Comparative efficacy of alternative hand-washing agents in reducing nosocomial infections in intensive care units

Is hand washing really needed in an intensive care unit?

OBJECTIVES

To determine whether a rigorous antiseptic hand washing of bare hands with 4% chlorhexidine and alcohol reduced fingertip microbial colonization as compared with the use of boxed, clean, nonsterile latex gloves. In addition, to investigate if aseptic donning technique and/or a prior hand washing would reduce the level of glove contamination.

DESIGN

Prospective, randomized, crossover design, with each subject serving as his/her own control.

SETTING

University intensive care unit.

SUBJECTS

Forty-three intensive care nurses.

INTERVENTIONS

The fingertips of 20 nurses were cultured before and after a strict antiseptic hand washing and before and after the routine and aseptic donning of sterile gloves. Subsequently, the fingertips of 43 nurses were cultured before and after the casual donning of nonsterile gloves over unwashed hands and before and after a strict antiseptic hand washing. Fingertip cultures were plated directly on agar, incubated for 24 hrs, and counted and recorded as the number of colony-forming units (cfu) for each hand. Different colony types were then subcultured.

MEASUREMENTS AND MAIN RESULTS

Hand washing with antiseptic reduced colonization from 84 to 2 cfu (p < .001). The proportion of cases with > or = 200 cfu/hand was reduced from 30% to 9%. Aseptic or casual donning of sterile gloves, with or without prior antiseptic hand washing, resulted in consistently low glove counts between 0 and 1.25 cfu. Nonsterile gloves casually donned over washed or unwashed bare hands diminished the bioburden to 2.17 and 1.34 cfu, respectively. No qualitative difference was found in the microorganisms recovered from gloved or bare hands.

CONCLUSIONS

Antiseptic hand washing and the use of nonsterile gloves over unwashed hands confer similar reductions in the number of microorganisms. There is no additional benefit with the use of aseptic donning technique, prior antiseptic hand washing, or the use of individually packaged sterile gloves.

Infection prevention strategies for children with cancer and AIDS: contrasting dilemmas

Infectious complications represent significant challenges for children with cancer and those infected with HIV. Although both have similarities in the disease- and treatment-related alterations in host defences, there are significant differences that can have an impact on the approach to treatment and prevention of the dominant infectious complications. An important difference is that children with cancer readily recover from neutropenia. Thus, the immune deficits are interspersed with intervals of immunological recovery. On the other hand, children with HIV infection do not appreciably recover from the progressive, immunological changes associated with the underlying HIV infection. The loss of cellular and humoral immunity is generally not reversible, and thus the risk of infection only increases over time. Bacteria constitute the predominant pathogen for paediatric cancer patients but invasive mycoses, viruses and parasitic infections are emerging as important pathogens. In paediatric cancer patients, strategies have been directed at altering or suppressing the endogenous colonization patterns of pathogenic bacteria. The success of this approach has been limited and at the expense of selecting for antibiotic-resistant bacterial infections. Children with HIV infection are at risk of developing a wide spectrum of pathogens. Strategies for infection prevention in the HIV setting have been directed at specific organisms, generally using more specific antimicrobial agents and with greater success.

Performance feedback increases the incidence of handwashing by staff following patient contact in intensive care

Nosocomial infections affect up to 30% of ICU patients. Although infection rates decline with increasing handwashing frequency, handwashing rates in ICU's are poor. This study investigated the hypotheses that the subjects' profession would not influence, and performance feedback would not increase, the incidence of handwashing post-patient contact. The study involved an initial period of covert observation to record the baseline level of handwashing, followed by a period of overt observation with regular feedback on handwashing performance by means of letters to staff and histograms of the data displayed in the ICU. Handwashing incidence was reassessed 6 months after performance feedback had ceased. Handwashing differed significantly between professions (P = 0.0001). Initially, the incidence of handwashing was highest amongst wardsmen (90%) and lowest amongst Visiting Medical Officers (VMOs) (20%). Sixty-nine percent (69%) of Registered Nurses (RNs), 57% of physiotherapists, 41% of Resident Medical Officers (RMOs) and 35% of radiographers washed their hands after touching patients. With the exception of the wardsmen, there was a trend towards an increased frequency in handwashing in all groups after performance feedback, but the differences were only statistically significant in the VMO and physiotherapist groups (P < 0.001). The improvements were maintained for 6 months after the feedback phase ended in 4 of the 6 groups.

