23 May 2008
Marc Lipsitch
Department of Epidemiology
Department of Immunology and Infectious Diseases
Harvard School of Public Health
Antimicrobial use causes the generation and spread of antimicrobial resistance in bacteria. It would be useful to understand this platitude in some quantitative detail in order to predict the future dimensions of drug resistance, predict the lifespan of particular drug classes, and predict the likely consequences of interventions to control resistance and conserve the usefulness of antibiotics.
I'll start by briefly some of the areas where we've made progress: linking the effects of treatement at the individual level to those at the group level; positing mechanisms for how the dynamics of community-acquired vs. hospital-acquired infections differ; and studying the likely impact of antimicrobial cycling.
Then I'll talk about some of the unsolved problems, in particular the problem of apparently long-term coexistence of resistant and sensitive bacteria in community-acquired obligate human colonizers (e.g. Streptococcus pneumoniae) and the question of the phase angle between seasonal fluctuations in antimicrobial use and those in resistance