Performance Evaluation of Serial SARS-CoV-2 Rapid Antigen Testing During a Nursing Home Outbreak

Details

• Alternative Title:
  Ann Intern Med
• Personal Author:
  McKay, Susannah L. ; Tobolowsky, Farrell A. ; Moritz, Erin D. ; Hatfield, Kelly M. ; Bhatnagar, Amelia ; LaVoie, Stephen P. ; Jackson, David A. ; Lecy, K. Danielle ; Bryant-Genevier, Jonathan ; Campbell, Davina ; Freeman, Brandi ; Gilbert, Sarah E. ; Folster, Jennifer M. ; Medrzycki, Magdalena ; Shewmaker, Patricia L. ; Bankamp, Bettina ; Radford, Kay W. ; Anderson, Raydel ; Bowen, Michael D. ; Negley, Jeanne ; Reddy, Sujan C. ; Jernigan, John A. ; Brown, Allison C. ; McDonald, L. Clifford ; Kutty, Preeta K.
• Corporate Authors:
  for the CDC Infection Prevention and Control Team and the CDC COVID-19 Surge Laboratory Group*
• Description:
  Background:
  
  To address high COVID-19 burden in U.S. nursing homes, rapid SARS-CoV-2 antigen tests have been widely distributed in those facilities. However, performance data are lacking, especially in asymptomatic people.
  
  Objective:
  
  To evaluate the performance of SARS-CoV-2 antigen testing when used for facility-wide testing during a nursing home outbreak.
  
  Design:
  
  A prospective evaluation involving 3 facility-wide rounds of testing where paired respiratory specimens were collected to evaluate the performance of the BinaxNOW antigen test compared with virus culture and real-time reverse transcription polymerase chain reaction (RT-PCR). Early and late infection were defined using changes in RT-PCR cycle threshold values and prior test results.
  
  Setting:
  
  A nursing home with an ongoing SARS-CoV-2 outbreak.
  
  Participants:
  
  532 paired specimens collected from 234 available residents and staff.
  
  Measurements:
  
  Percentage of positive agreement (PPA) and percentage of negative agreement (PNA) for BinaxNOW compared with RT-PCR and virus culture.
  
  Results:
  
  BinaxNOW PPA with virus culture, used for detection of replication-competent virus, was 95%. However, the overall PPA of antigen testing with RT-PCR was 69%, and PNA was 98%. When only the first positive test result was analyzed for each participant, PPA of antigen testing with RT-PCR was 82% among 45 symptomatic people and 52% among 343 asymptomatic people. Compared with RT-PCR and virus culture, the BinaxNOW test performed well in early infection (86% and 95%, respectively) and poorly in late infection (51% and no recovered virus, respectively).
  
  Limitation:
  
  Accurate symptom ascertainment was challenging in nursing home residents; test performance may not be representative of testing done by nonlaboratory staff.
  
  Conclusion:
  
  Despite lower positive agreement compared with RT-PCR, antigen test positivity had higher agreement with shedding of replication-competent virus. These results suggest that antigen testing could be a useful tool to rapidly identify contagious people at risk for transmitting SARS-CoV-2 during nascent outbreaks and help reduce COVID-19 burden in nursing homes.
  
  Primary Funding Source:
  
  None.
  
  
• Subjects:
  Original Research
• Source:
  Ann Intern Med. 2021;
• Pubmed ID:
  33900791
• Pubmed Central ID:
  PMC8108910
• Document Type:
  Journal Article
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:50b7b1ffffd7daf1135807a111faa49545a79f3c05c78bca34925ba04f84cb78
• Download URL:
  https://stacks.cdc.gov/view/cdc/107337/cdc_107337_DS1.pdf
• File Type:
  [PDF - 309.83 KB ]