Detection of SARS-CoV-2 RNA in Upper Respiratory Swap Samples by Pooling Method

Area of Science:

• Molecular Diagnostics
• Virology
• Public Health

Background:

• Widespread molecular diagnostic testing is crucial for controlling the SARS-CoV-2 pandemic.
• Resource depletion necessitates cost-effective testing strategies like sample pooling.
• Sample pooling has been successfully used in other large-scale screening programs.

Purpose of the Study:

• To evaluate the feasibility of using sample pooling for SARS-CoV-2 detection.
• To assess the diagnostic accuracy of pooled testing compared to individual testing.

Main Methods:

• A prospective diagnostic accuracy study involving 2815 samples tested for SARS-CoV-2.
• Samples were tested individually and in pools of five using three different RT-PCR kits.
• RT-PCR efficiency was analyzed using standard curves from serial dilutions.

Main Results:

• All three RT-PCR kits demonstrated high sensitivity, with minor variations in efficiency.
• Only one low-positive sample was missed due to pooling, indicating high overall accuracy.
• Sample pooling resulted in a calculated saving of 69.91% in testing resources.

Conclusions:

• Sample pooling is an effective strategy to conserve resources during the COVID-19 pandemic.
• Careful validation of RNA extraction and RT-PCR sensitivity is essential to avoid false negatives.
• Laboratories should validate pooling strategies based on regional disease prevalence and specific testing methods.