Detection of SARS-CoV-2 by RT-qPCR in pooled samples of staff and patients at hospital of So-nora, Mexico

Abstract

The RT-qPCR method is highly reliable for detecting SARS-CoV-2, but its cost hinders widespread use in large-scale screenings. This study aimed to assess and validate cost-effective alternative protocols for mass testing in low-morbidity, high-risk environments. 50 patient samples from the COVID in-patient care area and 50 samples from HGE personnel were analyzed using a pooling approach in varying prevalence settings. Individual RNA was pooled in groups of five, then tested for SARS-CoV-2 via RT-qPCR. This pooling strategy was employed for diagnosing SARS-CoV-2 in medical personnel, involving 885 HGE staff samples and 100 from HIES during the peak of the pandemic. Significant reductions in the number of RT-qPCR reactions were observed: a 77 % decrease in analysis cost for the 885 samples from HGE staff, and an 80 % reduction in reactions needed for the 100 samples from HIES staff. This study demonstrated the effectiveness and efficiency of analyzing pooled samples for widespread SARS-CoV-2 diagnosis in a population at low risk but with high exposure. This approach can be implemented in settings with high spatiotemporal density to mitigate hospital-based transmission risks.