Assessing the Potential for Unintended Microbial Consequences of Routine Chlorhexidine Bathing for Prevention of Healthcare-associated Infections

Chlorhexidine vs Routine Foot Washing to Prevent Diabetic Foot Ulcers: A Randomized Clinical Trial

Importance

Foot ulcers are a common and feared complication for people with diabetes because 20% of foot ulcers become infected and lead to a lower extremity amputation.

Objective

To evaluate the effect of daily foot care using chlorhexidine wipes vs soap-and-water wipes for 1 year on the risk of developing new foot complications in veterans with diabetes.

Design, Setting, and Participants

This double-blind, placebo-controlled, phase 2b randomized clinical trial was conducted at the Baltimore Veterans Affairs (VA) Medical Center between January 2019 to January 2023. Veterans were eligible if they had a diabetes diagnosis, were at high risk for diabetic foot complications, were ambulatory, had both feet, and did not have a current foot infection. Participants were randomly assigned 1:1 to receive either soap-and-water wipes (control group) or 2% chlorhexidine wipes (chlorhexidine group). Intention-to-treat data analysis was conducted from October 5, 2023, to April 24, 2024.

Intervention

Daily use of a 2% chlorhexidine wipe or a soap-and-water wipe on the feet for 1 year. Wipes were nearly identical in color, size, shape, thickness, feel, and scent. Both chlorhexidine and control groups received the same lotion for application on the feet after wipe use and education on foot self-care.

Main Outcomes and Measures

The primary outcome was time in days from randomization to new foot complication, including chronic foot ulcer, foot infection, or foot amputation.

Results

A total of 175 participants (170 males [97%]; mean [SD] age at enrollment, 68 [9] years; 1 Asian [1%], 117 Black or African American [67%], 53 White [30%] individuals) were randomly assigned to the chlorhexidine group (n = 88) or the control group (n = 87). Twelve participants (14%) in the chlorhexidine group and 14 participants (16%) in the control group developed a new foot complication within 1 year. Median (IQR) time from randomization to development of a new foot complication was 232 (115-315) days. The reduction in hazard of new foot complications in the chlorhexidine group compared with the control group was not significant (hazard ratio, 0.83; 95% CI, 0.39-1.80). The intervention was well tolerated, with 145 participants (83%) continuing it over the study period. Sixty adverse events occurred, but none was related to the study products or procedures.

Conclusions and Relevance

This randomized clinical trial found that daily use of chlorhexidine wipes for foot washing for 1 year did not lead to a significant reduction in the risk of new foot complications compared with daily use of soap-and-water wipes. The intervention was well tolerated, and the trial provides important lessons for future studies on diabetic foot ulcer prevention.

Trial Registration

ClinicalTrials.gov Identifier: NCT03503370.

Bathing with 2% chlorhexidine gluconate versus routine care for preventing surgical site infections after pancreatic surgery: a single-centre randomized controlled trial

OBJECTIVES

The study aims to investigate whether bathing with 2% chlorhexidine gluconate (CHG) reduces the incidence of surgical site infection (SSI) in patients undergoing routine pancreatic surgery.

METHODS

A randomized controlled trial was conducted at a large-volume pancreatic centre between 1 January 2021 and 31 December 2022. Patients undergoing clean-contaminated pancreatic surgery were enrolled and randomized into an intervention arm (bathing with a 2% CHG wipe) and a control arm (routine care, soap, and water). The primary outcome was the incidence of SSI after pancreatic surgery within 30 days.

RESULTS

Overall, 614 patients (intervention arm, 311; control arm, 303) were included in intention-to-treat analysis. In total, 8.8% (54/614) patients developed SSI. The incidence of SSI in the intervention arm was 6.8% (21/311) and 10.9% (33/303) in control arm, and the difference did not reach the level of statistical significance (p 0.070). The time to SSI was significantly extended when patients were in the intervention arm (log-rank test, p 0.047). The intervention did not significantly reduce the incidence of healthcare-associated infection, hospital-acquired pneumonia, and bloodstream infection. No adverse events were observed. However, in the per-protocol analysis among 519 patients, the intervention arm showed a significantly lower incidence of overall SSI than that of those in the control arm (21/272, 7.7% vs. 33/242, 13.4%, p 0.036).

