CDC: Infants with Zika can develop microcephaly later
MelissaJenco, News Content Editor
Infants with congenital Zika virus infection who do not have microcephaly at birth can develop it months later, according to a new study.
“These findings demonstrate the importance of early neuroimaging for infants exposed
to Zika virus prenatally and the need for comprehensive medical and developmental
follow-up,” authors said in Tuesday’s Morbidity and Mortality Weekly Report.
Researchers from Brazil and the Centers for Disease Control and Prevention (CDC) studied
13 infants in Brazil with laboratory evidence of congenital Zika virus infection and
normal head size.
While the infants did not meet the criteria for microcephaly at birth, all had brain
abnormalities such as decreased brain volume and subcortical calcifications, according
to the report. As early as 5 months of age, their head growth decelerated, and 11
were diagnosed with microcephaly.
“The decrease in head growth might be the consequence of earlier in utero destruction
of neuroprogenitor or other neural cells, persistent inflammatory response-associated
molecules, or continued infection of neural cells,” authors said in the study.
The infants also displayed “significant neurologic dysfunction, including hypertonia
and hemiparesis, dyskinesia/dystonia, dysphagia, epilepsy, and persistence of primitive
reflexes,” according to the report.
More than 60% had epilepsy and all had significant motor disabilities. They were too
young for a cognitive assessment.
The CDC emphasized the importance of its previous recommendations calling for all
infants whose mothers were infected with Zika during pregnancy to have a comprehensive
physical exam, neurologic assessment, postnatal cranial ultrasound, standard hearing
screen and Zika testing.
Babies who are found to be infected also should have a comprehensive eye exam and
hearing assessment by auditory brainstem response testing before 1 month of age regardless
of whether abnormalities are apparent at birth.
If abnormalities are detected, infants will need to be evaluated by an infectious
disease specialist, neurologist, endocrinologist, ophthalmologist and geneticist.
The primary care pediatrician and these specialists will need to provide coordinated,
ongoing examinations, which are detailed in the guidance.
Those who are not born with obvious, identifiable abnormalities will need careful
monitoring and screening for any that may present later in life such as those resulting
in seizures or trouble with vision or hearing.
Zika virus has spread to more than 45 countries in Central and South America. In U.S.
states, there have been 4,255 cases of Zika including 1,087 pregnant women. In U.S.
territories, there have been 32,068 cases including 2,451 pregnant women.
Last week, a World Health Organization committee removed the designation of Zika as
a Public Health Emergency of International Concern. However, it said in a news release
the virus and associated birth defects “remain a significant enduring public health
challenge requiring intense action.”