Association of epidemiological and clinical features with PCR cycle threshold values of SARS-CoV-2 infection: a cross-sectional study.

The cycle threshold (Ct) in quantitative real-time reverse-transcriptase polymerase chain reaction (qRT-PCR) is inversely correlated to the amount of viral nucleic acid or viral load and can be regarded as an indicator of infectivity. We examined the association of socio-demographic and clinical characteristics of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) polymerase chain reaction (PCR) positive cases with PCR cycle threshold (Ct) values at the time of diagnosis. SARS-CoV-2 cases reported between 12 October 2020 and 24 January 2021 in Regensburg were analyzed employing bivariate and multivariable methods. We included 3,029 SARS-CoV-2 cases (31% asymptomatic at diagnosis) and analyzed the association of case characteristics with Ct values in 2,606 cases. Among symptomatic patients, cough (38.0%), rhinitis (32.4%), headache (32.0), and fever/chills (29.9%) were the most frequent complaints. Ct values ≤20 were more frequent in symptomatic cases (20.9% vs. 11.3%), whereas Ct values >30 were more common in asymptomatic cases (32.6% vs. 18.0%). Ct values >20 and ≤30 were most common in symptomatic and asymptomatic cases (48.0% vs 40.7%). We observed lower median Ct values of E and N gene in symptomatic cases. In a random forest model, the total number of symptoms, respiratory symptoms, and age were most strongly associated with low Ct values. In conclusion, certain symptoms and age were associated with lower Ct values. Ct values can be used as a pragmatic approach in estimating infectivity at the first notification of a case and, thus, in guiding containment measures.

Intelligibility and recall of sentences spoken by adult and child talkers wearing face masks.

With the Covid-19 pandemic, face masks have become part of our daily lives. While face masks are effective in slowing down the spread of the virus, they also make face-to-face communication more challenging. The present study sought to examine the impact of face masks on listeners' intelligibility and recall of sentences produced by one German native adult and one child talker. In the intelligibility task, German native adult listeners watched video clips of either an adult or a child talker producing sentences with and without a face mask. In a cued-recall experiment, another group of German native listeners watched the same video clips and then completed a cued-recall task. The results showed that face masks significantly affected listeners' intelligibility and recall performance, and this effect was equally true for both talkers. The findings here contribute to the fast growing and urgent research regarding the impact of face masks on communication.

The impact of face masks on the recall of spoken sentences.

The effect of face covering masks on listeners' recall of spoken sentences was investigated. Thirty-two German native listeners watched video recordings of a native speaker producing German sentences with and without a face mask, and then completed a cued-recall task. Listeners recalled significantly fewer words when the sentences had been spoken with a face mask. This might suggest that face masks increase processing demands, which in turn leaves fewer resources for encoding speech in memory. The result is also informative for policy-makers during the COVID-19 pandemic, regarding the impact of face masks on oral communication.