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Adam Himmelsbach

Lost in transmission: The health risks pro sports will be taking as they reopen amid a pandemic

A lot has been learned about the spread of the coronavirus since Utah center Rudy Gobert tested positive in March.
A lot has been learned about the spread of the coronavirus since Utah center Rudy Gobert tested positive in March.Barry Chin/Globe Staff

When Jazz center Rudy Gobert tested positive for COVID-19 on March 11, a sense of fear, unease, and confusion swept through the sports world. Up to that point, teams had primarily combated the virus by encouraging the use of hand sanitizer, and now franchises that had recently played against Utah (including the Celtics) were quarantining and rushing to acquire coronavirus tests.

Ultimately, there were 14 reported positive cases among NBA teams. None required extensive medical care, and most were asymptomatic. But the unknown in those early days was unsettling.

In the nearly three months since, a much clearer picture has emerged of how the virus is spread and what precautions can be taken to ensure that it does not.


But as the pro sports world reopens this summer, it will remain complicated. There will be tackling and body-checking and fouling, close contacts that all but dismiss social distance guidelines. Medical experts caution that leagues must be flexible and vigilant.

“As we move forward and start resuming sports, there’s really not going to be a black-or-white answer,” said Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security. “Everything is going to be shades of gray, because in the era of the pandemic, until there’s a vaccine, any activity that enhances social interaction there’s going to be a non-zero risk of transmission. So the only thing we can do is try to reduce the harm.”

Pro sports, in the short term at least, could be transformed in ways that would have seemed unfathomable at the start of the year, with athletes wearing protective face shields, with coaches donning masks and keeping a distance from their players, with locker rooms mostly avoided, and with robust testing systems in place. But epidemiologists stress that even with all of that, there will be transmission risks.


The good news, as far as sports are concerned, is that research has shown that the virus cannot be transmitted through sweat. And while there has been discussion about the dangers of touching contaminated surfaces, medical experts say that by far the greatest risk comes from exposure to respiratory droplets and aerosols from an infected person.

The bad news is that when athletes are competing, they are more likely to disperse those droplets than someone who is just sitting on a park bench. And social distancing is usually not an option.

“If someone’s breathing really hard as opposed to breathing quietly, there’s going to be a fairly greater risk,” said Dr. Richard Ellison, an epidemiologist at UMass Memorial Medical Center. “So if you’re in a sport where you’re routinely within 2-3 feet of someone else’s face and they’re breathing hard or yelling, there’s a real possibility you’re going to get exposed to respiratory droplets and breathe in the virus.”

Ellison said these concerns could even extend to coaches who are yelling to their players — or even talking louder — expelling respiratory droplets. The virus can also spread from the hands of an infected person, either through direct contact like a foul or a high-five, or through a shared surface.

“If you touch the same basketball as somebody else and then touch your mouth, nose, or eyes before you wash your hands, that’s going to be a potential mode of transmission of the virus, too,” said Dr. Shira Doron, an infectious disease physician and hospital epidemiologist at Tufts Medical Center.


The epidemiologists stressed that risks vary among the four major American pro sports. They agreed that basketball and football, with their close, consistent contact, posed the greatest threats. Baseball, meanwhile, would be the safest, mostly played in outdoor venues with natural social distancing. When players are in close contact — a runner on first, a hitter in the batter’s box — those interactions are generally brief.

Doron said it would help to constantly disinfect or replace game equipment that is touched by multiple players. But the best way to avoid transmission is to try to ensure that no infected players are competing.

A real test

Celtics players are now allowed to work out at the Auerbach Center in Brighton, but only individually.
Celtics players are now allowed to work out at the Auerbach Center in Brighton, but only individually.Maddie Meyer/Getty

The NBA is sending 22 of its 30 teams to complete the season in a secure bubble environment at Walt Disney World in Orlando. The NHL is planning to resume games in two hub cities. Baseball is still finalizing a plan, but it will likely involve games at home stadiums, and the NFL, for now, is hoping that by fall it will be able to play its schedule as usual.

“The more teams move around, the worse it gets in terms of traveling,” Doron said. “They’re around different people and there’s different levels of risk in different cities. Some cities are going to be on the downslope and some are going to be back into a surge.”

But for all leagues, testing will be central to ensuring that the risk of infection and transmission remains low. It’s unclear how frequently athletes will be screened. Doron said that if the NBA is truly a sealed environment, for example, daily testing should not be needed. But if baseball teams are traveling around the country, there could be more urgency.


“Every time you test, if you’re not in a bubble, you will find positives,” Doron said. “And you have to isolate the positives and quarantine all the exposed people, people who have been within 6 feet for at least 15 minutes of that sick person while they were in a contagious stage.”

