Source: International Atomic Energy Agency – IAEA
The family of coronaviruses has four genera – Alphacoronavirus, Betacoronavirus, Gammacoronavirus and Delatacoronavirus – and accounts for 10 to 30 per cent of the agents responsible for a range of diseases, starting from common cold to much more serious diseases. COVID-19 is a novel coronavirus that had not been previously identified and is not the same as the coronaviruses that commonly circulate among humans causing the common cold.
The emergence of Severe Acute Respiratory Syndrome (SARS-CoV-1), caused by the Betacoronavirus in humans in China in 2002 was considered to have an animal origin (most likely from bats and transmitted through civets – cat-like mammals – to humans). Once the virus jumped from the animal host to humans, the predominant transmission was human-to-human. From 2002 to 2003, SARS-CoV-1 spread through 26 countries, causing approximately 8000 infections and 800 deaths, according to WHO.
About a decade later in 2012, another Betacoronavirus infection in humans – Middle East Respiratory Syndrome (MERS-CoV) – was identified in Saudi Arabia, introduced through camels or possibly other animals. The disease has affected 27 countries, according to WHO, with 2519 cases and 866 deaths, by the end of January 2020.
The emergence of the SARS-CoV-2 strain causing COVID-19 was reported in China at the end of 2019. WHO’s latest report tallies 53.2 million cases with more than 1.3 million deaths worldwide.
Read more about the IAEA’s work in transboundary animal and zoonotic diseases.