How high is the risk of contracting COVID-19 in a stadium?
The European Championship is being held in 11 different cities in 10 different countries. The images we are seeing on our television or computer screens seem strange to many  18 months into the pandemic: Crowds in confined spaces spreading aerosols through their chanting, thousands of people not wearing masks. Our fact check provides the initial answers. At some EURO 2020 matches, fans were screened out in advance due to of positive COVID-19 rapid tests; at others, spectators tested positive for the virus after the fact. In Denmark, spectators tested positive for the Delta variant after the match between the hosts and Belgium. The authorities then advised 4,000 spectators from certain stadium blocks to get a PCR test. In Budapest, a French family are reported to have tested positive after France's match against Hungary. By far the most COVID-19 cases were reported after Finland's match against Belgium, which took place in St. Petersburg. According to Finnish media, at least 86 infections were detected in people returning home from Russia. In most cases, it is unclear whether they were infected in the stadium itself or elsewhere, like during travel to and from the match. Experts agree that the chance of contracting COVID-19 at outdoor events is relatively low as fresh air dilutes aerosols  the airborne particles produced by breathing and talking that carry the virus. But only if the minimum personal distancing from others is maintained. William Schaffner, professor of infectious diseases at Vanderbilt University in the United States, also points out that stadium attendance during Euro 2020 in and of itself poses a very low risk of infection, provided safety measures such as limiting the number of spectators are observed. However, the measures vary from one European Championship venue to another. In Budapest they have been filling the Ferenc Puskas Stadium to capacity, but spectators need to provide a negative PCR test to be admitted. In Glasgow, Hampden Park has only been 25% full, but spectators have not been required to provide a PCR test. According to German aerosols researcher Gerhard Scheuch, dangers lurk in football stadiums  particularly in often poorly ventilated boxes, elevators and restrooms. Gatherings outside of the stadium, like these Danish fans in Amsterdam, are part of the problem  "If an infected person exhales the virus there, the aerosols linger for a relatively long time," he said. Most problematic, according to Scheuch and Schaffner, is what happens before and after a game; tens of thousands of fans use buses, trains and planes to get to and from the stadium. They stay overnight in hotels and may want to party in bars after a game. Scientific studies show that mask-wearing is a critical factor in preventing outbreaks. According to a still-unpublished study by the RWI Leibniz Institute for Economic Research and the SDU University of Southern Denmark in Sonderborg, obtained by DW, Bundesliga matches with large crowds led to a significant increase in new infections. This was particularly the case when the masks only had to be worn on the way to the seats, but not in the fan block. Danish fans in Copenhagen seemed comfortable gathering together without masks  Sporting events with a high number of spectators "pose an increased risk of infection," says the author of the study, Philipp Breidenbach. The researchers recorded an increase in local infection rates of about seven to eight percent after the Bundesliga matches studied. The results are clear evidence of how important it is to wear a mask and maintain one's personal distance rules when attending events, the study says. Schaffner agrees: "Masks are not perfect. But they do provide some protection if everybody is yelling around you in a soccer game." The first half of the European Championship has already shown that the specified minimum distances in the arenas are not being observed. In Copenhagen, Munich, Budapest and other venues, many fans stood and sat close together. At the same time, the maximum capacities in many stadiums were drastically reduced by UEFA so that such distances could be maintained. The exception so far has been Budapest, where not only a full stadium but also fan marches with up to 20,000 participants were allowed to go ahead. Worth a try: A steward in Munich holds up a sign reminding fans to keep their distance  The semifinals and the final are to be played at London's Wembley Stadium with up to 75% capacity. This means only every fourth seat will be free  too few to maintain a minimum distance of 1.5 meters between spectators. There are growing concerns about the fact that the number of infections being caused by the Delta variant of COVID-19 is on the rise in host countries Russia and in Great Britain. The last three matches of the tournament are to be held in London, with Wembley to be filled to 75% capacity. If UEFA has its way, Wembley will have even more spectators for the semis and final than for Austria vs. Italy  UEFA has also decreed that around 2,000 foreign spectators as well as 2,500 UEFA officials, media representatives and VIP guests are to be allowed into the stadium without going through the usually required quarantine after entering the country. Scheuch, like many others in his field, has warned against this. Nevertheless, Scheuch believes the risk that Euro 2020 will strongly drive the spread of the Delta variant of the virus in Europe is low. "At the final, we might have a seven-day incidence-rate of 200. Let's assume no tests were done and everyone was just let in. Then we would have about 120 people at most in that stadium who are infected." Of those people, Scheuch said, only a portion would be highly contagious. In this worst-case scenario, Scheuch arrives at a total of about 50 new infections. One can only hope that these Croatian fans don't bring home an unwelcome souvenir home from Copenhagen  "Of those, however, most will be English people who will stay in the country; only a few will return to Europe." According to the scientist, the more contagious Delta variant is already on the rise in Europe anyway, and a few more infected people will not greatly accelerate the rate of infection. Other experts also believe that Delta will soon be the dominant variant in other countries, regardless of the effect of Euro 2020  Still, many, such as the chairman of the World Medical Association, Frank Ulrich Montgomery, warn against traveling to London because of the higher risk associated surrounding Euro 2020 beyond actually attending games. According to the European Centre for Disease Prevention and Control, just under 36 percent of adult European Union citizens have been fully vaccinated (as of June 28).