The Zika virus, explained

Zika burst onto the world stage in 2015, the only known mosquito-borne virus that can cause severe birth defects. By the height of the epidemic the following year, when more than 200,000 people had been infected and some 3,000 babies experienced birth defects in Brazil, US health officials issued a first-of-its-kind travel advisory. Women of childbearing age, whether they were pregnant or wanted to be soon, were told not to travel to 68 countries where Zika had been circulating.

Flights were canceled, itineraries changed, and the tourism industries in the affected places were hit hard.

We are more than a year into the Zika outbreak, and the virus is spreading in the US and overseas. But Congress still hasn’t moved to fund the effort to beat it back. On Tuesday, the Senate once again failed to pass the $1.1 billion Zika funding package.

This is pathetic — but it’s also emblematic of how much the public health system depends on politics and how badly it needs financial independence from the political system.

In the lead-up to the Rio Olympics, there was a flurry of panic around whether the games might act as a super-spreading event for the Zika virus, flinging cases out of the hot zone (Brazil) and into the far corners of the earth. Some worried critics even called for the games to be postponed or moved. Some athletes dropped out in fear of the virus.

But researchers studying Zika and expert agencies like the World Health Organization insisted the fears were unfounded.

As Zika cases continue to pop up in Florida, a lot of the anxiety around the virus has understandably been focused on the disease’s future in the United States. Will Zika spread to other states? Will congressional lawmakers finally allocate funds for Zika research, detection, and prevention when they return from summer break?

But the narrow US focus misses where the real Zika threat lies. The worst Zika outbreaks right now are happening outside of the continental United States, in places like Puerto Rico. And the countries at risk of serious outbreaks in the future are even further afield, in Africa and Asia.

The Zika virus can be transmitted through sex, which is a bit chilling if you think about it: Not only can the virus pass through sexual partners but those encounters could, in theory, result in babies born with birth defects.

It’s this fact that has people worried that Zika could become the devastating STD of the decade. An op-ed in the New York Times recently called Zika “the millennials’ STD.“ The virus was also recently compared to HIV, one of the biggest killer viruses of our time.

With Zika moving through nearly every country in the Western Hemisphere over the past year and a half, it was only a matter of time before the virus made its way to the continental US.

At the end of July, health officials announced that a handful of Zika infections had originated from mosquitoes in Miami, Florida. As of August 22, there were 37 locally-acquired cases in Florida, mostly concentrated in a one square mile area of Miami’s Wynwood neighborhood.

Health officials have confirmed a small cluster of new, locally-transmitted Zika cases in Miami Beach, as well as another in the Tampa area.

This is important for one simple reason: It means more Zika cases are likely to pop up in the South soon.

When masses of people from around the world descend on a city for the Olympics, public health experts get a bit jittery. It’s easy to understand why: Thousands of tourists cramped into stadiums and bars inevitably swap bacteria and viruses. In the past, this has led to outbreaks of measles and norovirus.

This year, an extra layer of anxiety has shrouded the Summer Games in Rio de Janeiro: Host country Brazil is a hot zone for a Zika virus epidemic that has now reached more than 60 countries.

“How do you spell Zika?”

I stood at the front desk of a major Washington, DC, hospital last month. I had a head-to-toe rash that developed after I’d returned from the Dominican Republic, where Zika is much more common than it is stateside. The friend I’d traveled with was showing symptoms of the virus. I’d come to the emergency room to find out if I had it too.

Last week, the Centers for Disease Control and Prevention reported something it had been anticipating for months: Zika is now spreading locally in the United States.

The announcement came after the agency and the Florida Department of Health identified four individuals that officials believe contracted the disease from mosquitos in Miami carrying the virus.

The number of Zika virus infections in Florida is on the rise.

On Monday, Florida Gov. Rick Scott announced that a total of 14 people (12 men and two women) are believed to have contracted the virus in the state. This is up from the four infections reported last week by the Florida Department of Health and Centers for Disease Control and Prevention, an announcement that signaled local mosquitoes are likely now transmitting the virus.

Today, the Centers for Disease Control and Prevention announced that the Zika virus has begun to transmit locally in Florida. The mosquito-borne and sexually transmitted virus has, up to now, only entered the continental United States via travelers.

This announcement is based off four cases around Miami-Dade County. And as Vox’s Julia Belluz explains, it’s not a surprise. Health officials have for months been anticipating a small, local outbreak somewhere in the southeastern United States. Tom Frieden, the CDC’s director, predicted it in May: “We do expect there will be some spread — through mosquitos — in [these] parts of the continental US,” he said.

