Multidrug-resistant Acinetobacter Baumannii Colonization Research Articles

Controlling an Outbreak of Multidrug-resistant Acinetobacter baumannii in a Pediatric Intensive Care Unit: a Retrospective Analysis.

BackgroundMultidrug-resistant Acinetobacter baumannii (MDRAB) is widespread among intensive care units worldwide, posing a threat to patients and the health system. We describe the successful management of a MDRAB outbreak by implementing an infection-control strategy in a pediatric intensive care unit (PICU).MethodsThis retrospective study investigated the patients admitted to the PICU in periods 1 (8 months) and 2 (7 months), from the index MDRAB case to intervention implementation, and from intervention implementation to cessation of MDRAB spread. An infection-control strategy was designed following six concepts: 1) cohort isolation of colonized patients, 2) enforcement of hand hygiene, 3) universal contact precautions, 4) environmental management, 5) periodic surveillance culture study, and 6) monitoring and feedback.ResultsOf the 427 patients, 29 were confirmed to have MDRAB colonization, of which 18 had MDRAB infections. Overall incidence per 1,000 patient days decreased from 7.8 (period 1) to 5.8 (period 2). The MDRAB outbreak was declared terminated after the 6-month follow-up following period 2. MDRAB was detected on the computer keyboard and in condensed water inside the ventilator circuits. The rate of hand hygiene performance was the lowest in the three months before and after index case admission and increased from 84% (period 1) to 95% (period 2). Patients with higher severity, indicated by a higher Pediatric Risk of Mortality III score, were more likely to develop colonization (P = 0.030), because they had invasive devices and required more contact with healthcare workers. MDRAB colonization contributed to an increase in the duration of mechanical ventilation and PICU stay (P < 0.001), but did not affect mortality (P = 0.273).ConclusionThe MDRAB outbreak was successfully terminated by the implementation of a comprehensive infection-control strategy focused on the promotion of hand hygiene, universal contact precautions, and environmental management through multidisciplinary teamwork.

Multi-drug resistant Acinetobacter species: a seven-year experience from a tertiary care center in Lebanon

BackgroundAcinetobacter species have become increasingly common in the intensive care units (ICU) over the past two decades, causing serious infections. At the American University of Beirut Medical Center, the incidence of multi-drug resistant Acinetobacter baumannii (MDR-Ab) infections in the ICU increased sharply in 2007 by around 120%, and these infections have continued to cause a serious problem to this day.MethodsWe conducted a seven-year prospective cohort study between 2007 and 2014 in the ICU. Early in the epidemic, a case-control study was performed that included MDR-Ab cases diagnosed between 2007 and 2008 and uninfected controls admitted to the ICU during the same time.ResultsThe total number of patients with MDR-Ab infections diagnosed between 2007 and 2014 was 128. There were also 99 patients with MDR-Ab colonization without evidence of active infection between 2011 and 2014. The incidence of MDR-Ab transmission was 315.4 cases/1000 ICU patient-days. The majority of infections were considered hospital-acquired (84%) and most consisted of respiratory infections (53.1%). The mortality rate of patients with MDR-Ab ranged from 52% to 66%.ConclusionMDR-Ab infections mostly consisted of ventilator-associated pneumonia and were associated with a very high mortality rate. Infection control measures should be reinforced to control the transmission of these organisms in the ICU.

