Study: In-Room Air Purifiers Could Impact RSV Incidence Among Older Adults

New study findings assessed the effect of air purification in rooms of residential aged-care facilities (RACFs), compared with no air purification and its association with acute respiratory infections (ARIs) including respiratory syncytial virus (RSV).¹

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ARIs can have severe outcomes on older adults, especially those living in RACFs. ARIs include influenza, SARS-CoV2, rhinovirus, pneumonia, and RSV. However, RSV specifically imposes a significant threat among older adults as the infection accounts for up to 160,000 hospitalizations and around 10,000 deaths among older adults each year in the US. Symptoms typically present like a mild cold but could become more severe among this population.²

“The successful prevention of ARIs requires a thorough understanding of pathogen transmission. Risks of inhalation transmission and subsequent infection are associated with several factors, including pathogen-containing aerosol emission and removal rates, exposure, cumulative dose, and the probability of infection,” the study authors said in the press release.¹

Despite the increased use of portable air purification devices, the effectiveness of in-room air purification systems with a high-efficiency particulate air (HEPA) filter to reduce illnesses like RSV are unknown in RACFs. To assess the usage, the researchers conducted a multicenter, double-blind, crossover randomized clinical trial from April 7 to October 26, 2023, in 3 RACFs located in Australia. Individuals included in the study were followed up every 2 weeks throughout the 6-month study period.¹

The study included 135 individuals who were divided into the intervention-first group (70) and the control-first group (65). Among both groups, 78 individuals were female and the mean age was 85.2 years.¹

An air purifier containing a HEPA-14 filter was placed in the rooms of all individuals in the intervention group and an air purifier without a HEPA-14 filter was placed in the rooms of all individuals in the control group. The air purifiers were reported to provide a minimum of 8 air changes per hour during the day and a minimum of 3 air changes per hour at night. After a 3-month period, the groups crossed over, according to study authors.¹

The primary outcome of the study was the incidence of ARIs, defined by either infection or no infection. However, infection was divided between influenza, SARS-CoV-2, rhinovirus, RSV, or adenovirus. The secondary outcome of the study was time to first infection and numbers of visits to an emergency department, hospital admissions, and medical reviews caused by an ARI.¹

The results demonstrated that in the intention-to-treat analysis, air purifiers with HEPA-14 filers did not reduce ARIs compared with the control analysis. However, among the 104 individuals that completed the entirety of the study, the intervention reduced ARI incidence by 35.6% in the control group and 24% in the intervention group.¹

The findings suggest that the use of in-room air purifiers with HEPA-14 filters did not display a significant reduction in ARIs like RSV among RACF residents.¹

“Although the study results were not statistically significant, they may be clinically important. A reduction in the absolute number of ARIs among participants using the intervention who completed the study was identified,” said the study authors in the press release.¹

REFERENCES

1. Air Purifiers and Acute Respiratory Infections in Residential Aged Care. JAMA Network Open. News release. November 11, 2024. Accessed November 19, 2024. https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2825943?resultClick=3.

2. Ferruggia K. RSV Vaccine Displays Effectiveness Against RSV-Associated Hospitalizations. Pharmacy Times. News release. November 13, 2024. Accessed November 19, 2024. https://www.pharmacytimes.com/view/rsv-vaccine-displays-effectiveness-against-rsv-associated-hospitalizations.