The lives of ‘facts’: understanding disease transmission through the case of Haemophilus influenzae type b bacteria

This article studies how our understanding of disease transmission has evolved over time from the public health perspective. The main question is: What happens to ‘facts’ in the course of their life history? How do they lead their lives? The concept captures the process that shapes the facts of disease transmission, mobilises them via mathematical and graphical representations and allows them to evolve and change over time. So what is actually behind this concept? In my elaboration, the concept of life history provides not only analytical but also a metaphorical framework that leads us to follow the development and changes in terms of the phases in life of ‘facts’: Birth and youth, adulthood and reproductive years, seniority and passing away. Since disease transmission is not a singular ‘factual entity’, but a bundle of ‘facts’ binding together knowledge of the disease, its transmission routes, and susceptibility of the population, the particular analytical focus is on how these ‘facts’ are disseminated via mathematical, graphical and model-based representations. Just as life histories are stories full of interactions, surprises and struggles, this article shows the underlying contingencies in the dissemination and accumulation of factual knowledge.