tama / Getty Images Photo: Mario Tama / Getty Images Image 1 of / 3 Caption Close Yale study looks at how Zika can infect a fetus 1 / 3 Back to Gallery

A new study out of Yale Medical School gives insight into how the mosquito-borne Zika virus can be transmitted to a fetus by a pregnant woman.

“We were interested in understanding how the virus may breach the maternal-fetal barrier, so we aimed to determine the susceptibility of different primary placental cell types to Zika virus infection,” said the study’s first author, Kellie Ann Jurado, a postdoctoral fellow at Yale.

More than a year ago, Zika ignited an international health epidemic. More than 50 countries and territories have seen outbreaks of the disease. That includes the United States, where nearly 2,000 people have contracted the illness. Most of these cases were contracted via travel, though there have been some sexually transmitted cases, as well as a handful of locally-transmitted cases in Florida. In Connecticut alone, 58 people have tested positive for Zika.

Though the illness is mild in most people, it’s a particular risk to pregnant women, as researchers have linked Zika to microcephaly — a condition in which a baby is born with a small head, or the head stops growing after birth. In Connecticut, three of those who tested positive for Zika were pregnant women.

Jurado said despite the furor over Zika, little is understood about how the virus breaches the maternal-fetal barrier, which is a layer of cells protecting an unborn child from harmful substances. The Yale researchers used three different strains of Zika to infect three types of cells found in the tissue of the placenta. The cells — Hofbauer cells, cytotrophoblasts and fibroblasts — were taken from normal term pregnancies.

The team found that fibroblasts and Hofbauer cells were susceptible to infection by Zika virus in isolated culture, and that Hofbauer cells, which are thought to move around the placenta, may aid in delivery of Zika to the fetal brain.

Jurado said the findings help shed light on Zika infection, and how the virus invades and moves within the placenta. The hope is that the research could help in the development of strategies to prevent infections of the fetus. But, Jurado said, more information is needed. “We are interested in further understanding the mechanisms of vertical transmission of Zika virus,” she said.

One local doctor said the fact that researchers are seeking to learn more about Zika is heartening. “I think the more we learn about the virus and how it causes the injuries it does, the better able we’ll be to develop vaccines and treatments,” said Dr. Robert Stiller, director of maternal fetal medicine at Bridgeport Hospital.

Though he comment directly on the science of the study “as a clinician, I’m glad to see this work being done.”