Zika Fallout: More than just Microcephally

[Unorthodox]

http://www.medscape.com/viewarticle/869961

A new investigation of the Zika virus in Brazil has produced additional insights about the neurologic manifestations in babies exposed to this virus.

The analysis of 11 confirmed fetal cases of Zika determined that the babies had neurologic changes in addition to microcephaly.




The study, published October 3 in JAMA Neurology, highlights the importance of imaging at about 18 weeks of gestation in suspected cases of Zika infection, said study author Amilcar Tanuri, MD, PhD, professor, Universidade Federal do Rio de Janeiro, Brazil.

As with yellow fever, dengue, and West Nile viruses, the Zika virus is an arthropod-borne flavivirus transmitted mostly through the bite of an Aedes mosquito. The Zika virus, which can be found in body fluids, is spread through the placenta, during sexual intercourse, or via blood transfusions.

Patients with the infection can present with low-grade fever, arthralgia, rash, headache, and/or myalgia, but most infections are asymptomatic. In addition to congenital abnormalities, the virus infection has been associated with Guillain-Barré syndrome (GBS).

The current study included pregnant mothers referred to the fetal medicine service of the Instituto Paraibano de Pesquisa Professor Joaquim Amorim Neto in Brazil between October 2015 and February 2016.

The fetuses of these women had abnormalities in brain development, as shown by ultrasound imaging. Investigators performed amniocentesis in all women for laboratory confirmation of Zika infection by polymerase chain reaction.




Researchers observed the women until they gave birth. After birth, they did additional imaging and collected samples of amniotic fluid, cord blood, and placenta.

By these means, Zika diagnoses were confirmed in all but two patients. Both these patients were included in the study on the basis of a strong IgG anti-Zika immune profile.

"This means that we were sure that the 11 cases were infected by Zika, and we focused our attention on the kinds of lesions that showed up on images," said Dr Tanuri.


Three of the 11 babies died after birth. Two mothers consented to autopsies, which were performed less than 8 hours after death.

The surviving infants were followed from gestation to age 6 months.

The median cephalic perimeter at birth was 31 cm, which the authors said is lower than the limit for considering microcephaly. But they noted that some infants had a head circumference measure that was consistent with their gestational age.

Universal Neurologic Impairment 

The researchers found neurologic impairments in all cases. There was a common pattern of brain atrophy and changes associated with disturbances in neuronal migration.


Dr Tanuri pointed out that Zika induced "very specific lesions," with the difference in severity being based on where the virus replicates in the brain.

"We saw two different patterns: one where the whole brain is smaller and the other pattern with ventriculomegaly and water inside the brain. Both patterns are induced by the same virus." Continue Reading

More at link.  (multiple pages)