Investigation of Candida albicans transmission in a surgical intensive care unit cluster by using genomic DNA typing methods

An apparent outbreak of serious Candida albicans infections (n = 6) occurred in a surgical intensive care unit over a 4-week period. Four patients developed C. albicans bloodstream infections. An additional patient developed catheter-related C. albicans infection; the sixth patient developed an infection of cerebrospinal fluid. C. albicans was isolated from the hands of five health care workers (17%) and the throat of one health care worker (3%) during the outbreak investigation. Karyotyping and restriction endonuclease analysis of genomic DNA with BssHII of 23 C. albicans isolates from patients and the 6 health care worker isolates revealed 9 and 12 different patterns, respectively. Three of six patients appeared to be infected with the same C. albicans strain (two bloodstream infections and one cerebrospinal fluid infection). The hands of a health care worker were colonized with strain that appeared identical to an isolate from a patient prior to infection of the patient. However, restriction endonuclease analysis with SfiI found differences among the isolates determined to be identical by the other two methods. Karyotyping alone does not appear to be sufficient to differentiate between outbreak and control isolates. Restriction endonuclease analysis typing may be a more sensitive method than karyotyping alone in the investigation of a cluster of C. albicans infections. Furthermore, the use of more than one restriction enzyme may be necessary for optimal strain discrimination in restriction endonuclease analysis of genomic DNA.

Susceptibility of Streptococcus mutans and Streptococcus sobrinus to antimicrobial agents after short-term oral chlorhexidine treatments

Effects of three different types of short-term applications (1-3 times during 1 week) of chlorhexidine (1 or 40%) on the susceptibility of 863 clinical isolates of Streptococcus mutans and 53 isolates of Streptococcus sobrinus from 58 subjects were studied. Chlorhexidine-resistant isolates were not found either before or after the treatment. The minimum inhibitory concentrations (MICs) to chlorhexidine of all isolates of S. mutans were < or = 1 microgram/ml, and of S. sobrinus < or = 2 micrograms/ml. S. mutans and S. sobrinus were also susceptible to ampicillin, penicillin, cefuroxime, and tetracycline. In conclusion, different short-term chlorhexidine regimens do not induce resistance in S. mutans or S. sobrinus and, furthermore, these species have so far retained their susceptibility to common antibiotics.

Reality of glove use and handwashing in a community hospital

BACKGROUND

Since the advent of universal precautions and body substance isolation, few studies have examined the relationship between glove use and handwashing.

METHODS

During a 5-month period in 1991, 477 structured observations were conducted on 19 patients care units at a community teaching hospital during each of three shifts. Patient care contacts were defined as either high level or low level according to potential for blood or body fluid contact.

RESULTS

Health care workers were potentially exposed to body fluids (high-level contact) on 152 occasions. Eighty-eight percent of all high-level contacts were limited to the hands; 47% of these contacts occurred during the night shift. Handwashing occurred after 32% of high-level contacts. Health-care workers wore gloves in 57% of high-level contacts. Rates of handwashing and glove use varied markedly among patient care units. Correct handwashing (> or = 9 seconds) occurred after 20% of contacts when health care workers wore gloves but after only 3% of high-level contacts when gloves were not used (p = 0.004).

CONCLUSIONS

Despite universal precautions or body substance isolation, educational efforts, and written policies, rates of handwashing and glove use are inadequate in cases of potential blood and body fluid contact. The perceived need for gloves may encourage handwashing.