DISCUSSION

Bathing with 2% CHG could potentially reduce the incidence of SSI for the patients scheduled to undergo pancreatic surgery for which further well-designed clinical trials are warranted.

Implementation of 2% Chlorhexidine Bathing to Reduce Healthcare-Associated Infections Among Patients in the Intensive Care Unit

Healthcare-associated infections (HAIs) significantly increase morbidity, mortality, length of hospital stays, and costs, particularly among ICU patients. Despite standard interventions, catheter-associated urinary tract infections (CAUTI) and central line-associated bloodstream infections (CLABSI) remain major HAI contributors. This study evaluated the efficacy of daily 2% chlorhexidine gluconate (CHG) bathing in reducing HAI incidence, specifically CAUTI, CLABSI, and multidrug-resistant organisms (MDROs), in a 20-bed ICU at a regional hospital. Using a prospective, uncontrolled before-and-after design, we compared traditional soap-water bathing (pre-intervention period) with CHG bathing over a one-year intervention and one-year post-intervention follow-up. The total number of patients and patient days admitted to the ICU per year were around 1330-1412 patients and 6702-6927 patient days, respectively, during 2018-2020. Results showed a significant reduction in HAI incidence rates from 3.43‱ to 0.58‱ (p < 0.05) during the intervention and sustained benefits post-intervention. Incidences of CAUTI and CLABSI decreased markedly (p < 0.05), with reduced MDRO isolates, including methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococci, carbapenem-resistant Acinetobacter baumannii, and Pseudomonas aeruginosa. Our findings support the implementation of daily CHG bathing as an effective strategy to reduce HAI and MDROs in ICU settings.

Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) harboring mupirocin and biocide resistance genes in a large health care system

BACKGROUND

We aimed to determine the prevalence of genes associated with high-level mupirocin and biocide resistance in methicillin-resistant Staphylococcus aureus (MRSA) isolates among hospitalized patients and to characterize their genomic and epidemiologic features.

METHODS

Study conducted on an integrated health system. Clinical cultures with MRSA from hospitalized patients collected between March 1, 2023, and January 20, 2024 underwent prospective whole-genome sequencing, including assessment for the presence of markers of resistance against mupirocin (mupA) and biocides (qac). Demographic and clinical characteristics were reviewed.

RESULTS

We analyzed 463 MRSA isolates. The overall prevalence of mupA(+), qacA(+), and qacC(+) genes was 22.0%, 2.4%, and 19.0%, respectively. Most mupA(+) isolates belonged to ST8, but ST8732 (a novel variant of ST8) had the highest prevalence of mupA(+) isolates at 95%. Patients mupA(+) were older, and none of the isolates from pediatric patients harbored this gene.

DISCUSSION

Through prospective whole-genome sequencing of MRSA isolates, we detected a prevalence of genes conferring mupirocin resistance considerably higher than previously reported, particularly among MRSA ST8 variants.

CONCLUSIONS

Our findings highlight the need for monitoring resistance to agents used for the prevention of S aureus infections, as these trends have implications for infection prevention programs and public health at large.

Chlorhexidine gluconate versus povidone-iodine for nasal bacteria decolonization before transsphenoidal surgery in patients with pituitary neuroendocrine tumors: a prospective, randomized, double-blind, noninferiority trial

BACKGROUND

This study aimed to compare the nasal decolonization efficacy and comfort between chlorhexidine gluconate (CHG) and povidone-iodine (PVP) to provide an evidence basis for clinical guidance.

METHODS

A prospective, randomized, single-blinded, noninferior clinical trial was conducted in 174 patients with pituitary neuroendocrine tumors (PitNETs) who were scheduled to undergo transsphenoidal surgery. The noninferiority margin was δ=-0.1. The primary outcome was the effective rate of disinfection. The secondary outcomes included postoperative inflammatory indicators, the intracranial infection rate, and the proportion of intracranial infection.

