Department of Civil and Environmental Engineering, Environmental and Water Studies, Stanford University, Stanford, CA 94305-4020, USA.
Appl Environ Microbiol. 2011 Oct;77(19):6918-25. doi: 10.1128/AEM.05709-11. Epub 2011 Aug 5.
The role of fomites in infectious disease transmission relative to other exposure routes is difficult to discern due, in part, to the lack of information on the level and distribution of virus contamination on surfaces. Comparisons of studies intending to fill this gap are difficult because multiple different sampling methods are employed and authors rarely report their method's lower limit of detection. In the present study, we compare a subset of sampling methods identified from a literature review to demonstrate that sampling method significantly influences study outcomes. We then compare a subset of methods identified from the review to determine the most efficient methods for recovering virus from surfaces in a laboratory trial using MS2 bacteriophage as a model virus. Recoveries of infective MS2 and MS2 RNA are determined using both a plaque assay and quantitative reverse transcription-PCR, respectively. We conclude that the method that most effectively recovers virus from nonporous fomites uses polyester-tipped swabs prewetted in either one-quarter-strength Ringer's solution or saline solution. This method recovers a median fraction for infective MS2 of 0.40 and for MS2 RNA of 0.07. Use of the proposed method for virus recovery in future fomite sampling studies would provide opportunities to compare findings across multiple studies.
由于缺乏有关表面病毒污染程度和分布的信息，很难确定污染物在传染病传播中的作用相对于其他暴露途径的作用。由于采用了多种不同的采样方法，而且作者很少报告其方法的检测下限，因此，旨在填补这一空白的研究之间的比较很困难。在本研究中，我们比较了文献综述中确定的一组采样方法，以证明采样方法对研究结果有重大影响。然后，我们从综述中确定了一组方法，以确定使用 MS2 噬菌体作为模型病毒在实验室试验中从表面回收病毒的最有效方法。使用噬菌斑测定法和定量逆转录-PCR 分别测定感染性 MS2 和 MS2 RNA 的回收率。我们得出的结论是，从非多孔污染物中最有效地回收病毒的方法是使用预先润湿在 1/4 强度林格氏溶液或盐溶液中的聚酯拭子。该方法对感染性 MS2 的回收率中位数为 0.40，对 MS2 RNA 的回收率中位数为 0.07。在未来的污染物采样研究中使用建议的方法进行病毒回收，将为跨多项研究比较发现提供机会。
