March 18, 2016
Bulletin interne de l'Institut Pasteur
Zika and microcephaly: first trimester of pregnancy most critical
A new analysis of data from the 2013-2014 Zika epidemic in French Polynesia by scientists from the Institut Pasteur, Paris, and their French Polynesian colleagues has confirmed the incidence of grouped cases of microcephaly and quantified the risk of microcephaly associated with the virus. Using innovative mathematical modeling techniques, their research shows that the risk of microcephaly is around 1% for a fetus or newborn whose mother has been infected by the Zika virus during the first trimester of pregnancy. Their findings have been published in the journal The Lancet.
An epidemic caused by Zika virus disease is currently affecting several countries in the Americas. The emergence of this epidemic has coincided with a dramatic increase in the number of suspected cases of microcephaly, a severe neurological defect characterized by fetuses and newborns with unusually small heads. The data from this ongoing epidemic has yet to be consolidated and is hard to interpret, especially when it comes to quantifying the risk of microcephaly associated with Zika infection.