Arias, Cesar Andres Diaz

Abstract Immunoassays designed to detect SARS-CoV-2 protein antigens are now commercially available. The most widely used tests are rapid lateral flow assays that generate results in ~15 minutes for diagnosis at the point-of-care. Higher throughput, laboratory-based SARS-CoV-2 antigen (Ag) assays have also been developed. The overall accuracy of SARS-CoV-2 Ag tests, however, is not well defined. The Infectious Diseases Society of America (IDSA) convened an expert panel to perform a systematic review of the literature and develop best-practice guidance related to SARS-CoV-2 Ag testing. This guideline is the third in a series of rapid, frequently updated COVID-19 diagnostic guidelines developed by IDSA. IDSA’s goal was to develop evidence-based recommendations or suggestions that assist clinicians, clinical laboratories, patients, public health authorities, administrators, and policymakers in decisions related to the optimal use of SARS-CoV-2 Ag tests in both medical and nonmedical settings. A multidisciplinary panel of infectious diseases clinicians, clinical microbiologists, and experts in systematic literature review identified and prioritized clinical questions related to the use of SARS-CoV-2 Ag tests. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was used to assess the certainty of evidence and make testing recommendations. The panel agreed on 5 diagnostic recommendations. These recommendations address Ag testing in symptomatic and asymptomatic individuals as well as assess single versus repeat testing strategies. Data on the clinical performance of US Food and Drug Administration SARS-CoV-2 Ag tests with Emergency Use Authorization are mostly limited to single, one-time testing versus standard nucleic acid amplification testing (NAAT) as the reference standard. Rapid Ag tests have high specificity and low to modest sensitivity compared with reference NAAT methods. Antigen test sensitivity is heavily dependent on viral load, with differences observed between symptomatic compared with asymptomatic individuals and the time of testing post-onset of symptoms. Based on these observations, rapid reverse transcriptase–polymerase chain reaction (RT-PCR) or laboratory-based NAAT remain the diagnostic methods of choice for diagnosing SARS-CoV-2 infection. However, when molecular testing is not readily available or is logistically infeasible, Ag testing can help identify some individuals with SARS-CoV-2 infection. The overall quality of available evidence supporting use of Ag testing was graded as very low to moderate.

Abstract Background Accurate molecular diagnostic tests are necessary for confirming a diagnosis of coronavirus disease 2019 (COVID-19). Direct detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acids in respiratory tract specimens informs patient, healthcare institution and public health level decision-making. The numbers of available SARS-CoV-2 nucleic acid detection tests are rapidly increasing, as is the COVID-19 diagnostic literature. Thus, the Infectious Diseases Society of America (IDSA) recognized a significant need for frequently updated systematic reviews of the literature to inform evidence-based best practice guidance. Objective The IDSA’s goal was to develop an evidence-based diagnostic guideline to assist clinicians, clinical laboratorians, patients and policymakers in decisions related to the optimal use of SARS-CoV-2 nucleic acid amplification tests. In addition, we provide a conceptual framework for understanding molecular diagnostic test performance, discuss the nuance of test result interpretation in a variety of practice settings and highlight important unmet research needs in the COVID-19 diagnostic testing space. Methods IDSA convened a multidisciplinary panel of infectious diseases clinicians, clinical microbiologists, and experts in systematic literature review to identify and prioritize clinical questions and outcomes related to the use of SARS-CoV-2 molecular diagnostics. Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to assess the certainty of evidence and make testing recommendations. Results The panel agreed on 17 diagnostic recommendations. Conclusions Universal access to accurate SARS-CoV-2 nucleic acid testing is critical for patient care, hospital infection prevention and the public response to the COVID-19 pandemic. Information on the clinical performance of available tests is rapidly emerging, but the quality of evidence of the current literature is considered moderate to very low. Recognizing these limitations, the IDSA panel weighed available diagnostic evidence and recommends nucleic acid testing for all symptomatic individuals suspected of having COVID-19. In addition, testing is recommended for asymptomatic individuals with known or suspected contact with a COVID-19 case. Testing asymptomatic individuals without known exposure is suggested when the results will impact isolation/quarantine/personal protective equipment (PPE) usage decisions, dictate eligibility for surgery, or inform solid organ or hematopoietic stem cell transplantation timing. Ultimately, prioritization of testing will depend on institutional-specific resources and the needs of different patient populations.

