On November 16, 2002, a food handler in Foshan, China, became the first known case of severe acute respiratory syndrome (SARS), a novel coronavirus that would later be recognized as an ancestor to COVID-19. It took two months for health authorities to realize an outbreak was occurring, by which time the virus had already spread to healthcare workers.
The initial transmission is believed to have originated from live animal markets where exotic animals like civet cats were sold alongside poultry. The disease rapidly spread to Hong Kong, and from there, it was exported globally.
A traveler who visited Hong Kong in February 2003 became critically ill and died, playing a key role in the international dissemination of SARS. By March 2003, the World Health Organization issued an alert, and the Centers for Disease Control and Prevention named the disease SARS and identified the coronavirus cause.
The SARS epidemic lasted for months, affecting over 8,000 people in 28 countries, with a case-fatality rate of approximately 9.6%. While SARS briefly resurfaced in early 2004, it was quickly contained.
Investigations traced the virus to palm civets and raccoon dogs, with later research identifying bats as the likely original animal reservoir. The SARS epidemic served as a critical learning experience that informed the global response to the COVID-19 pandemic.
China significantly improved its disease surveillance and contact tracing systems after SARS, which proved crucial in identifying COVID-19 cases more rapidly. However, the SARS experience also presented a potential false sense of security, as SARS was more deadly but easier to contain due to its infectiousness peaking when patients were severely ill, unlike SARS-CoV-2 which is highly transmissible even before symptoms appear.
