WHO sees 3-4 million cases of Zika virus, role in birth defects

GENEVA (Reuters) - The Zika virus is strongly suspected of causing birth defects and may infect 3-4 million people in the Americas, including 1.5 million in Brazil, a World Health Organization expert said on Thursday. Marcos Espinal, head of communicable diseases at PAHO -- the WHO's Americas arm -- said a study would soon be published suggesting a correlation between Zika and microcephaly -- babies born with small heads and brains -- in Brazil. "We don't know yet if this virus crosses the placenta and generates or causes microcephaly. We think it plays a role. There's no doubt about that," he told the WHO's executive board meeting in Geneva. (Reporting by Tom Miles; editing by Stephanie Nebehay and John Stonestreet)