Zika virus (red) isolated from a microcephaly case in BrazilFLICKR, NIAIDZika virus has been linked to microcephaly in the babies of infected mothers, leading some organizations, including the Brazilian ministry of health, to focus on newborns’ head circumferences as an infection indicator. But this approach only identifies a fraction of Zika cases in newborns, researchers reported yesterday (June 29) in The Lancet, suggesting that measurements of head circumference should be combined with other criteria to provide a more accurate diagnosis.
“One in five definite or probable Zika cases had head circumference values in the normal range,” study coauthor Cesar Victora of the Federal University of Pelotas in Brazil said in a statement. “Therefore, the current focus on microcephaly screening alone is too narrow.”
In their review of 1,501 suspected cases of microcephaly investigated in Brazil between November 2015 and February 2016, the researchers also found that rashes—a potential indicator of infection—reported in mothers late in pregnancy were associated with brain abnormalities in newborns even if the babies’ head circumferences were in the normal range. “We should not equate Zika congenital infection with microcephaly,” Victora told CBC News. “We could well have many babies with normal head size who are affected. We will need to think ...
