The World Health Organization announced Monday that the explosive spread of the Zika virus in the Americas is an "extraordinary event" that merits being declared an international emergency, the AP reports. The agency convened a closed-door emergency meeting of independent experts Monday to assess the outbreak after noting a suspicious link between Zika's arrival in Brazil last year and a surge in the number of babies born with abnormally small heads. Although WHO Director-General Dr. Margaret Chan said there was no definitive proof that the Zika virus, spread by mosquitoes, is responsible for the birth defects, she acknowledged on Thursday that "the level of alarm is extremely high."
Such emergency declarations are meant as an international SOS signal and usually trigger increased money and efforts to stop the outbreak, as well as prompting research into possible treatments and vaccines. The last such public health emergency was declared for the devastating 2014 Ebola outbreak in West Africa, which killed more than 11,000 people; a similar declaration was made for polio the year before. WHO estimates there could be up to 4 million cases of Zika in the Americas in the next year. (Scientists warned the WHO just last week not to mess up dealing with Zika like it did with Ebola.)