Officials from the World Health Organization said on Thursday that the Zika virus was “spreading explosively” in the Americas and announced that they would convene an emergency meeting on Monday to decide whether to declare a public health emergency.
“The level of alarm is extremely high,” said Dr. Margaret Chan, the director general of the W.H.O., in a speech in Geneva.
As many as three to four million people in the Americas could be exposed to the virus in the next 12 months, said Dr. Sylvain Aldighieri, a unit chief for the Pan American Health Organization.
“As I told you, we have big gaps in terms of confirmation of the real situation,” he said. “These are estimates. These are mathematical estimations.”