A71-07 Post-recovery Hospitalization Risk Following Human Metapneumovirus and Respiratory Syncytial Virus Infections in Adults

Background and Objectives

Human metapneumovirus (hMPV) and respiratory syncytial virus (RSV) are increasingly recognized as important causes of respiratory illness in adults. While acute-phase outcomes have been relatively well described, data on post-recovery morbidity requiring hospitalization remain limited. Our aims were to compare the incidence and risk factors for hospitalization due to acute illness after recovery from hMPV or RSV infection in adults.

Methods

We conducted a retrospective cohort study of adults aged ≥18 years who tested positive for hMPV or RSV by multiplex PCR using nasopharyngeal swabs at the University of the Ryukyus Hospital between April 2023 and December 2025. Patients who achieved clinical recovery—defined as resolution of acute symptoms without ongoing need for antiviral or supportive treatment—were included. Patients who died during the index infection, had undergone tracheostomy, or lacked regular follow-up were excluded. Time from viral diagnosis to first hospitalization due to an acute illness after recovery was analyzed using Kaplan-Meier curves. Cox proportional hazards regression was performed to identify independent risk factors for post-recovery hospitalization, with clinically relevant entered into multivariable model.

Results

After exclusions, 86 patients were analyzed (median age 61 years; 50% male), including 44 with hMPV and 42 with RSV. Baseline comorbidities (hypertension, asthma, and malignancy were the most frequent), oxygen supplementation during infection (59% vs 45%), and hospitalization rates at the time of infection (66% vs 67%) were comparable between groups. Over a median follow-up of 246 days, hospitalization due to acute illness after recovery occurred in 36% of patients with hMPV and 33% with RSV. Kaplan-Meier analysis demonstrated no significant difference in post-recovery hospitalization risk between virus groups. Respiratory diseases accounted for the most frequent cause of hospitalization (23%), including bacterial pneumonia, subsequent influenza infection, and asthma exacerbation. In multivariable analysis, hypertension (hazard ratio [HR] 2.49, 95% confidence interval [CI] 1.03-6.02) and oxygen supplementation during the acute viral infection (HR 2.59, 95% CI 1.10-6.11) were independently associated with increased risk of post-recovery hospitalization.

Conclusions

Adults recovering from hMPV or RSV infection experienced a substantial burden of post-recovery hospitalization, with similar incidence between viruses. Hypertension and severe initial illness requiring oxygen supplementation identified patients at heightened risk. These findings highlight a prolonged period of clinical vulnerability following apparent recovery from adult respiratory viral infections and underscore the need for post-recovery monitoring strategies.

This abstract is funded by: None