Chronic wasting disease (CWD) has been identified in 30 states in the United States, four provinces in Canada, and recently emerged in Scandinavia. The association of CWD prions with environmental materials such as soil, plants, and surfaces may enhance the persistence of CWD prion infectivity in the environment exacerbating disease transmission. Identifying and quantifying CWD prions in the environment is significant for prion monitoring and disease transmission control. A systematic method for CWD prion quantification from associated environmental materials, however, does not exist. In this study, we developed an innovative method for extracting prions from swabs and recovering CWD prions swabbed from different types of surfaces including glass, stainless steel, and wood. We found that samples dried on swabs were unfavorable for prion extraction, with the greatest prion recovery from wet swabs. Using this swabbing technique, the recovery of CWD prions dried to glass or stainless steel was approximately 30% in most cases, whereas that from wood was undetectable by conventional prion immunodetection techniques. Real-time quake-induced conversion (RT-QuIC) analysis of these same samples resulted in an increase of the detection limit of CWD prions from stainless steel by 4 orders of magnitude. More importantly, the RT-QuIC detection of CWD prions recovered from stainless steel surfaces using this method was similar to the original CWD prion load applied to the surface. This combined surface swabbing and RT-QuIC detection method provides an ultrasensitive means for prion detection across many settings and applications.

慢性消耗性疾病 (CWD) 已在美国 30 个州、加拿大 4 个省以及最近在斯堪的纳维亚半岛出现。CWD 朊病毒与土壤、植物和表面等环境材料的结合可能会增强 CWD 朊病毒感染性在环境中的持久性，从而加剧疾病传播。识别和量化环境中的 CWD 朊病毒对于朊病毒监测和疾病传播控制具有重要意义。然而，尚不存在从相关环境材料中定量 CWD 朊病毒的系统方法。在这项研究中，我们开发了一种创新方法，用于从拭子中提取朊病毒，并回收从不同类型的表面（包括玻璃、不锈钢和木材）擦拭的 CWD 朊病毒。我们发现，在拭子上干燥的样品不利于朊病毒的提取，而湿拭子中的朊病毒回收率最高。使用这种拭子技术，在大多数情况下，干燥到玻璃或不锈钢上的 CWD 朊病毒的回收率约为 30%，而传统的朊病毒免疫检测技术无法检测到木材中的朊病毒。对这些相同样品进行的实时地震诱发转换 (RT-QuIC) 分析导致不锈钢中 CWD 朊病毒的检测限提高了 4 个数量级。更重要的是，使用这种方法从不锈钢表面回收的 CWD 朊病毒的 RT-QuIC 检测与施加到表面的原始 CWD 朊病毒负载相似。这种表面拭子和 RT-QuIC 检测相结合的方法为多种环境和应用中的朊病毒检测提供了超灵敏的方法。