Journal Article

Mechanisms by Which Antibiotics Promote Dissemination of Resistant Pneumococci in Human Populations

Matthew H. Samore, Marc Lipsitch, Stephen C. Alder, Bassam Haddadin, Greg Stoddard, Jacquelyn Williamson, Katherine Sebastian, Karen Carroll, Onder Ergonul, Yehuda Carmeli and Merle A. Sande

in American Journal of Epidemiology

Published on behalf of Johns Hopkins Bloomberg School of Public Health

Volume 163, issue 2, pages 160-170
Published in print January 2006 | ISSN: 0002-9262
Published online November 2005 | e-ISSN: 1476-6256 | DOI:
Mechanisms by Which Antibiotics Promote Dissemination of Resistant Pneumococci in Human Populations

More Like This

Show all results sharing this subject:

  • Public Health and Epidemiology


Show Summary Details


Mechanisms by which antimicrobials contribute to dissemination of pneumococcal resistance are incompletely characterized. A serial cross-sectional study of nasopharyngeal pneumococcal carriage in healthy, home-living children ≤6 years of age was conducted in four rural communities—two in Utah (1998–2003) and two in Idaho (2002–2003). Prevalence odds ratios for carriage of resistant pneumococci (ORres) and of susceptible pneumococci (ORsus) were estimated. Dynamic transmission models were developed to facilitate a mechanistic interpretation of ORres and ORsus and to compare the population impact of distinct antimicrobial classes. A total of 5,667 cultures were obtained; 25% of the cultures were positive, and 29% of isolates exhibited reduced susceptibility to penicillin. The adjusted ORres for recent individual and sibling cephalosporin use was 2.2 (95% confidence interval: 1.4, 3.4) and 1.8 (95% confidence interval: 1.0, 3.3), respectively. Neither individual nor sibling penicillin use was associated with increased ORres. Rather, recent use of penicillins was associated with decreased carriage of susceptible pneumococci (ORsus = 0.2, 95% confidence interval: 0.1, 0.3). In simulations, both types of effects promoted dissemination of resistant pneumococci at the population level. Findings show that oral cephalosporins enhance the risk of acquiring resistant pneumococci. Penicillins accelerate clearance of susceptible strains. The effect of penicillins in increasing resistance is shared equally by treated and untreated members of the population.

Keywords: cephalosporins; drug resistance, microbial; nasopharyngeal diseases; penicillins; Streptococcus pneumoniae; CI, confidence interval; ORC, odds ratio for carriage of resistant pneumococci using carriers of susceptible pneumococci as the comparison group; ORres, odds ratio for carriage of resistant pneumococci; ORsus, odds ratio for carriage of susceptible pneumococci

Journal Article.  7210 words.  Illustrated.

Subjects: Public Health and Epidemiology

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.