Relationship of various infection control interventions to the prevalence of multidrug-resistant Pseudomonas aeruginosa among U.S. hospitals
- •Nationwide prevalence of multidrug-resistant Pseudomonas aeruginosa was 20.6%.
- •Of the hospitals, 36% use molecular methods to confirm clonal outbreaks.
- •Antibiotic resistance was significantly associated with epidemiologic investigations using molecular methods.
- •Effective identification and isolation of infected patients was associated with decreased resistance.
- •Level of information and resources dedicated to controlling antimicrobial resistance was associated with multidrug resistance.
Health care–associated infections caused by antibiotic-resistant gram-negative bacteria, such asPseudomonas aeruginosa, are an emerging and increasingly important public health threat. However, there are very few studies that examine the relationships between antimicrobial resistance strategies and interventions and the prevalence of antibiotic-resistant and multidrug-resistant strains of Pseudomonas.
The membership of the Association for Professionals in Infection Control and Epidemiology was invited to participate in a Web-based survey of U.S. acute care hospital infection preventionists.
A final sample of 225 completed responses was analyzed using correlational techniques. Resistance to gentamicin (r = 0.17, P = .01), imipenem (r = 0.18, P = .02), ceftazidime (r = 0.20, P = .03), and ciprofloxacin (r = 0.15, P = .03) all showed significant direct associations with epidemiologic investigation using molecular testing. A significant inverse relationship was found between resistance to ceftazidime and effective efforts in the identification and isolation of infected patients (r = −0.18, P = .02).
The finding of significant direct relationships between antimicrobial resistance and epidemiologic investigations using molecular testing suggests that the increased burden of resistance is associated with molecular testing rather than the intervention driving down rates. Effective identification and isolation of infected patients appeared to be associated with lower resistance rates. Further research is needed to uncover causal relationships.