COVID 19 Testing:
IgG, IgM, IgA Antibody Tests
Significance of the Test:
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 coronavirus originated in China in the city of Wuhan, Hubei province. It caused an infection wave, which has spread rapidly within the country and worldwide [2, 3]. Just a few days after the first report about patients with pneumonia of unclear origin, the causative pathogen was identified as SARS-CoV-2 [2-4]. SARS-CoV-2 is predominantly transmitted by droplet infection via coughing or sneezing and through close contact with infected patients [2, 3, 5].
The incubation time of SARS-CoV is three to seven, maximally 14 days . The symptoms of SARS-CoV-2 infection are fever, coughing, breathing difficulties and fatigue [2, 3, 5]. In most patients the infection manifests with symptoms of a mild febrile illness with irregular lung infiltrates. Some patients, especially elderly or chronically ill patients, develop severe acute respiratory distress syndrome (ARDS). The disease is fatal in around 3% of cases [2, 3, 5]. In February 2020, the disease caused by SARS-CoV-2 was named COVID-19 by the WHO.
Suitable methods for diagnosis of SARS-CoV-2 infections are direct detection of the virus RNA by polymerase chain reaction (PCR) primarily in sample material from the upper (smear) or lower respiratory tract (bronchoalveolar lavage fluid, tracheal secretion, sputum, nasopharyngeal secretion, oropharyngeal secretion, etc) and the detection of antibodies against SARS-CoV-2 in blood. The determination of antibodies enables confirmation of SARS-CoV-2 infection in patients with typical symptoms and in suspected cases without symptoms. It also contributes to monitoring and outbreak control.
Gorbalenya AE, Baker SC, Baric RS, de Groot RJ, Drosten C, Gulyaeva AA, et al. Severe acute respiratory syndrome-related coronavirus: The species and its viruses – a statement of the Coronavirus Study Group. bioRxiv preprint. doi: 10.1101/2020.02.07.937862
Wang G, Jin X. The progress of 2019 Novel Coronavirus (2019-nCoV) event in China. J MedVirol. doi: 10.1002/jmv.25705
Gralinski LE, Menachery VD. Return of the Coronavirus: 2019-nCoV. Viruses 2020, 12(2), 135
Corman VM, Landt O, Kaiser M, Molenkamp R, Meijer A, Chu DKW, et al. Detection of 2019 novel coronavirus (2019-nCoV) by real-time RT-PCR. Euro Surveill. 2020; 25(3): pii=2000045
Xiao SY, Wu Y, Liu H. Evolving status of the 2019 novel coronavirus Infection: proposal of conventional serologic assays for disease diagnosis and infection monitoring. J Med Virol.2020; 1-4.