Disease evolution on networks: the role of contact structure
Proceedings of the Royal Society B: Biological Sciences, 270 (1516):
699--708 (2003)Аннотация
Owing to their rapid reproductive rate and the severe penalties for reduced fitness, diseases are under
immense evolutionary pressure. Understanding the evolutionary response of diseases in new situations
has clear public-health consequences, given the changes in social and movement patterns over recent
decades and the increased use of antibiotics. This paper investigates how a disease may adapt in response
to the routes of transmission available between infected and susceptible individuals. The potential trans-
mission routes are defined by a computer-generated contact network, which we describe as either local
(highly clustered networks where connected individuals are likely to share common contacts) or global
(unclustered networks with a high proportion of long-range connections). Evolution towards stable stra-
tegies operates through the gradual random mutation of disease traits (transmission rate and infectious
period) whenever new infections occur. In contrast to mean-field models, the use of contact networks
greatly constrains the evolutionary dynamics. In the local networks, high transmission rates are selected
for, as there is intense competition for susceptible hosts between disease progeny. By contrast, global
networks select for moderate transmission rates because direct competition between progeny is minimal
and a premium is placed upon persistence. All networks show a very slow but steady rise in the infec-
tious period.