According to the U.S. Department of Health and Human Services/Centers for Disease Control and Prevention (CDC), Chinese authorities identified an outbreak caused by a novel—or new—coronavirus, SARS-CoV-2. The virus can cause mild to severe respiratory illness, known as Coronavirus Disease 2019 (COVID-19). The outbreak began in Wuhan, Hubei Province, China, and has spread to a growing number of countries worldwide—including the United States. On March 11, 2020, the World Health Organization declared COVID-19 a pandemic.
SARS-CoV-2 is different from six other, previously identified human coronaviruses, including those that have caused previous outbreaks of Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS).
The Hazard Recognition page describes how COVID-19 is thought to spread.
Additional information on coronaviruses is available on the U.S. Centers for Disease Control and Prevention (CDC) coronavirus website.