SARS-CoV-2 infection / COVID-19

Clinical information

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, previously called 2019-nCoV) belongs to the family of coronaviruses and, like SARS-CoV, is classified in the genus Betacoronavirus. At the end of 2019, it caused an infection wave that rapidly worldwide and was declared a pandemic by the WHO in March 2020. Just a few days after the first report about patients with pneumonia of unclear origin, SARS-CoV-2 was identified as the causative pathogen and the associated disease named COVID-19. SARS-CoV-2 is mainly transmitted via aerosols during speaking, breathing, coughing or sneezing or at close contact with an infected person. The incubation period is usually three to seven, maximally 14 days. The symptoms and severity of SARS-CoV-2 infection can vary significantly. The most common symptoms encompass fever, coughing, breathing difficulties and fatigue. Therefore, in the majority of patients, the infection resembles a cold with light fever, with irregular lung infiltrates. Some patients, especially older and chronically ill persons, develop severe acute respiratory distress syndrome.

Diagnostics

Suitable methods for the diagnosis of SARS-CoV-2 infections are the detection of viral RNA by reverse transcriptase polymerase chain reaction (RT-PCR) or of virus protein by means primarily in sample material from the upper (nasopharyngeal or oropharyngeal swab) or lower respiratory tract (bronchoalveolar lavage fluid, tracheal secretion, sputum, etc.). The PCR allows detection of the pathogen even in subclinical or asymptomatic courses already few days after virus contact and up to 14 after onset of possible symptoms. Moreover, the combination of different parameters in an RT-PCR allows detecting and differentiating SARS-CoV-2 and other respiratory pathogens such as influenza viruses in one test.

The determination of antibodies enables confirmation of SARS-CoV-2 infection in patients with typical symptoms and in suspected cases. It also contributes to monitoring and outbreak control. For significant serological results, two patient samples should be investigated, one from the acute phase (week 1 of the illness) and one from the convalescent phase (3 to 4 weeks later).

EUROIMMUN offers the complete range of test systems for COVID-19 diagnostics – from two PCR  tests for acute diagnostics to serological tests for differentiated detection of antibodies (IgA, IgM, IgG) against different SARS-CoV-2 antigens and a surrogate virus neutralisation test.