Aqueous Chlorhexidine Research Articles

Chlorhexidine Gel Versus Aqueous for Preventive Use on Umbilical Stump

Recent trials of chlorhexidine cord cleansing have employed aqueous solution applied with cotton swabs. Care-takers may prefer gel, resulting in better compliance when implemented at large scale. We examined whether a guar-gum-thickened formulation was at least as efficacious as aqueous in reducing periumbilical flora. Newborns (n = 694) from normal deliveries at a hospital in Kathmandu were randomly allocated to cord cleansing with either gel or aqueous chlorhexidine, applied by finger. Immediately before and 24 hours after cleansing, periumbilical swabs were collected and cultured. The primary outcome was periumbilical colonization at 24 hours. Household-level acceptability and ease of use in a rural setting where most deliveries are not attended by health workers were assessed by providing 61 women with either gel or aqueous formulations and following up on their experience using the products. Babies allocated to gel and aqueous chlorhexidine were comparable on a range of variables measured at baseline. At 24 hours postapplication, 4.6% (15 of 327) of cultures were positive in the gel group and 10.7% (35 of 326) in the aqueous group. The absolute difference in rates (gel minus aqueous) was -6.1% (95% CI: -10.2%, -2.1%). The acceptability study found that satisfaction and compliance were high for both; use of either largely displaced the traditional use of oil-based mixtures. Overall, there was a preference for gel. The gel formulation was not inferior to aqueous and gel reduced bacterial colonization to a greater degree. A gel formulation might be considered in future research or program settings where chlorhexidine cleansing of the cord is being evaluated or promoted.

Diagnóstico Precoce, Tratamento Conservador e Remissão Completa de Osteorradionecrose de Mandíbula - Relato de Caso

IntroductionOsteoradionecrosis (ORN) is characterized as one of radiotherapy's late adverse effects which causes great suffering and compromises patient's quality of life. The classical treatments for ORN are the hyperbaric therapy and surgery (mandibulectomy), quite expensive procedures with controversial indication. Conversely, the effectiveness of conservative treatments, such as topical chlorhexidine mouthwashes, is not well established in the literature. ObjectiveTo report the clinical case and the results in the conservative treatment and control protocols of the ORN in mandible established in a public health service. Case reporta black 45-year-old female patient was treated for squamous cell carcinoma in the past 3 years. She underwent partial glossectomy and adjuvant radiotherapy (7500Cg) on primary tumor area and neck. Patient was referred with a painful condition exhibiting multiple areas of bone exposure of about 2.5cm in its longest axis. Three-times a day mouthwashes with aqueous chlorhexidine gluconate solution 0.12% was prescribed for an indefinite period associated with rigorous oral hygiene and elimination possible oral irritants. Clinical follow was performed weekly until early response and monthly after this period. Two weeks after initial treatment there was complete remission of prodromal symptoms, and after six months sequestrectomy treatment was indicated under antibiotic prophylaxis. Total mucosa covered the bone defect 4 weeks after surgery. Discussion and ConclusionThe treatment was effective. The institution of conservative therapy avoided the necessity of hyperbaric therapy or surgical resection block (mandibulectomy). The results offered less morbidity to the patient and rationalization of the public health resources.

Centers for Disease Control and Prevention guidelines for preventing central venous catheter-related infection: Results of a knowledge test among 3405 European intensive care nurses*

