Last Friday, November 18, the World Health Organization decided to take the Zika virus off of Public Health Emergency of International Concern (PHEIC) status on the grounds that, as the agency’s Peter Salama told the press, “Zika is here to stay, and the WHO’s response is here to stay.”
So Zika may now be added to the pantheon of viruses and bacteria that have recently emerged from obscurity to become permanent threats to human health. Welcome to the club, Zika—meet your peers, HIV, XDR-TB, Ebola, Marburg and a long list of other killers.
The WHO decision to downgrade Zika from emergency status is not good news, as there are now seventy-five countries that have suffered the virus since 2007, the majority of them only experiencing Zika over the last eighteen months. Among them, twenty-eight have had cases of microcephaly, the severe brain damage and deformation caused by viral infection of the fetus. And nineteen countries have had cases of Guillain-Barre Syndrome (GBS), a form of temporary, sometimes permanent paralysis seen in infected adults. At least a dozen countries, including the United States, have documented cases of sexual transmission of the virus, and both Puerto Rico and Brazil report that female cases are roughly double the number confirmed in males among adults between fifteen and forty years of age. The virus directly attacks brain cells, in both fetuses and adults.
Today’s declaration reflects defeat. In the official WHO statement and subsequent press conference the scientists and physicians advising the WHO said that the reason for removing the emergency status was the tremendous mystery surrounding Zika. There is no treatment, cure, reliable in utero diagnostic, or vaccine for the virus at this time. Nobody knows how often it is sexually transmitted, rather than, as is usual, being transmitted via the bite of an Aedes aegypti mosquito.
What good is an emergency if you have no tool kit with which to address it? As Tom Frieden, head of the Centers for Disease Control and Prevention put it, “Zika is not controllable.”
As has too often been the case in epidemics we have no point-of-care diagnostic tool for Zika that can swiftly and accurately answer these vital questions:
- Who is currently infected with the virus?
- Who was once infected, but recovered or never took ill?
- Which infected pregnant woman is likely to give birth to a Zika-damaged baby?
- Which fetus growing in utero is healthy, despite the mother’s Zika infection?
- How long can Zika remain contagious sexually in a man’s semen? In a woman’s vaginal fluids?
Just last week researchers published striking evidence that the scale of the 2015 Ebola epidemic in Sierra Leone was grossly underestimated, as there may have been many cases of infection without extreme disease symptoms. In 2009 the so-called “Swine Flu” caused by H1N1 created a global panic when it appeared that the new form of influenza was especially deadly, amid widespread hospitalizations and fatalities in Mexico --it turned out that the lack of a quick way to determine who had been infected meant the scale of the epidemic was wildly skewed. Yes, people died of H1N1 flu—they were, if you will, the numerator. But the denominator—the total number of people infected—was far greater than anybody imagined in the early stages of the outbreak, making the real fatality proportions of that outbreak less than an average, routine flu.
With every outbreak the world fails to invest in the proper toolkit. In the case of Zika, the United States Congress failed to invest a dime in research or control efforts until 251 days after President Barack Obama’s February 26th request for $1.9 billion. Funds ($1.1 billion) were finally approved on September 29. This snail’s pace partisan battle hampered American R&D on all aspects of Zika, though vaccines are in the pipeline, hopefully, for 2018-19.
So what is our take-home message from the Zika normalization?
Microbes win. And they will continue to do so until we, human beings, face up to our frailty and develop the proper tools for rapid identification and response to outbreaks, when, and where, they begin. Waiting until a newly emerging microbe is at your doorstep guarantees failure. And only investing in treatments and vaccines ties the hands of disease responders, leaving them without the tools to rapidly assess the scope and transmission of the unfolding nightmare.
Editor's Note: An out of date map, which appeared in an earlier version of this post, has been replaced