Human coronavirus OC43 (HCoV-OC43) is a member of the species ''
Betacoronavirus 1
''Betacoronavirus 1'' is a species of coronavirus which infects humans and cattle. The infecting virus is an enveloped, positive-sense, single-stranded RNA virus and is a member of the genus ''Betacoronavirus'' and subgenus ''Embecovirus.'' Li ...
'', which infects humans and cattle.
The infecting
coronavirus is an
enveloped,
positive-sense
In molecular biology and genetics, the sense of a nucleic acid molecule, particularly of a strand of DNA or RNA, refers to the nature of the roles of the strand and its complement in specifying a sequence of amino acids. Depending on the context ...
,
single-stranded
When referring to DNA transcription, the coding strand (or informational strand) is the DNA strand whose base sequence is identical to the base sequence of the RNA transcript produced (although with thymine replaced by uracil). It is this stra ...
RNA virus that enters its host cell by binding to the
N-acetyl-9-O-acetylneuraminic acid receptor. OC43 is one of
seven coronaviruses known to infect humans. It is one of the viruses responsible for the
common cold and may have been responsible for the
1889–1890 pandemic. It has, like other coronaviruses from genus ''
Betacoronavirus
''Betacoronavirus'' (β-CoVs or Beta-CoVs) is one of four genera (''Alpha''-, ''Beta-'', '' Gamma-'', and '' Delta-'') of coronaviruses. Member viruses are enveloped, positive-strand RNA viruses that infect mammals (of which humans are part). ...
,'' subgenus ''
Embecovirus
''Embecovirus'' is a subgenus of coronaviruses in the genus ''Betacoronavirus''. The viruses in this subgenus, unlike other coronaviruses, have a hemagglutinin esterase (HE) gene. The viruses in the subgenus were previously known as group 2a coro ...
'', an additional shorter
spike protein
In virology, a spike protein or peplomer protein is a protein that forms a large structure known as a spike or peplomer projecting from the surface of an enveloped virus. as cited in The proteins are usually glycoproteins that form dimers or ...
called
hemagglutinin-esterase (HE).
Virology
Four HCoV-OC43
genotypes (A to D) have been identified, with genotype D most likely arising from
genetic recombination. The
complete genome sequencing of genotypes C and D and bootscan analysis shows recombination events between genotypes B and C in the generation of genotype D. Of 29
viral variants identified, none belong to the more ancient genotype A.
Molecular clock
The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleo ...
analysis using spike and
nucleocapsid gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
s dates the
most recent common ancestor
In biology and genetic genealogy, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA) or concestor, of a set of organisms is the most recent individual from which all the organisms of the set are descended. The ...
of all genotypes to the 1950s. Genotype B and C date to the 1980s. Genotype B to the 1990s, and genotype C to the late 1990s to early 2000s. The recombinant genotype D variants were detected as early as 2004.
Comparison of HCoV-OC43 with the most closely related strain of Betacoronavirus 1 species,
bovine coronavirus
Bovine coronavirus (BCV or BCoV) is a coronavirus which is a member of the species ''Betacoronavirus 1''. The infecting virus is an enveloped, positive-sense, single-stranded RNA virus which enters its host cell by binding to the N-acetyl-9- ...
BCoV, indicated that they had a most recent common ancestor in the late 19th century, with several methods yielding most probable dates around 1890, leading authors to speculate that an
introduction
Introduction, The Introduction, Intro, or The Intro may refer to:
General use
* Introduction (music), an opening section of a piece of music
* Introduction (writing), a beginning section to a book, article or essay which states its purpose and g ...
of the former strain to the human population might have caused the
1889–1890 pandemic, which at the time was attributed to
influenza.
The
COVID-19 pandemic
The COVID-19 pandemic, also known as the coronavirus pandemic, is an ongoing global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The novel virus was first identi ...
brought further evidence of a link, as the 1889–1890 pandemic produced symptoms closer to those associated with
COVID-19
Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was identified in Wuhan, China, in December 2019. The disease quickly ...
(the infection caused by the
SARS-CoV-2
Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a ...
betacoronavirus) than to influenza. Brüssow, in August 2021, referred to the evidence that OC43 caused the 1889–1890 outbreak as "indirect, albeit weak" and was "conjectural", yet the 1889 epidemic was the best historical record to make predictions about the current COVID-19 path due to the similar "clinical and epidemiological characteristics".
The origin of HCoV-OC43 is uncertain, but it is thought that it may have originated in rodents, then passed through cattle as intermediate hosts.
A deletion from BCoV to HCoV-OC43 may have taken place for the interspecies transmission event from bovines to humans.
Pathogenesis
Along with
HCoV-229E, a species in the genus ''
Alphacoronavirus
Alphacoronaviruses (Alpha-CoV) are members of the first of the four genera (''Alpha''-, '' Beta-'', '' Gamma-'', and '' Delta-'') of coronaviruses. They are positive-sense, single-stranded RNA viruses that infect mammals, including humans. They ...
'', HCoV-OC43 is among the viruses that cause the
common cold. Both viruses can cause severe
lower respiratory tract infection
Lower respiratory tract infection (LRTI) is a term often used as a synonym for pneumonia but can also be applied to other types of infection including lung abscess and acute bronchitis. Symptoms include shortness of breath, weakness, fever, cough ...
s, including
pneumonia
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severi ...
in infants, the elderly, and
immunocompromised
Immunodeficiency, also known as immunocompromisation, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that a ...
individuals such as those undergoing
chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...
and those with
HIV/AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...
.
If HCoV-OC43 was indeed the pathogen responsible for the 1889–1890 pandemic, which resembled the
COVID-19 pandemic
The COVID-19 pandemic, also known as the coronavirus pandemic, is an ongoing global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The novel virus was first identi ...
, severe disease was much more common and mortality much higher in populations that had not previously been exposed.
Epidemiology
Coronaviruses have a worldwide distribution, causing 10–15% of common cold cases (the virus most commonly implicated in the common cold is a
rhinovirus
The rhinovirus (from the grc, ῥίς, rhis "nose", , romanized: "of the nose", and the la, vīrus) is the most common viral infectious agent in humans and is the predominant cause of the common cold. Rhinovirus infection proliferates in tem ...
, found in 30–50% of cases).
[ Infections show a seasonal pattern with most cases occurring in the winter months in temperate climates, and summer and spring in warm climates.]
See also
*''Human coronavirus HKU1
''Human coronavirus HKU1'' (''HCoV-HKU1'') is a species of coronavirus in humans and animals. It causes an upper respiratory disease with symptoms of the common cold, but can advance to pneumonia and bronchiolitis. It was first discovered in Jan ...
''
References
External links
Virology online
Virus Pathogen Database and Analysis Resource (ViPR): Coronaviridae
{{Taxonbar, from=Q16991954
Betacoronaviruses
Viral respiratory tract infections
Infraspecific virus taxa