Zika virus found in brain of microcephalic foetus, adding weight to brain-damage theory

Researchers on Wednesday reported new evidence strengthening the association between Zika virus and a spike in birth defects, citing the presence of the virus in the brain of an aborted foetus of a European woman who became pregnant while living in Brazil.

An autopsy of the foetus showed microcephaly or small head size, as well as severe brain injury and high levels of the Zika virus in fetal brain tissues, exceeding levels of the virus typically found in blood samples, researchers in Slovenia from the University Medical Centre in Ljubljana reported in the New England Journal of Medicine.

The findings help “strengthen the biologic association” between Zika virus infection and microcephaly, researchers from the Harvard School of Public Health and Massachusetts General Hospital in Boston, wrote in an editorial that accompanied the paper.

Researchers in Brazil are scrambling to determine whether the arrival of the Zika virus in that country has caused a major rise in microcephaly, with more than 4,000 suspected cases of the condition reported to date. Brazil has confirmed more than 400 of those cases as microcephaly, and identified the presence of Zika in 17 babies, but a link has yet to be proven.

The virus is transmitted by mosquitoes. There is no treatment or vaccine.

Professor Tatjana Avsic Zupanc, who led the researchers in Slovenia, said in an email her team’s findings “may present the most compelling evidence to date” that birth defects associated with Zika infection in pregnancy may be caused by replication of the virus in the brain.