Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission among non-close contacts is not infrequent. We evaluated the proportion and circumstances of individuals to whom SARS-CoV-2 was transmitted without close contact with the index patient in a nosocomial outbreak in a tertiary care hospital in Korea. From March 2020 to March 2021, there were 36 secondary cases from 14 SARS-CoV-2 infected individuals. Of the 36 secondary cases, 26 (72%) had been classified as close contact and the remaining 10 (28%) were classified as non-close contact. Of the 10 non-close contact, 4 had short conversations with both individuals masked, 4 shared a space without any conversation with both masked, and the remaining 2 entered the space after the index had left. At least one quarter of SARS-CoV-2 transmissions occurred among non-close contacts. The definition of close contact for SARS-CoV-2 exposure based on the mode of droplet transmission should be revised to reflect the airborne nature of SARS-CoV-2 transmission.

中文翻译：

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与 COVID-19 患者接触的非密切接触者中 SARS-CoV-2 传播的频繁发生。

非密切接触者之间的严重急性呼吸系统综合症冠状病毒 2 (SARS-CoV-2) 传播并不罕见。我们评估了在韩国一家三级医院爆发的院内疫情中，在没有与指示患者密切接触的情况下传播 SARS-CoV-2 的个体的比例和情况。2020 年 3 月至 2021 年 3 月，14 名 SARS-CoV-2 感染者共有 36 例继发病例。在 36 例继发病例中，26 例 (72%) 被归类为密切接触者，其余 10 例 (28%) 被归类为非密切接触者。10 名非密切接触者中，4 人与两个蒙面人进行了简短的交谈，4 人与蒙面人共享一个空间，没有任何对话，其余 2 人在索引离开后进入空间。至少四分之一的 SARS-CoV-2 传播发生在非密切接触者之间。