An outbreak of Pseudomonas aeruginosa respiratory tract infections associated with intrinsically contaminated ultrasound transmission gel

Infection Control for Perioperative Ultrasonography and Echocardiography

Ultrasound technology has revolutionized point-of-care diagnostics, decision-making, and the guidance of interventional procedures in Anesthesiology and Perioperative Medicine. Recent literature has highlighted important infection control considerations when performing transesophageal or transthoracic echocardiography, point-of-care ultrasound, and ultrasound-guided procedures. This narrative review focuses on operator precautions and disinfection methods and summarizes key recommendations from the international Echocardiography and Radiology Societies.

Pseudomonas aeruginosa countrywide outbreak in hospitals linked to pre-moistened non-sterile washcloths, Norway, October 2021 to April 2022

In November 2021, a clonal outbreak of Pseudomonas aeruginosa of novel sequence type ST3875 was detected in three patients who died of bloodstream infections in one hospital. By 25 April 2022, the outbreak included 339 cases from 38 hospitals across Norway. Initial hospital reports indicate Pseudomonas infection as the main contributing cause in seven deaths. In March 2022, the outbreak strain was identified in non-sterile pre-moistened disposable washcloths, used to clean patients, from three lots from the same international manufacturer.

[Disinfection of transvaginal ultrasound probes-A current overview of methods and recommendations]

Disinfection of ultrasound probes, especially of transvaginal probes, has been under discussion during recent years and there have been several new regulations and recommendations as well as trends in the field of disinfection methods. This article provides a review and summary of the current state of knowledge.

Ultrasound-guided arterial catheterization

Ultrasonography facilitates arterial catheterization compared to traditional palpation techniques, especially in small arteries. For successful catheterization without complications, practitioners should be familiar with the anatomic characteristics of the artery and ultrasound-guided techniques. There are two approaches for ultrasound-guided arterial catheterization: the short-axis view out-of-plane approach and the long-axis view in-plane approach. There are several modified techniques and tips to facilitate ultrasound-guided arterial catheterization. This review deals with the anatomy relevant to arterial catheterization, several methods to improve success rates, and decrease complications associated with arterial catheterization.

Ultrasound guidance and risk for intravascular catheter-related infections among peripheral arterial catheters: a post-hoc analysis of two large randomized-controlled trials

BACKGROUND

The impact on infectious risk of ultrasound guidance at insertion remains controversial in short-term arterial catheters (ACs). The present study investigated the association between ultrasound guidance (US) during AC insertion and major catheter-related infections (MCRI), catheter-related bloodstream infections (CR-BSI) or colonization, using univariate and multivariate marginal Cox model for clustered data. The skin colonization at catheter removal was evaluated to explain our results.

RESULTS

We used individual data from two multicenter randomized-controlled trials (RCTs) that included a total of 3029 patients, 10 ICUs and 3950 ACs. US guidance was used for 386 (9.8%) catheter placements. In the univariate Cox model analysis, AC insertion with US versus without US exhibited similar risks for MCRI (HR 0.86, CI 95% 0.27-2.72, p = 0.79), CR-BSI (HR 0.87, CI 95% 0.20-3.72, p = 0.85) and catheter colonization (HR 1.31, CI 95% 0.92-1.86, p = 0.13). After adjustment on confounders, risks associated with US guidance remained similar versus non-US for MCRI (HR 0.71, CI 95% 0.23-2.24, p = 0.56), CR-BSI (HR 0.71, CI 95% 0.17-3.00, p = 0.63) and catheter colonization (HR 0.92, CI 95% 0.63-1.34, p = 0.67). No differences between US and non-US for MCRI, CR-BSI and colonization were observed according to the insertion site, radial or femoral. At catheter removal, the skin colonization was similar between US and non-US groups (p = 0.69).

CONCLUSIONS

Using the largest dataset ever collected from large multi-centric RCTs conducted with relatively consistent insertion and maintenance catheter protocols, we showed that the risk of infectious complications for ACs inserted under US guidance is not superior compared to those inserted without US guidance. Trial registration These studies were registered within ClinicalTrials.gov (numbers NCT01629550 and NCT01189682).

