"A chicken being tested for Avian Influenza (Bird Flu) using an oropharyngeal swab" accessed April 6, 2021, Creative Commons Attribution-Sahre Alike 4.0 International, https://creativecommons.org/licenses/by-sa/4.0/deed.en
Severe acute respiratory syndrome (SARS) is a viral respiratory disease caused by a SARS-associated coronavirus. It was first identified at the end of February 2003 during an outbreak that emerged in China and spread to 4 other countries. WHO coordinated the international investigation with the assistance of the Global Outbreak Alert and Response Network (GOARN) and worked closely with health authorities in affected countries to provide epidemiological, clinical and logistical support and to bring the outbreak under control....SARS is an airborne virus and can spread through small droplets of saliva in a similar way to the cold and influenza. It was the first severe and readily transmissible new disease to emerge in the 21st century and showed a clear capacity to spread along the routes of international air travel.....SARS can also be spread indirectly via surfaces that have been touched by someone who is infected with the virus....Most patients identified with SARS were previously healthy adults aged 25–70 years. A few suspected cases of SARS have been reported among children under 15 years. The case fatality among persons with illness meeting the current WHO case definition for probable and suspected cases of SARS is around 3%.
--World Heath Organization, https://www.who.int/health-topics/severe-acute-respiratory-syndrome#tab=tab_1 (accessed April 6th, 2021)
Avian influenza refers to the disease caused by infection with avian (bird) influenza (flu) Type A viruses. These viruses occur naturally among wild aquatic birds worldwide and can infect domestic poultry and other bird and animal species. Avian flu viruses do not normally infect humans. However, sporadic human infections with avian flu viruses have occurred.
CDC, https://www.cdc.gov/flu/avianflu/index.htm (accessed April 6th, 2021)