Guidance and Standard Operating Procedure COVID-19 Virus Testing in NHS Laboratories

“5.0 Testing Standard Operating Procedure… Where Ct values are below an agreed value (based on analysis of Proficiency Testing performance and other local testing data) with satisfactory quality control parameters including internal control performance, the result is considered valid and should be telephoned and a report issued as a final result. Any such positive result will be recorded as ‘confirmed’ for Public Health reporting purposes and will be notifiable under recent legislation.

Results where: 

• the Ct value is => 40, AND/OR
  
  
• there is an abnormal assay curve, AND/OR
  
  
• the clinical context makes the positive result highly unexpected

should be considered interim or held until reviewed by a laboratory clinician.”