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

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.

Ultrasound gel as a source of hospital outbreaks: Indian experience and literature review

Purpose

Hospital outbreaks are observed increasingly worldwide with various organisms from different sources such as contaminated ultrasound gel, intravenous (IV) fluids and IV medications. Among these, ultrasound gel is one of the most commonly reported sources for Burkholderia cepacia complex (Bcc) outbreaks. In this study, we describe our experience on investigation and the management of Bcc bacteraemia outbreak due to contaminated ultrasound gel from a tertiary care centre, South India.

Materials and Methods

Over a 10-day period in October 2016, seven children in our Paediatric intensive care unit (ICU) were found to have bacteraemia with Bcc isolated from their blood culture. Repeated isolation of the same organism with similar antimicrobial susceptibility pattern over a short incubation period from the same location, confirmed the outbreak. An active outbreak investigation, including environmental surveillance, was carried out to find the source and control the outbreak. Isolates were subjected to multi-locus sequence typing (MLST) and global eBURST (goeBURST) analysis.

Results

Environmental surveillance revealed contaminated ultrasound gel as the source of infection. MLST and goeBURST analysis confirmed that the outbreak was caused by a novel sequence type 1362 with the same clonal complex CC517. The outbreak was controlled by stringent infection control measures, withdrawal of contaminated ultrasound gel from regular usage and implementing the practice of using ultrasonogram (USG) probe cover for USG screening and guided procedures.

Conclusion

This report highlights the importance of early identification of an outbreak, prompt response of the ICU and infection control teams, sound environmental and epidemiological surveillance methods to identify the source and stringent infection control measures to control the outbreak. Contaminated ultrasound gel can be a potential source for healthcare-associated infection, which cannot be overlooked.

Medical Ultrasound Disinfection and Hygiene Practices: WFUMB Global Survey Results

As ultrasound technology rapidly evolves and is used more frequently in every area of medical diagnosis and treatment, it may be overlooked as a potential vector in the transmission of a health care-associated infection. A survey on disinfection and hygiene practice in medical ultrasound was disseminated via the World Federation for Ultrasound in Medicine and Biology (WFUMB) to its six member federations and associated ultrasound societies globally. One thousand twenty-nine responses were obtained across a broad range of ultrasound practitioners. A total of 76% of respondents used transducer covers every time to scan open wounds and 71% when blood and bodily fluids were present or for an interventional procedure. Approved high-level disinfectants are not always used, even when blood comes into contact with the transducer or after endocavity scans. Alcohol-based wipes were used by many respondents to clean both external transducers and endocavity transducers. Open-ended responses indicated that a large caseload hindered the time required for cleaning and that access to clear guidelines would be beneficial. Global survey results indicate that some users do not comply with disinfection practice, and there is a gap in knowledge on basic infection prevention and control education within the ultrasound unit. As the infectious status of a patient is not often disclosed prior to an ultrasound examination, training in suitable protocols for the cleaning and disinfection of ultrasound equipment is imperative to mitigate the risk of potential infection.

Ultrasound guidance for central venous catheterisation. A Colombian national survey

Quality problem or issue

Ultrasound (US) is a widely propagated medical technology. Anaesthesiologists increase procedural safety by using US techniques, but training and availability are essential for its usage. Although its utility for central venous catheterisation (CVC) is well established, only a paucity of evidence is available regarding its use in low- and middle-income countries. This study is a nationwide survey of Colombian anaesthesiologists designed to explore the current use of US guidance for CVC.

Initial assessment and implementation

Web-based survey at National level. Anaesthesiologists registered in the Colombian Society of Anaesthesiology and Resuscitation database.

Choice of solution

Demographic variables (age and gender), anaesthesia expertise, years of anaesthesiology practice, US availability, use of US during CVC, reasons for not using US and training experience were collected.

Evaluation

Of 351 respondents (12.3% response rate), 45% reported using US sometimes and always for CVC (95% CI 39%-50%) (n = 157). Most anaesthesiologists obtained training in US through external courses (50.4%) or from colleagues (22.8%). Of the total respondents, 62.7% (n = 220) have US equipment available at all time and this factor was independently associated with the use of US for CVC (adjusted odds ratio [OR] = 38.6, P < 0.001).

