In this module, we will discuss how to characterize the infection states of different ID. We will look at this both from a medical perspective and from a public health perspective and discuss how these perspectives complement each other.

Learning Objectives

  • Accurately categorize infectious diseases according to medical and public health characteristics
  • Evaluate the impact of different infection states on medical outcomes and disease dynamics
  • Understand how medical states (e.g. symptoms) and public health states (e.g. infectiousness) do not always overlap.
  • Identify the features of infectious diseases that are most important to know for successful intervention planning
  • Understand how different infections states are represented in mathematical models


Read the chapter “Characterizing Infectious Disease States” of IDEMAB.

The book chapter gives you one introduction to a way of classification individuals with regard to infection and disease states. For some further discussions, watch the following videos.


The first video is from the “Epidemics” online course.

Mary Poss, one of the course instructors, talks about the difference between infection and disease.

The second video is from the HKU Epidemics course sequence.

Joseph Wu from the University of Hong Kong discusses some quantities relating to infection and disease state and duration and their importance for public health. Ignore anything we haven’t covered yet.