GENEVA, Rabi'II 19, 1437, January 29, 2016, SPA -- 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, according to AP. 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. The U.N. health agency called the special session in part to convey its concern about an illness that has sown fear among many would-be mothers. It may also have acted quickly because the agency was criticized for its slow response to the Ebola epidemic in West Africa. 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." Although there is no definitive proof that the Zika virus is behind the spike in brain defects in Brazil, "the level of alarm is extremely high," she added. "The possible links, only recently suspected, have rapidly changed the risk profile of Zika from a mild threat to one of alarming proportions," Chan said. WHO warned China and all other countries that have dengue fever to be on the lookout for Zika infections. The agency said it could be many years before a vaccine is available and it might take six to nine months before there's any data showing a causal relationship between Zika and the babies born with malformed heads. --SPA 02:38 LOCAL TIME 23:38 GMT www.spa.gov.sa/w