Multiple infections

Infections that consist of multiple parasite strains or species are common in the wild and are a major public health concern. Theory suggests that these infections have a key influence on the evolution of infectious diseases and, more specifically, on virulence evolution. However, we still lack an overall vision of the empirical support for these predictions.

We think that within-host interactions between parasites largely determine how virulence evolves and that experimental data support model predictions. We also think that it is possible to make sense out of the complexity inherent to multiple infections and that experimental evolution settings may provide the best opportunity to further our understanding of virulence evolution. Finally, it is necessary to take into account epidemiological feedback to understand ecological and evolutionary effects of multiple infections.

At the between host level, host contact structure is likely to shape the occurrence of multiple infections. We also try to determine how to use coinfection patterns to infer this contact structure.


Kamiya T, Mideo N, Alizon S (2018) Coevolution of virulence and immunosuppression in multiple infections J Evol Biol 31(7):995-1005

Sofonea M., Alizon S. & Michalakis Y. (2017) Exposing the diversity of multiple infection patterns J theor Biol 419:278-289

Sofonea M., Alizon S. & Michalakis Y. (2015) From within-host interactions to epidemiological competition: a general model for multiple infections Philos Trans R Soc Lond B 370:20140303

Alizon S., de Roode J. C. & Michalakis Y. (2013) Multiple infections and the evolution of virulence Ecol Lett 16(4):556-567 [review]

For further details, see our publications ยป