Impact of animal saliva on the performance of rapid antigen tests for detection of SARS-CoV-2 (wildtype and variants B.1.1.7 and B.1.351)

Vet Microbiol. 2021 Nov:262:109243. doi: 10.1016/j.vetmic.2021.109243. Epub 2021 Sep 20.

Abstract

SARS-CoV-2 infects several animal species and SARS-CoV-2 variants of concern (VOCs) may even show (as in humans) enhanced inter- and intra-species transmission rates. We correlated sensitivity data of SARS-CoV-2 rapid antigen tests (RATs) to viral RNA genome equivalents analyzed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Further, we checked their suitability for testing animals by assessing saliva and VOC effects. Viral loads up to 2 logs (RNA copy number) under the hypothetical SARS-CoV-2 infectivity threshold were detected by most analyzed RATs. However, while saliva from various animal species showed generally no adverse effects on the RATs' analytical sensitivities, the detection of VOCs B.1.1.7 and B.1.351 was in some RATs inferior to non-VOC viruses.

Keywords: Rapid antigen assays; Real-time RT-PCR; SARS-CoV-2; Saliva; Variants of concern (VOCs).

MeSH terms

  • Animals
  • Antigens, Viral / isolation & purification*
  • COVID-19 / diagnosis
  • COVID-19 / veterinary*
  • COVID-19 / virology
  • COVID-19 Serological Testing / standards
  • COVID-19 Serological Testing / veterinary*
  • Chlorocebus aethiops
  • Genetic Variation*
  • RNA, Viral / genetics
  • Real-Time Polymerase Chain Reaction / veterinary
  • SARS-CoV-2 / genetics
  • SARS-CoV-2 / immunology
  • SARS-CoV-2 / isolation & purification*
  • Saliva / virology*
  • Vero Cells
  • Viral Load / veterinary

Substances

  • Antigens, Viral
  • RNA, Viral