Agreement Between SARS-CoV-2 PCR Test Results Using Nasopharyngeal and Mid-Turbinate Specimens Among Asymptomatic Working-Age Adults.

OBJECTIVE: The aim of this study was to determine whether mid-turbinate specimens reliably detect active infection in asymptomatic adults undergoing regular COVID-19 PCR testing. METHODS: Qualitative agreement between 2481 paired nasopharyngeal and mid-turbinate PCR results was assessed. Mean cycle threshold values for each positive result were evaluated as an indicator of active infection. RESULTS: Overall agreement between nasopharyngeal and mid-turbinate tests was 98.4%. Positive percent agreement was 37.2%, and negative percent agreement was ~100%. Test pairs with lower cycle thresholds (≤30 and ≤25) reached 67% and 100% positive percent agreement, respectively. CONCLUSIONS: SARS-CoV-2 infections with high viral loads were detected regardless of specimen type. Mid-turbinate swabs reduced staff discomfort and may decrease repeated positive test results weeks or months after initial infection. Discordant pairs generally had high cycle threshold values (>30) indicating low viral load and little risk of transmitting COVID-19.

Reply to Schade G. Comment on Hess et al. "Assessing Agreement in Exposure Classifications between Proximity-Based Metrics and Air Monitoring Data in Epidemiology Studies of Unconventional Resource Development."

We appreciate the comments by Dr [...].

Assessing Agreement in Exposure Classification between Proximity-Based Metrics and Air Monitoring Data in Epidemiology Studies of Unconventional Resource Development.

Recent studies of unconventional resource development (URD) and adverse health effects have been limited by distance-based exposure surrogates. Our study compared exposure classifications between air pollutant concentrations and "well activity" (WA) metrics, which are distance-based exposure proxies used in Marcellus-area studies to reflect variation in time and space of residential URD activity. We compiled Pennsylvania air monitoring data for benzene, carbon monoxide, nitrogen dioxide, ozone, fine particulates and sulfur dioxide, and combined this with data on nearly 9000 Pennsylvania wells. We replicated WA calculations using geo-coordinates of monitors to represent residences and compared exposure categories from air measurements and WA at the site of each monitor. There was little agreement between the two methods for the pollutants included in the analysis, with most weighted kappa coefficients between -0.1 and 0.1. The exposure categories agreed for about 25% of the observations and assigned inverse categories 16%-29% of the time, depending on the pollutant. Our results indicate that WA measures did not adequately distinguish categories of air pollutant exposures and employing them in epidemiology studies can result in misclassification of exposure. This underscores the need for more robust exposure assessment in future analyses and cautious interpretation of these existing studies.