WHO Declares Zika Birth Defect Link a Public Health Emergency

A municipal worker carries out fumigation to help control the spread of the mosquito-borne Zika virus in Caracas, Venezuela, on January 28. Marco Bello/Reuters

As apprehension about the Zika virus goes global, the World Health Organization (WHO) on Monday declared the link between the virus and growing rates of infant birth defects "a public health emergency of international concern."

During an emergency meeting Monday, the International Health Regulations Emergency Committee, which provides technical advice to the WHO, said the mosquito-borne virus itself does not pose an urgent threat. However, the growing rates of microcephaly—a condition in which a baby is born with an abnormally small skull and incomplete brain development—warrant a coordinated international response that will include expediting research to prove there is a causal relationship.

The meeting, which was held in Geneva, comes after WHO Director-General Margaret Chan said the mosquito-borne virus was "spreading explosively."

The latest figures from Colombia show there are now 20,297 confirmed Zika cases in the South American country, including 2,116 among pregnant women.

The WHO can decide to declare a public health emergency in relation to the outbreak of the virus in 25 countries and territories affected by it. However, the global health body has done this on only three occasions: the swine flu pandemic in 2009, the Ebola outbreak in West Africa in 2014, and the resurfacing of polio in 2014.

The Zika virus is believed to be responsible for a rise in babies born with microcephaly in Brazil in the past three months, a condition that means babies are born with smaller brains. From October to January, there were over 4,000 cases in the country, in comparison with just 147 cases in 2014.

The virus is transmitted in the same way as dengue, yellow fever and the West Nile virus. It originated in Uganda but spread to the Western Hemisphere in May 2015. Symptoms can include fever, rash, joint pain and red eyes. The virus is not usually serious for adults, except for women who become infected while pregnant.

Officials in a number of Latin American countries, including El Salvador, Colombia and Ecuador, have said that women should consider delaying pregnancy until the virus is under control. The U.S. Centers for Disease Control and Prevention has recommended that women not travel to areas where the virus is prevalent.

The WHO said there could be 4 million cases of Zika in the Americas every year. More than two-thirds of those infected do not show any signs of symptoms and there is no vaccine for the virus.