Congenital Zika Virus Syndrome: Beyond Microcephaly

Although most individuals with Zika virus infection have mild symptoms or are asymptomatic, infected pregnant women often have offspring with microcephaly and other neurologic developmental abnormalities (e.g., NEJM JW Infect Dis Oct 2016 and BMJ 2016 Aug 9; 354:i3899).

To more fully characterize the spectrum of abnormalities associated with congenital Zika infection, investigators prospectively studied 11 pregnant women in northeastern Brazil, the center of an outbreak that is spreading throughout the Americas. The women's fetuses presented with brain lesions during fetal ultrasound imaging. The women had developed symptoms during pregnancy, primarily rash and headache, and diagnostic studies of amniotic fluid and other tissues confirmed Zika infection. Ten of the mothers had a history of rash in the first trimester, suggesting Zika virus infection early in pregnancy.

Three of these infants (27.3%) died within 48 hours of life, and two of them underwent a full autopsy, which showed very deranged gyri and evidence of cerebral inflammation and focal calcifications. Eye findings were frequently seen, as was arthrogryposis. Whereas many infants had microcephaly, some had a head circumference within the norm for gestational age. In these, the cerebral tissue was small, but because of hydrocephalus, the head circumference was not significantly smaller than expected. The viruses isolated from the infants' tissues suggested an Asian-Pacific lineage similar to viruses isolated from a French Polynesian outbreak.