Types of human coronaviruses

News:There are different types of coronaviruses that have been identified to infect humans.

Facts:

Coronavirus:

  • They are a large family of single-stranded RNA viruses that belong to the Nidovirales order which includes Coronaviridae among three others.
  • The first coronavirus was isolated in 1937 and it was the infectious bronchitis virus (IBV) that caused respiratory disease in chickens.

Coronaviruses that infect Humans:

  • There are seven types that infect humans which includes Two alpha coronaviruses (229E and NL63) and four beta coronaviruses (OC43, HKU1, MERS and SARS-CoV).
  • These viruses are named so because of spikes found on their surface that give them the appearance of a crown when looked through an electron microscope.

When were the Coronaviruses identified in Humans?

  • 229E: It was the first coronaviruses strains to be described possibly by D Hamre and JJ Procknow in 1966.
  • OC43: It was discovered  in 1967.However, it has been described as the first human coronavirus to be discovered in 1965 by Tyrrell and Bynoe who worked with the nasal swab titled B814.
  • NL63 and HKU1: It was first identified in the Netherlands in 2004.During this time, there was an increase in research on human coronaviruses, which led to the discovery of NL63 and HKU1 in Hong Kong in early 2005.
  • SARS-CoV: It was identified in China in 2003 (animal source not yet known bats thought to have given it to other animals probably civet cats)
  • MERS: It was first found in Saudi Arabia in 2012 (transmitted by dromedary camels)
  • SARS-CoV-2: It was identified in Wuhan,China in 2019 (source not yet known, possibly bats).