Zika as a Public Health Emergency

Disease vector mosquito known for dengue, yellow fever and zika virus
Joao Paulo Burini/Getty Images

In February 2016, the World Health Organization declared a public health emergency of international concern (PHEIC) over the spread of Zika in the Western Hemisphere. As of November 18th, 2016, it has been declared over.

Public Health Emergency of International Concern

It’s a Public Health Emergency of International Concern. This is a formal declaration made by the World Health Organization (WHO) in accordance with the International Health Regulations.

It is made when a public health crisis reaches a potentially global level.

This is part of the International Health Regulations (IHR). These are part of a legally binding agreement made by a number of countries—194, to be exact.

A PHEIC has only been declared four times. This is not surprising. The IHR date back to 2005. The option to declare a PHEIC was not possible until 2007.

Of the four times a PHEIC has been declared (since 2007), three were since 2014.

The Four PHEIC Declarations

April 2009 – H1N1 pandemic (Swine Flu)

May 2014 – Polio resurgence after the disease near-eradicate began to increase

August 2014 – Ebola in West Africa

February 2016 – Zika in the Western Hemisphere

The WHO has not declared MERS to be a PHEIC.

The WHO was criticized for not declaring Ebola a PHEIC earlier. The declaration was not made until August 8, 2014. This was after organizations like MSF had been ringing the alarm bell for months.

Such a declaration can galvanize a response and make the disease a priority for countries to tackle. The declaration also stresses the need to not enforce economic and transport limitations on affected countries which could hinder the fight against these diseases. The reflex to close borders can be more harmful than beneficial.

There was pressure on the WHO to not be slow in declaring the next PHEIC. This was over concerns that the virus rapidly spreading in the Western Hemisphere has been tied a to a birth defect—microcephaly, where babies are born with small heads and underdeveloped brains.

There are also concerns over Yellow Fever in Angola and the DRC and whether this outbreak given the limitations in vaccine supply and delivery should be declared a PHEIC.

Was Zika a Public Health Emergency?

The WHO declared Zika to be a PHEIC on the 1st of February 2016, though this is now over. Zika is now an endemic disease.

The largest infectious killers—TB, HIV, and malaria—are also not PHEICs. They are endemic and daily problems, but they do, unfortunately, kill more people overall than emergencies do. Fortunately, Zika has not been associated with the same loss of life as these more common illnesses have been.

What This Means for Zika

Zika, for most people affected, is a mild disease. The disease is also mild in pregnant women. The concern is that microcephaly—small heads and underdeveloped brains—appears associated with children born to women who had Zika during their pregnancies.

There is no vaccine and no treatment for Zika.

Response to Zika is largely preventative. This means keeping mosquitoes from biting, supporting reproductive health, and investing in research to better understand this disease.

How Mosquito Control Can Help

The Aedes mosquitoes can be pretty aggressive. They also bite twice a day—in the early morning and the early afternoon. They tend to not fly very far and often live where people live. Limiting open water sources like tires, puddles, and flower vases is important inside and outside of the home. Bug spray and large-scale mosquito spraying can help. Keeping skin covered can also protect against bites.

Bed nets may reduce their numbers, but most bites occur at times when people are not sleeping.

It can be very hard to prevent bites, no matter how much effort is taken. Many think they don’t get bitten, but they do. Because of the difficulty in avoiding bites, the CDC has recommended all women from the US avoid travel to affected areas (which include Puerto Rico) and return to the US if in an affected area.

However, it is important that countries do not close borders, affecting transport and economies in affected countries.

How Supporting Reproductive Health Can Help

Women in countries from El Salvador to Jamaica were told not to get pregnant. Many do not have access to reproductive health care needed to access and use contraception. Many may have difficulty controlling whether they become pregnant. Abortion—even a miscarriage thought to be an induced abortion—can carry heavy legal (and medical) penalties for women. Ensuring women have access to health care that allows them to decide when to become pregnant is a part of responding to Zika.

US women were told not to travel to affected countries (i.e. most of the Western Hemisphere) by the CDC if they were—or might be—pregnant.

Research Needs to Continue

The connection between microcephaly and Zika has not been proven. There remain many questions still about Zika. The number of babies who may be affected and the risk for each pregnant woman infected is not known. Most infections with Zika cause no symptoms; it’s unclear whether these asymptomatic infections will affect women and their babies. It is not known at what stage of pregnancy infection matters—or whether it could be at any point in infection. It’s also unknown how badly affected many babies will be. Some children grow up to live normal lives with microcephaly. Others can have severe delays.

More research is needed to better understand and tackle this disease.