Coronaviruses as the cause of respiratory infections

Background There are six human pathogenic coronaviruses (CoV), which mainly cause infections of the respiratory system. In everyday clinical practice, it is helpful to know the relevance and characteristics of these pathogens. Objective To present the epidemiology, clinical picture and differences of human pathogenic CoV and to provide information on the diagnostics and treatment of patients suspected of having CoV infections. Material and methods Selective literature search, presentation of results and discussion of fundamental works and expert recommendations, including publications by the World Health Organization (WHO), the European Centre for Disease Prevention and Control (ECDC) and the Robert Koch Institute. Results The four endemic human CoVs (HCoV-NL63, HCoV-229E, HCoV-OC43 and HCoV-HKU1) mainly cause mild respiratory tract infections. In addition to these four endemic HCoV, the two epidemic CoV, severe acute respiratory syndrome (SARS)-CoV and Middle East respiratory syndrome (MERS)-CoV can cause severe pneumonia. The SARS-CoV has not been detected in humans in the last 15 years and MERS-CoV has been circulating mainly on the Arabian Peninsula since 2012; however, neither a specific treatment nor approved vaccines exist for any of the six human pathogenic CoVs. Conclusion All six human CoVs can be diagnosed using RT-PCR on respiratory specimens but this is rarely necessary for the four endemic strains. In current clinical practice SARS-CoV has no importance as it has not been detected in humans for 15 years; however, a possible MERS-CoV infection should be taken into account in patients with typical symptoms and travel history to endemic regions. In this case, rapid diagnostic and general hygiene practices are important to prevent further transmission.