The alarming increase in Brazilian babies born with microcephaly

Thousands of Brazil’s newborns last year had abnormally tiny heads and potentially debilitating brain damage. In 2015 the country reported nearly3,000 cases of the incurable condition, called microcephaly—about 20 times more than the prior year. In the nation’s northeast, where most of the cases occurred, government officials have already declared a state of emergency. Now international researchers and Brazilian authorities are rushing to tamp down the problem.

The trouble is they are not sure exactly what is causing the phenomenon or how to address it. They do have one strong suspect—a mosquito-borne disease called Zika that usually causes short-term rashes and joint aches, and is plaguing the same areas in Brazil. There is already evidence the virus can cross the placental barrier: Zika has been detected in the amniotic fluid of two pregnant women with microcephalic fetuses in the state of Paraiba. What’s more, viruses from the same genus have the ability to replicate once they reach the central nervous system, providing some indication of how the viruses could potentially cause microcephaly in the first place.

Read more from Scientific American here.