3-4 million cases of Zika virus disease can be expected.
The World Health Organization faced flak for its delay by two months in 2014 in declaring the Ebola epidemic as a Public Health Emergency of International Concern (PHEIC). This might not happen in the case of Zika virus when the WHO will convene an emergency committee on February 1 (Monday) to help determine the level of the international response to the outbreak.
It is alleged that WHO declared Ebola as a PHEIC only after a U.S. health care person was infected with the virus. Likewise, is it because the risk to the U.S. is very high in the case of Zika virus that WHO has convened the Committee meeting on Monday? “I think it is safe to assume two things. First, we do know that political considerations factored strongly into the delay in calling a PHEIC for Ebola, due to pressure from West African countries. Second, when a disease has potentially strong impacts on North America and Europe the political calculations change very quickly. That drives the media and pushes WHO to act”, Lawrence O. Gostin from O'Neill Institute for National and Global Health Law, Georgetown University Law Center, Washington DC and Director, World Health Organization Collaborating Center on Public Health Law & Human Rights said in an email to this Correspondent.
But in the first place why should the Zika virus outbreaks be declared a Public Health Emergency of International Concern? The term PHEIC is defined as an “extraordinary event” which is determined if both these conditions are met — constitute a public health risk to other States through the international spread of disease, and potentially requires a coordinated international response.
According to the 2005 International Health Regulations (IHR) agreement, this definition “implies a situation that is: serious, unusual or unexpected, carries implications for public health beyond the affected State’s national border, and may require immediate international action”.
The Zika outbreak in 23 countries meets these conditions. “Given the rapidly spreading Zika epidemic, I think WHO should declare an emergency and use all their powers under the International Health Regulations,” Prof. Gostin said. “Actually there is a detailed algorithm [based on which WHO declares PHEIC], but essentially if the disease has cross border spread, if it is novel, and if it poses an international risk, it qualifies. All that applies to Zika in my view”.
Since its outbreak in Brazil in May 2015, there have been nearly 4,000 suspected cases of microcephaly — a foetal deformation where infants are born with abnormally small heads. Officials are still investigating whether Zika causes microcephaly in newborns, but the link is “strongly suspected,” according to the WHO.
Evidence of virus
“Evidence of the virus has been found in the placenta and amniotic fluid of mothers and in the brains of foetusesor newborns. Yet causation between Zika virus and microcephaly is not yet established”, Prof. Gostin, Corresponding author writes in a paper published recently in the Journal of the American Medical Association (JAMA).
The WHO estimates that 1.5 million people might have been infected in Brazil. “We can expect 3 to 4 million cases of Zika virus disease”, Marcos Espinal, an infectious disease expert at the WHO’s Americas regional office, told Reuters. And Dr. Margaret Chan, Director-General of WHO had said that the virus is “spreading explosively” through the Americas.
Since the first outbreak was reported in May 2015 in Brazil, the virus has already spread to 23 countries and territories in the Americas. It has spread even to Australia by travelers, and is anticipated to spread to rest of theAmericas, Europe and Asia.
Even now under the IHR, the WHO communicates with member countries about public health risks. But things may change or work differently if PHEIC were to be declared. “If a PHEIC were declared, WHO would provide detailed guidance for States, mobilize resources, and provide technical assistance. It would place the epidemic within the framework of binding international law. It will inject major urgency into R&D [to develop therapies and/or vaccines]”, Prof. Gostin explained.
Prof. Gostin says convening an emergency committee does not mean that WHO will declare a PHEIC. For instance, in the case of the Middle East Respiratory Syndrome (MERS), the emergency committee was convened 10 times to take stock of the situation but WHO did not declare a PHEIC; it offered “detailed recommendations to guide member States.”
But the very process of convening the committee would “catalyze international attention, funding and research”. For instance, Anthony S. Fauci, Director of the National Institute of Allergy and Infectious Disease, has already announced that Phase I clinical trials of a possible vaccine against Zika virus may begin before the end of 2016. The National Institutes of Health launched a Zika vaccine initiative late last year. Brazil too has gone on an overdrive to find an effective vaccine. It may take as long as 10 years before a vaccine becomes widely available, Dr. Fauci cautioned.
Little attention was paid as long as the Zika infection remained asymptomatic and self-limiting. But “emerging data on foetal complications altered this equation” and all focus has been directed at finding an efficacious vaccine urgently.
The Zika virus infection usually is asymptomatic in nearly 80 per cent of the cases. As a result, many cases of Zika go undetected, making it difficult to estimate the true scale of the outbreak in the Americas. One in four people infected with Zika develop symptoms — mild illness, such as fever, rash, muscle/joint pain, and conjunctivitis.
Since the infection is spread through Aedes species mosquito (which bites during daytime) which is commonly seen in these countries, and since it causes foetal abnormalities, countries such as Colombia, Ecuador, and Jamaica have recommended that women delay pregnancy. El Salvador has asked women to delay pregnancy until 2018.
On January 15, the Centersfor Disease Control and Prevention (CDC) advised pregnant women “to consider postponing travel to countries with ongoing Zika virus transmission”.
Public Health England (PHE) has said men should wear condoms for 28 days after returning from any of the countries where Zika infection has been reported if their partner was at risk of pregnancy, or already pregnant. It also said that men should use condoms for six months following recovery if a clinical illness “compatible with Zika virus infection or laboratory confirmed Zika virus infection was reported.”
