Coronaviruses

Categorization
Genome: RNA Virus, Positive ssRNA Virus Structure: Enveloped Virus, Helical Virus
Overview
  • Coronaviruses are a family of related viruses which cause respiratory infections. One serotype of the virus associated with more serious infections is termed SARS-Coronavirus (SARS-CoV).
Transmission
  • Transmission of coronaviruses is not completely understood but likely occurs via infectious respiratory droplets and secretions.
Pathogenesis
  • Most Coronaviruses replicate in and damage the mucosa of the upper respiratory tract, specifically the nasopharynx, thus causing the syndrome of the common cold. The SARS-CoV strain is able to bind and replicate in other tissues, including the lower respiratory tract, and can spread viremically, thus causing a more serious clinical syndrome. Interestingly, the expanded tropism of SARS-CoV appears to be due to its capacity to bind the Angiotensin Converting Enzyme-2 Receptor.
Clinical Consequences
  • Overview
    • Most Coronaviruses cause upper respiratory infections resulting in the syndrome of the common cold; however, the SARS-CoV strain can cause the Severe Acute Respiratory Syndrome (SARS).
  • Common Cold Syndrome
    • This self-limited syndrome is well-known to all individuals and manifests as a febrile illness with attendant headache, pharyngitis, coryza, and Cough.
  • Severe Acute Respiratory Syndrome (SARS)
    • SARS begins with a syndrome similar but more intense than the common cold. However, soon there after, patients display dyspnea which can progress to ARDS and respiratory failure.