Validation of High-Sensitivity Severe Acute Respiratory Syndrome Coronavirus 2 Testing for Stool-Toward the New Normal for Fecal Microbiota Transplantation

Clin Transl Gastroenterol. 2021 Jun 9;12(6):e00363. doi: 10.14309/ctg.0000000000000363.

Abstract

Introduction: Mounting evidence demonstrates potential for fecal-oral transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The US Food and Drug Administration now requires SARS-CoV-2 testing of potential feces donors before the use of stool manufactured for fecal microbiota transplantation. We sought to develop and validate a high-sensitivity SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) procedure for testing stool specimens.

Methods: A modified extraction method was used with an RT-PCR assay adapted from the Centers for Disease Control and Prevention PCR protocol for respiratory specimens. Contrived specimens were created using pre-COVID-19 banked stool specimens and spiking in known concentrations of SARS-CoV-2-specific nucleic acid. The highest transcript concentration at which 2/2 or 1/2 SARS-CoV-2 targets were detected in 9/10 replicates was defined as the dual-target limit and single-target limit of detection, respectively. The clinical performance of the assay was evaluated with stool samples collected from 17 nasopharyngeal swab RT-PCR-positive patients and 14 nasopharyngeal RT-PCR-negative patients.

Results: The dual-target and single-target limit of detection were 56 copies/μL and 3 copies/μL, respectively. SARS-CoV-2 was detected at concentrations as low as 0.6 copies/μL. Clinical stool samples from known COVID-19-positive patients demonstrated the detection of SARS-CoV-2 in stool up to 29 days from symptom onset with a high agreement with nasopharyngeal swab tests (kappa statistic of 0.95, P value < 0.001).

Discussion: The described RT-PCR test is a sensitive and flexible approach for the detection of SARS-CoV-2 in stool specimens. We propose an integrated screening approach that incorporates this stool test to support continuation of fecal microbiota transplantation programs.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • COVID-19 / diagnosis
  • COVID-19 / epidemiology
  • COVID-19 / transmission*
  • COVID-19 / virology
  • COVID-19 Testing / methods*
  • COVID-19 Testing / statistics & numerical data
  • Centers for Disease Control and Prevention, U.S. / standards
  • Fecal Microbiota Transplantation / methods*
  • Fecal Microbiota Transplantation / statistics & numerical data
  • Feces / virology*
  • Humans
  • Nasopharynx / virology
  • RNA, Viral / genetics
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • SARS-CoV-2 / genetics*
  • SARS-CoV-2 / isolation & purification
  • Tissue Donors / supply & distribution
  • United States

Substances

  • RNA, Viral