Pinpointing the Origin of the SARS-CoV-2, COVID-19 Pandemic

Science recently published two studies looking at the epidemiology of the COVID-19 virus. Understanding where the virus began and spread may help inform public health practices to mitigate the spread of the disease and its long-term effects.

According to the CDC, “epidemiology is the study (scientific, systematic, and data-driven) of the distribution (frequency, pattern) and determinants (causes, risk factors) of health-related states and events (not just diseases) in specified populations (neighborhood, school, city, state, country, global).”

Determining the sources of disease spread can drive research on current and future disease prevention and treatment, allowing for additional scientific advancement. Furthermore, an in-depth analysis of risk factors can help protect at-risk populations.

The two related publications identified the epicenter of the COVID-19 pandemic and hypothesized how the virus transmission occurred.

In one of the two publications, researchers determined that the Huanan Seafood Wholesale Market in Wuhan was the origin of the COVID pandemic. In the publication, the researchers state, “we show the earliest known COVID-19 cases from December 2019, including those without reported direct links, were geographically centered on this market.”

After mapping and modeling the earliest known COVID-19 cases, the researchers found that numerous cases were associated with the market in Wuhan. The study also concluded that many cases and positive samples were centered around market areas selling live animals, creating a chance for zoonotic disease transmission.

In addition to directly linked cases, the investigators found that other early cases had an indirect link or were close to the market where they believe the spread began.

“The live animal trade and live animal markets are a common theme in virus spillover events, with markets such as the Huanan market selling live mammals being in the highest risk category,” the researchers concluded in the study.

The other related publication analyzed the molecular epidemiology of the disease and determined that the virus likely came from infected animals at the market in Wuhan.

In the Science article, the researchers concluded that there was likely a zoonotic jump from host animals at the market to humans, sparking the spread of the SARS-CoV-2 virus.

According to the CDC, zoonotic diseases can be spread through direct or indirect contact, vectors, food, or water.

Although this current research has provided some insight into the start and spread of the SARS-CoV-2 virus, the studies did have some limitations. While considering these limitations, “maximum effort must now be applied to elucidate the upstream events that might have brought SARS-CoV-2 into the Huanan market, culminating in the COVID-19 pandemic. To reduce the risk of future pandemics, we must understand, and then limit, the routes and opportunities for virus spillover,” said the researchers in the publication.