see also:

• viruses

• single stranded enveloped RNA viruses
• coronaviruses primarily infect the upper respiratory and gastrointestinal tract of mammals and birds.
• four coronaviruses continually circulate in the human population and produce the generally mild symptoms of the common cold in adults and children worldwide of which they cause around 15% (most other common colds are caused by rhinovirus), and the mean age of primary infection is around 4yrs of age¹⁾: sOC43, sHKU1, s229E, sNL63
• they generally enter animal cells via binding to either:
  • the zinc peptidase, aminopeptidase N (APN)
  • ACE2 zinc metallopeptidase - SARS virus and COVID-19 coronavirus (2019-nCoV / SARS-CoV-2)
• The most recent common ancestor (MRCA) of all coronaviruses is estimated to have existed as recently as 8000 BCE, although some models place the common ancestor as far back as 55 million years or more, implying long term coevolution with bat and avian species

• human-infecting CoV are found in only the alpha and beta subgroups thus far

• a novel group 1 CoV called swine acute diarrhea syndrome CoV (SADS-CoV) emerged from bats causing the loss of over 20,000 pigs in Guangdong Province, China in 2018
• Alphacoronavirus 1
• Human coronavirus 229E
  • shared a common ancestor with bat coronavirus (GhanaGrp1 Bt CoV) between 1686–1800 CE
  • alpaca coronavirus and human coronavirus 229E diverged sometime before 1960
• Human coronavirus NL63
  • shared a common ancestor with a bat coronavirus (ARCoV.2) between 1190–1449 CE
• Miniopterus bat coronavirus 1
• Miniopterus bat coronavirus HKU8
• Porcine epidemic diarrhea virus
• Rhinolophus bat coronavirus HKU2
• Scotophilus bat coronavirus 512

• many group 2 SARS-like and MERS-like coronaviruses are circulating in bat reservoir species that can use human receptors and replicate efficiently in primary human lung cells without adaptation
• group 2b SARS-like CoV represent an existential and future threat to global health as evidenced by the emergence of SARS-CoV and SARS-CoV-2
• Betacoronavirus 1
  • Bovine Coronavirus
    • thought to have originated in rodents and not in bats
    • in the 1790s, equine coronavirus diverged from the bovine coronavirus after a cross-species jump.
  • Human coronavirus OC43
    • in the 1890s, human coronavirus OC43 diverged from bovine coronavirus after another cross-species jump which may have caused the 1890 “flu” pandemic
    • besides causing respiratory infections, it is also suspected of playing a role in neurological diseases
    • in the 1950s, it began to diverge into its present genotypes
• Hedgehog coronavirus 1
• Human coronavirus HKU1
  • originated in rodents
• MERS
  • MERS-CoV emerged in humans from bats through the intermediate host of camels having diverged from bat coronavirus several centuries ago
• Murine coronavirus
  • is related to human coronavirus OC43 and bovine coronavirus
• Pipistrellus bat coronavirus HKU5
• Rousettus bat coronavirus HKU9
• Severe acute respiratory syndrome-related coronavirus
  • SARS related coronaviruses appeared to have coevolved in bats for a long time
  • SARS-CoV
    • most closely related bat coronavirus and SARS-CoV diverged in 1986
  • SARS-CoV-2 / Covid-19
• Tylonycteris bat coronavirus HKU4

• Avian coronavirus
• Beluga whale coronavirus SW1

• Bulbul coronavirus HKU11
• Porcine coronavirus HKU15