The Zika virus is "spreading explosively" in the Americas, which could see up to 4 million cases over the next year, international health officials said Thursday, announcing a special meeting next week to decide if they should declare an international health emergency.
The warning from the World Health Organization came amid a call to arms by officials on both sides of the Atlantic over the mosquito-borne virus, which has been linked to a spike in a rare birth defect in Brazil.
Meanwhile, U.S. health officials said Thursday while they have not yet seen spread of the disease in the 50 states, the number of U.S. travelers infected over the last year in the Caribbean or Latin America has climbed to 31.
In Geneva, WHO Director-General Dr. Margaret Chan noted it had been less than a year since the virus arrived in the Americas, "where it is now spreading explosively."