Coronaviruses are enveloped RNA viruses that cause respiratory illnesses of varying severity from the common cold to fatal pneumonia.
In January 2020 a novel coronavirus, SARS-CoV-2, was identified as the causative agent of an outbreak of viral pneumonia centered around Wuhan, Hubei, China. That disease is now called COVID-19. The virus has caused a widespread outbreak of disease similar to SARS throughout China, with exported cases occurring in four other continents, including the United States.
The Centers for Disease Control and Prevention (CDC) has developed a test to diagnose COVID-19 in respiratory and serum samples from clinical specimens. NIAID also is accelerating efforts to develop additional diagnostic tests for COVID-19. These tests would help facilitate preclinical studies and aid in the development of medical countermeasures.
Much of NIAID’s work on COVID-19 is an expansion of its work on Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS). MERS-CoV is a viral respiratory disease that was first reported in Saudi Arabia in 2012 and has since spread to more than 27 other countries, according to the World Health Organization. Some people infected with MERS-CoV develop severe acute respiratory illness, including fever, cough, and shortness of breath. From its emergence through December 2019, WHO has confirmed 2,499 MERS cases and 861 deaths (or about 1 in 3). Among all reported cases in people, about 80% have occurred in Saudi Arabia. Only two patients in the United States have tested positive for MERS-CoV, both of whom recovered. They were healthcare providers who lived in Saudi Arabia, where they likely were infected before traveling to the U.S., according to the Centers for Disease Control and Prevention.
Infection with SARS-CoV can cause a severe viral respiratory illness. SARS was first reported in Asia in February 2003, though cases subsequently were tracked to late 2002. SARS quickly spread to about two dozen countries before being contained after about four months. Since 2004, there have been no known SARS cases.
Research evidence suggests that SARS-CoV-2, MERS-CoV, and the original SARS-CoV all originated in bats. SARS-CoV then spread from infected civets to people, while MERS-CoV spreads through infected dromedary camels to people. Scientists are trying to determine how SARS-CoV-2 spread to people.