Epidemics I: Understanding Disease Origins

This module introduces students to the fundamental concepts of epidemics, exploring their historical context and evolution. Students will learn the definition of an epidemic, how infectious disease epidemics arise from historical transitions, and why novel emerging infectious diseases continue to appear. The module covers key classifications including emerging infectious diseases, re-emerging infectious diseases, and zoonoses. It examines the various factors that contribute to disease emergence and re-emergence, including microbial factors, climate and weather, ecosystem changes, human demographics, international travel, technology, intensive animal husbandry, and breakdowns in public health infrastructure. Students will also identify high-risk regions for future infectious disease outbreaks and understand the economic impact of these emerging threats.

This module examines recent major outbreaks of Ebola and Zika viruses as case studies in epidemic management. Students will engage with critical questions about epidemic preparedness, including how to prepare for future epidemics, how to allocate resources among different pathogens, and where to direct research and development efforts. The module highlights key intervention strategies like vaccine development and addresses the growing concern of antimicrobial resistance. Additionally, a supplementary component introduces students to digital pathogen surveillance and the challenges of implementing advanced informatics solutions for global health monitoring. Through these discussions, students will gain insight into the practical challenges of epidemic management and the role of technology in tracking and responding to disease outbreaks.

This module explores the ecological and evolutionary dynamics that drive the emergence of infectious diseases, with special focus on the human-animal interface where many pathogens originate. Students will learn about phylogenetic trees and their application in studying infectious disease epidemics, gaining practical tools for tracking pathogen evolution. The module examines several significant case studies of influenza virus emergence, including the highly pathogenic H5N1 Avian Influenza virus in Asia, the H7N9 Influenza A virus in China, and the 2009 pandemic H1N1 (Swine Influenza). Through these examples, students will understand the complex interplay between viral evolution, ecological factors, and human activities that create conditions for new infectious diseases to emerge and spread.

This module provides an in-depth examination of the Ebola virus outbreak within its broader global health context. Students will critically analyze key public health interventions including border controls and the prohibition of bushmeat consumption. The module addresses important ethical and practical questions surrounding experimental treatments and vaccines, the centralization of care, and enforcement of lockdowns during outbreaks. It also explores scientific questions about Ebola's potential for airborne transmission and whether it could develop into a massive pandemic similar to HIV. A supplementary component examines global variation in the risk of influenza virus emergence, providing students with analytical frameworks for assessing geographic risk factors for future outbreaks. This discussion-based module encourages critical thinking about epidemic control strategies and their implications.

This module takes students through the process of identifying novel pathogens during disease outbreaks, using the discovery of SARS coronavirus as a detailed case study. Students will learn the step-by-step approach epidemiologists and medical researchers follow, from initial suspicion of a new pathogen to confirming its role as the causative agent of a disease. The module covers the identification process for novel viruses associated with unusual pneumonia cases, methods for proving association and causation between a pathogen and a disease, and principles for controlling emerging infections at their source. The module concludes with an alert about coronaviruses as causes of emerging infectious diseases and includes a supplementary component on using genetic data at multiple scales to understand constraints on viral evolution. This practical "detective work" perspective gives students insight into real-world epidemic investigation techniques.