"The level of alarm is extremely high," WHO general director Margaret Chan said

By Tiare Dunlap
Updated January 28, 2016 05:15 PM

The Zika virus is “spreading explosively” in the Americas, the World Health Organization said Thursday.

The virus has spread to 23 countries and territories since Brazil reported its first case in May 2014. “The level of alarm is extremely high,” WHO general director Margaret Chan said while announcing an emergency meeting on how to confront the virus.

The mosquito-borne illness has been linked to microcephaly, a rare condition that causes incomplete brain development in infants. While the U.S. Centers for Disease Control and Prevention have stated that further research on this link is needed, the outbreak of the virus in Brazil presents alarming data. There, more than a million people have been infected and nearly 4,000 children have been born with the condition.

Earlier this week, the government of El Salvador went so far as to advise women to hold off on getting pregnant until 2018. Officials in Ecuador and Colombia have issued a similar advisory.

Hawaii health officials said a baby recently born with microcephaly at an Oahu hospital to a mother who had lived in Brazil was infected with the virus while in utero.

To date, 31 travelers from 11 states and Washington, D.C., have returned to the United States with Zika virus since 2015. However, there have been no cases reported in which the virus was transmitted on U.S. soil, according to the CDC.

“Right now, I would say that the risk of Zika virus transmission over most of the United States is very low,” Dr. William Reisen, editor of the Journal of Medical Entomology told the New York Times.

Dr. Reisen added that risks of the virus spreading across the U.S. as it has in South America are lower because U.S. cities are less densely populated and most homes have window screens.

Los Angeles County of Public Health sounded alarms after a 12-year-old girl returning from El Salvador was confirmed to have Zika, NBC Los Angeles reports. The types of moquitios that carry Zika are not native to the United States, but have established presences in parts of Los Angeles.

There is a concern that a traveler returning to Southern California with the virus could be bit by one of these mosquitos that could spread the virus.

“If someone does become ill, we want them to stay inside, away from the Aedes mosquito to make sure they don’t cause a local infection to occur,” Ben Schwartz, MD, deputy director of the acute communicable diseases control program for Los Angeles County Public Health, said Friday, according to NBC LA.

Only about 1 in 5 people infected with the virus experience symptoms, according to the CDC. Symptoms are generally mild, including fever, rash, joint pain and conjunctivitis – and last for about a week. However, the apparent link between Zika infection during pregnancy and microcephaly is cause for concern.

There are currently no vaccines or treatments for Zika. However, scientists are working on developing both. The CDC has advised pregnant to women postpone travel to affected areas.