Importance: Respiratory infections caused by SARS-CoV-2, influenza, and respiratory syncytial virus (RSV) cause pronounced seasonal morbidity and mortality among residents of nursing homes (NHs). Objective: To assess the effect of an on-site point-of-care respiratory multiplex polymerase chain reaction (POC-RMPCR) instrument on NH outbreaks. Design, Setting, and Participants: This multicenter, open-label cluster randomized trial was conducted from November 12, 2024, to May 2, 2025, in NHs in Toronto, Ontario, Canada. The data analysis was performed from October 7, 2025, until December 31, 2025. Intervention: On-site POC-RMPCR by trained NH staff. Main Outcomes and Measures: The primary outcome was jointly SARS-CoV-2, influenza, and RSV outbreak size and number, and secondary outcomes included the rates of resident emergency department (ED) transfer and death. Results: Among 20 participating NHs with a total of 3963 beds, there was median of 5.5 units, with 30 beds per unit and a crowding index score of 1.42. The joint estimate of outbreak number (51 and 62, respectively) and size for the intervention group was no different from controls, with a rate ratio of 1.12 (95% CI, 0.78 to 1.58). ED transfers for confirmed (-3.5%; 95% CI, -7.2 to -0.2%) and confirmed/suspected infection (-11.0%; 95% CI, -20.6% to -2.0%) were lower among intervention NHs without a difference in death. Viral testing rates (3.69 tests/week vs 1.73 tests/week) and ratio of confirmed to suspect cases (4.2 vs 2.0) were higher in intervention homes along with a shorter time to initiation of antiviral therapy from symptom onset (-2.5 days; 95% CI, -3.1 to -1.9). Conclusions and Relevance: The results of this cluster randomized clinical trial suggests that use of a POC-RMPCR in NHs did not change outbreak number or size but decreased the number of ED transfers in the context of increased viral testing, improved case detection, and faster initiation of antiviral therapy for influenza. Seasonal adoption of POC-RMPCR in NHs would avoid an estimated 4 ED transfers per 100 beds. Trial Registration: ClinicalTrials.gov Identifier: NCT06660433.
Kandel et al. (Mon,) studied this question.