COVID-19 Chapter 7: Spillover

Coming at ya with our seventh episode in our Anatomy of a Pandemic series on the ongoing COVID-19 situation. So far in the series, we’ve discussed aspects of the virus’s biology, clinical disease, epidemiology, and control efforts. We’ve briefly touched on aspects of the virus’s ecology, including its origins, but we wanted to take a step back and ask, “how do spillover events happen and how do we stop them?” To answer those questions (and many more), we brought on Dr. Jonna Mazet, Professor of Epidemiology and Disease Ecology at the UC Davis School of Veterinary Medicine and Executive Director of the UC Davis One Health Institute, who has spent much of her professional life on the hunt for emerging pathogens (interview recorded April 2, 2020). We pick Dr. Mazet’s brain on how we look for and identify pathogens of possible public health concern, what work disease ecologists are currently doing on SARS-CoV-2, and what we can expect to see in terms of future spillover events. We wrap up the episode by discussing the top five things we learned from our expert. To help you get a better idea of the topics covered in this episode, we have listed the questions below: Can you take us through a step-by-step of how surveillance of novel pathogens is done? From the logistics of international coordination to the sampling to the reporting - what does that look like? What happens when you do identify a potential spillover event? Can you talk about how you decide what a hotspot is? What makes a hotspot a hotspot basically? We've talked a lot on this podcast about spillover events, and obviously they can happen in many different ways, but can you give us a general overview of how one occurs? What are some patterns we see with all spillover events? Over the past 100, 200 years, land use change has increased and the barrier between humans and wildlife has decreased - have we seen a corresponding increase in spillover events during that time? What do we know at this point about how SARS-CoV-2 spilled over into humans? I assume eventually we will get a clearer picture of how that spillover event occurred. How can we use that information in the future? Can you talk about what it means for a pathogen to "jump species"? Do viruses more easily "jump species" compared to bacteria, or is it just that we hear more about the viruses? I'd like to talk about what happens when prevention has to shift to control. What are the first steps taken for disease ecologists studying this outbreak? How is the One Health approach being used to study and slow down the current COVID-19 pandemic? What role do we see wildlife conservation playing in spillover events or preventing them? Can you talk about how there can be a conflict in wildlife conservation for the greater good when people are also just trying to feed their families? How do you determine whether something easily moves between species? Is that a genomic question or is it an experimental question?  What do you think are some of the biggest barriers or challenges in identifying these spillover events in the future? The One Health approach is such a great example of interdisciplinary collaboration. Can you talk about what some of the different fields are that work in One Health? What positive changes do you hope to see come out of this pandemic? Follow Dr. Jonna Mazet (@JonnaMazet), the PREDICT project (@PREDICTproject), and the Global Virome Project (@GlobalVirome). Or check out their websites: One Health Institute (https://ohi.vetmed.ucdavis.edu/), PREDICT (http://data.predict.global/), Global Virome Project (www.globalviromeproject.org). The firsthand account was taken from a piece by Craig Spencer, MD written for the Washington Post titled, “How long will we doctors last?”