Department of Parasitology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana.
Department of Virology, Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Accra, Ghana.
PLoS One. 2023 Oct 17;18(10):e0293001. doi: 10.1371/journal.pone.0293001. eCollection 2023.
Nose masks are widely worn for protection against respiratory pathogens, including SARS-CoV-2. They have been reported as possible substrates for viral sampling and testing for COVID-19 but, evaluations have so far been purposive; involving individuals known to have the infection and using improved materials on the nose masks to trap the virus. We investigated the feasibility of using the regular 3-ply surgical masks and, voluntary coughing as a mode of particle expulsion for detecting SARS-CoV-2 infections in a cross-sectional study at Ghana's first COVID-19 testing reference laboratory, the Noguchi Memorial Institute for Medical Research, University of Ghana. Paired samples of naso-oropharyngeal swabs and nose masks already worn by 103 consenting adult participants (retro masks) were collected. Participants were also required to produce three strong coughs into a newly supplied sterile surgical nose mask. Pre-wetted swabs in Viral Transport Media (VTM) were used in swabbing the inner lining of each nose mask. The swabs used were then stored in VTM to maintain the integrity of the samples. PCR results of SARS-CoV-2 detection from the nose masks were compared to those from naso-oropharyngeal swabs ('gold-standard'). Out of the 103 participants tested with all three methods, 66 individuals sampled with naso-oropharyngeal swabs were detected as positive, and the retro and new masks matched 9 and 4, respectively. Only 3 individuals were positive across all three sampling methods accessed. The retro nose masks performed better in matching the gold-standard results than the new mask + coughing method, with 90% vs 80% sensitivity, positive predictive value of 13.6% vs 6%, and a weak but significant linear relationship (adj. R2 = 0.1; P = 0.0004). Importantly, we also show that the nose masks would work for sampling whether individuals are symptomatic or asymptomatic since gold-standard PCR cycling threshold (Ct) values for positive individuals did not differ between the two groups (P< 0.05). We recommend including features such as talking during participant engagement, use of a spontaneous cough inducer and increased coughing bouts > 3, to improve the performance of sterile nose masks for SARS-CoV-2 detection.
口罩广泛用于预防呼吸道病原体，包括 SARS-CoV-2。有报道称，口罩可能是用于新冠病毒采样和检测的基质，但迄今为止的评估都是有目的的；涉及已知感染病毒的个体，并使用口罩上改进的材料来捕获病毒。我们在加纳第一家新冠病毒检测参考实验室——恩科西纪念医学研究所，进行了一项横断面研究，调查了使用普通的 3 层外科口罩，以及自愿咳嗽作为一种排粒方式，用于检测 SARS-CoV-2 感染的可行性。这项研究共招募了 103 名同意的成年参与者（旧口罩），收集了他们已佩戴的鼻口咽拭子和口罩的配对样本。参与者还被要求向新提供的无菌外科口罩中强力咳嗽三次。使用湿的拭子在病毒转运培养基（VTM）中擦拭每个口罩的内层。然后将使用的拭子储存在 VTM 中，以保持样本的完整性。将口罩上 SARS-CoV-2 的 PCR 检测结果与鼻口咽拭子（“金标准”）的检测结果进行比较。在使用三种方法检测的 103 名参与者中，66 名使用鼻口咽拭子采样的个体被检测为阳性，而旧口罩和新口罩分别匹配了 9 人和 4 人。只有 3 名个体在所有三种采样方法中均呈阳性。与新口罩+咳嗽法相比，旧口罩在匹配金标准结果方面表现更好，敏感性为 90%，阳性预测值为 13.6%，6%，以及存在微弱但显著的线性关系（调整后 R2 = 0.1；P = 0.0004）。重要的是，我们还表明，口罩可以用于采样，无论个体是否有症状，因为金标准 PCR 循环阈值（Ct）值在两组阳性个体之间没有差异（P<0.05）。我们建议在参与者参与时加入如交谈、使用自发咳嗽诱导剂和增加咳嗽次数>3 次等特征，以提高无菌口罩用于 SARS-CoV-2 检测的性能。
