How one views a recent article on the mortality due to antibiotic resistant infections depends on whether you’re a glass half-full or half-empty type (me, I just worry about dropping the damn glass). A recent article in Clinical Infectious Diseases notes that there has been no change in the death rate due to antibiotic resistant infections in Staphylococcus aureus bloodstream infections, Pseudomonas aeruginosa pneumonias, and Escherichia coli urinary tract infections.
The authors conclude (italics mine):
We initiated this study to evaluate whether the impact of antimicrobial resistance on mortality was higher during the period 2000-2004 [than in 1990-1994]. We observed no change in the relative risk of death. The lack of improvements reducing the risk of death due to antimicrobial-resistant organisms is of great concern. In this study, we cannot evaluate specific reasons for the observed lack of improvements; antimicrobial resistance and complications are multifactorial. Factors that might influence progress include the global nature of the problem, factors inherent to the microorganisms, widespread use of antibiotics, and the lack of novel treatments.
I think the phrase “factors inherent to the microorganisms” is key. Antibiotic resistant organisms, in this paper, are defined as resistant to a particular antibiotic: S. aureus is methicillin resistant, P. aeruginosa is ceftazidime resistant, and E. coli is ciprofloxacin resistant. However, there is no analysis of resistance to other antibiotics, which increased during that time. In other words, part of the lack of change may be that advances in treatment (i.e., keeping an infected alive) were offset by decreases in the effectiveness of antibiotics that worked well in the earlier period–choosing an antibiotic that the microbe is resistant to significantly increases the risk of mortality.
Oh well, at least death rates aren’t worse….
Cited article: Klevens R.M., Jonathan R. Edwards, & R. P. Gaynes. 2008. The Impact of Antimicrobial-Resistant, Health Care-Associated Infections on Mortality in the United States. Clinical Infectious Diseases 47:927-930. DOI: 10.1086/591698.