Incidence, risk factors, and outcome of multidrug-resistant Acinetobacter baumannii acquisition during an outbreak in a burns unit

Multidrug-resistant Acinetobacter baumannii (MR-AB) can cause outbreaks in a burns unit. To study the incidence, risk factors and outcome of MR-AB colonization during an outbreak. A prospective study was conducted from April to November 2014 in a burns unit in Paris. Weekly surveillance cultures of patients and their environment were performed. MR-AB acquisition, discharge, or death without MR-AB colonization were considered as competing events. To identify risk factors for colonization, baseline characteristics and time-dependent variables were investigated in univariate and multivariate analyses using Cox models. MR-AB strains were genotypically compared using multi-locus sequence typing. Eighty-six patients were admitted in the burns unit during the study period. Among 77 patients without MR-AB colonization at admission, 25 (32%) acquired MR-AB with a cumulative incidence of 30% at 28 days (95% CI: 20-40). Median time to MR-AB acquisition was 13 days (range: 5-34). In multivariate analysis, risk factors for MR-AB acquisition were ≥2 skin graft procedures performed [hazard ratio (HR): 2.97; 95% confidence interval (CI): 1.10-8.00; P= 0.032] and antibiotic therapy during hospitalization (HR: 4.42; 95% CI: 1.19-16.4; P= 0.026). A major sequence type of MR-AB (ST2) was found in 94% and 92% of patients and environmental strains, respectively, with all strains harbouring the blaOXA-23 gene. MR-AB colonization increased length of hospitalization (HR: 0.32; 95% CI: 0.17-0.58; P=0.0002) by a median of 12 days. A high incidence of MR-AB acquisition was seen during this outbreak with most strains from patients and their environment belonging to single sequence type. MR-AB colonization was associated with more skin graft procedures, antibiotic use, and prolonged hospitalization.

Co-Colonization with Neisseria species Is a Risk Factor for Prolonged Colonization with Multidrug-Resistant Acinetobacter baumannii in the Respiratory Tract.

Multidrug-resistant Acinetobacter baumannii (MDRAB) colonization increases the risk of bacterial spread in the hospital setting. The impact of clinical factors, including antibiotic use, on prolongation of MDRAB colonization has not been investigated. Patients with respiratory tract MDRAB detected using culture were enrolled in this study. Long-term colonizers and short-term colonizers were defined as patients whose colonization periods were >30 days or ≤30 days, respectively. Clinical data were abstracted from medical records. MDRAB was isolated in 34 patients. There were 13 long-term colonizers and 9 short-term colonizers. Twelve patients were lost to follow-up and excluded from the study. There were no significant differences in average leukocyte counts, numbers of antibiotic classes administered, duration of antibiotic use in the 30 days following colonization, or rates of central catheterization or mechanical ventilation between the 2 groups. Long-term colonizers carried Neisseria species (spp.) more frequently in the 30 days following colonization than short-term colonizers (7/13 vs 1/9, p = 0.01); however, this was not the case prior to colonization with MDRAB (5/13 vs 1/9, p = 0.33). The 90-day MDRAB colonization rates for Neisseria-negative patients and Neisseria-positive patients were 10.0% and 83.3%, respectively (P < 0.01). Prolonged MDRAB colonization in the respiratory tract was associated with Neisseria spp. co-colonization.

A Epidemiological Investigation of a Nosocomial Outbreak of Multidrug-Resistant Acinetobacter baumannii in a Critical Care Center in Japan, 2011-2012.

In 2011, a multidrug-resistant Acinetobacter baumannii (MDRAB) outbreak occurred at a Japanese critical care center (CCC) in a tertiary care hospital. Multidrug-resistance in Japan is defined as resistance to the antimicrobials amikacin, carbapenem, and fluoroquinolone. We conducted a retrospective epidemiological investigation of this outbreak to identify the risk factors for MDRAB respiratory tract acquisition in this hospital. Cases were defined as hospitalized patients with MDRAB-positive cultures at least 3 days post admission to the CCC between June 1, 2011 and April 20, 2012. Fifteen MDRAB cases were identified, including 3 with infection and 12 with colonization. This case-control study demonstrated that hypoalbuminemia along with carbapenem administration were associated with MDRAB respiratory tract acquisition. Pulsed-field gel electrophoresis analysis and multilocus sequence typing using MDRAB isolates suggested a clonal dissemination of MDRAB strains with sequence type 74 occurred primarily among patients admitted to the CCC. From April 16, 2012, a decreased isolation rate of MDRAB in the hospital occurred after the implementation of the following infection control measures: closing the emergency room, discontinuing admission to the CCC, isolating patients with MDRAB colonization or infection to single room status, and conducting environmental cleaning. No MDRAB cases were detected between March 23 and April 20, 2012.

