Research and Evaluation, UK Health Security Agency, Porton Down, United Kingdom.
Statistics, Modelling and Economics Department, UK Health Security Agency, United Kingdom.
Appl Environ Microbiol. 2022 Jul 26;88(14):e0076422. doi: 10.1128/aem.00764-22. Epub 2022 Jul 11.
Most studies on surface persistence of SARS-CoV-2 have been conducted at temperatures between 20°C and 30°C. There is limited data on the survival of SARS-CoV-2 at low temperatures. In this study, the stability of SARS-CoV-2 Alpha and Delta variants on stainless steel was investigated at two temperatures (4°C and 24°C). The results show that both variants decayed more rapidly at 24°C compared with 4°C. At 24°C, Alpha and Delta variants showed reductions of 0.33 log and 1.02 log, respectively, within the first 2.5 h. However, at 4°C, Alpha variant showed a reduction of 0.16 log within the first 2.5 h while no reduction was observed with Delta variant. After remaining for 24 h at 24°C, log reductions of 2.66 (Alpha) and 3.11 (Delta) were observed. No viable Alpha and Delta variant was recovered after 48 h and 72 h, respectively. After 24 h in a refrigerated environment (4°C) log reductions of 1.16 (Alpha) and 0.95 (Delta) were observed. Under these experimental conditions, both viruses survived on stainless steel for at least 1 week. No viable Alpha and Delta variant was recovered after 10 days. These findings support the potential for increased fomite transmission of SARS-CoV-2 during winter months in colder regions worldwide and in some industrial sectors. Human transmission is believed to occur primarily through direct transfer of infectious droplets or aerosols. However, fomite transmission through contact with contaminated surfaces may also play an important role. This study provides novel evidence comparing the stability of Alpha and Delta variants on stainless steel surfaces at 4°C and 24°C. At 4°C both variants were found to be still detectable for up to 7 days. At 24°C Delta variant could be recovered over 2 days compared with Alpha variant which could not be recovered after 2 days. This has implications for fomite transmission interventions for people living and working in cold environments.
大多数关于 SARS-CoV-2 表面持久性的研究都是在 20°C 至 30°C 之间进行的。关于 SARS-CoV-2 在低温下存活的资料有限。在这项研究中，研究人员在两个温度（4°C 和 24°C）下研究了 SARS-CoV-2 Alpha 和 Delta 变体在不锈钢上的稳定性。结果表明，与 4°C 相比，两种变体在 24°C 下的衰减速度更快。在 24°C 下，Alpha 和 Delta 变体在最初的 2.5 小时内分别减少了 0.33 对数和 1.02 对数。然而，在 4°C 下，Alpha 变体在最初的 2.5 小时内减少了 0.16 对数，而 Delta 变体则没有减少。在 24°C 下放置 24 小时后，观察到 Alpha（2.66）和 Delta（3.11）的对数减少。分别在 48 小时和 72 小时后，未回收有活性的 Alpha 和 Delta 变体。在冷藏环境（4°C）下放置 24 小时后，观察到 Alpha（1.16）和 Delta（0.95）的对数减少。在这些实验条件下，两种病毒在不锈钢表面上至少存活了 1 周。10 天后，未回收有活性的 Alpha 和 Delta 变体。这些发现支持在全球较冷地区和一些工业部门，SARS-CoV-2 在冬季月份通过表面接触传播的可能性增加。人们认为人际传播主要通过传染性飞沫或气溶胶的直接转移发生。然而，通过接触受污染的表面进行的接触传播也可能发挥重要作用。本研究提供了在 4°C 和 24°C 下比较 Alpha 和 Delta 变体在不锈钢表面稳定性的新证据。在 4°C 下，两种变体在长达 7 天内仍可检测到。在 24°C 下，Delta 变体可在 2 天内回收，而 Alpha 变体在 2 天后无法回收。这对生活和工作在寒冷环境中的人们的接触传播干预措施具有重要意义。
