The infectious respiratory disease COVID-19 has spread rapidly within China, neighboring countries and beyond, since the new coronavirus was first identified in Wuhan, China in December.
The first confirmed cases of coronavirus outside of China occurred in Japan, Thailand and South Korea on Jan. 20.
The first U.S. case was found on Jan. 21 in the state of Washington.
The disease was declared a pandemic by the World Health Organization on March 11 – the first time since H1N1 in 2009.
That specific virus, currently known as SARS-CoV-2, is just the third type of coronavirus known to also cause serious human symptoms.
The other two strains cause respiratory syndrome in the Middle East.