Factors associated with return-to-sport outcomes following pathogen-confirmed acute respiratory infections in...

To identify factors associated with return-to-sport (RTS) outcomes following confirmed acute respiratory infections (ARinf) in athletes.

This prospective cohort study included 114 confirmed ARinf cases among athletic individuals. Causative pathogens were identified using multiplex PCR testing, and illness severity was classified per International Olympic Committee consensus (mild, moderate and severe). RTS outcomes included time (days) to return-to-training (RTT), return-to-full-training (RTFT) and return-to-full-performance (RTFP). Cox regression models (HRs) assessed associations between RTS outcomes and demographics, sport participation, pathogen groups and illness severity.

The median (IQR) days to RTT were 3.5 (0-7), RTFT 8 (6-11) and RTFP 11 (7-14). Amateur athletes had prolonged RTS outcomes (HR range=0.51-0.59; p≤0.03) compared with professional athletes. RTS outcomes differed between the most common pathogen groups: influenza and SARS-CoV-2 had longer RTS than rhinovirus (HR range=0.11-0.23; p≤0.003). Severe illness was associated with prolonged RTS outcomes compared with mild and moderate illnesses (HR range=0.17-0.31; p<0.0001). Pathogen-related differences in RTS persisted within each severity group. Within mild/moderate illnesses, the influenza/SARS-CoV-2 subgroup had longer RTS than rhinovirus (HRs: RTT=0.35; RTFT=0.05; RTFP=0.06; p<0.05) and within severe illnesses (HRs: RTT=0.23; RTFT=0.21; RTFP=0.13; p≤0.01).

Factors associated with RTS outcomes following ARinf in athletes are level of sport participation, illness severity at presentation and the causative pathogen. Clinical assessment of illness severity remains valuable in RTS decision-making, particularly in low-resource settings. However, identifying the causative pathogen may provide additional predictive value and refine RTS clinical decision-making.