SARS and MERS: recent insights into emerging coronaviruses

• Published in: Nature reviews. Microbiology 2016-08, Vol.14 (8), p.523-534
• Main Authors: de Wit, Emmie, van Doremalen, Neeltje, Falzarano, Darryl, Munster, Vincent J.
• Format: Article
• Language: English
• Subjects: 631/326/596/1296; 631/326/596/2078; 631/326/596/2555; 631/326/596/2563; 631/326/596/2564; Animals; Camelus - virology; Care and treatment; Communicable Diseases, Emerging - prevention & control; Communicable Diseases, Emerging - virology; Coronavirus; Coronavirus Infections - immunology; Coronavirus Infections - therapy; Coronavirus Infections - transmission; Coronavirus Infections - virology; Coronaviruses; COVID-19; Cross Infection; Development and progression; Disease Outbreaks - prevention & control; Epidemiology; Evaluation; Fatalities; Human populations; Humans; Immune Evasion; Infection control; Infectious Diseases; Laboratories; Life Sciences; Medical Microbiology; Medical research; Medicine, Experimental; Microbiology; Middle East respiratory syndrome; Middle East Respiratory Syndrome Coronavirus - pathogenicity; Middle East Respiratory Syndrome Coronavirus - physiology; Middle East Respiratory Syndrome Coronavirus - ultrastructure; Mortality; Nosocomial infection; Pandemics; Pandemics - prevention & control; Parasitology; Respiratory diseases; review-article; SARS coronavirus; SARS Virus - pathogenicity; SARS Virus - physiology; SARS Virus - ultrastructure; Severe acute respiratory syndrome; Severe Acute Respiratory Syndrome - immunology; Severe Acute Respiratory Syndrome - transmission; Severe Acute Respiratory Syndrome - virology; Travel; Virology; Virus Replication
• ISSN: 1740-1526; 1740-1534
• DOI: 10.1038/nrmicro.2016.81

Key Points Severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) are zoonotic pathogens that can cause severe respiratory disease in humans. Although disease progression is fairly similar for SARS and MERS, the case fatality rate of MERS is much higher than that of SARS. Comorbidities have an important role in SARS and MERS. Several risk factors are associated with progression to acute respiratory distress syndrome (ARDS) in SARS and MERS cases, especially advanced age and male sex. For MERS, additional risk factors that are associated with severe disease include chronic conditions such as diabetes mellitus, hypertension, cancer, renal and lung disease, and co-infections. Although the ancestors of SARS-CoV and MERS-CoV probably circulate in bats, zoonotic transmission of SARS-CoV required an incidental amplifying host. Dromedary camels are the MERS-CoV reservoir from which zoonotic transmission occurs; serological evidence indicates that MERS-CoV-like viruses have been circulating in dromedary camels for at least three decades. Human-to-human transmission of SARS-CoV and MERS-CoV occurs mainly in health care settings. Patients do not shed large amounts of virus until well after the onset of symptoms, when patients are most probably already seeking medical care. Analysis of hospital surfaces after the treatment of patients with MERS showed the ubiquitous presence of infectious virus. Our understanding of the pathogenesis of SARS-CoV and MERS-CoV is still incomplete, but the combination of viral replication in the lower respiratory tract and an aberrant immune response is thought to have a crucial role in the severity of both syndromes. The severity of the diseases that are caused by emerging coronaviruses highlights the need to develop effective therapeutic measures against these viruses. Although several treatments for SARS and MERS (based on inhibition of viral replication with drugs or neutralizing antibodies, or on dampening the host response) have been identified in animal models and in vitro studies, efficacy data from human clinical trials are urgently required. Insights into coronavirus emergence, replication and pathogenesis gained from the SARS and MERS outbreaks have guided the development of preventive and therapeutic measures. In this Review, Munster and colleagues highlight recent achievements and areas that need to be addressed to combat novel coronaviruses. The emergence of Middl