Laboratory diagnosis of COVID-19

Objectives: This was a non-systematic review of the literature on the laboratory diagnosis of COVID-19. Data sources: Searches in PubMed and Google Scholar for articles made available in 2020, using the terms diagnosis'' OR diagnostic'' OR diagnostic tests'' OR tests'' AND COVID-19'' OR SARS-CoV-2'' in the title. Summary of findings: Tests for the etiological agent identify genetic material of SARS-CoV-2 or humoral responses to it. The gold standard for diagnosis is the identification of viral genome targets by real-time polymerase chain reaction (RT-PCR) in respiratory tract materials during the first week of symptoms. Serological tests should be indicated from the second week of symptoms onwards. A wide range of different tests is available, with variable sensitivity and specificity, most of which require validation. Laboratory tests such as complete blood count, C-reactive protein (CRP), D-dimer, clotting tests, lactic dehydrogenase (LDH), ferritin, and procalcitonin identify risk of disease with greater severity, thromboembolic complications, myocardial damage, and/or worse prognosis. Imaging tests may be useful for diagnosis, especially when there is a compatible clinical picture, and other tests presented negative results or were unavailable. Conclusions: The identification of genetic material of the virus by RT-PCR is the gold standard test, but its sensitivity is not satisfactory. The diagnosis of COVID-19 should be based on clinical data, epidemiological history, tests for etiological diagnosis, and tests to support the diagnosis of the disease and/or its complications. New diagnostic methods with higher sensitivity and specificity, as well as faster results, are necessary. (C) 2020 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda.

Automated summary

This paper provides a non-systematic review on the laboratory diagnosis of COVID-19, highlighting the importance of different diagnostic methods such as pathogen detection, serological responses, laboratory tests, and imaging tests.