The World Health Organization has declared the spread of the Zika virus to be a global emergency. The virus has been linked to serious birth defects in Central and South American, with WHO experts calling it an "extraordinary event" that poses a public health threat to other parts of the world.
WHO took the rare step of declaring the emergency despite a lack of definite evidence that the mosquito-borne virus is causing babies to be born with microcephaly (brain defects and abnormally small heads) in Brazil. Babies were born with the same defects during a Zika outbreak in 2013 and 2014 in French Polynesia. Health officials in French Polynesia documented a connection between Zika and neurological complications when the virus was spreading there.
The health organization called an emergency meeting of independent experts in response to the spike in babies born with microcephaly in Brazil since the virus was first detected there in 2015. "After a review of the evidence, the committee advised that the clusters of microcephaly and other neurological complications constitute an extraordinary event and public health threat to other parts of the world," said Dr. Margaret Chan, director-general of WHO.
It may take 6 to 9 months before a connection is proven between the virus and babies born with microcephaly, but WHO is to taking any chances on waiting that long. WHO has been fast to start work against Zika because it is still smarting from criticism of its slow response to the Ebola crisis in West Africa. WHO did not declare an emergency over Ebola until months after that outbreak started. A declaration of an emergency is meant to be an international warning and usually triggers increased funding for efforts to halt a disease outbreak.
There could be up to 4 million cases of Zika in the Americas in the next year, WHO officials said.
Zika was first identified in 1947 in Uganda, but until last year it wasn't believed to cause any serious effects; about 80 percent of infected people never experience symptoms. The virus has also been linked to Guillain-Barre syndrome, which causes muscle weakness and nerve problems.