Clinical Review
Zika virus: Counseling considerations for this emerging perinatal threat
Zika virus infection, although typically mild and often asymptomatic, can have serious consequences in pregnancy. As the pandemic rapidly spreads...
We recently reviewed the most current information on the epidemiology, clinical manifestations, and diagnosis of maternal and congenital Zika virus (ZV) infection.1 We also offered tentative recommendations for reducing the risk of infection and for managing the treatment of women exposed to the virus.
In this update, we present new information on the broadened spectrum of anomalies now known to be causally related to congenital ZV infection and on the increasing number of serious neurologic complications directly related to ZV infection in adults. We also update recommendations for diagnosing maternal, fetal, and neonatal infection and present guidelines for preventing sexual transmission of ZV infection.
CASE Woman from Brazil gives birth to stillborn baby with microcephaly
A 23-year-old woman (G2P1) recently emigrated from Pernambuco in Brazil to the United States and now presents to the hospital in advanced labor. Based on results of first-trimester ultrasonography performed in Brazil, it is determined that she is at 39 weeks’ gestation. The patient has not had any prenatal care since early in the second trimester because of low income and lack of medical insurance. She reports no serious illness before or during the pregnancy.
In the labor and delivery suite, she rapidly delivers a stillborn female infant—5 pounds 3 ounces, growth restricted, with multiple congenital anomalies. Postmortem examination reveals microcephaly, ventriculomegaly, extensive brain atrophy, intracranial calcifications, cerebellar agenesis, cataracts, ocular calcifications, redundant scalp tissue, and multiple joint contractures.
What is the most likely cause of these multiple anomalies?
The patient’s findings are most consistent with a diagnosis of severe intrauterine infection. Possible pathogenic organisms include rubella virus, cytomegalovirus, lymphocytic choriomeningitis virus, toxoplasmosis, and ZV.2 Given the patient’s recent move from Pernambuco in northeastern Brazil, the epicenter of the ZV epidemic in the Americas, the most likely diagnosis is congenital ZV infection.
The initial reports of congenital anomalies associated with ZV infection focused on microcephaly, usually defined as head circumference less than 3 standard deviations below the mean, or less than the third or fifth percentile for gestational age. Subsequent reports have linked many other serious central nervous system (CNS) anomalies to the virus. In a retrospective case series, de Fatima Vasco Aragao and colleagues3 described neuroimaging findings in 23 infants with presumed congenital ZV infection. Of the 22 with computed tomography scans, all had calcifications at the junction of cortical and subcortical white matter, 21 (95%) had disordered cortical development, 20 (91%) had a significant decrease in brain volume, 19 (86%) had ventriculomegaly, and half had distinct hypoplasia of either cerebellum or brainstem. In addition, of the 8 infants with magnetic resonance imaging (MRI) studies, 7 (88%) had an enlarged cisterna magna, 7 (88%) had delayed myelination, 6 (75%) had a simplified gyral pattern, and 3 (38%) had hypoplasia of corpus callosum.
De Paula Freitas and colleagues4 recently found congenital ZV infection associated with severe ocular abnormalities. Comprehensive ophthalmologic examination of 29 infants with microcephaly, presumed caused by congenital ZV infection, revealed 10 (35%) had abnormalities, which included focal pigment mottling, chorioretinal atrophy, hypoplasia and cupping of optic disk, loss of foveal reflex, macular atrophy, lens subluxation, and coloboma of iris.
Other conditions linked to congenital ZV infection include intrauterine growth restriction, redundant scalp tissue, contractures of multiple joints, and clubfoot.2
Bottom line. Although the ocular abnormalities are undetectable by prenatal ultrasound, many of the CNS and skeletal anomalies can be identified antenatally. Therefore, serial ultrasound examinations should be performed on adults who have a clinical illness consistent with ZV infection or who have traveled to an endemic area or have a sexual partner who has been in an endemic area. Patients should be assessed for possible microcephaly, ventriculomegaly, agenesis of corpus callosum, hypoplasia of cerebellum, and skeletal deformities.
