Human Metapneumovirus Epidemiology Among Middle-aged and Older Adults Hospitalized With Acute Respiratory Infection.

BACKGROUND

Human metapneumovirus (hMPV) significantly impacts young children, older adults, and those with preexisting conditions. This study examines frailty and clinical outcomes in middle-aged and older adults hospitalized due to hMPV infections.

METHODS

Data from the Canadian Immunization Research Network's Serious Outcomes Surveillance Network were analyzed. Included were adults aged ≥50 with lab-confirmed hMPV infection. Severe infection was marked by pneumonia, oxygen need, intensive care unit admission, mechanical ventilation, or death within 30 days. The Frailty Index (FI) categorized individuals as nonfrail (FI < 0.08), prefrail (FI ≥ 0.08, FI < 0.21), and frail (FI ≥ 0.21). Multivariate ridge regression identified factors linked to disease severity.

RESULTS

Among 212 patients (median age 76), 85.4% had severe disease and 61.3% were frail. Frail patients had higher rates of severe disease (80.8% vs. 63.4%), oxygen therapy need (80.8% vs. 63.4%), and longer hospital stays (median 8 vs. 4 days) than patients who were nonfrail. Any cardiac illness (odds ratio [OR], 1.76; 95% confidence interval [CI], 1.02-3.09), congestive heart failure (OR, 1.91; 95% CI, 1.12-3.09), chronic obstructive pulmonary disease (OR, 1.93; 95% CI, 1.14-3.35), and frailty (OR, 1.99; 95% CI, 1.18-3.38) were significantly associated with increased odds of severe disease.

CONCLUSIONS

Frailty, assessable with standardized tools, is associated with severe hMPV infections in middle-aged and older adults. Recognizing frailty in clinical management and as a vaccination criterion is necessary as hMPV vaccines become available.

CLINICAL TRIALS REGISTRATION: NCT01517191 (ClinicalTrials.gov).