Olympics virus cases raise tricky questions about testing

By Emily Anthes and Alexandra E. Petri

On Sunday, officials announced that two players on South Africa’s soccer team had become the first athletes to test positive for the coronavirus inside Tokyo’s Olympic Village. The next day, news broke that an alternate on the American women’s gymnastics team, training outside of Tokyo, tested positive.

Another cluster of cases has reportedly popped up on the Czech men’s beach volleyball team. There will be more.

“The Olympic Village isn’t the type of lockdown bubble that you saw in the NBA,” said Zachary Binney, a sports epidemiologist at Oxford College of Emory University. “So I think you are going to continue to see cases pop up, including among vaccinated people.”

It is too early to judge what effect, if any, the Olympics will have on the COVID-19 pandemic writ large — or if the Games may ultimately fuel larger outbreaks.

But the discovery of isolated cases, even in vaccinated athletes, is entirely expected, scientists say, and not necessarily a cause for alarm. “This isn’t really that much of a surprise,” said Angela Rasmussen, a virus expert at the Vaccine and Infectious Disease Organization at the University of Saskatchewan.

Still, these cases do raise thorny questions about how to design testing programs — and respond to test results — at this phase of the pandemic, in which the patchy rollout of vaccines means that some people and communities are well protected from the virus while others remain at risk.

As Rasmussen put it: “When does a positive test really indicate that there’s a problem?”

— Counting cases

COVID-19 tests, which were once profoundly limited, are now widely available in most of the developed world, making it possible for organizations — including private employers, schools, professional sports leagues and the Olympics organizers — to routinely screen people for the virus.

Vaccination is not required for Olympic participants, and officials are relying heavily on testing to keep the virus at bay in Tokyo. Those headed to the Games must submit two negative tests taken on separate days within 96 hours of leaving for Japan regardless of vaccination status, according to the Olympic playbooks, or manuals.

At least one of the two tests must be taken within 72 hours of departure. Participants are again tested upon arrival at the airport.

Athletes, coaches and officials are also required to take daily antigen tests, which are less sensitive than the more invasive PCR tests but are generally quicker and cheaper. (Olympic staff and volunteers may be tested less frequently, depending on their level of interaction with athletes and officials.) If a test comes back unclear or positive, a PCR test is administered.

“Each layer of filtering is a reduction in the risk for everybody else,” Brian McCloskey, the chair of the Independent Expert Panel of the International Olympic Committee, told reporters this week, adding that the number of confirmed infections is “lower than we expected.”

But when you look that hard for infections — especially in a group of people who have recently flown in from all over the globe and have had varying levels of access to vaccines — you’re all but destined to find some.

“The bottom line is there’s still just a lot of SARS-CoV-2 around the world that’s spreading,” Rasmussen said, referring to the virus that causes COVID-19.

So far, 75 people with Olympic credentials have tested positive for the coronavirus, including six athletes, according to Tokyo 2020’s public database. That number does not include those who tested positive before their departure to Japan. Little information has been released about the severity of most of these cases, though public reports suggest that the athletes are generally experiencing mild or no symptoms.

“You’re going to pick up on these low-grade infections, and the players are going to be quarantined and out of competition,” said John Moore, a virus expert at Weill Cornell Medicine in New York. “And they’re probably not going to be ill, because they’re young, healthy athletes.”

According to the Olympic playbooks, athletes with positive PCR tests are to be isolated at designated facilities, though the location and length of isolation vary depending on the severity of the case. Japan’s health authorities require a 10-day quarantine at facilities outside the Olympic Village, and multiple negative PCR tests before discharge, an IOC official said in an email.

— Changing course

Given these kinds of disruptions, some experts say that the benefits of routine testing of asymptomatic vaccinated individuals may not be worth the costs.

“Many places are still continuing to asymptomatically screen fully vaccinated individuals, which isn’t something that the CDC guidance recommends,” said Dr. Amesh A. Adalja, an infectious disease expert at Johns Hopkins Center for Health Security. “It lends itself to all of these kind of pseudo outbreaks that you might see with a bunch of asymptomatic infections.”

Testing remains vital for people who have symptoms of COVID-19, he noted. But it no longer makes sense for those who feel fine and have been fully vaccinated, particularly with one of “the big four” vaccines — Pfizer, Moderna, Johnson & Johnson or AstraZeneca — for which there is the most data, he added.

But officials may not always know who has been vaccinated and what vaccine they have received, Rasmussen noted. In those instances, they “really have no choice” but to use testing and contact tracing to minimize risks.

Moreover, questions about transmission remain unsettled. Vaccinated people with asymptomatic or breakthrough infections may still be able to pass the virus on to others, but it is not yet clear how often that happens.

Until that science is more definitive, or until vaccination rates rise, it is best to err on the side of safety and regular testing, many experts said. At the Olympics, for instance, frequent testing could help protect the broader Japanese population, which has relatively low vaccination rates, as well as the support staff, who may be older and at higher risk.

“It’s those folks I’m most worried about, really,” said Dr. Lisa Brosseau, a research consultant at University of Minnesota’s Center for Infectious Disease Research and Policy.

Not only can they contract the virus, adding strain on the Japanese health care system, but they can also become sources of transmission: “Everybody’s at risk, and everybody could potentially be infected,” she said.