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. The new virus has its origin in China. At the end of 2019, it caused a first infection wave that has spread rapidly over the country and worldwide. Just a few days after the first report about patients with pneumonia of unclear origin, SARS-CoV-2 was identified as the causative pathogen.
SARS-CoV-2 is mainly transmitted via aerosols during coughing or sneezing or at close contact with an infected person. The incubation period is three to seven, maximum 14 days. In February 2020, the disease caused by SARS-CoV-2 was named COVID-19 by the WHO. The symptoms of SARS-CoV-19 infection are fever, coughing, breathing difficulties and fatigue. Some patients, especially older and chronically ill persons, develop a severe acute respiratory distress syndrome with sometimes fatal outcome.
Suitable methods for diagnosis of SARS-CoV-2 infections are direct detection of the virus by reverse transcriptase polymerase chain reaction (RT-PCR) primarily in sample material from the upper (nasopharyngeal or oropharyngeal swab) or lower (bronchoalveolar lavage fluid, tracheal secretion, sputum, etc.) respiratory tract and the detection of antibodies against SARS-CoV-2 in blood. The latter allows pathogen detection even in subclinical or asymptomatic cases within a few days after virus contact up to approx. 14 days after the onset of symptoms (Liu et al., 2020).
The detection of specific antibodies against SARS-CoV-2 in blood expands the diagnostic window beyond the first one to two weeks. Antibody detection helps to identify persons who present a persisting (no longer acute) or past infection with SARS-CoV-2. Moreover, serology plays an important role in outbreak monitoring and tracking of infection chains, as well as in answering clinical, epidemiological and virological questions related to SARS-CoV-2 and COVID-19.
EUROIMMUN offers a comprehensive portfolio of products for COVID-19 diagnostics, ranging from PCR for diagnostics of acute cases to ELISAs for detection of antibodies of different immunoglobulin classes and against different SARS-CoV-2 antigens.