Coronavirus
Original Article by: Teri Shors, Department of Biology and Microbiology, University of Wisconsin, Oshkosh, Wisconsin.
Content
• Background
• Coronavirus structure
• Coronavirus research
• Coronavirus classification/taxonomy
• Coronaviruses and spillover events
• Coronaviruses are masters of RNA recombination
Key Concepts
• Coronaviruses cause upper and lower respiratory tract
diseases, gastroenteritis, hepatitis, and central nervous sys-
tem infections in birds and mammals, including humans.
• Since the start of the twenty-first century, coronaviruses
have caused three large-scale pandemics: SARS, MERS,
and COVID-19.
• The name coronavirus is derived from the Latin word
corona because its spike (S) proteins, which protrude
outside of the virion, resemble a royal crown or the Sun's
corona when viewed using an electron microscope.
• Coronaviruses are classified in the family Coronaviridae
and the subfamily Orthocoronavirinae. The subfamily is
divided into four genera, based on differences in protein
sequences: Alphacoronavirus, Betacoronavirus, Gamma-
coronavirus, and Deltacoronavirus.
• Seven coronaviruses are known to cause infections in
humans. Four of these coronaviruses cause mild respira-
tory illness, including instances of the common cold. The
remaining three coronaviruses are emergent viruses that
cause severe respiratory distress/pneumonia and even
death: SARS-CoV-1, MERS-CoV, and SARS-CoV-2.
Access to this article is being offered to Ward's World readers for free from McGraw Hill's
AccessScience. An award-winning online gateway to scientific knowledge, AccessScience
offers exclusive articles writing by prominent scientists, links to primary research material,
videos and animations, plus faculty-designed curriculum maps for teachers.
All human coronaviruses have
animal origins.
Any of a group of viruses that cause upper and lower respi-
ratory tract diseases, gastroenteritis, hepatitis, and central
nervous system infections in birds and mammals, including
humans. Coronaviruses (Fig. 1) comprise a major group of
common animal viruses that typically infect mammals and
birds. Most notably, since the start of the twenty-first century,
coronaviruses have emerged as threatening zoonotic patho-
gens (originating in wild animals) that have caused three large-
scale pandemics: severe acute respiratory syndrome (SARS),
Middle East respiratory syndrome (MERS), and coronavirus
disease 2019 (COVID-19). The COVID-19 pandemic is a once-
in-a-century event similar in scope to the influenza pandemic
of 1918–1919, and these two pandemics have caused high
morbidity, mortality, and social and economic disruption on a
global scale. Mild, less-severe coronavirus diseases of the up-
per respiratory tract include certain cases of the common cold.
More-severe coronavirus infections can lead to lower respira-
tory illness (pneumonia), gastroenteritis, peritonitis, reproduc-
tive diseases, nephritis (kidney disease), hepatitis, and central
nervous system infections.
+
ward
'
s
science
Fig. 1: Highly magnified, digitally colorized electron micrograph of MERS-CoV virions
(red color). (Credit: National Institute of Allergy and Infectious Diseases)
