Speaker
Description
The observation that infectious agents (such as viruses and bacteria) limit their ability to persist if they kill their hosts too rapidly underpins a large body of work related to the evolution of virulence. Theory stemming from this explains many phenomena, such as the sustainment of deadly infectious diseases in large, dense populations. However, it is not clear whether the existing theory explains one of the most salient features of tuberculosis (TB) epidemiology, which is its capacity to cause latent (symptom-free and non-infectious) disease for decades before transitioning to a symptomatic and infectious stage. TB’s epidemiology today is likely shaped by its evolutionary history with humans spanning over ten thousand years. During much of this time, host populations were smaller and more dispersed than today, and local eradication of disease would have posed a challenge for the pathogen. With a view to the impact of demographic stochasticity in small, weakly interconnected populations, we examine how latency might have helped the disease survive to the present day, where it continues to plague humanity.
