Efficacy of surgical hand scrub products based on chlorhexidine is largely overestimated without neutralizing agents in the sampling fluid

Comparative antimicrobial efficacy of 4 surgical hand-preparation procedures prior to application of an alcohol-based hand rub in veterinary students

OBJECTIVE

To determine the influence of skin preparations before application of an alcohol-based hand rub (ABHR) on bacterial counts before and after elective surgery.

STUDY DESIGN

Clinical prospective study.

SAMPLE POPULATION

Veterinary students (n = 103) performing ovariohysterectomies on 140 dogs.

METHODS

Participants were randomly assigned to 1 initial surgical preparation on the day of surgery: A - hand preparation with medicated solution (4% w/v chlorhexidine bigluconate followed by an ABHR; B - application of a medication solution (benzalkonium chloride 0.1%-1% and polymeric biguanide hydrochloride 0.01%-0.1%) followed by an ABHR; C - nonmedicated pH-neutral soap hand wash followed by ABHR, and D - direct application of an ABHR. Samples were taken by pressing the distal finger tips to an agar plate before the hand preparation, after the hand preparation (n = 3), after ABHR application, and 120 minutes later. Colony-forming units (CFUs) for samples were determined. Total log CFU and CFU log10 reduction were calculated and used for comparison with P < .05.

RESULTS

Two hours after surgery commenced, the participants of groups that performed a hand preparation had lower total CFUs than those that did not perform a hand preparation (P = .001). In particular, the number of CFUs was lower when ABHR was performed after application of pHN compared to direct ABHR (P = .001).

CONCLUSION

In this population, performing a hand preparation with pHN prior to applying an ABHR had better antimicrobial effect for the duration of surgery than not performing a hand preparation.

CLINICAL SIGNIFICANCE

Surgeons should wash their hands prior to ABHR before starting their first surgery of the day, even when hands appear clean.

Comparison of the antimicrobial efficacy of povidone-iodine-alcohol versus chlorhexidine-alcohol for surgical skin preparation on the aerobic and anaerobic skin flora of the shoulder region

Background

Cutibacterium acnes is part of the anaerobic skin microbiome and resides in deeper skin layers. The organism is an agent of surgical site infections (SSI) in shoulder surgery. We hypothesized that prolonged skin preparation with an agent that penetrates deeply into the skin would be beneficial. Thus, we compared two classes of antiseptics, each combined with alcohol, each applied with two different contact times.

Methods

Using a cross-over arrangement, shoulders of 16 healthy volunteers were treated for 2.5 min (standard) or 30 min (prolonged) with alcohol-based chlorhexidine (CHG-ALC) or alcohol-based povidone-iodine (PVP-I-ALC). Skin sites were sampled before, immediately after, and 3 h after treatment, using a standardized cup-scrub technique.

Results

Aerobic skin flora was reduced more effectively by PVP-I-ALC than by CHG-ALC after 2.5 min application and immediate sampling (reduction factor [RF] 2.55 ± 0.75 vs. 1.94 ± 0.91, p = 0.04), but not after prolonged contact times and 3-h sampling. Coagulase-negative staphylococci were completely eliminated after PVP-I-ALC application, but still recovered from 4 of 32 samples after CHG-ALC application. Anaerobic flora was reduced more effectively by PVP-I-ALC than CHG-ALC after standard (RF 3.96 ± 1.46 vs. 1.74 ± 1.24, p < 0.01) and prolonged (RF 3.14 ± 1.20 vs. 1.38 ± 1.16, p < 0.01) contact times and immediate sampling, but not after 3-h sampling. No adverse events were reported.

Conclusions

PVP-I-ALC showed marginal benefits concerning the aerobic flora, but more substantial benefits over CHG-ALC concerning the anaerobic flora of the shoulder. Standard and prolonged contact times showed superiority for PVP-I-ALC for anaerobic flora at all immediate sampling points, but missed significance at 3-h sampling. The results underscore the need for protection against C. acnes and coagulase-negative staphylococci in orthopaedic surgery. The clinical relevance of these findings, however, should be studied with SSI as an endpoint.

