Published 3/25/2022
Ariel DeMaio

How Safe and Effective Are COVID-19 Return-to-play Protocols?

A case study from the Union of European Football Associations

When the World Health Organization (WHO) declared the COVID-19 public health emergency a pandemic on March 11, 2020, and stay-at-home and shelter-in-place orders were imposed across the globe, normal life came to a halt. Professional sports play was interrupted worldwide until a greater understanding of COVID-19 and its spread created a path for reopening. In the European Union, COVID-19 safety protocols were implemented in August 2020, but according to findings presented at the AAOS 2022 Annual Meeting, the protocols did not significantly curb COVID-19 spread. However, the time lost to COVID-19 was shorter than expected, leading the researchers to adopt an “optimistic view” of the protocols’ effectiveness.

Lead author Daniele Mazza, MD, from the Orthopaedic Unit and Kirk Kilgour Sports Injury Centre at Sant’Andrea Hospital at the University of Rome, and colleagues noted one potential explanation for the undeterred spread. “Unfortunately, football is a close-contact sport, so most hygiene procedures and social distancing were not always applied,” Dr. Mazza and colleagues acknowledged.

In this study, Dr. Mazza and coauthors reviewed epidemiologic data of COVID-19 infection incidence among the top 15 European Leagues’ professional football associations during the 2020–2021 season. They sought to evaluate the impacts of the return-to-play (RTP) protocols and operational protocols that the Union of European Football Associations (UEFA) implemented to restart official matches between national teams.

Three principles to minimize COVID-19 spread governed the reopening: social distancing, hygiene principles, and COVID-19 testing. The rules were adopted on Aug. 5, 2020.

During the season, 801 cases of COVID-19 infection among players were recorded, for a positivity rate of 9.32 percent. COVID-19 reinfection occurred in 18 cases (2.2 percent).

The average duration of RTP—defined as the number of days from a positive COVID-19 test to the first match appearance with the first team, reserve team, youth team, or national team—was 14.75 ± 2.27 days. The average number of games not played by a player who tested positive for COVID-19 was 2.61 ± 1.82 games lost.

For the smaller group of athletes who had COVID-19 reinfection, the average RTP was 8.47 ± 5.24 days, which the researchers noted was significantly shorter than the RTP with first infection (P <0.001). consequently, games lost after reinfection were 1.88 ± 0.99.>

The position with the highest rate of infection was defender, at 34 percent (n = 272), and the position with the highest rate of reinfection was goalkeeper, at 33.3 percent (n = 6 cases).

Regarding incidence among the football leagues, the Turkish league recorded the highest number of infections (n = 184; 22.2 percent of all first infections), and the Italian league had the highest rate of reinfections (n = 10; 55.6 percent).

“The goalkeeper was the role most infected,” the authors commented. “This finding is interesting, considering the low number of goalkeepers on the teams compared to other roles. Otherwise, the infection of a goalkeeper was frequently followed by the contagion of other players, as caused by the different training practices carried out.”

Looking at variance in the rates of infection throughout the season, Dr. Mazza and colleagues found that the month with the highest number of first infections was November 2020, when nearly one-quarter of all first infections were recorded. The month with the largest number of reinfections was April 2021, representing 44.4 percent of the total number of second infections.

“The resumption of sport has contributed to the restoration of normality in society, but in a COVID-19 context, this would have led to an increase in cases, despite the health protocols,” the authors concluded. “The incidence of COVID-19 in professional football restart after the stop due to the pandemic state declaration was significant, and the diffusion curve trend followed the trend of the European diffusion, reaching the highest number of cases in October and November.”

Although the findings from this retrospective analysis offered some optimism about the effectiveness of return-to-play protocols during the COVID-19 pandemic, the authors noted several limitations. For example, some teams did not communicate COVID-19 positivity rates to the press due to privacy reasons, which could affect precise exposure results.

“To the best of our knowledge, the current study presents the most extensive series of elite European football players suffering from COVID-19, analyzing RTP rate and incidence,” Dr. Mazza and colleagues concluded. “The short RTP and the long observation period led to an optimistic view of the UEFA return-to-play protocol effectiveness.”

The study will be on display as Poster P0914 on Friday in Academy Hall, from 7 a.m. to 5 p.m.

Dr. Mazza’s coauthors of “The Incidence of COVID-19 in European Professional Football: Were COVID-19 Protocols Safe and Effective?” are Giorgio Princi, MD; Alessandro Carrozzo, MD; Alessandro Annibaldi, MD; Leonardo Previ, MD; Leopoldo Arioli, MD; Andrea Redler, MD; and Andrea Ferretti, MD.

Ariel DeMaio is managing editor of AAOS Now.