Infection control and prevention strategies in the ICU

Although only 5-10% of all hospitalized patients are treated in ICUs, they account for approximately 25% of all nosocomial infections, and the incidence of nosocomial infections in ICUs is 5-10 times higher than that observed in general hospital wards. Systemic and respiratory infections are far more common than in general wards, and most epidemics originate in ICUs. Nosocomial infections are the primary focus of most infection control programmes because they are the cause of high mortality rates in ICUs. Effective programmes are usually based on the cooperation of the intensive care physician, the infectious disease specialist, the microbiologist and the clinical epidemiologist. The infectious disease specialist develops specific guidelines for the antimicrobial therapy of typical infections which minimize the selective pressure for microorganisms within the ICU. The microbiologist provides rapid and accurate diagnosis of the pathogens involved. The clinical epidemiologist identifies epidemics at early stages, using epidemiological tools and molecular typing methods, as well as summarizing trends of antimicrobial susceptibility patterns and setting standards for isolation practices. A simple and inexpensive way to reduce nosocomial infections in ICUs is to ensure that staff disinfect their hands after dealing with a patient. Intravascular devices, mechanical ventilation and urinary catheterization are major risk factors for nosocomial infections, and their use should be evaluated daily and discontinued as soon as clinically possible. Selective decontamination of the digestive tract and the use of standard immunoglobulin for prophylaxis are still controversial and need further investigation.(ABSTRACT TRUNCATED AT 250 WORDS)

Effectiveness of liquid soap vs. chlorhexidine gluconate for the removal of Clostridium difficile from bare hands and gloved hands

OBJECTIVE

To compare liquid soap versus 4% chlorhexidine gluconate in 4% alcohol for the decontamination of bare or gloved hands inoculated with an epidemic strain of Clostridium difficile.

DESIGN

C difficile (6.7 log10 colony-forming units [CFU], 47% spores), was seeded onto bare or latex gloved hands of ten volunteers and allowed to dry. Half the volunteers initially washed with soap and half with chlorhexidine, followed by the other agent 1 week later. Cultures were done with Rodac plates at three sites on the hand: finger/thumbtips, the palmar surfaces of the fingers, and the palm. Statistical comparison was by paired Student's t test.

RESULTS

On bare hands, soap and chlorhexidine did not differ in residual bacterial counts on the finger/thumbtips (log10 CFU, 2.0 and 2.1, P = NS) and fingers (log10 CFU, 2.4 and 2.5, P = NS). Counts were too high on bare palms to quantitate. On gloved hands, soap was more effective than chlorhexidine on fingers (log10 CFU 1.3 and 1.7, P < .01) and palms (log10 CFU 1.5 and 2.0, P < .01), but not finger/thumbtips (log10 CFU 1.6 with each, P = NS). Residual C difficile counts were lower on gloved hands than bare hands (P < 0.01 to < 0.0001).

CONCLUSIONS

The two agents did not differ significantly in residual counts of C difficile on bare hands, but on gloved hands residual counts were lower following soap wash than following chlorhexidine wash. These observations support the use of either soap or chlorhexidine as a handwash for removal of C difficile, but efficacy in the prevention of C difficile transmission must be determined by prospective clinical trials.

Biocidal action of chlorhexidine is annulled by nicotinic acid

An analytical system comprising a bacterium and a protozoan was used to pinpoint the metabolic lesion whereby chlorhexidine (CLX) produced cell death. Nicotinic acid but not nicotinamide annulled the biocidal action of CLX. The results suggest that CLX may not permit bioconversion of nicotinamide to nicotinic acid to annul the growth inhibition induced by CLX.

Epidemiology of nosocomial infections in adult intensive care units

Patients in intensive care units (ICUs) are a small subgroup of all hospitalized patients, but they account for approximately 25% of all hospital infections. Nosocomial infection rates among ICU patients are 5-10 times higher than among general ward patients. ICU infection rates are higher due to complex interactions between the patients' underlying disease, severity of illness, type of ICU, duration of stay, and invasive devices used. Antimicrobial resistance is a major clinical problem despite potent and newer antibiotics. Organisms that pose a clinically significant resistance problem among ICU patients include methicillin-resistant staphylococci, enterococci, a wide variety of enterobacteriaceae, Pseudomonas aeruginosa, Pseudomonas cepacia, Xanthomonas maltophila, Acinetobacter and Candida species. Traditional infection control measures include identification of reservoirs, halting transmission between patients, stopping progression from colonization to infection and modifying host risk. In addition, sound selection procedures and guidelines for antibiotic usage are necessary to control the spread of multi-resistant micro-organisms.

