# Optimizing oropharyngeal swabbing techniques: the relationship between force applied and SARS-CoV-2 detection sensitivity

## TL;DR

This study shows that applying more force during oropharyngeal swabbing does not improve SARS-CoV-2 detection and may even reduce test accuracy.

## Contribution

The study reveals that increased force during swabbing does not enhance NAT sensitivity for SARS-CoV-2 detection.

## Key findings

- Greater force during swabbing increases cell count but does not improve SARS-CoV-2 NAT sensitivity.
- Higher cell counts in swab samples lead to lower Ct values, but increased force had the opposite effect on NAT results.
- Optimizing swab design is suggested to improve sample quality and cell collection.

## Abstract

Nasopharyngeal and oropharyngeal swabs are essential for diagnosing SARS-CoV-2 infections, with nucleic acid testing (NAT) being the most sensitive method. However, NAT results are heavily influenced by preanalytical factors, including quality of the sample. This study examines the effect of applied force during oropharyngeal sampling on sample quality, specifically assessing cell count and the associated NAT cycle threshold (Ct) values.

A three-phase investigation was conducted to explore the relationship between sampling force and cell quantity, as well as the impact of cell count on NAT sensitivity.

A significantly lower Ct value was achieved by artificially increasing the cell count in a swab sample and applying a greater force resulted in higher cell counts, but the opposite effect on Ct values of SARS-CoV-2 NAT was shown.

These findings indicate that while applying greater force during sample collection increases the number of collected cells, it does not improve the sensitivity of SARS-CoV-2 detection and can even lead to poorer results. Further research should focus on optimizing swab design to improve sample quality and the number of cells obtained.