TOPLINE:

Hospitalised adults with SARS‑CoV‑2, parainfluenza virus, or respiratory syncytial virus (RSV) infection are more likely to develop acute respiratory failure than those with influenza A/B infection — with SARS‑CoV‑2 infection carrying the highest risk.

METHODOLOGY:

• Researchers in Norway conducted a retrospective cohort study to compare the risk and severity of acute respiratory failure among patients hospitalised with different respiratory virus infections.
• They included 4927 patients (median age, 70.7 years; 48.7% men) with polymerase chain reaction-confirmed infections with influenza A/B, RSV, parainfluenza virus types 1-4, SARS-CoV-2, or human metapneumovirus, tested within 2 days of hospitalisation or within 14 days if the test was performed in primary care.
• Clinical, radiographic, and laboratory data were extracted from electronic medical records.
• The primary outcome was acute respiratory failure, defined as the need for high-flow oxygen, non-invasive ventilation, or mechanical ventilation during hospitalisation.

TAKEAWAY:

• Overall, 11.3% of patients experienced acute respiratory failure. Influenza A/B was detected in 43.0% of patients, RSV in 16.4%, SARS‑CoV‑2 in 15.8%, parainfluenza virus in 13.4%, and human metapneumovirus in 11.4%.
• Among the virus groups, SARS‑CoV‑2 was linked to the highest risk for acute respiratory failure (> 20% in adjusted analysis) compared with influenza A/B; in contrast, parainfluenza virus and RSV were associated with modest but significant increases in risk compared with influenza A/B (P < .01 for all).
• Patients with SARS‑CoV‑2 infection were most likely to need non-invasive or mechanical ventilation, followed by those with parainfluenza virus or RSV infection; those with influenza A/B infection had the lowest risk.
• In a separate analysis, only SARS-CoV-2 was associated with severe acute respiratory failure requiring mechanical ventilation (odds ratio, 14.90; 95% CI, 6.53-33.98).

IN PRACTICE:

"These results underline the need for careful clinical surveillance of adults with non-influenza respiratory viruses and have implications for hospital preparedness and preventive strategies," the authors wrote.

SOURCE:

The study was led by Kirill Neumann, MD, PhD, Akershus University Hospital, Nordbyhagen, Norway. It was published online on 08 April, 2026, in Open Forum Infectious Diseases.

LIMITATIONS:

The study was limited by its single-centre retrospective design and the absence of data on vaccination, frailty, and baseline functional status. The smaller sample sizes for human metapneumovirus and parainfluenza virus limited the precision of subgroup estimates. Additionally, the study excluded non-hospitalised patients.

DISCLOSURES:

The study was supported by the Norwegian Association for Pulmonary Medicine. The authors disclosed having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.