Lessons learned on when, how Zika infection occurs could help shape response plans, programs

After evaluating 36 women and fetuses exposed to Zika from January 2016 to May, researchers at Children’s National Health System found that 89 percent of those infected were exposed through a mosquito bite and 48 percent of were also exposed through an infected sexual partner.

Roberta DeBiasi, the chief of the Division of Pediatric Infectious Diseases and co-leader of the Congenital Zika Virus Program at Children’s National Health System, and her team have now consulted 90 mothers and Zika-affected fetuses or infants. Lessons learned about how and when infection occurs could help other institutions launch similar programs, DeBiasi said.

Twenty percent of women were exposed before conception, 46 percent were exposed in the first trimester, 26 percent were exposed in the second trimester and 8 percent were exposed in the third trimester, researchers found. Patients experienced symptoms in only 12 percent of the cases.

“The Zika virus continues to circulate in dozens of nations, from Angola to the U.S. Virgin Islands,” DeBiasi said. “Clinicians considering a strategic approach to managing pregnancies complicated by Zika may consider enlisting an array of specialists to attend to infants’ complex care needs, including experts in fetal imaging, pediatric infectious disease, physical therapists, audiologists, ophthalmologists and radiologists skilled at reading serial magnetic resonance images as well as ultrasounds.”

DeBiasi and additional doctors from the Congenital Zika Virus Program will present lessons they’ve learned about Zika virus at IDWeek 2017 on Saturday. A Zika overview, differential neuronal susceptibility and apoptosis in congenital Zika infection, and evaluation of pregnant women, fetuses, and infants with Zika exposure will be among the topics discussed.

“At Children’s we have a devoted Zika hotline to triage patient and family concerns,” DeBiasi said. “We provide detailed instructions for referring institutions explaining protocols before and after childbirth, and we provide continuing education for healthcare professionals.”

While detecting viral fragments can be used to confirm Zika shortly after infection, 50 percent of women referred to the Congenital Zika Virus Program were outside the 12-week testing window.
An alternate test method that detects antibodies produced by the body to neutralize Zika virus was used in those cases.
Diagnostic tests enabled doctors to rule out Zika in 14 percent of cases. Zika infection was confirmed in 22 percent of cases, and an infection within Zika’s broad flavivirus family was confirmed in 28 percent of cases.

“Tragically, four fetuses had severe Zika-related birth defects,” DeBiasi said. “Due to the gravity of those abnormalities, two pregnancies were not carried to term. The third pregnancy was carried to term, but the infant died immediately after birth. The fourth pregnancy was carried to term, but that infant survived less than one year.”