Clinical Impact of Acute Respiratory Virus Infections in Nursing Home Residents

OBJECTIVES: To investigate the suspected acute respiratory infection (ARI) risk and the clinical impact of a range of respiratory viruses in Dutch nursing home (NH) residents. DESIGN: Prospective cohort study (March 2023-May 2025). SETTING AND PARTICIPANTS: Residents from 15 Dutch NHs were enrolled when suspected of an ARI. METHODS: Clinical data were collected on days 0, 14, and 28. Residual nasopharyngeal and oropharyngeal swabs were tested for a broad respiratory virus panel. A Bayesian multilevel logistic model including seasonal and NH-level random effects estimated suspected ARI risk. Relative clinical outcomes were compared by virus. RESULTS: Among 3195 residents, 526 suspected ARI episodes occurred. The estimated suspected ARI risk was 10.2% (95% credible interval, 1.7-43.8). Viruses were identified in 291 episodes: severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; 29.0%), influenza A virus (23.6%), rhinovirus/enterovirus (18.8%), respiratory syncytial virus (11.8%), human metapneumovirus (hMPV; 6.4%), parainfluenza viruses (5.1%), and human coronaviruses (5.4%). hMPV and respiratory syncytial virus tended to be associated with higher odds of moderate or severe disease, and hMPV was linked to a 4-fold increase in bed hours. Influenza A was associated with delayed recovery, oxygen requirement, and a 3-fold risk of secondary bacterial pneumonia. SARS-CoV-2 cases had higher estimated odds of recovery by day 14 and spent fewer additional hours in bed during ARI episodes. CONCLUSIONS AND IMPLICATIONS: Influenza remains a major contributor to ARI burden in NH residents, whereas SARS-CoV-2 has relatively limited impact. The pronounced clinical impact of hMPV suggests its relevance for ARI management in this population.