The World Health Organization announced this morning that it will set up an emergency committee to combat the spread of the Zika Virus throughout North and South America. The disease has spread throughout Mexico, Central America and through Brazil.

WHO Director-General Margaret Chan briefed the Executive Board today in Geneva and announced her decision to call for an Emergency Committee to meet on Monday. She will ask the committee “for advice on the appropriate level of international concern and for recommended measures that should be undertaken in affected countries and elsewhere.”

The Zika Virus was first discovered in Uganda in 1947 and is carried by mosquitos. In 2007, it was found outside Africa in the Pacific islands. It was first reported in Brazil in May 2015, notes The BBC. It is predicted that the disease could infect 3 to 4 million people in the Americans in 2016. In Brazil alone, 1.5 million people are estimated to be infected.

As the disease spreads, more cases of microcephaly, a condition that causes babies to be born with abnormally small heads, have arisen. The Zika Virus is believed to be connected to this condition, but this is not yet confirmed, Chan said.

“The situation today is dramatically different,” Chan said. “Last year, the virus was detected in the Americas, where it is now spreading explosively. As of today, cases have been reported in 23 countries and territories in the region.”

The Centers for Disease Control and Prevention has issued a travel alert, telling women who are pregnant to avoid travel to the countries affected.

As the New York Times notes, there is no cure for the virus or even a quick test to figure out if someone is carrying it. The National Institute of Allergy and Infectious Diseases and the National Institutes of Health are working on solutions to both issues.