term care facilities, correctional and detention facilities, homeless shelters).
• Nucleic acid amplification testing (NAAT) of viral RNA, most commonly reverse-transcription polymerase chain reaction (RT-PCR) testing (detects viral nucleic acid).
• Screening hospitalized patients at locations where prevalence is moderate or high (e.g., ≥10 percent PCR positivity in the community).
• SARS-CoV-2 antigen testing (detects a specific viral antigen).
• Prior to time-sensitive surgical procedures or aerosol- generating procedures.
• Antibody testing (detects antibody to spike or nucleocapsid proteins).
• Prior to receiving immunosuppressive therapy including prior to transplantation. OVERVIEW OF DIAGNOSTIC TESTS FOR SARS-COV-2 There are 3 classes of tests available to diagnose active or prior COVID-19:
Authorized assays for acute viral testing include those that detect SARS-CoV-2 nucleic acid or antigens. These viral specific tests detect viral nucleic acid or antigens from respiratory tract samples (including nasal, nasopharyngeal, oral, or oropharyngeal swabs or saliva samples) to diagnose active infection with SARS-CoV-2. In contrast, serologic assays detect antibodies in the blood that indicate prior infection with SARS-CoV-2. A summary of SARS-CoV-2 diagnostics is detailed below.
Table1: Summary of Diagnostic Tests for SARS-CoV-2 (4) table 1 NAAT Antigen Test
Antibody Test
Intended use
• Detect current infection • Detect current infection • Prior infection (usually >3-4 weeks)
Analyte detected • Viral RNA
• Viral Antigen
• Antibodies to spike and nucleocapsid proteins
Specimen type(s)
• Nasal, Nasopharyngeal, Sputum, Saliva
• Nasal, Nasopharyngeal
• Blood
Sensitivity
• Varies by test, but gen- erally high
• Moderate
• Variable
Specificity
• High
• High
• Variable
Test complexity
• Varies by test
• Relatively easy to use • Relatively easy to use
Authorized use at Point-of-Care
• Most are not, some are not
• Most are, some are not
• N/A
Turnaround time
• 15 mins to >2 days
• Less than 1 hour
• 15 mins to 2 hours
Cost
• Moderate (~$100/test)
• Low (~$5-50/test)
• Low (~$40/test)
Adapted from CDC Guidance.
13
Made with FlippingBook Digital Publishing Software