Lessons learned

US guidance is not a common technique used for CVC by Colombian anaesthesiologists; an important barrier for its use is lack of equipment.

The ultrasound unit and infection control - Are we on the right track?

Best practice guidelines for the disinfection of ultrasound transducers and infection prevention in ultrasound departments are generally recommended by either government health groups or the ultrasound societies of individual countries. The literature shows a wide variance in not only transducer cleaning methods but basic hygiene practices in the ultrasound workplace. This paper describes results from a UK survey of disinfection of ultrasound transducers and hygiene practice in the workplace. The survey revealed that some ultrasound practitioners did not follow current guidelines with regard to the correct disinfection method of transducers, cords or ultrasound machine keyboards. Furthermore, the survey exposed the lack of training from the product manufacturers on how to use the disinfection product appropriately. These inconsistencies may be responsible for compliance issues and highlight the need for an awareness campaign and a unified approach to infection control by ultrasound practitioners.

Disinfection of transvaginal ultrasound probes in a clinical setting: comparative performance of automated and manual reprocessing methods

OBJECTIVES

Transvaginal and intracavitary ultrasound probes are a possible source of cross-contamination with microorganisms and thus a risk to patients' health. Therefore appropriate methods for reprocessing are needed. This study was designed to compare the standard disinfection method for transvaginal ultrasound probes in Germany with an automated disinfection method in a clinical setting.

METHODS

This was a prospective randomized controlled clinical study of two groups. In each group, 120 microbial samples were collected from ultrasound transducers before and after disinfection with either an automated method (Trophon EPR®) or a manual method (Mikrozid Sensitive® wipes). Samples were then analyzed for microbial growth and isolates were identified to species level.

RESULTS

Automated disinfection had a statistically significantly higher success rate of 91.4% (106/116) compared with 78.8% (89/113) for manual disinfection (P = 0.009). The risk of contamination was increased by 2.9-fold when disinfection was performed manually (odds ratio, 2.9 (95% CI, 1.3-6.3)). Before disinfection, bacterial contamination was observed on 98.8% of probes. Microbial analysis revealed 36 different species of bacteria, including skin and environmental bacteria as well as pathogenic bacteria such as Staphylococcus aureus, enterobacteriaceae and Pseudomonas spp.

CONCLUSIONS

Considering the high number of contaminated probes and bacterial species found, disinfection of the ultrasound probe's body and handle should be performed after each use to decrease the risk of cross-contamination. This study favored automated disinfection owing to its significantly higher efficacy compared with a manual method. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Ultrasound transducer disinfection in emergency medicine practice

Background

External ultrasound transducer disinfection is common practice in medicine. Unfortunately, clinically significant organisms, such as methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and Klebsiella pneumonia spread throughout healthcare facilities via direct contact despite disinfection protocols. Ultrasound transducers and coupling gel provide potential vectors for pathogen transmission, especially in immunocompromised and high-risk patient populations. Our objective was to conduct a survey to investigate the variety of cleaning solutions or sanitary wipes used and evaluate current standard practice for transducer disinfection across emergency medicine training programs in the United States.

Findings

Eighty-three academic emergency medicine programs participated in this study. Eighty-seven percent (95 % CI 80–94 %) of responding programs do not have a mandated protocol or standard contact time for transducer disinfection. Ninety percent (95 % CI 84–96 %) of institutions use disinfectant solution or disinfectant wipes, as the standard of practice, to cleanse ultrasound transducers after every use.

Conclusions

Currently, there is a great deal of variability with regard to non-endocavitary transducer disinfection protocols that seems to stem from the vast number of disinfectant products and ultrasound manufacturer disparate recommendations. In order to mitigate risk to patients and reduce health care costs linked to nosocomial infections; healthcare providers, ultrasound companies, and disinfectant manufacturers must develop a universal use disinfectant and a standard protocol for ultrasound device disinfection for noncritical device disinfection in the emergency department.

Electronic supplementary material

The online version of this article (doi:10.1186/s13756-016-0110-y) contains supplementary material, which is available to authorized users.