Zika virus causes birth defects, health officials confirm

Officials at the Centers for Disease Control and Prevention said on Wednesday that there was now enough evidence to definitively say that the Zika virus could cause unusually small heads and brain damage in infants born to infected mothers. The conclusion should settle months of debate about the connection between the infection and these birth defects, called microcephaly, as well as other neurological abnormalities, the officials said. “There is no longer any doubt that Zika causes microcephaly,” said Dr. Thomas R. Frieden, the C.D.C. director. He said the conclusion, reached after evaluating “mounting evidence from many studies,” signifies “an unprecedented association” in medicine. “Never before in history has there been a situation where a bite from a mosquito can result in a devastating malformation,” Dr. Frieden said. He and other agency officials said they hoped that the announcement increased awareness and concern about the potential threat to Americans who travel to affected areas in Latin...