Though Brazil has been in the news all year for a massive Zika epidemic, health officials aren’t concerned that the Olympics in Rio will pose a big risk for spread of the virus.

The World Health Organization, the US Centers for Disease Control and Prevention, and the European Center for Disease Prevention and Control have all said the risk is low. The key reasons: It’s winter there, so mosquitoes aren’t around in great numbers, biting people. (Mosquito bites are thought to be the main way the Zika virus spreads.) And the number of new cases recorded in the country has been on the decline for months, while authorities have been taking precautions to kill off and control mosquito populations.

With peak mosquito season here, fears of an outbreak of the mosquito-borne (and sexually transmitted) virus Zika in the United States are mounting.

Meanwhile, Congress has done nothing to prevent the situation from getting worse.

Scientists have suggested that oral sex may be yet another possible way Zika can be transmitted from person to person, raising concerns that more cases of the virus may be transmitted through semen.

In a letter to the New England Journal of Medicine, a group of French researchers detailed a case that involved a 24-year-old Parisian woman and a 46-year-old man who had traveled to Brazil.

Zika has been spreading throughout the Western Hemisphere, carried mainly by a type of mosquito called Aedes aegypti. The virus is a major concern in countries such as Brazil, Venezuela, and El Salvador, and mosquitos have begun to transmit the virus locally in Puerto Rico.

Zika isn’t yet transmitting in mosquitoes the United States — all of the people with Zika here were infected while traveling or through sexual transmission. But the number of those cases is rising. According to a May 18 update from the Centers for Disease Control and Prevention, there are currently 544 Zika infections in the US. And as of May 12, the CDC reports there are 157 pregnant women with a possible Zika infection on the mainland.

If you’ve been watching cable news, you might get the impression that an epidemic of Zika among pregnant women has suddenly spiraled out of control in the United States.

According to a report on Friday from the Centers for Disease Control and Prevention, 279 pregnant women with possible Zika infection in US states and territories are being monitored — tripling the agency’s previous estimates.

A situation playing out right now among top health officials in the United States is giving us a bit of déjà vu.

Let’s call it the looming-health-disaster money scramble.

The pesky Aedes aegypti mosquito has been buzzing around infecting millions of people in the Western Hemisphere with the Zika virus. Now some scientists think we should retaliate — and infect the mosquito with a strange little bug of our own.

It sounds zany, but it might actually work. Scientists have long known that if they infect just a few A. aegypti mosquitoes with a type of bacterium known as Wolbachia, the microbe will rapidly spread and infect much of the population. Once that happens, the infected mosquitoes lose their ability to transmit dengue fever among humans.

As mosquito season in the United States approaches, we’ve been hearing stories of pregnant women anxiously emailing each other about how to Zika-proof their lives. Some are cancelling trips to Brazil or Florida because of fears of the virus.

It’s no wonder: While Zika seems to be pretty benign in most people, not even causing symptoms in about half of those infected, it’s extremely harmful to fetuses.

>

With every disease outbreak, researchers try to figure out how far — and how fast — a virus is likely to spread through a population.

Disease outbreaks are terrible for people but great for our scientific understanding of viruses. That’s especially true for the Zika virus, which seemingly burst out of nowhere to become a top health research priority in the past year.

Prior to the massive, ongoing outbreak in the Americas, there had only been about 25 published research papers on the disease since 1952. Researchers long thought Zika was a fairly benign virus, spread mainly by mosquitoes and endemic to Africa. It wasn’t on the radar as any sort of threat. It wasn’t even a disease health officials in the US bothered to track.

The Zika virus was first discovered in the 1940s, though most people had never heard of it until this year. That’s because for decades, Zika outbreaks were sporadic and tiny, and the disease seemed to do little harm.

That changed in 2015. A massive outbreak in Brazil — which affected up to 1.3 million people there in 2015 alone — has altered the scientific community’s view of the mosquito-borne virus. Scientists are learning that Zika may actually be a lot more dangerous than anyone thought, potentially damaging the brains of fetuses and causing incurable and lifelong health and cognitive problems. In light of this evidence, the World Health Organization declared a public health emergency on February 1.

When it comes to Zika, there are many more unknowns than knowns. One big question about the virus has been whether a Zika infection can cause Guillain-Barré, a rare and sometimes deadly neurological condition in which people’s immune systems damage their nerve cells, leading to muscle weakness, paralysis, or, in rare cases, death.

New proof of a link with Guillain-Barré was published Monday in the Lancet.

In Florida, three pregnant women have tested positive for the Zika virus — the mosquito-borne disease that’s currently raging across Central and South America.

All of the women were infected while traveling abroad, the Miami Herald reports.