why it s so hard to prove zika is causing birth defects /

For weeks,Zika virus has been all over the news. Stark photos of babies with microcephaly, a birth defect in which the infant’s head is abnormally small and its brain often not fully developed, and have accompanied stories approximately the ongoing spread of Zika across more than 20 countries. Several Latin American countries have advised women […]

Source: fivethirtyeight.com