On the probability of strain invasion in endemic settings: accounting for individual heterogeneity and control in multi-strain dynamics

摘要: The rise of antimicrobial drug resistance is an imminent threat to global health that has warranted, and duly received, considerable attention within the medical, microbiological modelling communities. Outbreaks drug-resistant pathogens are ignited by emergence transmission mutant variants descended from wild-type strains circulating in community. In this work we investigate stochastic dynamics a novel disease strain, introduced into population which it must compete with existing endemic strain. analogy past on single-strain epidemic outbreaks, apply branching process approximation calculate probability new strain becomes established. As expected, critical determinant survival prospects any invading magnitude its reproduction number relative background Whilst most circumstances ratio exceed unity order for invasion be viable, show differential control scenarios can lead less-fit populations hosting fitter one. This analysis accompanying findings will inform our understanding mechanisms have led instances successful invasion, provide valuable lessons thwarting future incursions.