Comparative Antimicrobial Efficacy of Two Hand Sanitizers in Intensive Care Units Common Areas: A Randomized, Controlled Trial

OBJECTIVE

Contaminated hands of healthcare workers (HCWs) are an important source of transmission of healthcare-associated infections. Alcohol-based hand sanitizers, while effective, do not provide sustained antimicrobial activity. The objective of this study was to compare the immediate and persistent activity of 2 hand hygiene products (ethanol [61% w/v] plus chlorhexidine gluconate [CHG; 1.0% solution] and ethanol only [70% v/v]) when used in an intensive care unit (ICU).

DESIGN

Prospective, randomized, double-blinded, crossover study

SETTING

Three ICUs at a large teaching hospital

PARTICIPANTS

In total, 51 HCWs involved in direct patient care were enrolled in and completed the study.

METHODS

All HCWs were randomized 1:1 to either product. Hand prints were obtained immediately after the product was applied and again after spending 4–7 minutes in the ICU common areas prior to entering a patient room or leaving the area. The numbers of aerobic colony-forming units (CFU) were compared for the 2 groups after log transformation. Each participant tested the alternative product after a 3-day washout period.

RESULTS

On bare hands, use of ethanol plus CHG was associated with significantly lower recovery of aerobic CFU, both immediately after use (0.27 ± 0.05 and 0.88 ± 0.08 log10 CFU; P = .035) and after spending time in ICU common areas (1.81 ± 0.07 and 2.17 ± 0.05 log10 CFU; P<.0001). Both the antiseptics were well tolerated by HCWs.

CONCLUSIONS

In comparison to the ethanol-only product, the ethanol plus CHG sanitizer was associated with significantly lower aerobic bacterial counts on hands of HCWs, both immediately after use and after spending time in ICU common areas.

CLINICAL TRIAL IDENTIFIER

Clinicaltrials.gov identifier NCT02258412

Infect Control Hosp Epidemiol 2018;39:267–271

Chlorhexidine is not an essential component in alcohol-based surgical hand preparation: a comparative study of two handrubs based on a modified EN 12791 test protocol

BACKGROUND

Surgical hand preparation is an essential part of modern surgery. Both alcohol-based and antiseptic detergent-based hand preparation are recommended practices, with a trend towards use of alcohol based handrubs. However, discussion has arisen whether chlorhexidine is a required ingredient in highly efficacious alcohol-based formulations, in view of providing sustained antimicrobial efficacy.

METHODS

One alcohol-only formulation (product A), containing ethanol and n-propanol, and one formulation containing a chlorhexidine-ethanol combination (product B) were directly compared with each other using a modified test protocol based on European standard EN 12791 (2016) with 25 volunteers. The alcohol-only formulation (product A) was applied for only 90 s, the chlorhexidine-alcohol formulation (product B) for 180 s. Microbial log reduction factors were determined and statistically compared immediately after application and at 6 h under surgical gloves.

RESULTS

The alcohol-only formulation (product A) achieved mean log reduction factors of 1.96 ± 1.06 immediately after application and 1.67 ± 0.71 after 6 h. The chlorhexidine-alcohol combination (product B) achieved mean log reduction factors of 1.42 ± 0.79 and 1.24 ± 0.90 immediately and after 6 h, respectively. The values for product A were significantly greater than those for product B at both measured time points (p ≤ 0.025 immediately after application and p ≤ 0.01 after 6 h).

CONCLUSIONS

An optimized alcohol-only formulation tested according to a modified EN 12791 protocol in 25 healthy volunteers outperformed a chlorhexidine-alcohol formulation both immediately after application and at 6 h under surgical gloves, despite a much shorter application time. Thus, optimized alcohol-only formulations do not require chlorhexidine to achieve potent immediate and sustained efficacy. In conclusion, chlorhexidine is not an essential component for alcohol-based surgical hand preparation.

