Medical Device-Associated Biofilm Infections and Multidrug-Resistant Pathogens

Medical devices such as venous catheters (VCs) and urinary catheters (UCs) are widely used in the hospital setting. However, the implantation of these devices is often accompanied by complications. About 60 to 70% of nosocomial infections (NIs) are linked to biofilms. The main complication is the ability of microorganisms to adhere to surfaces and form biofilms which protect them and help them to persist in the host. Indeed, by crossing the skin barrier, the insertion of VC inevitably allows skin flora or accidental environmental contaminants to access the underlying tissues and cause fatal complications like bloodstream infections (BSIs). In fact, 80,000 central venous catheters-BSIs (CVC-BSIs)-mainly occur in intensive care units (ICUs) with a death rate of 12 to 25%. Similarly, catheter-associated urinary tract infections (CA-UTIs) are the most commonlyhospital-acquired infections (HAIs) worldwide.These infections represent up to 40% of NIs.In this review, we present a summary of biofilm formation steps. We provide an overview of two main and important infections in clinical settings linked to medical devices, namely the catheter-asociated bloodstream infections (CA-BSIs) and catheter-associated urinary tract infections (CA-UTIs), and highlight also the most multidrug resistant bacteria implicated in these infections. Furthermore, we draw attention toseveral useful prevention strategies, and advanced antimicrobial and antifouling approaches developed to reduce bacterial colonization on catheter surfaces and the incidence of the catheter-related infections.

Effectiveness of chlorhexidine dressings to prevent catheter-related bloodstream infections. Does one size fit all? A systematic literature review and meta-analysis

Objective:

To evaluate the effectiveness of chlorhexidine (CHG) dressings to prevent catheter-related bloodstream infections (CRBSIs).

Design:

Systematic review and meta-analysis.

Methods:

We searched PubMed, CINAHL, EMBASE, and ClinicalTrials.gov for studies (randomized controlled and quasi-experimental trials) with the following criteria: patients with short- or long-term catheters; CHG dressings were used in the intervention group and nonantimicrobial dressings in the control group; CRBSI was an outcome. Random-effects models were used to obtain pooled risk ratios (pRRs). Heterogeneity was evaluated using the I2 test and the Cochran Q statistic.

Results:

In total, 20 studies (18 randomized controlled trials; 15,590 catheters) without evidence of publication bias and mainly performed in intensive care units (ICUs) were included. CHG dressings significantly reduced CRBSIs (pRR, 0.71; 95% CI, 0.58–0.87), independent of the CHG dressing type used. Benefits were limited to adults with short-term central venous catheters (CVCs), including onco-hematological patients. For long-term CVCs, CHG dressings decreased exit-site/tunnel infections (pRR, 0.37; 95% CI, 0.22–0.64). Contact dermatitis was associated with CHG dressing use (pRR, 5.16; 95% CI, 2.09–12.70); especially in neonates and pediatric populations in whom severe reactions occurred. Also, 2 studies evaluated and did not find CHG-acquired resistance.

Conclusions:

CHG dressings prevent CRBSIs in adults with short-term CVCs, including patients with an onco-hematological disease. CHG dressings might reduce exit-site and tunnel infections in long-term CVCs. In neonates and pediatric populations, proof of CHG dressing effectiveness is lacking and there is an increased risk of serious adverse events. Future studies should investigate CHG effectiveness in non-ICU settings and monitor for CHG resistance.