The 4th PHEIC of the Apocalypse: Zika?

Today, the World Health Organization convened and determined that cases of microcephaly and Guillain-Barre Syndrome potentially linked to the spread of the Zika virus in South America represents a public health emergency of international concern (PHEIC). This is a designation only H1N1 influenza, polio, and Ebola have been granted. Before the past few weeks Zika virus was not something on the radar of most Americans but is now the subject of headlines warning of devastating complications in the fetuses of pregnant women. Post-Ebola, many infectious diseases prompt doom-and-gloom headlines that do not provide full context and threat analysis—an essential process to help the general public determine the level of concern they should have.

A declaration of this sort deserves some discussion because it is not obviously clear to many, including me, what criteria are used in the deliberation. Ideally, the criteria for a PHEIC should be transparent, objective, and entirely derived from the medical and scientific facts that are known. The chain of reasoning employed should be reproducible by anyone with the same facts. While formal objective criteria might be deviated from in what often is a highly politicized process, at least it will be better known when it does. 

However, after polio -- a disease that has been largely eliminated from the globe via vaccination --- was declared a PHEIC, it became clear that other extraneous considerations might be at play. Similarly, when Middle East Respiratory Syndrome (MERS), a zoonotic disease without treatment or vaccine transmissible from person to person and similar to SARS (from which the whole apparatus of PHEIC derives from), did not meet the criteria, it was puzzling. Chikungunya is another case in point.

While the Zika PHEIC is, contrary to the way it is being reported upon, narrowly focused on microcephaly and other neurologic complications (and not Zika as such) it seems that in a post-Ebola world public health authorities are seizing the opportunity to capitalize on the importance infectious disease is now given. This is a two-edged sword as many diseases like MERS are given short-shrift but others given the spotlight.

What is needed is clear objective criteria bereft of any consideration but the science, something that is difficult to ascertain in the current context.