They deal withwhole cities and countries, trying to pinpoint why winds, soil, climates,diets, crowding, or different degreesof wealth accelerateor stop theevolution of epidemics.
You might be reminded of the Foot & Mouth disease essay now. Both the authors of that work were hugely inspired by Latour and were early adopters of a method of analysis he championed called "Actor-network-theory" ANT. Just mentioning this for those of you who may be interested in reading further.
As you might recall, this is the difference between Veterinary Science and Epidemiology - vets study individual animals (sheep, goats, pigs etc) while epidemiologists study the conditions which allow diseases to spread so not animals but things like sewage, water, wind, soil etc