On Nov. 17, 2019, an unknown but highly contagious illness was spreading in central China. For at least a month, the virus went undetected, silently infecting hundreds of people until Chinese doctors and officials noticed something unusual in late December and stepped in.
As the number of patients began to multiply in the country and beyond, the world scrambled to figure out how to defeat the virus, putting under the microscope both the pathogen and China’s response to the outbreak.
But as scientists’ work to study the virus evolved, some of the assumptions held about the pathogen in early 2020 turned out to be shakier than they first appeared.
Here are some key instances of how our understanding of the COVID-19 pandemic has changed.
When it started
A 55-year-old man from the central Chinese province of Hubei was believed to be the first person to have contracted COVID-19 in China, on Nov. 17 last year, according to Chinese government documents cited by the South China Morning Post.
But multiple studies of the virus’s evolution suggested that the first case could have emerged as early as October.
And a study by the National Cancer Institute in Milan published this month said that the virus was circulating in Italy last September. Researchers reached the conclusion by testing the presence of coronavirus antibodies in blood samples collected between September last year and March 2020.
The World Health Organization (WHO) is reviewing the study, Reuters reported. The search for patient zero continues.
Where it started
Wet markets have long been a staple of daily life for many in China and across Asia.
But they took on a new and darker reputation after a wet market in the central Chinese city of Wuhan was suspected of being the source of the outbreak. The market, where seafood and live animals were traded, was shut down on Jan. 1, 2020.
Studies suggested that the virus jumped from animals, possibly bats, to humans. The Huanan Seafood Wholesale Market in Wuhan reportedly sold wild animals that could host the pathogen.
But a growing body of research has suggested that the virus was spreading months before a cluster at the market was discovered.
This means the market was unlikely the source of the global pandemic, only where a large-scale outbreak was detected.
Whether to lock down a city
The Chinese government’s drastic decision to cut off the city of Wuhan from the rest of China shocked international communities in its severity.
But as many places around the world still struggle to control the pandemic, similar measures have become more commonplace.
Rapidly rising infection numbers prompted the Chinese government to impose aggressive lockdown measures in Wuhan on Jan. 23, 2020, including the suspension of all flights and trains. Millions of Wuhan residents spent weeks sealed off from the outside world. People were confined to their homes and schools and businesses shut.
But Wuhan’s lockdown would come to serve an important purpose, becoming a model for what was to come for the rest of the world undergoing their respective second and third waves of infection.
Today, life in Wuhan has largely returned to normal. One music festival, held in a popular water park, set the internet ablaze in August.
Observers expressed outrage at the lack of social distancing in the packed pools, where thousands of party-goers stood shoulder-to-shoulder without masks.
But one local resident previously had this to say: “Do not forget how it must have felt like for all of us actually living in Wuhan who were the first people in the world to experience such unsettling beginnings of an unknown and dangerous virus that was emerging and then being forced under state lockdown in our homes.”