To determine European intensive care unit (ICU) nurses' knowledge of guidelines for preventing central venous catheter-related infection from the Centers for Disease Control and Prevention. Multicountry survey (October 2006-March 2007). Twenty-two European countries. ICU nurses. Using a validated multiple-choice test, knowledge of ten recommendations for central venous catheter-related infection prevention was evaluated (one point per question) and assessed in relation to participants' gender, ICU experience, number of ICU beds, and acquisition of a specialized ICU qualification. We collected 3405 questionnaires (70.9% response rate); mean test score was 44.4%. Fifty-six percent knew that central venous catheters should be replaced on indication only, and 74% knew this also concerns replacement over a guidewire. Replacing pressure transducers and tubing every 4 days, and using coated devices in patients requiring a central venous catheter >5 days in settings with high infection rates only were recognized as recommended by 53% and 31%, respectively. Central venous catheters dressings in general are known to be changed on indication and at least once weekly by 43%, and 26% recognized that both polyurethane and gauze dressings are recommended. Only 14% checked 2% aqueous chlorhexidine as the recommended disinfection solution; 30% knew antibiotic ointments are not recommended because they trigger resistance. Replacing administration sets within 24 hrs after administering lipid emulsions was recognized as recommended by 90%, but only 26% knew sets should be replaced every 96 hrs when administering neither lipid emulsions nor blood products. Professional seniority and number of ICU beds showed to be independently associated with better test scores. Opportunities exist to optimize knowledge of central venous catheter-related infection prevention among European ICU nurses. We recommend including central venous catheter-related infection prevention guidelines in educational curricula and continuing refresher education programs.

The status of occupational safety among health service providers in hospitals in Tanzania

Occupational hazards exist wherever health care is practised. However, there is dearth of information on the status of occupational safety among hospital workers in Tanzania. This study was therefore carried to assess the current status of occupational health and safety (OHS) in Tanzanian hospitals and identify key areas for intervention. Data was collected using a self-administered questionnaire randomly distributed to the health service providers (HSPs) working in 14 district, regional and referral hospitals in Tanzania. A total of 430 HSPs (mean age = 42+/-8.8 years) were involved in the study. Female workers accounted for the majority (71%) of the respondents. None of the 430 respondents had received training on OHS as a profession. Most of the supervisors were holders of certificates (54.4%). Only 42.9% (6/14) of the hospitals, had at least a supervisor with post-graduate degree. Needlestick injuries accounted for the largest part of the most common accidents (52.9%); followed by splash of blood from patients (21.7%); burn injury from chemicals (10.6%); and slippery floors (5.9%). There was lack of qualified personnel for OHS in all hospitals. Most of the hazardous activities were carried out by nurses and attendants. Chemicals used in hospitals were mainly antiseptics and disinfectants, which causes skin burns during handling and use. Seminars and workshops were the major source (N = 429; 33%) of information on OHS. The seven major hazardous activities were injection, cleaning, patient care, bedding, dressing of wounds, medication and surgical operation. The largest proportion of HSPs involved in hazardous activities was found at referral hospitals. The mostly available antiseptics were 70-90% alcohol, 3% aqueous iodine, chlorhexidine gluconate and cetrimide. In conclusion, the OHS was observed to be inadequate in most workplaces in Tanzanian hospitals. Special efforts including training, exposure to information and creation of awareness, are recommended for improving occupational health and safety in hospitals in Tanzania.

Prospective Randomized Trial of 3 Antiseptic Solutions for Prevention of Catheter Colonization in an Intensive Care Unit for Adult Patients

To compare the effectiveness for prevention of central venous and arterial catheter colonization of 3 skin antisepsis with 1 of 3 antiseptic solutions: 10% aqueous povidone iodine (aqueous PI), 2% aqueous chlorhexidine gluconate (aqueous CG), and 0.5% alcoholic chlorhexidine gluconate (alcoholic CG). Prospective, randomized controlled trial. Intensive care unit in a teaching hospital. Patients were randomly assigned to 1 of the 3 skin antisepsis groups. The distal tips of catheters were semiquantitatively cultured when the catheters were no longer necessary or if there was a suspicion of catheter-related infection. Rates of catheter colonization, catheter-related sepsis, and catheter-related bacteremia were compared among the 3 groups. A total of 631 catheters were included in the study (194 from the aqueous PI group, 211 from the aqueous CG group, and 226 from the alcoholic CG group). The incidence of catheter colonization was significantly lower in the alcoholic CG than in the aqueous PI group (14.2% vs 24.7%; relative risk, 0.5 [95% confidence interval, 0.3-0.8; P < .01]); it was also significantly lower in the aqueous CG group than in the aqueous PI group (16.1% vs 24.7%; relative risk, 0.6 [95% confidence interval, 0.4-0.9; P = .03]). There were no significant differences between the aqueous CG and the alcoholic CG groups. Incidences of catheter-related bacteremia were similar for all 3 groups. The aqueous and alcoholic CG solutions were superior to the aqueous PI solution in preventing catheter colonization due to gram-positive bacteria. The aqueous and alcoholic CG solutions for cutaneous antisepsis were similarly effective in preventing colonization of central venous catheters and arterial catheters. Both had significantly lower incidences of colonization than did the aqueous PI solution; this effect seems to be related to the CG solutions' more efficacious prevention of colonization with gram-positive bacteria.

