About 14% of 1-year-olds with prenatal Zika virus exposure show at least one health problem probably related to the virus, according to a study published in Morbidity and Mortality Weekly Report.
Many of the problems are brain and eye abnormalities, which occurred at 30 times the 0.16% background rate among unexposed babies, Margaret Honein, PhD, and colleagues reported.
In a press briefing, Dr. Honein, chief of the Birth Defects Branch at the National Center on Birth Defects and Developmental Disabilities, described findings from the U.S. Zika Pregnancy and Infant Registry (USZPIR).
“Today’s report is the largest to date with long-term outcomes of babies born to mothers with [lab-confirmed] Zika infections, and the first published data on children 1 year or older from the ongoing surveillance network,” Dr. Honein said. It “clearly shows that the Zika story is not over, especially for the children and families who are affected by it.”
USZPIR is monitoring the outcomes of 7,300 pregnancies with lab-confirmed Zika infection. From these, 4,800 babies were born in the U.S. territories and freely associated states, had reached the age of 1 year by Feb. 1, 2018, and were included in the study.
In addition to clinical outcomes, the investigators looked at how many babies received the recommended evaluations, including neuroimaging, hearing screens, opthalmologic exams, developmental screening, and physical exams.
Almost all (95%) had at least one exam in the first 2 weeks of life; 76% had at least one developmental screening; 60% had postnatal neuroimaging; 48% at least one hearing exam; and 36% at least one eye exam by a specialist, the investigators found.
Findings that many didn’t get all the recommended health screenings are concerning, CDC Director Robert Redfield, MD. said during the briefing. “We are still learning about the full range of long-term health problems these babies could face. We thank clinicians for their continued commitment to conduct all necessary tests and evaluations to ensure appropriate care.”
Zika-associated birth defects occurred 203 babies (14%). Another 136 (9%) had at least one neurodevelopmental abnormality possibly associated with congenital Zika virus infection, and 20 (1%) had both. Most babies (1,386; 96%) did not have microcephaly detected at birth. But there was some “misclassification” of the condition, the investigators found. “Five infants had microcephaly at birth with brain or eye anomalies identified at birth; 59 had microcephaly at birth with no brain or eye anomalies identified at birth; and 20 infants did not have microcephaly identified at birth but had postnatal identification of microcephaly.”
Neurodevelopmental abnormalities possibly associated with Zika occurred in 136 (9%) of the cohort; 116 (8%) had no Zika-associated birth defects. Among these, half (58) had only possible developmental delay.
Zika transmission appears to be slowing, Lyle Peterson, MD, said during the press briefing, with no cases in the continental U.S. since 2017. That year, there were two cases in Florida and five in Texas. However, it is now endemic in many regions. Everyone should continue to take precautions against mosquito bites, he urged.
The MMWR also included updated guidance for men who are planning a pregnancy with a partner and may have been exposed to Zika.
CDC now recommends that these men wait at least 3 months after onset of Zika symptoms or any possible exposure, including travel to or living in a risk area. Past guidance recommended a 6-month waiting period. The new recommendation reflects emerging data suggesting that the risk of infectious Zika in semen declines during the 3 months after symptom onset.
Men who want to avoid passing Zika through sex should abstain for 3 months, or use a condom every time they have sex, the new recommendation said.
“All other Zika guidance remains unchanged,” the guidelines note. “Men with possible Zika virus exposure whose partner is pregnant should use condoms or the couple should not have sex for the entire pregnancy to reduce the risk of transmission.”
SOURCE: Honein, MA et al. MMWR 2018; 67: 1-10.