RESULTS

The effective clearance rate of postoperative nasal bacteria was nonsignificantly different between the CHG and PVP groups (88.64% vs. 82.56%; between-group difference 6.10%; 95% CI [-5.30 to 17.50]). There was no significant difference in the incidence of postoperative central nervous system infections or serum inflammation-related indications between the two groups, but sterilization tended to occur quicker and last longer in the CHG group. CHG seemed to have advantages in terms of comfort, including less nasal irritation, less pungency, and better intranasal coloration.

CONCLUSION

CHG and PVP have equal efficacy in nasal decolonization before transsphenoidal surgery, but CHG seems to have comfort-related advantages in terms of less nasal irritation, less pungency, and better intranasal coloration.

Povidone Iodine vs Chlorhexidine Gluconate in Alcohol for Preoperative Skin Antisepsis: A Randomized Clinical Trial

Importance

Preoperative skin antisepsis is an established procedure to prevent surgical site infections (SSIs). The choice of antiseptic agent, povidone iodine or chlorhexidine gluconate, remains debated.

Objective

To determine whether povidone iodine in alcohol is noninferior to chlorhexidine gluconate in alcohol to prevent SSIs after cardiac or abdominal surgery.

Design, Setting, and Participants

Multicenter, cluster-randomized, investigator-masked, crossover, noninferiority trial; 4403 patients undergoing cardiac or abdominal surgery in 3 tertiary care hospitals in Switzerland between September 2018 and March 2020 were assessed and 3360 patients were enrolled (cardiac, n = 2187 [65%]; abdominal, n = 1173 [35%]). The last follow-up was on July 1, 2020.

Interventions

Over 18 consecutive months, study sites were randomly assigned each month to either use povidone iodine or chlorhexidine gluconate, each formulated in alcohol. Disinfectants and skin application processes were standardized and followed published protocols.

Main Outcomes and Measures

Primary outcome was SSI within 30 days after abdominal surgery and within 1 year after cardiac surgery, using definitions from the US Centers for Disease Control and Prevention's National Healthcare Safety Network. A noninferiority margin of 2.5% was used. Secondary outcomes included SSIs stratified by depth of infection and type of surgery.

Results

A total of 1598 patients (26 cluster periods) were randomly assigned to receive povidone iodine vs 1762 patients (26 cluster periods) to chlorhexidine gluconate. Mean (SD) age of patients was 65.0 years (39.0-79.0) in the povidone iodine group and 65.0 years (41.0-78.0) in the chlorhexidine gluconate group. Patients were 32.7% and 33.9% female in the povidone iodine and chlorhexidine gluconate groups, respectively. SSIs were identified in 80 patients (5.1%) in the povidone iodine group vs 97 (5.5%) in the chlorhexidine gluconate group, a difference of 0.4% (95% CI, -1.1% to 2.0%) with the lower limit of the CI not exceeding the predefined noninferiority margin of -2.5%; results were similar when corrected for clustering. The unadjusted relative risk for povidone iodine vs chlorhexidine gluconate was 0.92 (95% CI, 0.69-1.23). Nonsignificant differences were observed following stratification by type of surgical procedure. In cardiac surgery, SSIs were present in 4.2% of patients with povidone iodine vs 3.3% with chlorhexidine gluconate (relative risk, 1.26 [95% CI, 0.82-1.94]); in abdominal surgery, SSIs were present in 6.8% with povidone iodine vs 9.9% with chlorhexidine gluconate (relative risk, 0.69 [95% CI, 0.46-1.02]).

Conclusions and Relevance

Povidone iodine in alcohol as preoperative skin antisepsis was noninferior to chlorhexidine gluconate in alcohol in preventing SSIs after cardiac or abdominal surgery.

Trial Registration

ClinicalTrials.gov Identifier: NCT03685604.

