Amber Barnes Headshot
Amber Barnes | Assistant Professor

Global Food Markets and Disease


The graduate Environmental Health 6215 course within the Master of Public Health program presents a One Health framework to demonstrate the relationships between environmental, human and animal health. Using this course description, two complementary assignments were created to examine the potential zoonotic origins of SARS-CoV-2 and environmental disease transmission using the investigative information we had at that time. Utilization of the One Health lens allowed students to address these questions with a holistic approach to the interconnected health of all living beings and their shared environment. In the first week, students provided thoughtful discussion posts to a case study on the industry, importance, and also the risks associated with food markets, sometimes referred to as “wet markets”. These markets are critical to food security, culture, community, and the provision of economic opportunities for small farmers. Students discussed the role of these markets in both the United States and abroad. In the following week, students designed their own conceptual models to demonstrate disease exposure and transmission pathways for both humans and animals in the acquisition of a pathogen spread through the environment. Students were able to contemplate the complex relationships humans have with infectious disease in our environment and the opportunities and barriers for prevention and control.

The field of public health has been front and center during the pandemic with experts on the front lines of the epidemiological research, vaccination efforts, and policy discussions. Global health has never felt more local. But many graduate students have felt powerless to assist and are unsure of their place within the larger conversations of pandemic response. Although the Environmental Health course for our Master of Public Health students has been working well as a hybrid course to accommodate our working professionals, it has been challenging to deliver this class during the pandemic. Typically, lively small group discussions and hands-on activities help to generate a strong bond in the cohort and allow our students to share their own experiences and expertise from their health-related careers. However, with Covid-19, it has been difficult to require, or depend on, all of the students safely meeting together inside the classroom for the on-campus sessions. This is particularly true for those working in health care and the loss of peer support and engagement has been hard to overcome.

I realized early on that trying to adhere to the traditional topics of a course couldn’t compete with the headlines and news stories demonstrating our global response to Covid-19. My best option would be to integrate as much of the current events into the classroom as possible but with consideration to our collective fatigue, fear and grieving surrounding its severity and longevity. Since I conduct One Health research in global settings and study zoonoses, or diseases shared between animals and humans, I have been following studies looking into the risk factors for transmission of the virus between humans but also between humans and animals. Because of my background and research interests, I have been able to talk to my students about what we know as a global community on the epidemiology of SARS-CoV-2 but more importantly, the obstacles that exist in answering our remaining questions and in preventing another pandemic of zoonotic origin.

A pair of assignments that I added to the spring 2021 course revolved around a Case Study Discussion Board Posting and Peer Replies as well as the design of a Conceptual Map regarding zoonotic disease and its potential transmission pathways in our environment. For the case study, students were asked to watch a One Health webinar that was created to present the benefits and risks associated with food markets, or “wet markets”, which often have fresh fruits and vegetables but may also have dairy, meat or seafood products, and even live animals for butcher or preparation. The webinar featured presentations by Dr. Laura Khan titled, “A One Health Perspective on the Wildlife Trade: Social, Cultural, and Political Stakes” and by Dr.  Bernardo Moreno titled “Wildlife Trade: Social, Cultural, and Political Stakes”. The assignment asked for posts that contained a paragraph each on: a) what the student thinks are the biggest risks associated with live animal markets or “wet markets”. The response should have considered the multiple One Health angles related to human, animal, and or environmental health; b) what cultural components and food security concerns the student thinks are associated with live animal markets or “wet markets”, whether located in the United States or abroad. Benefits from the market could have also been discussed; and finally, c) the promotions of a strategy, intervention, or policy the student thinks should be implemented either domestically or internationally to combat the risk outlined in their first paragraph and why they think this would be an acceptable and effective measure. Students had excellent insight into the concept of open markets and farmer’s markets and how they provide important food security, cultural connection, but can also lead to foodborne and zoonotic disease transmission if the right environmental public health preventative measures are not adhered. Examples below demonstrate a cross-section of the student initial posts for the case study assignment:

In the following week, a secondary assignment asked the students to design their own Conceptual Map to illustrate the transmission pathways for a zoonotic disease which can be spread through food, water, and/or the environment. They needed to use references to describe exposure and/or transmission risks for both human and animal hosts. The conceptual map instructions suggested using a Venn diagram but the students were encouraged to design their own format to put together their ideas and findings. Less rigidity in the instructions lead to many unique and creative maps indicating the relationship of humans, animals, and their shared environment in the spread of disease. Outlining the zoonotic disease transmission pathways also demonstrated to the student where the opportunities for prevention, control, and surveillance exist for the collaborating areas of public and global health.

The assimilation of One Health principles into the course and in the context of Covid-19 has been a natural fit. Employing this framework within the assignments and discussions has been an excellent way to illustrate the significance of multidisciplinary response in environmental health and to showcase prospects for collaboration between seemingly unrelated fields. The case study discussions and conceptual map assignments can be updated each semester to combine the broader topics of the course with current events impacting public and environmental health both at domestic and international levels. These discussions can then be reinforced through my own fieldwork and research experiences but more notably during our on-campus sessions with the chance for students to connect to their peers and continue their conversations on the One Health-related drivers and solutions to environmental health issues.

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