key: cord-0991654-bd3sthh0 authors: Abe, Toshikazu; Tokuda, Yasuharu; Iriyama, Hiroki; Iwagami, Masao; Komori, Akira; Sugiyama, Takehiro; Tamiya, Nanako title: Surgical mask use by healthcare personnel to prevent COVID‐19 spread in a long‐term care facility date: 2020-10-26 journal: J Gen Fam Med DOI: 10.1002/jgf2.394 sha: fd84e4e105c5d118327c1c5e8bca9518c6e40cdf doc_id: 991654 cord_uid: bd3sthh0 Long‐term care facilities are a recognized high‐risk setting for severe outcomes during the coronavirus disease 2019 (COVID‐19) outbreak. This study describes a COVID‐19 outbreak in a long‐term care facility in Japan. The index case was a nurse who wore a surgical mask and used standard precautions. Of the 17 confirmed cases of COVID‐19, 14 (14/93, 15.1%) were residents and three (3/69, 4.3%) were healthcare personnel (HCP); no visitors tested positive 0 (0/22, 0.0%). Mask utilization by HCP was not much effective in preventing COVID‐19 transmission, even when interaction was not considered as being in close contact. Long-term care facilities are frequently recognized as high-risk settings for severe outcomes from coronavirus disease 2019 (COVID-19) outbreak. Most residents are elderly or have baseline diseases, and it is difficult for some cognitively impaired residents to comply with physical distancing. Furthermore, frequent close contact occurs between residents and healthcare personnel (HCP). 1, 2 The universal use of a surgical mask has been a widely adopted practice for infection prevention during epidemics of respiratory viruses in Asian countries, including Japan. 3 Surgical masks have also been recommended for use in Europe and the United States during the COVID-19 outbreak because of its possible effect in preventing transmission to asymptomatic or from presymptomatic persons. 4, 5 However, it remains unclear whether mask use among HCP could prevent transmission to residents in long-term care facilities. Here, we report a COVID outbreak in such a facility in Japan, where all HCP were required to wear a surgical mask, including a nurse who identified as the index patient. This descriptive study investigated efforts used to prevent COVID-19 transmission in a long-term care facility where all HCP adhered to infection control measures, such as wearing a surgical mask. We describe a COVID-19 outbreak that occurred at a 100-bed longterm care facility in Ibaraki, Japan, in March 2020. We collected data on reverse transcription-polymerase chain reaction (RT-PCR) test results as well as the disposition and clinical characteristics of the residents. The clinical characteristics of the residents were compared with the RT-PCR test result. A description of the outbreak and subsequent control measures are shown in Figure 1 and below. The long-term care facility is situated in Tsukuba, Japan. Nurses and caregivers routinely checked vital signs and physical condition of the residents twice daily. Both noncontact (temporal) and contact thermometers were used, which were disinfected after every application. Additionally, hand hygiene and the wearing of masks and cloth aprons were routinely practiced by all HCP before the COVID-19 outbreak. Disposable gloves were worn as needed. The facility had restricted visitors from November 1, 2019, in response to an influenza epidemic; however, a few visitors were allowed to meet with a resident in a private meeting room. Following the COVID-19 outbreak, the facility completely banned visitation and mandated the wearing of surgical masks for both HCP and residents on February 24, 2020. A nurse at the care facility complained of fever and upper respiratory symptoms after a night shift on March 26. Subsequently, all daytime rehabilitation services were restricted and communal activities were canceled. The index case was identified by surveyors associated with the local healthcare center. As the index case was confirmed to be COVID-19 positive by RT-PCR testing, the local health center and an affiliate hospital immediately initiated case investigation, contact tracing, quarantine of exposed persons, isolation of persons with suspected COVID-19, and on-site enhancement of infection prevention and control measures on March 29. Further, all HCP entering the rooms of symptomatic residents were required to wear eye protection, a gown, gloves, and an N95 mask. The index case was immediately admitted to an infectious disease-designated hospital despite mild symptoms. COVID-19 surveillance among all residents and HCP by RT-PCR testing was initiated on March 30. All symptomatic patients and HCP in close contact with the index case were tested first because of the limited availability of RT-PCR tests. While these tests were completed by April 1, testing of the remaining asymptomatic residents was completed by April 2 and that of the remaining HCP was completed by April 6. The index case was a nurse. She had visited Tokyo that was considered as a major outbreak area in Japan before her symptoms The Japanese government advised that all cases of COVID-19 infection should have been hospitalized, regardless of symptoms. further cases of infection were reported, and among the infected residents, 4/14 (28.6%) had died due to COVID-19, 9/14 (64.3%) returned to the facility, and 1/14 (7.1%) remain hospitalized. Among them, two residents had died after RT-PCR was negative. All HCP with COVID-19 infection have returned to work. Among those residents without confirmed COVID-19 infection, 3/79 (3.8%) died from unrelated causes during the observation period. The index case was a nurse who routinely used a surgical mask, and the secondary spread ratio from the index case to facility residents was determined to be approximately 15%. This ratio is comparable to that reported by other studies that have investigated the effects of surgical mask utilization in healthcare workers, 6 families, 7 and animals. 8 A meta-analysis to investigate the effects of face masks showed similar results to our study. 5 Although mask use by all HCP as source control is considered to prevent transmission from a mildly symptomatic HCP (not considered as being in "close contact"), 9, Mask utilization by HCP was not much effective in preventing COVID-19 transmission, even when interaction was not considered as being in close contact. We appreciate all healthcare personnel who are fighting against COVID-19 in the facility and Tsukuba Memorial Hospital. This work was supported by JSPS KAKENHI Grant Number JP19K19376. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. TA, YT, AK, and HI conceived and designed the study. TA acquired and analyzed the data. TA, YT, MI, TS, and NT interpreted the data. TA wrote the manuscript. All authors revised the manuscript critically for important intellectual content and final approval of the version to be submitted. 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