Coronavirus History
Coronaviruses were discovered in the 1960s; the earliest ones discovered were
infectious bronchitis virus in chickens and two viruses from the
nasal cavities of human patients with the
common cold that were subsequently named
human coronavirus 229E and
human coronavirus OC43.
[28] Other members of this family have since been identified, including
SARS-CoV in 2003,
HCoV NL63 in 2004,
HKU1 in 2005,
MERS-CoV in 2012, and
2019-nCoV in 2019; most of these have been involved in serious
respiratory tract infections.
On 31 December 2019, a novel strain of coronavirus, officially designated as
2019-nCoV by the
World Health Organization, was reported in
Wuhan,
China, as responsible for the
2019–20 Wuhan coronavirus outbreak.
[29] By 24 January 2020, 25 deaths have been reported and 547 confirmed cases.
[30][31] The Wuhan strain has been identified as a new strain of
Betacoronavirus from group 2B with an ~70% genetic similarity to the SARS-CoV.
[32] The virus was suspected to have originated in
snakes,
[33] but many leading researchers disagree with this conclusion.
[34]
Evolution
The most recent common ancestor of the coronavirus has been placed at 8000 BCE.
[35] They may be considerably older than this. Another estimate places the
most recent common ancestor (MRCA) of all coronaviruses around 8100 BCE.
[36] The MRCA of Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus have been placed at about 2400 BCE, 3300 BCE, 2800 BCE and 3000 BCE, respectively. It appears that bats and birds, the warm-blooded flying vertebrates, are ideal hosts for the coronavirus gene source (with bats for Alphacoronavirus and Betacoronavirus, and birds for Gammacoronavirus and Deltacoronavirus) to fuel coronavirus evolution and dissemination.[
citation needed]
Bovine coronavirus and canine respiratory coronavirus diverged from a common ancestor in 1951.
[37] Bovine coronavirus and human coronavirus OC43 diverged in 1899. Bovine coronavirus diverged from the equine coronavirus species at the end of the 18th century. Another estimate suggests that human coronavirus OC43 diverged from bovine coronavirus in 1890.
[38]
The MRCA of human coronavirus OC43 has been dated to the 1950s.
[39]
Middle East respiratory syndrome coronavirus, although related to several bat species, appears to have diverged from these several centuries ago.
[40] The human coronavirus NL63 and a bat coronovirus shared an MRCA 563–822 years ago.
[41]
The most closely related bat coronovirus and the SARS coronavirus diverged in 1986.
[42] A path of evolution of the SARS virus and keen relationship with bats have been proposed.
[43][44] The authors suggest that the coronaviruses have been coevolved with bats for a long time and the ancestors of SARS virus first infected the species of the genus
Hipposideridae, subsequently spread to species of the
Rhinolophidae and then to
civets, and finally to humans.[
citation needed]
Alpaca coronavirus and human coronavirus 229E diverged before 1960.
[45]