Clinical characteristics, outcomes, and subtype diversity in hospitalized human rhinovirus (HRV) patients

Background Human rhinovirus (HRV) is a major cause of respiratory illness, however data on clinical presentation, outcomes across age-groups and associations with HRV subtypes are limited. Methods Clinical characteristics and outcomes of hospitalized HRV-positive patients with cycle threshold (Ct)≤32 were collected retrospectively and analyzed in relation to age-groups and subtypes. Results Among 738 patients, the age distribution was: 0–1 (148,20.1%), 1–3 (94,12.7%), 3–5 (44,5.9%), 5–18 (76,10.3%), 18–40 (51,6.9%), 40–65 (95,12.9%) and ≥65 (230,31.2%). Younger children more frequently presented with bronchiolitis and asthma exacerbation, while older adults experienced higher rates of pneumonia and chronic obstructive pulmonary disease (COPD) exacerbation. ICU admissions and mechanical ventilation were more common in younger children, whereas oxygen support was predominant in older adults. Of 119 sequenced samples, HRV-A was the predominant species (69%), followed by HRV-C (28.5%), with both exhibiting considerable genetic subtype diversity. Lower respiratory tract infection (LRTI) associated with HRV-C was found only in adults while severe and critical outcomes with HRV-A and HRV-C occurred in both children and adults. When compared with human metapneumovirus (hMPV), a known pathogenic respiratory virus, no differences in severe outcomes were noted, however, HRV patients aged ≥65 had a higher proportion of critical outcomes. Conclusions HRV infection is associated with significant morbidity across age-groups, with distinct clinical presentation and outcomes. ICU admissions were more frequent in children, while older adults required oxygen support. The genetic diversity and age-related differences in HRV subtypes underscore its clinical impact in both pediatric and adult populations.