The Culinary Roots of Pandemics: Insights from SARS and COVID-19

By Jonathan Latham, PhD and Allison Wilson, PhD

In the southern city of Guangzhou, China, there’s a humorous anecdote that encapsulates the region’s renowned culinary culture. An inquisitive alien arrives in the bustling city, eager to learn about Chinese customs. Upon asking the locals about their interests, they humorously respond by placing the alien in a soup pot to cook it. This joke underscores the Cantonese penchant for unique culinary experiences, often utilizing exotic species sourced from far and wide.

This cultural trait is not merely amusing; it has real implications for public health and has been linked to infectious disease outbreaks. The original SARS (Severe Acute Respiratory Syndrome) pandemic from 2002-2004 traced its roots back to Guangzhou, where it is believed the virus emerged from palm civets, a delicacy that was brought into the city for culinary purposes.

Interestingly, this connection to Cantonese cuisine sharply contrasts with the outbreak of COVID-19 (SARS-CoV-2), which arose in Wuhan. Notably, Wuhan lacks the cultural, geographic, and climatic features that typically predispose locations to zoonotic virus spillovers. For example, bats—often carriers of coronaviruses—are less prevalent in Wuhan. Hubei Province, where Wuhan is located, has not been identified as a hotspot for bat coronaviruses compared to regions like Yunnan and Guangdong.

The Geographic Puzzle of COVID-19

Zheng-li Shi, head of coronavirus research at the Wuhan Institute of Virology (WIV), expressed her surprise at COVID-19’s emergence in Wuhan, stating in March 2020, “I had never expected this kind of thing to happen in Wuhan.” Her reaction becomes even more intriguing when one considers the geographical and ecological factors that would typically contribute to virus spillovers. The lack of bats in the area, coupled with the city’s absence of exotic food customs, leads to questions about why COVID-19 would originate there.

To quantify this unlikely scenario, we can calculate the probability of a zoonotic coronavirus outbreak occurring in Wuhan. Given that bats, which harbor coronaviruses, are found globally and considering Wuhan’s population of 11 million against a global population of 7 billion, the odds of Wuhan being ground zero for a natural outbreak can be estimated at about 1 in 630. This numerical perspective suggests that, like Dr. Shi, many researchers would also have been surprised at the outbreak’s location.

Coincidences in Evolution

Another fascinating coincidence revolves around the evolutionary biology of coronaviruses. At the WIV, Zheng-li Shi and her team particularly focused on one subset of coronaviruses: the SARS-related coronaviruses. Among the 28 known species of coronaviruses, the emergence of SARS-CoV-2 from this specific group, especially in proximity to an institute dedicated to their study, raises further eyebrows. The randomness of viral evolution suggests that the next novel coronavirus could emerge from any point on the evolutionary tree. Yet, SARS-CoV-2 did not follow this path; it emerged specifically from the type of coronaviruses that the WIV had been studying in detail.

Risky Endeavors in Research

Zheng-li Shi’s research output prominently features SARS-related coronaviruses, underscoring a deep institutional focus on understanding zoonotic spillovers from this specific group. This focus included multiple publications discussing the properties, immunogenicity, and evolution of these viruses. In contrast to the broader research undertaken on other coronaviruses, it is clear that the laboratory’s investments align tightly with the very species that later contributed to the COVID-19 pandemic.

Given the concentrated research focus on this particular group, one can multiply the probabilities: If we account for the improbability of a natural outbreak occurring in Wuhan (1 in 630) and the chance of that outbreak being caused by a SARS-related coronavirus (1 in 28), the combined probability becomes an astonishing 17,640 to 1.

Circumstantial Yet Compelling

Critics may argue that the evidence is circumstantial; however, as historical philosophers like David Hume have suggested, all evidence of causation is inherently composed of coincidences. Thus, these coincidences build a case that may surpass the threshold of reasonable doubt. The burden of proof shifts to those proposing an alternative zoonotic origin theory that can robustly account for these myriad coincidences.

Currently, despite extensive investigations and public curiosity, there remains a striking lack of credible zoonotic origin theories for SARS-CoV-2. Various potential intermediate hosts, from snakes to pangolins, have been proposed without yielding substantial evidence to substantiate a natural spillover scenario.

The Pangolin Hypothesis

Of particular interest is the pangolin hypothesis, suggesting that these creatures may carry coronaviruses transmitted from bats to humans. However, new evidence casts doubt on this theory, as pangolins are not generally recognized as natural reservoirs for coronaviruses. Moreover, investigations into samples taken from confiscated pangolins have led to revelations that significantly undermine the notion of a strong connection between pangolins and SARS-CoV-2.

In stark contrast, several lab origin theories have been posited, garnering increasing attention in scientific discourse. Each celebrates the plausibility of an engineered or accidental release from a facility such as the WIV, where research centered on bat coronaviruses was ongoing at the time of the outbreak.

Final Thoughts

Considering the exceptional probabilities calculated, alongside the circumstantial evidence presented, it remains difficult to ignore the lab escape hypothesis as a leading contender for understanding the emergence of COVID-19. As the events surrounding the pandemic unfold, the narrative surrounding its origin continues to evolve, invoking both a rich mix of cultural practices and the complexities of scientific exploration.

The implications of these explorations remain profound, reminding us that our interactions with nature can have far-reaching consequences—a theme as rich and intricate as the culinary traditions of Guangdong.