It's been more than a year since the Centers for Disease Control and Prevention issued the first warning about travel to Brazil and the Caribbean because of the Zika virus. From January to August of 2016, it dominated headlines and sent travel agents and hoteliers into a frenzy. Hotels in Zika zones saw losses of up to 30 percent.
But for the past few months, Zika has been out of sight and out of mind. Does that mean you should stop worrying about it? Probably not.
Zika was never eradicated from the 30 Caribbean islands and 18 countries in South America where it appeared last year, and the disease is now showing up everywhere from Southeast Asia to the South Pacific.
Between November and January, the CDC has logged almost 4,000 new cases of Zika in the U.S., Puerto Rico, the U.S. Virgin Islands, and American Samoa.
"The disease as we understand it now is scarier than we originally thought," said Kristin Lamoureux, associate dean of New York University's Jonathan M. Tisch Center for Hospitality and Tourism. "We know we're going to see Zika again in the spring," she said.
The good news: Miami has served as a useful case study. When the city saw its first few cases of Zika transmission last summer, the local government acted quickly, enforcing a strategy of aerial spraying, manual spraying, and local awareness that eradicated the disease. "Miami Beach is a beacon of hope that Zika can be contained," said Lamoureux.
Other locales have managed to stay free of Zika altogether. Bermuda has never appeared on the CDC travel notice list, and neither have Uruguay, Chile, and Hawaii. There's evidence that Puerto Rico has curtailed the number of cases dramatically.
Even better, according to former Food and Drug Administration chief and public health expert Dr. Jesse Goodman, nearly a dozen Zika vaccines are currently in trial phases, and at least one of them is entering early human studies. Eventually, Zika will be no different from malaria: a mosquito-borne virus that can be reliably combated whenever exposure puts you at risk.
But a safe and effective vaccine is still a few years away. Until then, Goodman, who has served on boards and committees for the CDC, National Institutes of Health, and World Health Organization, said he sees Zika becoming endemic, just like malaria and dengue. "My suspicion is that over a period of a couple of years, the people most exposed to Zika will become immune to it — which will make the rates of infection go down a lot," he said.
The link between Zika and microcephaly was called into question last fall by a story in the Washington Post, which claimed that the correlation has primarily been limited to a small area in northern Brazil. "The scientific community has come to a consensus that there's a clear risk between Zika and microcephaly," Goodman said, "along with a variety of other severe pregnancy outcomes, in some cases including miscarriages."
For women in their first trimester, the risk of incidence has been estimated at 15 to 20 percent, he said. And while that's not small, early studies had pinned the numbers as being higher.
The correlation between Zika and Guillain-Barré syndrome is still much smaller: Only 13 of the 4,973 Americans who contracted Zika got the autoimmune disorder.
What's less clear, said Goodman, is whether gestational Zika can lead to other pediatric conditions such as learning disabilities, and why microcephaly has been so much more prevalent in some regions, such as northern Brazil, than others. He said the recommendation is still that "pregnant women and women looking to get pregnant avoid all nonessential travel, or get tested during their pregnancy if they've been exposed."