A Tale of Two Epidemics: Unveiling the Origins of SARS and its Impact on COVID-19
In the annals of science history, a single date stands out as the beginning of a journey that would shape our understanding of viral outbreaks: November 16, 2002. On this fateful day, an unsuspecting food handler in Foshan, China, became the first person to be infected with SARS (Severe Acute Respiratory Syndrome), an older cousin of the COVID-19 virus.
Quick Facts:
- Milestone: The first-ever SARS infection.
- Date: November 16, 2002.
- Location: Foshan, China.
- Patient: A food handler, likely exposed to live animals at wet markets.
The Unraveling Mystery:
It wasn’t until January 2003 that Chinese epidemiologists identified two cases of “atypical pneumonia” in Guangdong province. These patients had visited healthcare workers, and through contact tracing, it was discovered that the virus had been circulating since November 16, 2002. The early cases were linked to food handlers working in restaurants or wet markets, where live animals, including poultry and exotic species like civet cats and raccoon dogs, were kept in cramped conditions.
A Rapid Spread:
By the time Chinese disease investigators realized an outbreak was underway, the virus had already been spreading for two months. It had reached healthcare workers and, in February, made its way to Hong Kong. The disease then exploded when a nephrologist from southern China traveled to Hong Kong for a wedding on February 21, 2003. He fell ill during his trip and later succumbed to the disease.
International Impact:
In March, Dr. Carlo Urbani, a case investigator for the World Health Organization (WHO), was called to investigate a case in a businessman who had traveled to Hong Kong before being hospitalized in Hanoi, Vietnam. Urbani contracted the disease and passed away the same month. By March 12, the WHO issued an alert about a severe pneumonia of unknown origin affecting people from China, Hong Kong, and Vietnam. The CDC officially named the disease SARS on March 15 and identified a novel coronavirus as the cause on March 24.
The Pandemic’s Peak:
The SARS pandemic lasted for months, spreading to 28 countries beyond China, with 29 cases in the U.S. It affected over 8,000 people, with 774 deaths, resulting in a case-fatality rate of approximately 9.6%. The outbreak reached its peak by March 12, 2003.
A Brief Resurgence:
In early 2004, SARS flared up again briefly, but an aggressive contact-tracing strategy quickly contained its spread. This second wave allowed scientists to trace the SARS virus back to palm civets and raccoon dogs sold at markets. The following year, scientists proposed that horseshoe bats were the original animal hosts, and in 2017, researchers discovered a colony of bats carrying SARS-like viruses in remote caves in China’s Yunnan province, just a mile away from nearby villages.
A Warning Unheeded:
Researchers at the time warned of the risk of a similar disease emerging from these bats. “The risk of spillover into people is possible,” they wrote. Unfortunately, their warning went unheeded, and the world was ill-prepared for the COVID-19 pandemic that emerged in November 2019, sweeping across the globe until May 2023.
Lessons Learned, and Unlearned:
The SARS epidemic served as a dress rehearsal for the COVID-19 pandemic. China, having learned from SARS, implemented a robust contact-tracing and disease-surveillance system, which proved crucial when SARS-CoV-2 emerged. The virus was identified within two weeks, and vaccine development began immediately, thanks to mRNA technology. However, some lessons were only partially learned. Dr. Kwok-Yung Yuen, a virologist who co-discovered the SARS virus, emphasized the importance of respecting wildlife habitats, but this practice continued, leading to the COVID-19 outbreak.
A False Sense of Security:
The SARS epidemic gave public health agencies a false sense of security. SARS and related diseases like MERS were deadlier but easier to contain. Outbreaks were controlled through contact tracing, unlike COVID-19, which had a longer infectious window and was more easily transmitted, sometimes even before symptoms appeared.
The story of SARS and its impact on the COVID-19 pandemic is a complex web of scientific discovery, public health measures, and missed opportunities. It serves as a reminder of the importance of learning from past outbreaks and respecting the delicate balance of nature.