Penetration of Chlorhexidine into Human Skin

This study evaluated a model of skin permeation to determine the depth of delivery of chlorhexidine into full-thickness excised human skin following topical application of 2% (wt/vol) aqueous chlorhexidine digluconate. Skin permeation studies were performed on full-thickness human skin using Franz diffusion cells with exposure to chlorhexidine for 2 min, 30 min, and 24 h. The concentration of chlorhexidine extracted from skin sections was determined to a depth of 1,500 microm following serial sectioning of the skin using a microtome and analysis by high-performance liquid chromatography. Poor penetration of chlorhexidine into skin following 2-min and 30-min exposures to chlorhexidine was observed (0.157 +/- 0.047 and 0.077 +/- 0.015 microg/mg tissue within the top 100 microm), and levels of chlorhexidine were minimal at deeper skin depths (less than 0.002 microg/mg tissue below 300 microm). After 24 h of exposure, there was more chlorhexidine within the upper 100-microm sections (7.88 +/- 1.37 microg/mg tissue); however, the levels remained low (less than 1 microg/mg tissue) at depths below 300 microm. There was no detectable penetration through the full-thickness skin. The model presented in this study can be used to assess the permeation of antiseptic agents through various layers of skin in vitro. Aqueous chlorhexidine demonstrated poor permeation into the deeper layers of the skin, which may restrict the efficacy of skin antisepsis with this agent. This study lays the foundation for further research in adopting alternative strategies for enhanced skin antisepsis in clinical practice.

Intensive care nurses’ knowledge about the evidence-based guidelines of preventing centralvenous catheter related infection

To determine intensive care unit (ICU) nurses' knowledge of evidence-based guidelines for preventing central venous catheter (CVC) related infection. We used a validated multiple-choice questionnaire which was distributed to intensive care units between October and December 2006. We collected demographic data, like gender, years of ICU experience, number of ICU beds and whether respondents hold a special degree in intensive care. We collected 178 questionnaires from 11 intensive care units; the mean score was 3.66 on 10 questions (37%). Eighteen per cent knew that CVCs should be replaced on indication only, and 61% knew that this recommendation concerns also replacement over a guidewire. Recommendations for replacing pressure transducers and tubing every 4 days, and for using coated devices in patients requiring a CVC < 5 days in settings with high infection rates were recognized only by 48% and 66%, respectively. Regarding CVC dressings, 15% knew that these should be changed only when indicated and at least once weekly, and 35% recognized that both poly-urethane and gauze dressings can be recommended. Only 20% checked 2% aqueous chlorhexidine as recommended disinfection solution; 14% knew antibiotic ointments are not recommended because they trigger resistance. The recommendation to replace administration sets within 24 hours after administering lipid emulsions was recognized by 85%, but it was known by 5% only that these sets should be replaced every 96 hours when administering neither lipid emulsions nor blood products. Professional seniority and the number of intensive care beds in the ICU where nurses work showed not to be associated with better scores on the test. Knowledge regarding CVC-related infection is poor among Hungarian nurses. Prevention guidelines should be included in the nurse education curriculum as well as in continuing refresher nursing education programs.

