Diagnosis of covid-19 at the Primary Care Level: Diagnostic Tests

Abstract

The disease caused by the new coronavirus (sars-CoV-2) has affected virtually everyone since its first report in the city of Wuhan, China, in December 2019. In most cases, the disease will have a mild to moderate symptomatology; in cases of severe symptomatology, hospital care and monitoring with supportive treatment is necessary. Due to the absence of specific directed treatment or vaccines with proven effectiveness, a tool of great impact to reduce the transmission of sars-CoV-2 is a timely identification and isolation of the infected people, as well as of the asymptomatic people with antecedent of close contact with a confirmed case. The tests currently available consist of nucleic acid sequence detection using the Reverse Transcriptase Polymerase Chain Reaction (rt-pcr) test, serology and viral antigen detection. The standard test for the covid-19 diagnosis is the rt-pcr. The sensitivity and specificity of the test varies according to the time the sample is taken with respect to the beginning of symptoms. The nasopharyngeal sample has a higher sensitivity. A correct interpretation of the tests depends on the context of the patient, the stage of the disease in which it is found and the pre-analytical variants. The updated information continues so it is essential to stay ahead of new diagnostic tests and the management of covid-19.