Comparison of an alcohol-based hand sanitation product with a traditional chlorhexidine hand scrub technique for hand hygiene preparation in an equine hospital

AIMS

To investigate the efficacy of an alcohol gel-based hand antisepsis protocol compared with a traditional chlorhexidine-based protocol under conditions of routine clinical contamination, and following heavy faecal contamination.

METHODS

Twelve adult participants were recruited and on four separate days completed a hand sanitation protocol using a chlorhexidine scrub or an alcohol-based gel, with hands that were grossly clean but contaminated or with faecal contamination. Bacterial samples were obtained from participants' hands before sanitation, immediately after and then 2 hours later. All samples were cultured on blood and MacConkey agar and bacterial colonies counted after 48 hours.

RESULTS

for clean contaminated hands, the percentage reduction in bacterial colonies on blood agar immediately after hand sanitation was similar for both protocols (p=0.3), but was greater for the alcohol gel than chlorhexidine after 2 hours (p=0.005). For hands with faecal contamination, the percentage reduction in bacterial colonies on blood agar was similar for both protocols immediately and 2 hours after sanitation (p>0.2), but positive cultures were obtained on blood agar from samples collected after both protocols, for almost all participants.

CONCLUSIONS

The results indicate equivalent efficacy of the alcohol-based gel and the pre-surgical chlorhexidine protocol.

CLINICAL RELEVANCE

The alcohol-based gel protocol is an effective hand asepsis technique for grossly clean contaminated hands and those following faecal contamination, with comparable efficacy to chlorhexidine based scrub.

Pneumonia caused by extensive drug-resistant Acinetobacter baumannii among hospitalized patients: genetic relationships, risk factors and mortality

BACKGROUND

The clonal spread of multiple drug-resistant Acinetobacter baumannii is an emerging problem in China. We analysed the molecular epidemiology of Acinetobacter baumanni isolates at three teaching hospitals and investigated the risk factors, clinical features, and outcomes of hospital-acquired pneumonia caused by extensive drug-resistant Acinetobacter baumannii (XDRAB) infection in Guangzhou, China.

METHODS

Fifty-two A. baumannii isolates were collected. Multilocus sequence typing (MLST) was used to assess the genetic relationships among the isolates. The bla _OXA-51-like gene was amplified using polymerase chain reaction (PCR) and sequencing. The resistance phenotypes were determined using the disc diffusion method. A retrospective case-control study was performed to determine factors associated with XDRAB pneumonia.

RESULTS

Most of the 52 A. baumannii isolates (N = 37, 71.2%) were collected from intensive care units (ICUs). The respiratory system was the most common bodily site from which A. baumannii was recovered (N = 45, 86.5%). Disc diffusion classified the isolates into 17 multidrug-resistant (MDR) and 35 extensively drug-resistant (XDR) strains. MLST grouped the A. baumannii isolates into 5 existing sequence types (STs) and 7 new STs. ST195 and ST208 accounted for 69.2% (36/52) of the isolates. The clonal relationship analysis showed that ST195 and ST208 belonged to clonal complex (CC) 92. According to the sequence-based typing (SBT) of the bla _OXA-51-like gene, 51 A. baumannii isolates carried OXA-66 and the rest carried OXA-199. There were no significant differences with respect to the resistance phenotype between the CC92 and non-CC92 strains (P = 0.767). The multivariate analysis showed that the APACHE II score, chronic obstructive pulmonary disease (COPD) and cardiac disease were independent risk factors for XDRAB pneumonia (P < 0.05). The mortality rate of XDRAB pneumonia was high (up to 42.8%), but pneumonia caused by XDRAB was not associated with in-hospital mortality (P = 0.582).

CONCLUSIONS

ST195 may be the most common ST in Guangzhou, China, and may serve as a severe epidemic marker. SBT of bla _OXA-51-like gene variants may not result in sufficient dissimilarities to type isolates in a small-scale, geographically restricted study of a single region. XDRAB pneumonia was strongly related to systemic illnesses and the APACHE II score but was not associated with in-hospital mortality.