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.
Despite these pronouncements, however, some athletes are simply not willing to take the risk. More than a dozen, including top-ranked tennis players Simona Halep and Milos Raonic and golfers Jason Day and Rory McIlroy, have dropped out of the competition, citing concerns about the virus.
Meanwhile, other athletes have used the occasion to mock the fear. As South African golf legend Gary Player told Fox News last week, "You’ve got more of a chance of being killed by a gun or a motorcar in America than getting Zika."
That may be true, but if you’re still not satisfied about the degree of risk, we’ve got you covered. Here’s a full rundown of potential Zika concerns in Brazil (with the strong caveat that the odds of people contracting or spreading the virus there are low!) and other more pressing health threats facing the games.
Avoiding Zika in Brazil will mean practicing safe sex — not just avoiding mosquito bites
Catching Zika from mosquitoes is a remote risk at the Summer Games, but health officials have been warning people in Brazil to avoid mosquito bites by wearing protective clothing and repellent. They’re also telling folks that Zika can be spread through sex.
There have been more than 20 cases of Zika sexual transmission in 10 countries, involving oral, anal, and vaginal sex. The virus has been shown to spread from women to men, men to men, and men to women.
The best evidence so far suggests infectious Zika can last in semen for up to 62 days. Researchers have also found Zika in a woman’s vaginal fluid 11 days after she showed symptoms of infection. Zika virus symptoms usually clear up in about a week. So this means Zika can spread through sex long after its symptoms disappear. And in any country that’s been battling a Zika outbreak, that’s a risk to be aware of.
It’s also important to keep in mind that this is a relatively new virus, and researchers are exploring other potential ways Zika can spread — in addition to sexual contact and through mosquito bites.
We know Zika can be passed on from mothers to fetuses, and through blood transfusions. It’s possible Zika could also be spread through urine and saliva. In a recent case in Utah, a man who died from Zika passed it on to his caregiver, though the two didn’t engage in sex (the caregiver was reportedly the man’s son) and officials don't believe Aedes mosquitoes, which carry the virus, are established in Utah. So we may have more to learn about how Zika spreads.
Zika poses the most risk to pregnant women and their babies
For most people, however, Zika isn’t a serious health threat. For four out of five people, the virus doesn’t cause any symptoms. The 20 percent who do get sick typically have mild symptoms — a low-grade fever, sore body, and headache, as well as red eyes and an itchy body rash. Complications from the virus in adults seem to be very rare.
But in fetuses infected with Zika, the virus isn’t mild at all.
Zika can cause a range of birth complications, most notably microcephaly, a severe birth defect characterized by a shrunken head and incomplete brain development.
In addition, researchers have found that the virus seems to kill off the tissue in entire regions of the brain, damage babies' eyes and ears, and heighten the risk of miscarriage and fetal death.
Researchers believe pregnant women are at the greatest risk of having babies with birth defects if they are infected in the first trimester. (More from the CDC here.) "Although preliminary data from Colombia suggest that Zika virus infection during the third trimester of pregnancy is not linked to birth defects like microcephaly," Margaret Honein, the CDC’s co-lead of the pregnancy and birth defects task force for the Zika response, told Vox in an email, "continued monitoring of the impact of Zika virus on pregnancy and infant outcomes is important and ongoing."
Health officials also think the risk is pretty rare (about one in 100 pregnant women infected with the virus will pass it on to their babies).
But in order to protect people, the CDC is advising women who are pregnant not to go to the Olympics, and for couples who are thinking of becoming pregnant soon to consult a physician before traveling. They also suggest using condoms or abstaining from sex for between eight weeks and six months, depending on the likelihood of infection, to avoid putting a fetus at risk of Zika:
The risk of Zika is lower than for other diseases
Now that we’ve gotten all the important Zika info out of the way, let’s be clear that this virus won’t be the only health risk in Brazil during the Olympics.
The WHO has been reminding people to get vaccinated against measles and rubella, among other diseases, at least two weeks before traveling, so you don’t bring any potentially outbreak-sparking bugs there or pick up diseases that may be circulating.
To put all the Olympic health risks in perspective, the ECDC ranked them. Interestingly, while it classified Zika as posing a "low risk," gastrointestinal infections (caused by everything from food poisoning to norovirus, salmonella, E. coli, and Campylobacter) are considered a "moderate risk." This is no doubt because Rio has a massive sewage contamination problem in the water system, which the city has been working to — but unlikely to — contain for the games.
Influenza, meanwhile, is "high risk" — the most urgent of all potential health problems.
That's because it'll be flu season in Brazil. Thinking rationally about these health concerns, John McConnell, editor of the journal Lancet Infectious Diseases, told Vox, "People are much more likely to go home carrying flu than Zika virus, and flu is a much more dangerous disease."
The flu kills more than 30,000 people a year in the United States. Zika, meanwhile, has killed one person in the continental US.