Evaluation of methods for the detection of nasal carriage of Staphylococcus aureus

In the present study we investigate the optimal methodology for determination of the nasal carriage rate of Staphylococcus aureus. Tests were performed on 91 healthy laboratory staff. The reproducibility of different sampling, transportation, storage and culture methods was examined. We compared sterile dry cotton wool swabs with sterile dry cotton wool swabs impregnated with charcoal and 5% blood agar plates with mannitol salt agar plates after different incubation periods. Finally, we investigated the detection rate for S. aureus following direct plating compared to storage in Stuart's transport medium for 7 days. There were no differences in isolation rates from the right or left nostril using either cotton or charcoal swabs. Charcoal swabs gave an increased isolation rate as compared to cotton swabs, and incubation in broth enrichment medium containing 6.5% NaCl also increased the isolation rate. Storage in Stuart's transport medium for 7 days gave an increase in isolation rate as compared to direct plating on blood agar. With mannitol salt agar plates the increase in isolation rate when incubation was performed for from 2 to 4, 2 to 7, and 4 to 7 days was 5.9%, 16.7%, and 11.5%, respectively. For the detection of S. aureus nasal carriers we find the use of charcoal swabs and Stuart's transport medium combined with cultivation on mannitol salt agar for 7 days to be the optimal method.

Hand washing frequency in an emergency department

STUDY OBJECTIVE

Previous studies, conducted mainly in ICUs, have shown low compliance with hand-washing recommendations, with failure rates approaching 60%. Hand washing in the emergency department has not been studied. We examined the frequency and duration of hand washing in one ED and the effects of three variables: level of training, type of patient contact (clean, dirty, or gloved), and years of staff clinical experience.

DESIGN

Observational.

SETTING

ED of an 1,100-bed tertiary referral, central city, private teaching hospital.

PARTICIPANTS

Emergency nurses, faculty, and resident physicians. Participants were informed that their activities were being monitored but were unaware of the exact nature of the study.

INTERVENTIONS

An observer recorded the number of patient contacts and activities for each participant during three-hour observation periods. Activities were categorized as either clean or dirty according to a scale devised by Fulkerson. The use of gloves was noted and hand-washing technique and duration were recorded. A hand-washing break in technique was defined as failure to wash hands after a patient contact and before proceeding to another patient or activity.

RESULTS

Eleven faculty, 11 resident physicians, and 13 emergency nurses were observed. Of 409 total contacts, 272 were clean, 46 were dirty, and 91 were gloved. Hand washing occurred after 32.3% of total contacts (SD, 2.31%). Nurses washed after 58.2% of 146 contacts (SD, 4.1%), residents after 18.6% of 129 contacts (SD, 3.4%), and faculty after 17.2% of 134 contacts (SD, 3.3%). Nurses had a significantly higher hand washing frequency than either faculty (P < .0001) or resident physicians (P < .0001). Hand washes occurred after 28.4% of 272 clean contacts (SD, 2.34%), which was significantly less (P < .0001) than 50.0% of 46 dirty contacts (SD, 7.4%) and 64.8% of 91 gloved contacts (SD, 5.0%). The number of years of clinical experience was not significantly related to hand-washing frequency (P = .82). Soap and water were used in 126 of the hand washes, and an alcohol preparation was used in the remaining six. The average duration of soap-and-water hand washes was 9.5 seconds.

CONCLUSION

Compliance with hand washing recommendations was low in this ED. Nurses washed their hands significantly more often than either staff physicians or resident physicians, but the average hand-washing duration was less than recommended for all groups. Poor compliance in the ED may be due to the large number of patient contacts, simultaneous management of multiple patients, high illness acuity, and severe time constraints. Strategies for improving compliance with this fundamental method of infection control need to be explored because simple educational interventions have been unsuccessful in other health care settings.

