It officially started on December 31st, when China notified the World Health Organization (WHO) that it detected 44 cases of pneumonia of unknown etiology, in Wuhan City, Hubei Province of China. Several infections were linked to the Huanan Seafood Wholesale Market, and it was shut down on January 1st.
By January 7th, China had identified the new strain of coronavirus — what later became known as Coronavirus Disease 2019 (COVID-19).
On January 11th, China reported its first coronavirus death; and on January 12th, China shared the genetic sequence of the novel coronavirus for countries to use in developing specific diagnostic kits.
Germany and China developed the earliest tests, and the protocols were published by WHO on January 17th and 24th respectively.
By January 17th, a second coronavirus death was reported in Wuhan. By January 21th — when WHO released its first situation report — China, Japan, the Republic of Korea, and Thailand had already reported cases.
By January 31st, one month after it was first reported, COVID-19 had officially spread to 19 countries across the Western Pacific, South-East Asia, North America, Europe, and the Middle East.
Still, global testing was very limited in January and February, and some countries were much slower than others. Take the United States as one example. It started testing as early as January 18th, but with four lab specimens. Mass testing did not pick up until mid-March. The chart below displays the number of specimens tested for COVID-19. The CDC reported a total of 4141 tests in January and February!
Less developed countries were much slower, and only took things somewhat seriously after WHO characterized COVID-19 as a pandemic on March 11th. Mass testing is still limited across many countries, and only those with severe cases are tested for COVID-19. The actual number of cases is expected to be much larger.
A new study, co-led by Francois Balloux, suggests that the COVID-19 pandemic started between October and December of 2019! Up to three months before it was first detected!
One French hospital has retested old samples from pneumonia patients and found that they had a case of COVID-19 as early as December 27th. Almost a month before France officially announced its first case!
If COVID-19 started spreading globally between October and December 2019, then hundreds if not thousands were infected before anyone noticed. China was the first to notice and report unusual cases of pneumonia!