There is more optimism now than there was several months ago, however. According to Dr. Paul Sax, clinical director of the Division of Infectious Diseases at Brigham and Women’s Hospital, recent research has shown that virus carriers appear to be contagious for just 1-2 weeks, even if they continue to test positive after that point.

“One of the debates in the professional health care system, and I’m sure it will apply to professional athletes as well, is whether we should just use a time-based criteria for bringing people back rather than a test-based,” Sax said. “And increasingly, we’re moving to time-based criteria. Say someone is at least 14 days after the onset of their symptoms, they can return to work and we don’t require them to have a negative test before returning.”

Ever since a group of NBA teams procured COVID-19 tests in March for asymptomatic athletes, just as the virus was beginning to envelop cities and nationwide testing capacity was inadequate, there has been unease about leagues using tests just to get their games going while pressing needs existed elsewhere. Test production and processing have been ramped up nationally, though, and games will not resume for another two months.


Even with a positive test result, the risk of complications for young, healthy people remains low. But Adalja said it will be important for leagues to consider anyone with an underlying health condition, and older team staffers. NBA commissioner Adam Silver on Thursday even suggested that some coaches might not even lead their teams from the bench.

“You’re going to have to think about the vulnerable populations that are involved with the teams, meaning the coaches, the other ancillary personnel,” Adalja said. “There are many coaches that are over 50 years old that are in higher-risk groups, and coaches with other medical problems like hypertension that you’re going to have to think about.”

A layer of protection

Face shields, like the one worn by the Flames' Matthew Tkachuk (left) could be useful for protecting athletes in other sports.
Face shields, like the one worn by the Flames' Matthew Tkachuk (left) could be useful for protecting athletes in other sports.Larry MacDougal/Associated Press

Beyond testing, leagues are studying measures to limit spread, from baseball players sitting apart in the stands rather than in the dugout to NBA traveling parties being considerably reduced. And on the courts and fields, medical experts say, there could be creative ways to use personal protective equipment.

For example, most hockey players wear face shields, so perhaps those could become mandatory and a bit bigger. Some football players wear visors, and those could possibly be extended to offer more coverage, too. Even if they only cover the eyes, that would help block another point of entry for the virus.

“Face shields are actually a favorite of some infectious disease doctors, because they feel like they provide more protection than just a mask because they cover the eyes,” Sax said. “In addition to safety for the hockey players, it also may prevent some respiratory spread.”

Added Doron: “Some epidemiologists think face shields may be the way of the future. It’s not proven, and if this concern of aerosols plays a bigger role than previously thought, then maybe the face shield won’t help so much, because the aerosol will just go around it. But if it’s more of the droplets, the face shield probably does do something even in the absence of wearing a mask under it.”

Aside from goggles, face protection is not feasible in an NBA game. Sax said that it would be useful for coaches and players on the bench to wear masks, however. That may sound somewhat trivial, as players then enter the game and start breathing all over each other, but the belief in is that any measure that reduces risk is worthwhile. Furthermore, Sax said, the sight of coaches in any sport wearing masks would send an important message to the general public.

‘The biggest risk’

The confined, often-dirty spaces of a locker room can become a breeding ground for COVID-19.
The confined, often-dirty spaces of a locker room can become a breeding ground for COVID-19.The Boston Globe/Globe Freelance

The medical experts said research has continued to confirm that the outdoors is considerably safer than indoors, where virus particles cannot be dispersed as easily. That’s good for baseball and football teams.

Sax said that basketball and hockey arenas are slightly more risky, but the cavernous, high-ceilinged venues are about the next best thing to being outside. The real dangers for teams, the experts said, lurk in the bowels of the arenas.

“Locker rooms,” Ellison said, “are going to be a very difficult setting. They would potentially end up being the biggest risk for players.”

These rooms are generally small, with no windows, and stalls that do not provide social distance.

In normal times, the locker room is a place that buzzes with activity, with players, medical staffers, equipment managers, public relations employees, and media members cycling in and out. Visiting-team locker rooms, by design, can feel more cramped than a pre-COVID subway car. Those settings will probably not exist now.

“Locker room etiquette will have to change,” Adalja said, “from the design and structure to the number of people. All of that would have to really be modified.”

In the end, Ellison said, there needs to be a high level of trust as these leagues resume. When teams play on the road, they will be hoping that the opposing team is taking the situation just as seriously as they are.

“The risk for the player is going to be only as good as how the other team is doing in terms of protection,” Ellison said. “Every team is going to have to do a very good job.”

Adam Himmelsbach can be reached at adam.himmelsbach@globe.com. Follow him on Twitter @adamhimmelsbach.