Clinical manifestations of different viral respiratory infections in athletes: implications for risk assessment and return-to-sport - AWARE VII study in 116 cases

The aims of this study were to describe the etiology of acute respiratory infections (ARinf) in athletic individuals, and to identify differences in the clinical presentation, evidence of possible multi-organ involvement, and illness classification between common pathogen groups. One-hundred-and-sixteen cases of confirmed ARinf in athletic individuals were evaluated ≤ 5 days of the onset of an ARinf. Nasopharyngeal swab multiplex PCR testing was performed to identify a causative pathogen. Symptomatology, clinical examination findings, results of selected blood tests, and the clinical syndrome and illness severity classifications were compared between four common pathogen groups. The etiologies of ARinf in this cohort were: rhinovirus = 34(29%), influenza = 17(15%), SARS-CoV-2 = 15(13%), common coronavirus = 13(11%), ‘unidentified’ = 16(14%), ‘dual pathogen’ = 9(8%), and ‘other’ = 12(10%). Clinical presentation differed among the four common pathogen groups as follows: Influenza had more <i>total symptoms</i>, <i>lower respiratory &amp; regional</i> symptoms, and <i>systemic &amp; non-respiratory</i> symptoms than rhinovirus (<i>p</i> ≤ 0.002) and common coronavirus (<i>p</i> &lt; 0.05). Influenza and SARS-CoV-2 had higher <i>total symptoms</i> and <i>systemic &amp; non-respiratory</i> symptom severity scores than rhinovirus (<i>p</i> ≤ 0.0006 and <i>p</i> &lt; 0.03 respectively) and common coronavirus (<i>p</i> ≤ 0.03 and <i>p</i> = 0.02 respectively). Evidence of <i>other non-respiratory organ involvement</i> on clinical examination was highest for influenza (53%). Illness classification for pathogen groups differed: common coronavirus had the highest percentage (%) of <i>rhinitis-like (‘common cold’)</i> illnesses (69%), and influenza had the highest % of ‘<i>flu-like’</i> illnesses (82%). Influenza had the highest % of <i>severe</i> illnesses (88%) and common coronavirus the lowest (31%). 41% of rhinovirus presented with severe illness. Influenza and SARS-CoV-2 had greater number and severity of symptoms than rhinovirus and common coronavirus. Among the four common pathogen groups, influenza had the highest percentage of abnormal clinical examination and serological findings and severe illnesses. Knowledge of the causative pathogen and the clinical presentation may add value to the risk assessment and guide clinical decision-making in return-to-sport following ARinf in athletic individuals.