Comparative in vivo efficiencies of hand-washing agents against hepatitis A virus (HM-175) and poliovirus type 1 (Sabin)

The abilities of 10 hygienic hand-washing agents and tap water (containing approximately 0.5 ppm of free chlorine) to eliminate strain HM-175 of hepatitis A virus (HAV) and poliovirus (PV) type 1 (Sabin) were compared by using finger pad and whole-hand protocols with three adult volunteers. A mixture of the two viruses was prepared in a 10% suspension of feces, and 10 microliters of the mixture was placed on each finger pad. The inoculum was allowed to dry for 20 min, and the contaminated area was exposed to a hand-washing agent for 10 s, rinsed in tap water, and dried with a paper towel. In the whole-hand protocol, the hands were contaminated with 0.5 ml of the virus mixture, exposed for 10 s to a hand-washing agent, washed, and dried as described above. Tryptose phosphate broth was used to elute any virus remaining on the finger pads or hands. One part of the eluate was assayed directly for PV with FRhK-4 cells, while the other part was first treated with a PV-neutralizing serum and then assayed for HAV with the same cell line. The results are reported as mean percentages of reduction in PFU compared with the amount of infectious virus detectable after initial drying.(ABSTRACT TRUNCATED AT 250 WORDS)

Is the use of boxed gloves in an intensive care unit safe?

PURPOSE

To identify the type, rate, burden, and pattern of contamination of boxed, clean but nonsterile gloves in our intensive care unit (ICU).

MATERIALS AND METHODS

The fingertips of the first, middle, and last two pairs of gloves in 29 boxes in routine service in our ICU were cultured. The first of each of these three sets were removed aseptically, the second in a routine fashion.

RESULTS

We found 16 of 29 (55%) first pairs removed aseptically to be contaminated with a mean bioburden of 1.8 colony-forming units (CFU). The percentage contamination and bioburden did not change significantly with position in the box. Use of routine compared with strict aseptic technique increased the rate of contamination by only 11% (95% confidence interval [CI] -0.05 to +0.27 percentage points) and bioburden by only a mean of 3.4 colonies per pair (CI -0.51 to +4.90 CFU). The length of the time the boxes were open and in use was unrelated to whether the final aseptically removed pair was sterile or contaminated. The predominant organisms were coagulase-negative staphylococci.

CONCLUSIONS

One half the pairs of latex examination gloves in our ICU were sterile despite repeated barehanded access to the boxes. Those contaminated exhibited a small bioburden of low pathogenic potential. No pattern of contamination or unsafe duration of box use were observed. The use of boxed, clean, nonsterile gloves appears safe for routine use in an ICU.

In vitro susceptibility of Streptococcus mutans to chlorhexidine and six other antimicrobial agents

The susceptibility of Streptococcus mutans to chlorhexidine and to six commonly used, systemic antibacterial agents (amoxicillin, cefuroxime, penicillin, sulfamethoxazole-trimethoprim, tetracycline, and erythromycin) was studied for 424 clinical isolates from 116 children and students. The MIC of chlorhexidine for all isolates was < or = 1 micrograms/ml. No resistance to the other antimicrobial agents was detected. Although widely exposed to various antimicrobial agents, S. mutans has remained susceptible to common antimicrobial agents, most importantly to chlorhexidine.

Ethical considerations in the use of subliminal stimulation to improve handwashing compliance: scientific utility versus autonomy of the individual

Nosocomial infections remain a significant problem for the healthcare system in the United States. At least 5% of patients will acquire an infection during their hospital stay, extending hospitalization by four days per infection, directly accounting for an estimated 60,000 deaths per year and an additional $10 billion of the amount spent on healthcare.

Previous studies have demonstrated that pathogenic bacteria can be recovered from the hands of healthcare workers and transmitted to patients. Moreover, a recent study has shown that hand carriage of organisms and subsequent contact may be the most important mechanism of nosocomial infection transmission in the intensive care unit setting.