Zika Cases Down, But Not Out: Public Health Watch Report

What a difference a year makes.

Last August (2016), news outlets the world over were all Zika, all the time. Coverage of the mosquito-borne virus was everywhere, from The New York Times, to CNN, to The New England Journal of Medicine, and, of course, Contagion^®. And no wonder: According to Pan-American Health Organization figures, there were more than 300,000 suspected and confirmed cases of the mosquito-borne virus in Brazil in 2016 alone. Centers for Disease Control and Prevention (CDC) data, meanwhile, identified more than 5,100 cases in the 50 states, last year, and more than 30,000 in the territory of Puerto Rico.

In other words, a little media attention was probably warranted—and we certainly got it. Once the outbreak in Brazil was confirmed in 2014, we learned about the differences between “local” and travel-related cases as well as sexual transmission and the devastating effects of Zika virus on pregnant women and their newborns. Much attention was given to the stories of leading athletes who turned down opportunities to represent their countries at the 2016 Summer Olympics over fears of getting infected. The games were, of course, held in Rio de Janeiro, arguably ground zero for Zika.

And although all that media attention certainly seemed shrill at times, it had an impact: A year on, the United States and most of the other countries affected by the Zika virus are better prepared to prevent outbreaks and control their spread. The proof is in the data.

Indeed, the number of Zika virus cases reported thus far in 2017 is down significantly from where it was over the same period last year. In the United States, for example, the CDC has recorded 185 confirmed Zika cases this year, through August 3, 2017. A total of 184 of those cases have been deemed travel-related, meaning those infected became so as a result of a mosquito bite sustained while traveling within a Zika-endemic area. In 2016, according to the CDC, there were more than 224 “local” cases confirmed in Florida (218) and Texas (6).

In Puerto Rico, one of the regions most affected by Zika in 2016, there have been only 474 cases of the virus so far, this year. And, in Brazil, there have been fewer than 10,000 cases in 2017 to date. In fact, in May, the South American nation officially declared its Zika-related public health emergency over.

Although these case reductions can be attributed, at least in part, to education about Zika virus and its complications delivered via the media, it’s the work of the world’s experts that has, sadly, gone unnoticed—at least in the mainstream media. After an often-heated battle on Capitol Hill, Congress in September 2016 agreed to provide $1.1 billion in funds for the fight against Zika, and those monies, coupled with hundreds of millions already re-allocated from efforts to combat other diseases, have played a vital role. In less than a year’s time, the CDC has already used the money to partner with multiple state and local health departments to establish vector-control initiatives (such as pesticide spraying and/or the use of genetically modified mosquitoes) in areas susceptible to the virus. Such efforts proved key in curtailing the summer 2016 Zika outbreak in the Miami area.

In addition, the CDC, Department of Health and Human Services, and National Institutes of Health have earmarked some of the funds to support clinical trials of novel vaccines for the prevention of Zika virus, and new drugs to treat it. These studies have already yielded significant—and positive—findings.

Furthermore, education and outreach efforts supported with the funds likely prevented a significant number of new cases in the United States, as the CDC developed Zika-related guidance for travel to endemic areas and for pregnant women. The CDC also spearheaded efforts to create a surveillance protocol to track new cases in general, and new cases among pregnant women and newborns, specifically. The data has been and will be used to inform management strategies for the virus, according to CDC officials.

US agencies have also partnered with their counterparts in South America to assist in efforts to combat Zika there. As part of an initiative launched just prior to the 2016 Summer Olympics, Brazil used genetically modified mosquitoes—as well as pesticide spraying in more than 20 million homes—to dramatically reduce the populations of Aedes aegypti mosquitoes, the insects that transmit Zika.

However, it is important to note that, in spite of these accomplishments, the threat posed by Zika is far from over. In fact, Florida recently announced their first case of sexually-transmitted Zika virus infection, and, just last month, officials in Houston announced plans to use genetically modified mosquitoes as a means of vector control, and not without controversy.

And so, although much of the media’s coverage of Zika is history, it’s important not to overlook how we got here one year on. After all, as the old cliché goes, those who cannot learn from history…

Brian P. Dunleavy is a medical writer and editor based in New York. His work has appeared in numerous healthcare-related publications. He is the former editor of Infectious Disease Special Edition.