A simplified alternative diagnostic algorithm for SARS-CoV-2 suspected symptomatic patients and confirmed close contacts (asymptomatic): A consensus of Latin American experts.

INTRODUCTION: Latin America accounts for one-quarter of global COVID-19 cases and one-third of deaths. Inequalities in the region lead to barriers to the best use of diagnostic tests during the pandemic. There is a need for simplified guidelines that consider the region's limited health resources, international guidelines, medical literature, and local expertise. METHODS: Using a modified Delphi method, 9 experts from Latin American countries developed a simplified algorithm for COVID-19 diagnosis on the basis of their answers to 24 questions related to diagnostic settings, and discussion of the literature and their experiences. RESULTS: The algorithm considers 3 timeframes (≤7 days, 8-13 days, and ≥14 days) and presents diagnostic options for each. SARS-CoV-2 real- time reverse transcription-polymerase chain reaction is the test of choice from day 1 to 14 after symptom onset or close contact, although antigen testing may be used in specific circumstances, from day 5 to 7. Antibody assays may be used for confirmation, usually after day 14; however, if clinical suspicion is very high, but other tests are negative, these assays may be used as an adjunct to decision-making from day 8 to 13. CONCLUSION: The proposed algorithm aims to support COVID-19 diagnosis decision-making in Latin America.

Algorithms for testing COVID-19 focused on use of RT-PCR and high-affinity serological testing: A consensus statement from a panel of Latin American experts.

The COVID-19 pandemic has caused an unprecedented public health, social, and economic crisis. Improving understanding on available tests for detecting COVID-19 is critical for effective management of the pandemic. We proposed that a multidisciplinary expert panel can establish recommendations on ideal use of diagnostic tools, with a focus on RT-PCR and serological high-affinity antibodies (both IgM and IgG) tests for the Latin America region. STUDY DESIGN: A collaborative multidisciplinary panel of 5 recognized experts in Latin America (an infectious disease specialist, three pathologists, and an immunologist) was convened and supported by Roche Diagnostics to develop standard guidelines and an evidence-based document of best practices on the use of diagnostic tools for COVID-19. RESULTS: The authors reached consensus on the applicability of diagnostic tools to provide testing algorithms for the use of RT-PCR and serological high-affinity antibodies (both IgM and IgG) tests in three settings: 1) For asymptomatic subjects exposed to a SARS-CoV-2 infected person; 2) For epidemiological purposes and; 3) For symptomatic subjects. CONCLUSION: The serological high-affinity SARS-CoV-2 antibodies (both IgM and IgG) tests play a key role in COVID-19 diagnosis. These tests can be applied for suspected false-negative RT-PCR results and for individual determination of response. The use of these tests can also contribute greatly to public health strategies, such as population screening and supporting vaccination planning. Serological status for high-affinity antibodies (both IgM and IgG) should be performed ideally 21 days after potential infectious contact, given that the majority of exposed individuals will have seroconverted.