Outbreak of Acinetobacter baumannii associated with extrinsic contamination of ultrasound gel in a tertiary centre burn unit

Abstract

Summary Background During 2011 and 2012, an increase in occurrence of multidrug-resistant Acinetobacter baumannii infections was recorded in the Shands Hospital Burn Intensive Care Unit (BICU). An epidemic curve together with strain typing was consistent with an intermittent common source outbreak. An investigation was therefore initiated. Aim To identify risk factors for A. baumannii infection, characterize the source of the pathogen, implement control measures to terminate the outbreak, and institute preventive measures. Methods We conducted a retrospective case-control study; reviewed BICU infection control policies, practices and procedures, and patient exposure to healthcare workers (HCWs), and obtained epidemiologically-directed environmental cultures. Findings Eleven patients met the case definition. On multivariate analysis, case-patients were more likely to have undergone an ultrasound procedure in the BICU (adjusted odds ratio [AOR]: 19.5; confidence interval [CI]: 2.4–435) or have a FlexiSeal™ device (AOR: 11.9, CI:1.3–276). Epidemiologically-directed cultures of the environment, ultrasound equipment, and ultrasound gel from opened containers on the ultrasound trolley and in the Ultrasound Department were negative for the outbreak pathogen. Culture of an open ultrasound gel dispenser stored in the Ultrasound Department yielded an A. baumannii strain with DNA banding patterns identical to the outbreak strain. Conclusions Based on data from our epidemiologic, microbiologic, and observational studies, we believe that inadvertent extrinsic contamination of the gel dispenser occurred in the Ultrasound Department. Contaminated gel was then dispensed into multiuse vials of gel stored on the mobile carts. The outbreak was stemmed by instituting changes in practices in the Ultrasound Department, including introduction of single-use ultrasound vials and storage of ultrasound gel.

Multi-center Qualitative Observational Evaluation of Ultrasound Probe Protection using a Sterile Transparent Barrier and Securement Dressing to Standardize UGPIV Catheter Insertions

“…As the number of patients with difficult access increases, UGPIV becomes a standard solution and procedure for establishing intravenous access. However, ultrasound probes and gels are common sources of contamination, requiring recommendations for probe protection for percutaneous vascular access procedures [9,12]. Aseptic techniques, probe protection, barrier methods, and incorporation of single-use or sterile gel packets are used to safeguard against insertion site contamination [8,10].…”

“…The use of conductive gel is problematic because it is often contaminated during ultrasound procedures and can introduce pathogens at the insertion site. Infection outbreaks have identified gel contamination as the mode of transmission in numerous reports [9]. Single-use, sterile gel packets are recommended for percutaneous procedures where the gel is applied to the skin, with probe covers requiring gel [7,8,10].…”

Clonal spread of PER-1 and OXA-23 producing extensively drug resistant Acinetobacter baumannii during an outbreak in a burn intensive care unit in Tunisia

“…In our study, we reported an outbreak of OXA-23 and PER-1 XDR-Ab with probable environmental origin during a period not exceeding two months. A. baumannii remains one of the highest causes of outbreaks in BICU [18] and most of them have been traced to environmental sources [19]. The ability of A. baumannii to form biofilms on abiotic surfaces, its high degree of resistance to drying and disinfectants and its ability to develop resistance to commonly used antimicrobial agents, lead to its long term persistence in the environmental setting [20].…”

In Vitro Antimicrobial Activity of the Siderophore Cephalosporin Cefiderocol against Acinetobacter baumannii Strains Recovered from Clinical Samples

“…Species belonging to the Acinetobacter genus are strictly-aerobic, non-fermentative Gram-negative coccobacilli, predominantly found in water, soil, and sewage. Over 50 different species of Acinetobacter genus are known, but only a few species, belonging to the A. calcoaceticus-baumannii complex, cause the majority of community and healthcare associated infections [ 1 , 2 , 3 ]. A. baumannii is considered an opportunistic pathogen, and risk factor for developing an infection include mechanical ventilation, prolonged hospitalization, immune suppression, comorbidities, major trauma or burns, previous antibiotic use, invasive procedures, and presence of urinary catheters [ 1 , 2 , 3 , 4 ].…”

“…Over 50 different species of Acinetobacter genus are known, but only a few species, belonging to the A. calcoaceticus-baumannii complex, cause the majority of community and healthcare associated infections [ 1 , 2 , 3 ]. A. baumannii is considered an opportunistic pathogen, and risk factor for developing an infection include mechanical ventilation, prolonged hospitalization, immune suppression, comorbidities, major trauma or burns, previous antibiotic use, invasive procedures, and presence of urinary catheters [ 1 , 2 , 3 , 4 ]. A. baumannii can be transmitted via aerosol droplets, person-to-person contact, skin, sputum, urine, and feces [ 1 , 2 ].…”