Carbapenem-resistant Enterobacteriaceae (CRE) are a significant clinical and public health concern. Understanding the distribution of CRE colonization and developing a coordinated approach are key components of control efforts. The prevalence of CRE in the District of Columbia is unknown. We sought to determine the CRE colonization prevalence within healthcare facilities (HCFs) in the District of Columbia using a collaborative, regional approach.

Point-prevalence study.

This study included 16 HCFs in the District of Columbia: all 8 acute-care hospitals (ACHs), 5 of 19 skilled nursing facilities, 2 (both) long-term acute-care facilities, and 1 (the sole) inpatient rehabilitation facility.

Inpatients on all units excluding psychiatry and obstetrics-gynecology.

CRE identification was performed on perianal swab samples using real-time polymerase chain reaction, culture, and antimicrobial susceptibility testing (AST). Prevalence was calculated by facility and unit type as the number of patients with a positive result divided by the total number tested. Prevalence ratios were compared using the Poisson distribution.

Of 1,022 completed tests, 53 samples tested positive for CRE, yielding a prevalence of 5.2% (95% CI, 3.9%–6.8%). Of 726 tests from ACHs, 36 (5.0%; 95% CI, 3.5%–6.9%) were positive. Of 244 tests from long-term-care facilities, 17 (7.0%; 95% CI, 4.1%–11.2%) were positive. The relative prevalence ratios by facility type were 0.9 (95% CI, 0.5–1.5) and 1.5 (95% CI, 0.9–2.6), respectively. No CRE were identified from the inpatient rehabilitation facility.

A baseline CRE prevalence was established, revealing endemicity across healthcare settings in the District of Columbia. Our study establishes a framework for interfacility collaboration to reduce CRE transmission and infection.

Infect Control Hosp Epidemiol 2017;38:921–929

To investigate potential sources and risks associated with multidrug-resistant (MDR) bacteria in a deployed US military hospital.

Retrospective analysis of factors associated with recovery of MDR bacteria, supplemented by environmental sampling.

The largest US military hospital in Afghanistan.

US and Afghan patients with positive bacterial culture results, from September 2007 through August 2008.

Microbiologic, demographic, and clinical data were analyzed. Potential risk factors included admission diagnosis or mechanism of injury, length of stay, gender, age, and nationality (US or Afghan). Environmental sampling of selected hospital high-touch surfaces and equipment was performed to help elucidate whether environmental MDR bacteria were contributing to nosocomial spread.

A total of 266 patients had 411 bacterial isolates that were identified during the study period, including 211 MDR bacteria (51%). Gram-negative bacteria were common among Afghan patients (241 [76%] of 319), and 70% of these were classified as MDR. This included 58% of bacteria recovered from Afghan patients within 48 hours of hospital admission. The most common gram-negative bacteria were Escherichia coli (53% were MDR), Acinetobacter (90% were MDR), and Klebsiella (63% were MDR). Almost one-half of potential extended-spectrum β-lactamase (ESBL) producers were community acquired. Of 100 environmental swab samples, 18 yielded MDR bacteria, including 10 that were Acinetobacter, but no potential ESBL-producing bacteria.

Gram-negative bacteria from Afghan patients had high rates of antimicrobial resistance. Patients experiencing Complex trauma and prolonged hospital stays likely contribute to the presence of MDR bacteria in this facility. However, many of these patients had community-acquired cases, which implies high rates of colonization prior to hospital admission.

To investigate potential sources of gram-negative multidrug-resistant organisms (MDROs) in a deployed US military healthcare facility.

Active surveillance.

Swab sampling of patients, hospital personnel, and environmental surfaces was performed before the opening of a new medical treatment facility in Iraq and then serially for the next 6 months. Multidrug resistant isolates were genotypically characterized using pulsed-field gel electrophoresis (PFGE). Univariate and multivariate analysis were performed to evaluate associations between patient characteristics and MDRO carriage.

Deployed US military medical facility.

A total of 1,348 samples were obtained, yielding 654 isolates, 42 of which were MDROs. One hundred fifty-eight patients were sampled; swabs from 18 patients yielded 29 MDR isolates. Host nation patients comprised 89% of patients with MDROs and 37% of patients without MDROs (P < .001 ). Host nation patient status was also significantly associated with MDRO carriage in multivariate logistic regression analysis (adjusted odds ratio, 2.9; confidence interval, 1.3-6.3; P = .009). Bacteria with PFGE patterns matching those recovered from host nation patients were later isolated from environmental surfaces including recovery room patient monitors and the trauma bay floor.

At this facility, MDRO isolation was predominantly obtained from newly admitted host nation patients,,which may reflect baseline colonization with MDROs in the community. Patient MDRO carriage was linked to subsequent environmental contamination. These findings support intensive infection control efforts in forward deployed facilities.

To determine the anatomic sites and natural history of colonization with gram-negative multidrug-resistant organisms (MDROs).

Prospective, longitudinal cohort study.

Walter Reed Army Medical Center, a 236-bed tertiary care center in Washington, DC.

Deployed subjects (ie, inpatients medically evacuated from Iraq or Afghanistan) or nondeployed subjects admitted to the same hospital.

Consenting patients had 6 anatomic sites cultured every 3 days for 2 weeks and then weekly. Gram-negative organisms resistant to 3 or more classes of antibiotics were considered MDROs. Isolates were genotyped using pulsed-field gel electrophoresis. Clinical data, data on antibiotic use, and clinical culture results were collected.

Of 60 deployed subjects, 14 (23%) were colonized with an MDRO at admission, and 13 (22%) had incident colonization during hospitalization. The groin was the most sensitive anatomic site for detecting MDRO colonization, and all but one subject remained colonized for the duration of their hospitalization. Sixty percent of subjects with incident Acinetobacter colonization and 25% of subjects with incident Klebsiella colonization had strains that were related to those isolated from other subjects. Of 60 nondeployed subjects, 5 (8%) were colonized with an MDRO at admission; all had recent healthcare contact, and 1 nondeployed subject had an isolate related to a strain recovered from a deployed subject.

Colonization with gram-negative MDROs is common among patients with war-related trauma admitted to a military hospital and also occurs among nondeployed patients with recent healthcare contact. The groin is the most sensitive anatomic site for active surveillance, and spontaneous decolonization is rare.