Weighing several lines of evidence, scientists at the US Centers for Disease Control and Prevention (CDC) have determined that Zika virus infection can cause microcephaly and other birth defects. CDC’s Lyle Petersen and colleagues published their conclusion yesterday (April 13) in The New England Journal of Medicine.
“As is typically the case in epidemiology and medicine, no ‘smoking gun’ (a single definitive piece of evidence that confirms Zika virus as a cause of congenital defects) should have been anticipated,” the authors wrote in their paper. Applying diverse data sets and criteria to assess causality, “sufficient evidence has accumulated to infer a causal relationship between prenatal Zika virus infection and microcephaly and other severe brain anomalies,” the authors added.
“This study marks a turning point in the Zika outbreak,” CDC Director Tom Frieden said in a statement. “We are also launching further studies to determine whether children who have microcephaly born to mothers infected by the Zika virus is the tip of the iceberg of what we could see in damaging effects on the brain and other developmental problems.”