A data-driven mathematical model of multi-drug resistant Acinetobacter baumannii transmission in an intensive care unit.

Major challenges remain when attempting to quantify and evaluate the impacts of contaminated environments and heterogeneity in the cohorting of health care workers (HCWs) on hospital infections. Data on the detection rate of multidrug-resistant Acinetobacter baumannii (MRAB) in a Chinese intensive care unit (ICU) were obtained to accurately evaluate the level of environmental contamination and also to simplify existing models. Data-driven mathematical models, including mean-field and pair approximation models, were proposed to examine the comprehensive effect of integrated measures including cohorting, increasing nurse-patient ratios and improvement of environmental sanitation on MRAB infection. Our results indicate that for clean environments and with strict cohorting, increasing the nurse-patient ratio results in an initial increase and then a decline in MRAB colonization. In contrast, in contaminated environments, increasing the nurse-patient ratio may lead to either a consistent increase or an initial increase followed by a decline of MRAB colonization, depending on the level of environmental contamination and the cohorting rate. For developing more effective control strategies, the findings suggest that increasing the cohorting rate and nurse-patient ratio are effective interventions for relatively clean environments, while cleaning the environment more frequently and increasing hand washing rate are suitable measures in contaminated environments.

Risk factors for acquired multidrug-resistant Acinetobacter baumannii colonization in respiratory intensive care unit

To determine the risk factors for respiratory intensive care unit (RICU)-acquired colonization of multidrug-resistant Acinetobacter baumannii (MDR-AB). From January 2010 to June 2011, active screening was performed to define patients with RICU-acquired colonization of MDR-AB. And environment surveillance was carried out and patient data were collected. Logistic regression was applied to identify the risk factors of RICU-acquired colonization of MDR-AB. Active screening for MDR-AB was performed for 110 patients in RICU and 50 patients turned out to be positive. After eliminating 3 input positive patients, the RICU-acquired colonization rate of MDR-AB was 43.9% (47/107). The environmental contaminated rate of MDR-AB was 66.0% (31/47) for 47 positive patients and 33.9% (19/56) for 56 negative ones (χ(2) = 10.494, P < 0.01). Five risk factors were associated with the colonization of MDR-AB through univariate analysis: consciousness disturbance, use of carbapenems, nasal feeding tube, endotracheal intubation and mechanical ventilation (all P < 0.05). The Logistic regression equation contained 3 risk factors of conscious disturbance, use of carbapenems and mechanical ventilation (OR = 3.412, 3.211, 3.002; 95% CI: 1.165 - 9.992, 1.117 - 9.233, 1.101 - 8.182). Three risk factors are independently associated with the RICU-acquired colonization of MDR-AB: consciousness disturbance, use of carbapenems and mechanical ventilation.

Control of an Outbreak of Multi-drug Resistant Acinetobacter Baumannii Colonization in a Neonatal Intensive Care Unit

Outbreaks of multi-drug resistant Acinetobacter Baumannii (MDR-Ab) frequently occur in adult intensive care units, however, it is rarely reported as the source of an outbreak in neonatal intensive care units (NICU). The first appearance of Acinetobacter Baumannii in our NICU, and the presumed index was admitted to the NICU 28 days prior to identification of MDR-Ab in his sputum. This positive culture initiated an investigation. Between January 2010 and February 2010, 7 neonates were identified with MDR-Ab colonization, 6 in the sputum and one from a rectal culture. We describe our investigation of an outbreak of MDR-Ab colonization in our NICU, and discuss methods used to control transmission.