Brazil has confirmed 907 cases of microcephaly and 198 babies with the birth defect who have died since the Zika virus outbreak started in October, authorities said Tuesday. Health officials are still working on 4,293 suspicious cases, the Health Ministry said.

Scientists in Brazil say the increase in microcephaly—in which a baby is born with an abnormally small head and often incomplete brain development—is linked to an explosion of the mosquito-transmitted Zika virus, with an estimated 1.5 million people infected. The World Health Organization is studying the possible connection and calls the Zika outbreak an international health emergency. Brazil typically reports 150 cases of microcephaly per year. READ MORE