James Rudolph, MD, Professor and Palliative care Physician, Providence VAMC and Warren Alpert Medical School of Brown University
PROVIDENCE, RI — Older adults living in nursing homes have a similar likelihood of hospitalization and death from human metapneumovirus (hMPV) infection compared to an infection with influenza virus or respiratory syncytial virus (RSV), according to a recent study.
The retrospective, propensity-matched study published in The Journal of Infectious Diseases compared cases of hMPV infection with cases of influenza virus and RSV infection for hospitalization and death outcomes in older adults living in Community Living Centers (CLCs), which are nursing homes operated by the VA.1
Study authors are affiliated with the Providence (RI) VAMC; Brown University in Providence, RI; and North Carolina Agricultural and Technical State University in Greensboro, NC.
Nursing home residents have considerable morbidity and mortality risks associated with respiratory virus infections, particularly influenza virus, seasonal coronaviruses, RSV and hMPV, the four most prevalent respiratory viruses that infect older adults. Similar to influenza virus and RSV infections, hMPV infection, identified in 2001, can lead to hospitalization and death, especially in older adults and children. Increased use of respiratory panel-based, multiplex diagnostic assays has enhanced hMPV identification, but nursing homes typically lack basic laboratory facilities and laboratory-trained personnel required for diagnostic testing. The authors pursued this study because of the increasing awareness of hMPV in older patients and the vulnerability of nursing home residents, the study reported.
“As geriatricians, we are trained to care and protect those who are vulnerable due to age, disability and disease,” explained James Rudolph, MD, a professor and geriatrician and palliative care physician at the Center of Innovation in Long Term Services and Supports, Providence VAMC and Warren Alpert Medical School of Brown University. “There is an “outsized effect” of respiratory viruses in older people, with more death and disability from these infections. Geriatricians need to be vigilant and informed. Knowing hMPV exists in nursing homes broadens our outlook of addressing respiratory infection outbreaks”.
In this study, the researchers evaluated the electronic medical records of all residents of VA CLCs from July 1, 2017, to June 30, 2024. The VA owns and operates 134 CLCs, which have an average daily census of nearly 6,000 and serve more than 24,000 unique veterans each year. The study included CLC residents with laboratory-confirmed hMPV, influenza virus or RSV infections. The analysis balanced demographic and clinical characteristics. Proportional hazards models estimated the risk of hospitalization, death or the combined outcome over the 90 days after diagnosis, according to the study.
Click to Enlarge: Positive human metapneumovirus (hMPV), influenza virus, and respiratory syncytial virus (RSV) test results by month. For hMPV and influenza virus, we examined the proportion of positive tests relative to the total number of tests done in that month. A, hMPV data over all years of the study (except the year of coronavirus disease 2019 [COVID-19], July 2020 to June 2021) B–D, Data for each year individually for hMPV (B), influenza virus (C) and RSV) (D). The infection control practices of the COVID-19 year resulted in a markedly low number of positive tests for all viruses and were thus excluded from the cumulative analysis in A.
Source: The Journal of Infectious Diseases
The study found that hMPV has a similar risk of hospitalization and death as influenza and RSV in older adults and nursing home residents, Rudolph explained.
“Any respiratory virus is dangerous for a nursing home resident,” Rudolph told U.S. Medicine. “We found that human metapneumovirus (hMPV) ‘season’ seems to pick up just as influenza ‘season’ tapers off in the spring.”
The researchers identified 178 hMPV, 1,379 influenza virus and 681 RSV laboratory-confirmed infections. Residents with hMPV infection (n=173) were well-matched to those with influenza virus infection (n=746). The matched cohort proportional hazard analysis (hMPV versus influenza virus infection) showed similar hazards for 90-day outcomes of hospitalization (adjusted hazard ratio, 1.00 [95% confidence interval, 0.67-1.49]), death (0.79 [0.48-1.29]) or both combined (0.81 [0.58-1.12]).
In addition, residents with hMPV (n=170) were well-matched to those with RSV (n=437). The matched cohort proportional hazard analysis showed similar 90-day outcomes of hospitalization (adjusted hazard ratio, 1.00 [95% confidence interval, 0.66-1.51]), death (0.93 [0.58-1.56]) or both combined (0.97 [0.68-1.37]), the study reported.
“The results of our study make the case that steps should be taken to test for and more quickly identify outbreaks of human metapneumovirus,” Rudolph said. “Differentiating respiratory infections from each other is difficult when the primary symptoms of all infections are cough, fever, chills and delirium. Further, any respiratory infection is going to have higher morbidity and mortality in older people who reside in nursing homes, so there are important consequences of making a specific diagnosis.”
“Two viruses, influenza and SARS-CoV-2, have treatments for early detected infections. So, we need laboratory testing to help distinguish among these different types of viruses. Taking steps to include hMPV infection in laboratory testing helps to identify the pathogen of any outbreak and enables nursing homes to manage the infection and potential for spread at their facilities,” he added.
Increased understanding of hMPV and appropriate testing are needed to accurately detect, prevent and manage hMPV in nursing homes, the study authors suggested.
Despite its clinical importance, hMPV remains undertested in diagnostic testing and underreported in surveillance data, leading to gaps in recognition of its role in respiratory outbreaks. HMPV is the “newcomer” to the respiratory infections, Rudolph pointed out.
“During our study, we witnessed practice evolving as rapid respiratory test panels are increasingly including hMPV,” Rudolph said. “This helps to identify the current outbreak, initiate infection control practices including prophylaxis, and protect nursing home residents.”
The investigators determined the “underdog” status of hMPV compared to influenza, and RSV poses a significant challenge to actively engaging nursing homes. The findings recommend that hMPV shouldn’t be an afterthought once COVID-19, influenza and RSV have been ruled out. Analyses suggest that hMPV peaks later in the year than influenza or RSV, indicating the need for targeted infection control measures during these periods. Including hMPV on respiratory testing panels is crucial to raise awareness and development and implementation of a vaccine for hMPV could significantly reduce its impact (morbidity and 90-day mortality risks), especially in vulnerable nursing home populations.
Enhanced infection control measures and investigation into comprehensive management approaches also can help to reduce morbidity and 90-day mortality rates associated with hMPV, ensuring better health outcomes for nursing home residents and similar vulnerable populations at risk of hMPV infection, the authors reported.
Rudolph noted the VA CLCs provide crucial information about respiratory infections in older people across the United States. Understanding of respiratory infection patterns is made possible by the integration across sites, use of a common medical record, laboratory standards and more.
“Harnessing that data could be a national resource about the next respiratory infection outbreak,” Rudolph recommended.
- Bhaskar N, Abul Y, DeVone F, McConeghy KW, Leonard T, Halladay CW, Gravenstein S, Rudolph JL. Outcomes of Human Metapneumovirus Infections in Nursing Home Residents: A Matched Cohort Analysis. J Infect Dis. 2025 Jul 16;232(Supplement_1):S29-S36. doi: 10.1093/infdis/jiaf151. PMID: 40668098; PMCID: PMC12265058.