Evolution and Ecology Program - Virulence Management

Evolution and Ecology Program

Virulence Management

Overview • Illustrations • Publications

Overview

For a long time, countermeasures to infectious diseases have been focused either on medical treatment of individuals or on epidemiological processes at the population level. However, the emergence of new types and varieties of diseases clearly indicates that pathogens are continuously adapting, partially supplanting control efforts by medical institutions. The evolution of resistance to antibiotics is already crippling traditional treatment strategies world wide.

The properties of diseases are evolutionarily regulated by their potential to acquire future hosts. To this end, viruses have (1) to keep their host alive, and (2) to out-reproduce their competitors within that same host, an activity conducive to debilitating and killing the host. These conflicting processes can be biased by medication and by changing the contact patterns between hosts.

Four reasons make this area promising for the effective application of adaptive dynamics theory. First, disease organisms evolve fast, so that the resulting evolutionary time scales have an immediate relevance. Second, it is possible to utilize animal and plant models (for which a great deal of experimental options are readily available) in order to gear the theory towards real-life levels of biological complexity. Third, close connections exist to the theory of repeated games (among the agents residing in one host) for which there exists a considerable store of results. Fourth, there are clear practical implications for crop disease management, for veterinary medicine, and for human diseases.

Illustrations

Coevolution of virulence and resistance patterns in the Australian myxomatosis epidemics, one of the classical cases of pathogen-host coevolution.
Coevolution of virulence and resistance patterns in the Australian myxomatosis epidemics, one of the classical cases of pathogen-host coevolution.

After a fast initial decline in the virulence of the myxoma pathogen (upper figure), and a subsequent increase in the resistance of infected rabbit hosts (lower figure), current virulence levels appear to increase again (upper figure). The shape of the resulting evolutionary trajectory is in line with forecasts obtained from adaptive dynamics models.

Publications

1.	Dieckmann U, Metz JAJ, Sabelis MW, Sigmund K, (eds): Adaptive Dynamics of Infectious Diseases: In Pursuit of Virulence Management. Cambridge University Press, Cambridge, UK (2002).

2.	Dieckmann U, Sigmund K, Sabelis MW, Metz JAJ: Epilogue. Dieckmann U, Metz JAJ, Sabelis MW, Sigmund K (eds): Adaptive Dynamics of Infectious Diseases: In Pursuit of Virulence Management, Cambridge University Press, Cambridge, UK, pp. 460-463 (2002).

3.	Dieckmann U: Adaptive Dynamics of Pathogen-Host Interacations. IIASA Interim Report IR-02-007 (2002). Dieckmann U, Metz JAJ, Sabelis MW, Sigmund K (eds): Adaptive Dynamics of Infectious Diseases: In Pursuit of Virulence Management, Cambridge University Press, Cambridge, UK, pp. 39-59 (2002).

4.	Diekmann O, de Jong MCM, Metz JAJ: A Deterministic Epidemic Model Taking Account of Repeated Contacts Between the Same Individuals. Journal of Applied Probabilities 35:448-462 (1998).

5.	Diekmann O, de Koeijer AA, Metz JAJ: On the Final Size of Epidemics within Herds. Canadian Applied Mathematics Quarterly 4:21-30 (1996).

6.	Diekmann O, Metz JAJ, Heesterbeek H: The Legacy of Kermack and McKendrick. Mollison D (ed): Epidemic Models: Their Structure and Relation to Data, Cambridge University Press, Cambridge, UK, pp. 95-115 (1995).

7.	Ferrière R, Michod RE: The Evolution of Cooperation in Spatially Heterogeneous Populations. IIASA Working Paper WP-96-029 (1996). The American Naturalist 147:692-717 (1996).

8.	Heesterbeek JAP, Metz JAJ: The Saturating Contact Rate in Epidemic Models. Isham V, Medley G (eds): Models for Infectious Human Diseases: Their Structure and Relation to Data. Cambridge University Press, UK, pp. 308-310 (1996).

9.	May RM, Nowak MA, Sigmund K: Antigenic Oscillations and Shifting Immunodominace in HIV-1 Infections. Nature 375:606-611 (1995).

10.	May RM, Nowak MA, Sigmund K: Immune Response Against Multiple Epitopes. Journal of Theoretical Biology 175:325-353 (1995).

11.	Metz JAJ, van den Bosch F: Velocities of Epidemic Spread. Mollison D (ed): Epidemic Models: Their Structure and Relation to Data, Cambridge University Press, Cambridge, UK, pp. 150-186 (1995).

12.	Nowak MA, Sigmund K: Super- and Coinfection: The Two Extremes. IIASA Interim Report IR-02-008 (2002). Dieckmann U, Metz JAJ, Sabelis MW, Sigmund K (eds): Adaptive Dynamics of Infectious Diseases: In Pursuit of Virulence Management, Cambridge University Press, Cambridge, UK, pp. 124-137 (2002).

13.	Read AF, Metz JAJ, et al.: Group Report: Genetics and Evolution of Infectious Diseases in Natural Populations. Grenfell BT, Dobson AP (eds): Ecology of Infectious Diseases in Natural Populations, Cambridge University Press, UK, pp. 450-477 (1995).

14.	Sabelis MW, Metz JAJ: Evolution Management: Taking Stock - Relating Theory to Experiment. IIASA Interim Report IR-02-009 (2002). Dieckmann U, Metz JAJ, Sabelis MW, Sigmund K (eds): Adaptive Dynamics of Infectious Diseases: In Pursuit of Virulence Management, Cambridge University Press, Cambridge, UK, pp. 379-398 (2002).

15.	Sigmund K, Sabelis MW, Dieckmann U, Metz JAJ: Introduction. Dieckmann U, Metz JAJ, Sabelis MW, Sigmund K (eds): Adaptive Dynamics of Infectious Diseases: In Pursuit of Virulence Management, Cambridge University Press, Cambridge, UK, pp. 1-6 (2002).

16.	van den Bosch F, Metz JAJ, Zadoks J: Pandemics of Focal Plant Disease: A Model. IIASA Interim Report IR-97-083 (1997). Phytopathology 89:495-505 (1999).

17.	van den Bosch F, Metz JAJ: The Continental Spread of Plant Disease. Aspects in Applied Biology 46:249-251 (1996).

Responsible for this page: Melanie Wenighofer
Last updated: 23 Nov 2005

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