Insights into the Cytotoxicity and Irritant Potential of Chlorhexidine Digluconate: An In Vitro and In Ovo Safety Screening

Chlorhexidine (CHX) represents one of the most commonly used antiseptics in dentistry and other medical-pharmaceutical fields due to its broad-spectrum antimicrobial activity. However, the potential toxic events arising from its common use in practice has become a subject of increasing concern. Thus, the present study was designed to investigate the potential toxicity of CHX digluconate at concentrations covering its antibacterial properties (0.0002-0.2%) in HGF primary gingival fibroblasts, HaCaT immortalized human keratinocytes, and JB6 Cl 41-5a epidermal cells, as well as its irritant action in ovo. Our results indicate that CHX exerted a concentration- and time-dependent cytotoxicity in all cell lines, which was evidenced by the reduction in cell viability, number, and confluence, damaged cell membrane integrity, impaired cell morphology, and specific apoptotic nuclear shape. The highest cytotoxicity was caused by CHX digluconate 0.02% and 0.2%, concentrations, at which an irritant effect on the chorioallantoic membrane was also observed. The novel findings revealed in this research contribute to the overall safety profile of CHX and stand as a basis for further investigations in this regard.

Decolonization and Pathogen Reduction Approaches to Prevent Antimicrobial Resistance and Healthcare-Associated Infections

Antimicrobial resistance in healthcare-associated bacterial pathogens and the infections they cause are major public health threats affecting nearly all healthcare facilities. Antimicrobial-resistant bacterial infections can occur when colonizing pathogenic bacteria that normally make up a small fraction of the human microbiota increase in number in response to clinical perturbations. Such infections are especially likely when pathogens are resistant to the collateral effects of antimicrobial agents that disrupt the human microbiome, resulting in loss of colonization resistance, a key host defense. Pathogen reduction is an emerging strategy to prevent transmission of, and infection with, antimicrobial-resistant healthcare-associated pathogens. We describe the basis for pathogen reduction as an overall prevention strategy, the evidence for its effectiveness, and the role of the human microbiome in colonization resistance that also reduces the risk for infection once colonized. In addition, we explore ideal attributes of current and future pathogen-reducing approaches.

The laboratory investigation, management, and infection prevention and control of Candida auris: a narrative review to inform the 2024 national guidance update in England

The emergent fungal pathogen Candida auris is increasingly recognised as an important cause of healthcare-associated infections globally. It is highly transmissible, adaptable, and persistent, resulting in an organism with significant outbreak potential that risks devastating consequences. Progress in the ability to identify C. auris in clinical specimens is encouraging, but laboratory diagnostic capacity and surveillance systems are lacking in many countries. Intrinsic resistance to commonly used antifungals, combined with the ability to rapidly acquire resistance to therapy, substantially restricts treatment options and novel agents are desperately needed. Despite this, outbreaks can be interrupted, and mortality avoided or minimised, through the application of rigorous infection prevention and control measures with an increasing evidence base. This review provides an update on epidemiology, the impact of the COVID-19 pandemic, risk factors, identification and typing, resistance profiles, treatment, detection of colonisation, and infection prevention and control measures for C. auris. This review has informed a planned 2024 update to the United Kingdom Health Security Agency (UKHSA) guidance on the laboratory investigation, management, and infection prevention and control of Candida auris. A multidisciplinary response is needed to control C. auris transmission in a healthcare setting and should emphasise outbreak preparedness and response, rapid contact tracing and isolation or cohorting of patients and staff, strict hand hygiene and other infection prevention and control measures, dedicated or single-use equipment, appropriate disinfection, and effective communication concerning patient transfers and discharge.

Emergence and clonal expansion of a qacA-harbouring sequence type 45 lineage of methicillin-resistant Staphylococcus aureus

The past decade has seen an increase in the prevalence of sequence type (ST) 45 methicillin-resistant Staphylococcus aureus (MRSA), yet the underlying drivers for its emergence and spread remain unclear. To better understand the worldwide dissemination of ST45 S. aureus, we performed phylogenetic analyses of Australian isolates, supplemented with a global population of ST45 S. aureus genomes. Our analyses revealed a distinct lineage of multidrug-resistant ST45 MRSA harbouring qacA, predominantly found in Australia and Singapore. Bayesian inference predicted that the acquisition of qacA occurred in the late 1990s. qacA was integrated into a structurally variable region of the chromosome containing Tn552 (carrying blaZ) and Tn4001 (carrying aac(6')-aph(2")) transposable elements. Using mutagenesis and in vitro assays, we provide phenotypic evidence that qacA confers tolerance to chlorhexidine. These findings collectively suggest both antimicrobial resistance and the carriage of qacA may play a role in the successful establishment of ST45 MRSA.

