On February 1st, the World Health Organization declared that Zika was an international public health emergency. As noted in the Pearl from January 20th, 2016, Zika is a mosquito-borne RNA flavivirus that is usually asymptomatic. However, congenital malformations have been seen in pregnant women infected with Zika.
While it is clear that the decision to declare an international public health is a judgement call, what are the criteria for considering this declaration?
Per the WHO, the term Public Health Emergency of International Concern is defined in the IHR (2005) as “an extraordinary event which is determined, as provided in these Regulations:
· to constitute a public health risk to other States through the international spread of disease; and
· to potentially require a coordinated international response”. 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 responsibility of determining whether an event is within this category lies with the WHO Director-General and requires the convening of a committee of experts – the IHR Emergency Committee.
For Zika, the sequalae of concern are the clusters of microcephaly and Guillain-Barré syndrome suspected to have resulted from Zika infection.
