BACKGROUND AND OBJECTIVE: An improved understanding of the transmission dynamics of multidrug-resistant (MDR) gram-negative bacteria and the mechanism of acquisition in long-term care facilities (LTCFs) could aid in the development of prevention strategies specific to LTCFs. We thus investigated the incidence of acquisition of these pathogens among an LTCF population. DESIGN: Prospective cohort study. SETTING: Three separate wards at a 600-bed LTCF in metropolitan Boston, Massachusetts, during the period October 31, 2006, through October 22, 2007. PARTICIPANTS: One hundred seventy-two LTCF residents. METHODS: A series of rectal samples were cultured to determine acquisition of MDR gram-negative bacteria, defined as absence of MDR gram-negative bacterial colonization at baseline and de novo recovery of MDR gram-negative bacteria from a follow-up culture. Molecular typing was performed to identify genetically linked strains. A nested matched case-control study was performed to identify risk factors associated with acquisition. RESULTS: Among 135 residents for whom at least 1 follow-up culture was performed, 52 (39%) acquired at least 1 MDR gram-negative organism during the study period. Thirty-two residents (62%) had not been colonized at baseline and had acquired at least 1 MDR gram-negative species at follow-up culture, and 20 residents (38%) were colonized at baseline and had acquired at least 1 MDR gram-negative species at follow-up culture. The most common coresistance pattern was resistance to extended-spectrum penicillins, ciprofloxacin, and gentamicin (57 isolates [42.5%]). Genetically related strains of MDR gram-negative bacteria were identified among multiple residents and between roommates. On conditional logistic regression analysis, antibiotic exposure during the study period was significantly associated with acquisition of MDR gram-negative bacteria (odds ratio, 5.6 [95% confidence interval, 1.1-28.7]; P = .04). CONCLUSIONS: Acquisition of MDR gram-negative bacteria occurred frequently through resident-to-resident transmission. Existing infection control interventions need to be reevaluated.
BACKGROUND AND OBJECTIVE: An improved understanding of the transmission dynamics of multidrug-resistant (MDR) gram-negative bacteria and the mechanism of acquisition in long-term care facilities (LTCFs) could aid in the development of prevention strategies specific to LTCFs. We thus investigated the incidence of acquisition of these pathogens among an LTCF population. DESIGN: Prospective cohort study. SETTING: Three separate wards at a 600-bed LTCF in metropolitan Boston, Massachusetts, during the period October 31, 2006, through October 22, 2007. PARTICIPANTS: One hundred seventy-two LTCF residents. METHODS: A series of rectal samples were cultured to determine acquisition of MDR gram-negative bacteria, defined as absence of MDR gram-negative bacterial colonization at baseline and de novo recovery of MDR gram-negative bacteria from a follow-up culture. Molecular typing was performed to identify genetically linked strains. A nested matched case-control study was performed to identify risk factors associated with acquisition. RESULTS: Among 135 residents for whom at least 1 follow-up culture was performed, 52 (39%) acquired at least 1 MDR gram-negative organism during the study period. Thirty-two residents (62%) had not been colonized at baseline and had acquired at least 1 MDR gram-negative species at follow-up culture, and 20 residents (38%) were colonized at baseline and had acquired at least 1 MDR gram-negative species at follow-up culture. The most common coresistance pattern was resistance to extended-spectrum penicillins, ciprofloxacin, and gentamicin (57 isolates [42.5%]). Genetically related strains of MDR gram-negative bacteria were identified among multiple residents and between roommates. On conditional logistic regression analysis, antibiotic exposure during the study period was significantly associated with acquisition of MDR gram-negative bacteria (odds ratio, 5.6 [95% confidence interval, 1.1-28.7]; P = .04). CONCLUSIONS: Acquisition of MDR gram-negative bacteria occurred frequently through resident-to-resident transmission. Existing infection control interventions need to be reevaluated.
Authors: Yohei Doi; Jennifer M Adams-Haduch; Anton Y Peleg; Erika M C D'Agata Journal: Diagn Microbiol Infect Dis Date: 2012-06-20 Impact factor: 2.803
Authors: Susan L Mitchell; Michele L Shaffer; Mark B Loeb; Jane L Givens; Daniel Habtemariam; Dan K Kiely; Erika D'Agata Journal: JAMA Intern Med Date: 2014-10 Impact factor: 21.873
Authors: Alyssa B Dufour; Michele L Shaffer; Erika M C D'Agata; Daniel Habtemariam; Susan L Mitchell Journal: J Am Geriatr Soc Date: 2015-11-28 Impact factor: 5.562