The COVID-19 Infection Did Not Aggravate the Mortality of Long-Term Care Facility Residents Under Strict Infection Control and with Immediate Anti-Viral Treatment: Real World Analysis

Between January 2022 and December 2023, the Toshiwakai long-term care facility (LTCF) experienced a COVID-19 cluster. Among 231 infected residents, 253 episodes were identified, including 20 residents who were reinfected once and one who was reinfected twice. The strict infection control operation and antiviral treatments were promptly administered; however, four residents died, and five were hospitalized within 10 days (two due to fractures). Most symptomatic cases resolved within 10 days. A comparison of mortality rates between infected and uninfected residents showed no statistically significant differences, underscoring the effectiveness of robust infection control measures and prompt antiviral therapy in mitigating the adverse outcomes of COVID-19. Mortality trends were analyzed across three periods: Period 1 (pre-COVID-19, 2018–2019), Period 2 (COVID-19 present in Japan but absent in our facility, 2020–2021), and Period 3 (Omicron-driven cluster, 2022–2023). Mortality rates in Periods 1 and 2 were comparable, whereas Period 3 unexpectedly demonstrated lower mortality despite Omicron's high transmissibility. Although further research is warranted, enhanced infection control measures may also mitigate other severe infections among high-risk populations, such as the elderly and immunocompromised individuals. Additionally, the viral dynamics during the Omicron surge, including potential suppression of other viral pathogens, may have contributed to these outcomes. These findings emphasize the critical role of proactive clinical and public health strategies in managing COVID-19 outbreaks in long-term care settings.