SARS is a severe respiratory disease that was first recognized in human beings in 2003. SARS stands for severe acute respiratory syndrome. SARS begins with a high fever followed by such symptoms as a cough and difficulty breathing. Some cases progress to pneumonia and respiratory failure. More than 6 percent of those who develop SARS die.
The first outbreak of SARS occurred in southeastern China in November 2002. However, scientists initially thought it was a type of influenza, and it was not recognized as a new disease for several months. SARS was recognized only after cases appeared in Hong Kong . By then, the disease had already spread to several countries. Scientists believe that SARS is usually transmitted through close contact with infected patients. Many cases have occurred among health care workers. About 800 people died from SARS in the outbreak. After 2004, however, no new cases of SARS were reported anywhere in the world.
Scientists identified the likely cause of SARS as a previously unrecognized variety of coronavirus. In human beings, coronaviruses are among the many viruses that cause common colds. Other types of coronaviruses cause serious or fatal disease in such livestock as hogs, cattle, and chickens. However, the SARS coronavirus appears unrelated to the varieties of viruses that infect livestock or cause colds in human beings. Scientists have found that the SARS virus closely resembles a coronavirus found in civets, catlike mammals eaten as a delicacy in China. Scientists also discovered SARS-related coronaviruses in a type of bat called a horseshoe bat that is common in China. Scientists think the virus originated in these bats and was passed to civets. The civets then transmitted the virus to people at markets where live animals are sold for food.
In 2012, a SARS-like coronavirus was identified in an outbreak of severe respiratory disease in the Middle East. The disease is known as MERS, which stands for Middle East respiratory syndrome.
In late 2019, another SARS-like coronavirus, called COVID-19, caused an outbreak of respiratory disease and deaths in China. The newly identified virus quickly started a pandemic. It spread throughout the world in 2020, infecting millions of people and causing hundreds of thousands of deaths.
