The World Health Organization on Monday declared that a rise in the number of birth defects and other neurological conditions possibly linked to the Zika virus constitutes a global public health emergency.The United Nations public health agency, acting on the recommendations of an emergency committee, called for more surveillance, research, and efforts to control the virus’s spread. It also pushed for the development of more readily available tests to diagnose the virus—none are commercially available now—as well as drugs and vaccines.“The evidence is growing and it’s getting strong,” WHO Director-General Margaret Chan said at a news conference, of the suspected link between Zika and the birth defect, known as microcephaly, in which babies are born with undersized heads and brains. “We need a coordinated international response to make sure we get to the bottom of this.”Dr. Chan convened the emergency committee last week, when she declared that Zika was spreading “explosively.”
The agency’s decision shows how a once-obscure virus, which generally makes people only mildly ill for a few days, has become a major global health concern as it has spread first in Brazil and now throughout the Americas. Brazil health authorities believe as many as 1.5 million Brazilians may be infected with the Zika virus.The WHO said it declared the Zika epidemic an emergency only because of its possible links to microcephaly and Guillain-Barré, a rare disorder in which the body’s immune system attacks nerve cells.
“Zika alone would not be a public health emergency of international concern,” said David Heymann, the committee’s chairman and professor of infectious disease epidemiology at the London School of Hygiene and Tropical Medicine. “Zika is not a clinically serious infection. It’s only because of this association, if it’s proven.”The WHO also said travel and trade shouldn’t be restricted due to Zika. That put it seemingly at odds with the U.S. Centers for Disease Control and Prevention, which added four more countries and territories to a growing list, now totaling 28, of places to which it has warned pregnant women to avoid travel because Zika is circulating there. But those alerts don’t constitute a travel ban.
The WHO’s decision followed a four-hour teleconference Monday afternoon Geneva time with the 12-member emergency committee and a team of advisers, including medical experts and representatives of the tourism and aviation industries. The governments of Brazil, El Salvador, France and the U.S. provided their findings on the possible link between Zika and microcephaly and other neurological disorders, the WHO said.Brazil’s health ministry has confirmed 270 cases of microcephaly since October, when observations by doctors in the northeastern city of Recife led to the country mandating the reporting of suspected cases. Of those, six cases have confirmed links to the Zika virus. The Brazil health ministry is investigating thousands more suspected cases of microcephaly.
Brazil isn’t alone. Authorities now say they believe that some cases of microcephaly in babies in French Polynesia may be linked to an outbreak of Zika that occurred there in 2013 and 2014. Brazilian and international health authorities also say Zika may be linked to a rise in the number of cases of Guillain-Barré syndrome. Cases are being investigated in Brazil, El Salvador, and French Polynesia.The emergency committee called for more surveillance for microcephaly and GBS and research into whether there is a causal link with the rise in Zika cases. It also called for more surveillance for Zika virus itself, and measures to combat the mosquitoes that spread it—primarily the Aedes aegypti species, which is common in the tropics and subtropics, including the southern U.S.
The species is considered a formidable threat to public health because it is an aggressive biter, hard to eliminate, and it spreads dengue and chikungunya, which exact an even harsher toll on many of their victims than the normally mild Zika virus.The committee said women of childbearing age should be taught how to reduce exposure to Zika, and those who are pregnant should be counseled and monitored.Declarations of global health emergencies are a way for the WHO to mobilize resources and coordinate a response, said Lawrence Gostin, an expert in public health law at Georgetown University Law Center. He praised the WHO Monday for sounding the global alert, given Zika’s spread and the fact that very few people have developed immunity to it.