Severe acute respiratory syndrome

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The severe acute respiratory syndrome (SARS) is a zoonotic illness caused by severe acute respiratory syndrome-related coronavirus (SARS-CoV-1), a coronavirus. The disease was first seen in the city of Foshan in Guangdong Province in China in 2002 and was traced back to the ​Himalayan (masked) palm civet, racoon dogs and the Chinese ferret-badger. All of these animals are sold in the live wild animal markets in China . The civet cats were thought to be the intermediaries who passed the SARS virus from bats to humans.

Terminology

Following the discovery of SARS-CoV-2, the numeric digit 1 was suffixed to the name of the SARS-related coronavirus, creating SARS-CoV-1 .

Epidemiology

From 2002-2003 there were over 8,000 confirmed cases of SARS (21% of which were in health care workers), leading to 813 deaths . Outside of Asia, Canada was the most affected nation, with the majority of cases secondary to exposure within a healthcare facility. The severe acute respiratory syndrome crisis in Canada lead to a major revision of infection control practice, surge capacity planning, and the formation of the Canadian public health agency .

Currently there are no active reported cases of SARS-CoV-1 infection worldwide.

Clinical presentation

Patients with SARS present with flu-like symptoms that will either show clinical improvement after the first week (30% of patients) or require intensive care treatment (20-30% of patients). A history of SARS-CoV-1 contact is often found. Initial symptoms include :

Complications

Pathology

The SARS-related coronavirus-1 (SARS-CoV-1) is a member of the Betacoronavirus genus, one of the genera of the Coronaviridae family of viruses. Coronaviruses are enveloped single-stranded RNA viruses, that are found in humans, many other mammals and birds. These viruses are responsible for pulmonary, hepatic, CNS and intestinal disease.

Hitherto, seven coronaviruses have been found to be responsible for human diseases, two more are zoonoses, COVID-19 and Middle East respiratory syndrome coronavirus (MERS-CoV), both of which may sometimes be fatal. The remaining four viruses are ubiquitous in human societies worldwide and cause mild coryzal illnesses.

Radiographic features

Plain radiograph/CT

In up to 21% of patients , the initial chest radiograph may be normal. It is important to note that the findings are quite non-specific and clinical context is of the utmost importance :

  • focal opacity (most common)
  • multifocal opacity often contrasted to the middle and lower zones
  • ground-glass opacities (unilateral or bilateral)

Treatment and prognosis

No specific treatment exists for severe acute respiratory syndrome. Patients are given broad-spectrum antibiotics as well as antivirals, steroids, and supportive therapy . Vaccines for MERS-CoV and SARS-CoV-2 are under development .