Posted 01 February 2016
By Michael Mezher
The World Health Organization (WHO) on Monday declared a public health emergency in response to clusters of microcephaly and Guillain-Barré Syndrome (GBS) in Brazil and French Polynesia suspected to be caused by the Zika virus.
"I am now declaring that the recent clusters of microcephaly and other neurological abnormalities reported in Latin America, following a similar cluster reported in French Polynesia in 2014 constitutes a Public Health Emergency of International Concern [PHEIC]," said WHO Director-General Margaret Chan.
The announcement was made following an Emergency Committee meeting in Geneva, Switzerland, on Monday morning, where 18 experts and advisers weighed the evidence associating spikes in cases of microcephaly and GBS with outbreaks of Zika virus.
WHO defines a Public Health Emergency of International Concern (PHEIC) as "an extraordinary event which is determined … to constitute a public health risk to other States through the international spread of disease; and to potentially require a coordinated international response."
Prior to today's announcement, WHO has only declared three public health emergencies: in 2009 in response to the H1N1 pandemic influenza, and twice in 2014 in response to outbreaks of polio and Ebola.
While the declaration is specific to microcephaly and other neurological disorders, rather than the Zika virus itself, Chan said that a causal relationship with the Zika virus is "strongly suspected."
"Zika alone would not be a public health emergency of international concern [PHEIC]. Zika, as we understand it today is not a clinically serious infection … it is only because of this association, if its proven, that Zika could be considered a [PHEIC]," David Heymann, chair of the Emergency Committee, said.
Indeed, only 20% of people infected with Zika virus will develop symptoms such as fever, rash or joint pain, and hospitalization and death from the disease is rare. However, much greater concern would be warranted if scientists can prove a link between the virus and microcephaly.
Based on the evidence available, Chan said that "a coordinated international response is needed to minimize the threat in affected countries and reduce the risk of further international spread."
As part of its response, WHO is already making use of new tools established in the wake of the 2014 Ebola outbreak in West Africa.
"We already activated the new incident management system across WHO [and] the new contingency fund for emergencies is also being used to step up the initial response," said Bruce Aylward, executive director of outbreaks and health emergencies at WHO.
Under the PHEIC, WHO is calling for "standardized and enhanced" surveillance of microcephaly and GBS as well as intensified research into the causes of those conditions to determine if Zika is to blame.
The agency also recommended a host of precautionary measures, such as enhanced surveillance of the virus' spread, development of diagnostics and vector control measures.
WHO also called for information to be made available for women who are pregnant or of childbearing age, and emphasized the need for counselling and monitoring for pregnant women exposed to the virus.
Long term, WHO says research must be done to develop potential vaccines and drugs to treat or prevent Zika virus, though experts say it could be years before a vaccine is approved. Another option, outlined by UK company Oxitec, would be to genetically engineer the particular type of mosquitoes that cause Zika so that their offspring die before maturing. The Food and Drug Administration Center for Veterinary Medicine (FDA-CVM) have jurisdiction to regulate the Oxitec mosquito under the Federal Food Drug and Cosmetic Act (FFDCA) as the genetic construct affects "the structure and function" of the mosquito.
FDA is currently conducting an independent review of a trial that would use the genetically modified mosquitoes in Florida. A timeline for that review has not been unveiled.
And as part of WHO's emergency alert, the agency says it is not recommending any restrictions on travel and trade to affected countries, though the agency is recommending for people living in or traveling to affected countries to take precautionary measures to limit the risk of mosquito bites.
In the US, the Centers for Disease Control and Prevention (CDC) has already issued travel advisories cautioning travelers, especially pregnant women, about travelling to Zika-affected countries.