Abstract

While efficacy of chlorine against Phi6, a widely-used surrogate for pathogenic enveloped viruses, is well-documented, surfaces common to low-resource contexts are under-researched. We evaluated seven surfaces (stainless steel, plastic, nitrile, tarp, cloth, concrete, wood) and three environmental conditions—temperature (4, 25, 40 °C), relative humidity (RH) (23, 85%), and soiling—to determine Phi6 recoverability and the efficacy of disinfection with 0.5% NaOCl. Overall, Phi6 recovery was >4 log₁₀ PFU/mL on most surfaces after drying 1 hour at all temperature/humidity conditions. After disinfection, all non-porous test conditions (48/48) achieved ≥4 LRV at 1 and 5 minutes of exposure; significantly more non-porous surfaces met ≥4 LRV than porous (p < 0.001). Comparing porous surfaces, significantly fewer wood samples met ≥4 LRV than cloth (p < 0.001); no differences were observed between concrete and either wood (p = 0.083) or cloth (p = 0.087). Lastly, no differences were observed between soil and no-soil conditions for all surfaces (p = 0.712). This study highlights infectious Phi6 is recoverable across a range of surfaces and environmental conditions, and confirms the efficacy of chlorine disinfection. We recommend treating all surfaces with suspect contamination as potentially infectious, and disinfecting with 0.5% NaOCl for the minimum contact time required for the target enveloped virus (e.g. Ebola, SARS-CoV-2).

摘要

虽然氯对 Phi6（一种广泛使用的致病性包膜病毒的替代物）的功效已得到充分证明，但对资源匮乏环境中常见的表面的研究不足。我们评估了七种表面（不锈钢、塑料、丁腈、防水布、布、混凝土、木材）和三种环境条件——温度（4、25、40°C）、相对湿度（RH）（23、85%）和污染— 确定 Phi6 的可回收性和 0.5% NaOCl 的消毒效果。总体而言，在所有温度/湿度条件下干燥 1 小时后，大多数表面的 Phi6 回收率 > 4 log ₁₀ PFU/mL。消毒后，所有无孔测试条件 (48/48) 在暴露 1 分钟和 5 分钟时均达到 ≥4 LRV；满足 ≥4 LRV 的无孔表面明显多于多孔（p < 0.001)。比较多孔表面，满足 ≥4 LRV 的木材样品明显少于布（p  < 0.001）；混凝土和木材（ p  = 0.083）或布（p  = 0.087）之间没有观察到差异。最后，在所有表面的土壤和无土壤条件之间没有观察到差异（p  = 0.712）。这项研究强调了传染性 Phi6 在一系列表面和环境条件下是可恢复的，并证实了氯消毒的功效。我们建议将所有疑似污染的表面视为具有潜在传染性，并使用 0.5% NaOCl 进行消毒，以达到目标包膜病毒（例如埃博拉病毒、SARS-CoV-2）所需的最短接触时间。