Novel anionic surfactant-modified chlorhexidine and its potent antimicrobial properties

Chlorhexidine dodecyl sulfate (CHX-DS) was synthesized and characterized via single-crystal X-ray diffraction (SC-XRD), 1H nuclear magnetic resonance (NMR) spectroscopy, 1H nuclear Overhauser effect spectroscopy (NOESY), and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). The solid-state structure, comprising a 1 : 2 stoichiometric ratio of chlorhexidine cations [C22H30Cl2N10]2+ to dodecyl sulfate anions [C12H25SO4]-, is the first report of chlorhexidine isolated with a surfactant. CHX-DS exhibits broad-spectrum antibacterial activity and demonstrates superior efficacy for reducing bacteria-generated volatile sulfur compounds (VSCs) as compared to chlorhexidine gluconate (CHG). The minimum inhibitory concentrations (MICs) of CHX-DS were 7.5, 2.5, 2.5, and 10 μM for S. enterica, E. coli, S. aureus, and S. mutans, respectively. Furthermore, MIC assays for E. coli and S. mutans demonstrate that CHX-DS and CHX exhibit a statistically significant efficacy enhancement in 2.5 μM treatment as compared to CHG. CHX-DS was incorporated into SBA-15, a mesoporous silica nanoparticle (MSN) framework, and its release was qualitatively measured via UV-vis in aqueous media, which suggests its potential as an advanced functional material for drug delivery applications.

Development of a Broth Microdilution Method To Characterize Chlorhexidine MICs among Bacteria Collected from 2005 to 2019 at Three U.S. Sites

Chlorhexidine bathing to prevent transmission of multidrug-resistant organisms has been adopted by many U.S. hospitals, but increasing chlorhexidine use has raised concerns about possible emergence of resistance. We sought to establish a broth microdilution method for determining chlorhexidine MICs and then used the method to evaluate chlorhexidine MICs for bacteria that can cause health care-associated infections. We adapted a broth microdilution method for determining chlorhexidine MICs, poured panels, established quality control ranges, and tested Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Enterobacter cloacae complex isolates collected at three U.S. sites. Chlorhexidine MICs were determined for 535 isolates including 129 S. aureus, 156 E. coli, 142 K. pneumoniae, and 108 E. cloacae complex isolates. The respective MIC distributions for each species ranged from 1 to 8 mg/L (MIC50 = 2 mg/L and MIC90 = 4 mg/L), 1 to 64 mg/L (MIC50 = 2 mg/L and MIC90 = 4 mg/L), 4 to 64 mg/L (MIC50 = 16 mg/L and MIC90 = 32 mg/L), and 1 to >64 mg/L (MIC50 = 16 mg/L and MIC90 = 64 mg/L). We successfully adapted a broth microdilution procedure that several laboratories were able to use to determine the chlorhexidine MICs of bacterial isolates. This method could be used to investigate whether chlorhexidine MICs are increasing. IMPORTANCE Chlorhexidine bathing to prevent transmission of multidrug-resistant organisms and reduce health care-associated infections has been adopted by many hospitals. There is concern about the possible unintended consequences of using this agent widely. One possible unintended consequence is decreased susceptibility to chlorhexidine, but there are not readily available methods to perform this evaluation. We developed a method for chlorhexidine MIC testing that can be used to evaluate for possible unintended consequences.