Abstract Background The availability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serologic testing has rapidly increased. Current assays use a variety of technologies, measure different classes of immunoglobulin or immunoglobulin combinations, and detect antibodies directed against different portions of the virus. The overall accuracy of these tests, however, has not been well defined. The Infectious Diseases Society of America (IDSA) convened an expert panel to perform a systematic review of the coronavirus disease 2019 (COVID-19) serology literature and construct best-practice guidance related to SARS-CoV-2 serologic testing. This guideline is the fourth in a series of rapid, frequently updated COVID-19 guidelines developed by IDSA. Objective IDSA’s goal was to develop evidence-based recommendations that assist clinicians, clinical laboratories, patients, and policymakers in decisions related to the optimal use of SARS-CoV-2 serologic tests in a variety of settings. We also highlight important unmet research needs pertaining to the use of anti–SARS-CoV-2 antibody tests for diagnosis, public health surveillance, vaccine development, and the selection of convalescent plasma donors. Methods A multidisciplinary panel of infectious diseases clinicians, clinical microbiologists, and experts in systematic literature review identified and prioritized clinical questions related to the use of SARS-CoV-2 serologic tests. Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology was used to assess the certainty of evidence and make testing recommendations. Results The panel agreed on 8 diagnostic recommendations. Conclusions Information on the clinical performance and utility of SARS-CoV-2 serologic tests is rapidly emerging. Based on available evidence, detection of anti–SARS-CoV-2 antibodies may be useful for confirming the presence of current or past infection in selected situations. The panel identified 3 potential indications for serologic testing, including (1) evaluation of patients with a high clinical suspicion for COVID-19 when molecular diagnostic testing is negative and ≥2 weeks have passed since symptom onset, (2) assessment of multisystem inflammatory syndrome in children, and (3) conducting serosurveillance studies. The certainty of available evidence supporting the use of serology for either diagnosis or epidemiology was, however, graded as very low to moderate. For the most updated version of these guidelines, please go to https://www.idsociety.org/covid19guidelines.

Abstract IDSA Disclaimer As of the time of this publication, updates have been made to IDSA’s Guidelines on the Diagnosis of COVID-19. For the most updated version of these guidelines, please go to https://www.idsociety.org/covid19guidelines. Background Accurate molecular diagnostic tests are necessary for confirming a diagnosis of coronavirus disease 2019 (COVID-19). Direct detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acids in respiratory tract specimens informs patient, healthcare institution, and public health–level decision-making. The number of available SARS-CoV-2 nucleic acid detection tests is rapidly increasing, as is the COVID-19 diagnostic literature. Thus, the Infectious Diseases Society of America (IDSA) recognized a significant need for frequently updated systematic reviews of the literature to inform evidence-based best practice guidance. Objective The IDSA’s goal was to develop an evidence-based diagnostic guidelines to assist clinicians, clinical laboratorians, patients, and policy makers in decisions related to the optimal use of SARS-CoV-2 nucleic acid amplification tests. In addition, the society provides a conceptual framework for understanding molecular diagnostic test performance, discusses the nuance of test result interpretation in a variety of practice settings, and highlights important unmet research needs in the COVID-19 diagnostic testing arena. Methods IDSA convened a multidisciplinary panel of infectious diseases clinicians, clinical microbiologists, and experts in systematic literature review to identify and prioritize clinical questions and outcomes related to the use of SARS-CoV-2 molecular diagnostics. Grading of Recommendations Assessment, Development and Evaluation methodology was used to assess the certainty of evidence and make testing recommendations. Results The panel agreed on 15 diagnostic recommendations. Conclusions Universal access to accurate SARS-CoV-2 nucleic acid testing is critical for patient care, hospital infection prevention, and the public response to the COVID-19 pandemic. Information on the clinical performance of available tests is rapidly emerging, but the quality of evidence of the current literature is considered low to very low. Recognizing these limitations, the IDSA panel weighed available diagnostic evidence and recommends nucleic acid testing for all symptomatic individuals suspected of having COVID-19. In addition, testing is recommended for asymptomatic individuals who have had a known or suspected contact with a COVID-19 case. Testing asymptomatic individuals without known exposure is suggested when the results will impact isolation/quarantine/personal protective equipment usage decisions, dictate eligibility for surgery, or inform administration of immunosuppressive therapy. Ultimately, prioritization of testing will depend on institution-specific resources and the needs of different patient populations.