Both Zika and Ebola Virus Disease were declared to be Public Health Emergency of International Concern (PHEIC), a label not given liberally to diseases. In a recent commentary in The Lancet, the people behind the labeling, the members of the Emergency Committee on Zika virus, have clarified the logic and reason behind their decision.
On February 1, 2016, the World Health Organization (WHO) released the “WHO statement on the first meeting of the International Health Regulations (2005) (IHR 2005) Emergency Committee on Zika virus and observed increase in neurological disorders and neonatal malformations”, which declared that the recent cluster of microcephaly and other neurologic disorders reported from Brazil, following a similar cluster from French Polynesia in 2014, constitutes a Public Health Emergency of International Concern. The committee also published a commentary in The Lancet (free PDF) clarifying the decision to label the Zika-attributed cluster of microcephaly cases and other neurologic disorders as a PHEIC.
A PHEIC must: (1) constitute a health risk to other countries through international spread; (2) potentially require a coordinated response because it is unexpected, serious, or unusual; and (3) have implications beyond the aff ected country that could require immediate action.
After the WHO was criticized for the passive role it played in handling the Ebola Virus Disease outbreak in West Africa, this was a chance for proactive decision-making – a chance to nip the evil of Zika in the bud before it exploded into another major crisis. The declaration of Zika as a PHEIC was followed by some murmurings and misgivings, including skepticism regarding the very issue that brought it into the media limelight for the first time – a high rate of microcephaly born to children whose mothers suffered infection with the Zika virus in course of their pregnancy.
However, the Committee took a very difficult decision, of declaring a PHEIC, and at the same time admitting the real reason for the PHEIC was NOT what we knew about it, but what we did not know about it, specifically with respect to the reports of clusters of microcephaly cases and neurologic disorders that have been linked to it. In the Lancet commentary, they observe:
Since the Director-General declared the PHEIC on microcephaly and neurological disorders, many of us have had questions about how our recommendation relates to the PHEIC called by the Director-General for the 2014 Ebola outbreaks in west Africa based on the recommendation of a diff erent Emergency Committee. The answer to us is clear. The Director-General declared the Ebola outbreaks a PHEIC because of what science knew about the Ebola virus from many years of research during outbreaks in the past, whereas she declared the current PHEIC because of what is not known about the current increase in reported clusters of microcephaly and other disorders, and how this might relate to concurrent Zika outbreaks.
This goes a long way to show that we are just beginning to scrape the surface of the risks posed by zoonotic and emerging infectious diseases, making it even more vital to invest in understanding the way in which these diseases function in the real world.