Chlorhexidine and octenidine susceptibility of bacterial isolates from clinical samples in a three-armed cluster randomised decolonisation trial

BACKGROUND

Routine use of chlorhexidine or octenidine for antiseptic bathing may have unintended consequences. Our analysis aimed to assess the phenotypic susceptibility of bacterial isolates from clinical samples to chlorhexidine and octenidine collected from intensive care units (ICU) that routinely used 2% chlorhexidine-impregnated wash cloths or 0.08% octenidine wash mitts (intervention) or water and soap (control) for daily patient care.

METHODS

This study was conducted within the context of a three armed cluster-randomised controlled decolonisation trial (Registration number DRKS00010475, registration date August 18, 2016). Bacterial isolates were collected prior to and at the end of a 12-month-intervention period from patients with ≥ 3 days length of stay at an ICU assigned to one of two intervention groups or the control group. Phenotypic susceptibility to chlorhexidine and octenidine was assessed by an accredited contract research laboratory determining minimal inhibitory concentrations (MIC) as percentage of extraction solutions used. MIC were reported as estimated concentrations in μg/ml derived from the chlorhexidine and octenidine extraction solutions. Statistical analyses including generalized estimating equation models were applied.

RESULTS

In total, 790 ICU-attributable bacterial isolates from clinical samples (e.g. blood, urine, tracheal aspirate) were eligible for all analyses. Pathogens included were Staphylococcus aureus (n = 155), coagulase-negative staphylococci (CoNS, n = 122), Escherichia coli (n = 227), Klebsiella spp. (n = 150) and Pseudomonas aeruginosa (n = 136). For all species, chlorhexidine and octenidine MIC did not increase from baseline to intervention period in the antiseptic bathing groups. For proportions of bacterial isolates with elevated chlorhexidine / octenidine MIC (≥ species-specific chlorhexidine / octenidine MIC50), adjusted incidence rate ratios (aIRR) showed no differences between the intervention groups and the control group (intervention period).

CONCLUSION

We found no evidence for reduced phenotypic susceptibilities of bacterial isolates from clinical samples to chlorhexidine or octenidine in ICUs 12 months after implementation of routine antiseptic bathing with the respective substances.

Effect of antiseptic bathing with chlorhexidine or octenidine on central-line associated bloodstream infections in intensive care patients: a cluster-randomised controlled trial

OBJECTIVES

Our study aimed to compare the effect of daily bathing with chlorhexidine, octenidine or water and soap (routine care = control) on central-line (CL) associated bloodstream infection (CLABSI) rates in intensive care units (ICUs).

METHODS

A multi-center cluster-randomised controlled trial was done with a 12-months intervention period from February 1, 2017, to January 31, 2018 (octenidine and routine care group) or from June 1, 2017 to May 31, 2018 (chlorhexidine group). Wards were randomly assigned to one of two decolonisation regimes or routine care (control). Intervention included daily bathing with 2% chlorhexidine-impregnated cloths or 0.08% octenidine wash mitts for 12 months, while the control group used water and soap (routine care). The primary outcome was incidence density of CLABSI per 1,000 CL days. Poisson regression and generalised estimating equation models (GEE) were applied.

RESULTS

A total of 72 ICUs with 76,815 patients (22,897 patients in the chlorhexidine group, 25,127 in the octenidine group and 28,791 in the routine care group) were included. Incidence densities were 0.9 CLABSI per 1,000 CL days (95%CI 0.67 - 1.19) in the chlorhexidine group, 1.47 (95%CI 1.17 - 1.81) in the octenidine group and 1.17 (95%CI 0.93 - 1.45) in the routine care group. Adjusted incidence rate ratios of CLABSI were 0.69 (95%CI 0.37-1.22, p=0.25) in the chlorhexidine and 1.22 (95%CI 0.54-2.75, p=0.63) in the octenidine group (compared with routine care).

CONCLUSION

Antiseptic bathing with 2% chlorhexidine-impregnated cloths and 0.08% octenidine wash mitts lack a significant preventive effect on CLABSI rates in ICUs. However, our trial has a high likelihood of being underpowered as CLABSI rates in the routine care group were approximately 40% lower than initially assumed. This trial is registered with the German register for clinical trials (18/08/2016, number DRKS00010475).