Respiratory illness in the context of "Muscles of respiration"

Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a coronavirus that causes COVID-19, the respiratory illness responsible for the COVID-19 pandemic that began in late 2019. The virus previously had the provisional name 2019 novel coronavirus (2019-nCoV), and has also been called human coronavirus 2019 (HCoV-19 or hCoV-19). First identified in the city of Wuhan, Hubei, China, the World Health Organization designated the outbreak a public health emergency of international concern from January 30, 2020, to May 5, 2023. SARS‑CoV‑2 is a positive-sense single-stranded RNA virus that is contagious in humans.

SARS‑CoV‑2 is a virus of the species Betacoronavirus pandemicum (SARSr-CoV), as is SARS-CoV-1, the virus that caused the 2002–2004 SARS outbreak. Some animal-borne coronaviruses are more closely related to SARS-CoV-2 than SARS-CoV-1 is. The closest known relative is the BANAL-52 bat coronavirus. SARS-CoV-2 is of zoonotic origin; its close genetic similarity to bat coronaviruses suggests it emerged from such a bat-borne virus. Research is ongoing as to whether SARS‑CoV‑2 came directly from bats or indirectly through any intermediate hosts. The virus shows little genetic diversity, indicating that the spillover event introducing SARS‑CoV‑2 to humans is likely to have occurred in late 2019.

Severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1), previously known as severe acute respiratory syndrome coronavirus (SARS-CoV), is a coronavirus that causes severe acute respiratory syndrome (SARS), the respiratory illness responsible for the 2002–2004 SARS outbreak. It is an enveloped, positive-sense, single-stranded RNA virus that infects the epithelial cells within the lungs. The virus enters the host cell by binding toangiotensin-converting enzyme 2. It infects humans, bats, and palm civets. The SARS-CoV-1 outbreak was largely brought under control by simple public health measures. Testing people with symptoms (fever and respiratory problems), isolating and quarantining suspected cases, and restricting travel all had an effect. SARS-CoV-1 was most transmissible when patients were sick, so its spread could be effectively suppressed by isolating patients with symptoms.

On April 16, 2003, following the outbreak of SARS in Asia and secondary cases elsewhere in the world, the World Health Organization (WHO) issued a press release stating that the coronavirus identified by a number of laboratories was the official cause of SARS. The Centers for Disease Control and Prevention (CDC) in the United States and the National Microbiology Laboratory (NML) in Canada identified the SARS-CoV-1 genome in April 2003. Scientists at Erasmus University in Rotterdam, the Netherlands, demonstrated that the SARS coronavirus fulfilled Koch's postulates, thereby confirming it as the causative agent. In the experiments, macaques infected with the virus developed the same symptoms as human SARS patients.

"Coughs and sneezes spread diseases" was a slogan first used in the United States during the 1918–20 influenza pandemic – later used in the Second World War by Ministries of Health in Commonwealth countries – to encourage good public hygiene to halt the spread of the common cold, influenza and other respiratory illnesses.