Sample pooling is efficient in PCR testing of SARS-CoV-2: a study in 7400 healthcare professionals

Diagn Microbiol Infect Dis. 2021 May;100(1):115330. doi: 10.1016/j.diagmicrobio.2021.115330. Epub 2021 Jan 30.

Abstract

SARS-CoV-2 pandemic shows the importance of having efficient virus diagnosis, especially in groups of particular relevance such as health care professionals, without involving a large economic expense. This is a prevalence study carried out in 7400 health care professionals in a 1350-bed hospital in Madrid, Spain. Pools of 10 samples were performed, using the Xpert® Xpress SARS-CoV-2 test for the diagnosis from clinical samples of nasopharyngeal exudate. A previous study was performed to evaluate the effect of the dilution in terms of sensitivity. The estimated sensitivity was over 95%. A total of 740 pools were performed, with a final result of 218 health care professionals being positive. Using the pooling system, the reagent cost reduction to the institution was 75.3%. It can be concluded that the described sample pooling system is a useful and efficient tool in the diagnosis of SARS-CoV-2 in certain groups, assuming a cost reduction without reducing the sensitivity.

Keywords: COVID-19; PCR; SARS-CoV-2; pooling.

MeSH terms

  • COVID-19 / epidemiology
  • COVID-19 Nucleic Acid Testing / methods*
  • False Positive Reactions
  • Humans
  • Nasopharynx / virology
  • Personnel, Hospital / statistics & numerical data*
  • Polymerase Chain Reaction / methods*
  • Prevalence
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Spain / epidemiology
  • Specimen Handling / methods