The effects of surface preparation on the penetration of hydrocortisone through canine skin

This study investigated the effects of common skin surface preparations on the penetration kinetics of hydrocortisone through canine skin. Thoracic skin from five dogs was clipped of hair, divided between five treatment groups and prepared as follows: shaved (S); tape-stripped with adhesive bandage (TS); cleaned with aqueous chlorhexidine (Aq-C); cleaned with alcoholic chlorhexidine (Al-C); or allocated to the control group and had no further preparation performed (C). The skin samples were mounted in Franz-type diffusion cells and transdermal hydrocortisone penetration was measured over 30 h. The pseudo-steady-state flux ( J SS) of hydrocortisone through S, Al-C, Aq-C and TS skin was, respectively, 2.3 ( P = 0.021), 2.2 ( P = 0.037), 2.0 ( P = 0.070) and 1.5 ( P = 0.351) times greater than through the control skin, but there were no significant differences in the lag times ( t lag) for hydrocortisone penetration between the groups. The study has shown that some skin surface preparations can significantly increase the subsequent penetration of hydrocortisone through canine skin in vitro.

Disinfection of gutta-percha cones with chlorhexidine

This study investigated the effectiveness of detergent and aqueous solutions of 2% chlorhexidine digluconate in decontaminating gutta-percha cones (gpc) contaminated with bacteria, yeast, or bacterial spores. Gutta-percha cones were contaminated with 107-108 colony-forming units per milliliter (cfu/ml) of the following test organisms: Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, or Candida albicans. Spores of Bacillus subtilis were also tested. Contaminated gpc were treated with the chlorhexidine solutions for 1, 5, 10, or 15 min. Each cone was then transferred to a tube containing saline and the micoorganisms were recovered after homogenization for cfu determination. Both detergent and aqueous chlorhexidine solutions were effective in eliminating S. aureus, E. faecalis, and C. albicans cells adhered on the surface of gpc within 1 min of exposure. E. coli was eliminated in 5 min with detergent solution. The Bacillus subtilis spores were eliminated by chlorhexidine solutions within 5 min. The results of this study demonstrated that both aqueous and detergent solutions of 2% chlorhexidine digluconate were effective in decontaminating gpc within 5 minutes of exposure.

Tolérance clinique des antiseptiques cutanés chez 3 403 malades en pratique de ville

We prospectively studied the prevalence and the clinical forms of adverse cutaneous reactions associated with the main antiseptics used in France, the incidence of which is not well known. Patients were included by 773 French dermatologists from May to June 2003. The 8 first consecutive adult patients for whom ambulatory treatment with a cutaneous antiseptic was prescribed were included. Patients were evaluated at inclusion and after treatment, either in person or by telephone. All reported adverse cutaneous reactions were validated by two independent experts. 3,403 patients (61% women, 39% men; mean age: 47) were included. Antiseptics were indicated for ambulatory surgery (45%), technical procedures (33%), and in combination with other treatments for various dermatoses, wounds and burns (12%). The 6 most widely used treatments (96% of prescriptions) were hexamidine (37%), chlorhexidine-benzalkonium (28%), chlorhexidine-alcohol (16.5%), aqueous chlorhexidine (7%), polyvidone iodine (6%) and hexamidine-chlorhexidine (1.8%). The antiseptic was prescribed for application by dabbing (57%) or spraying (40%), twice daily for a mean 10 days (3-30 days). A transient burning sensation was noticed by 4 to 7% of the patients, without any significant difference between antiseptics. Twelve adverse events were reported: contact dermatitis in 9 patients, persistent burning sensation in 2 and yellow discoloration of the skin in one. This latter case, caused by the colour of the antiseptic, cannot be considered as an adverse event. Furthermore one patient with contact dermatitis should have not been included because he had a history of cutaneous reaction related to the use of the same antiseptic. Therefore only 10 cutaneous reactions were eventually taken into account (overall prevalence=2.9 per thousand, ranging from 0% to 0.5% according to the antiseptic). There was no significant difference in terms either of the antiseptic used or the site of the treated lesion. A history of contact dermatitis was associated with a significant risk of adverse reaction (OR=7.2; CI 95: 2.0-26.4; p=0.007). The median time from onset of treatment to appearance of contact dermatitis was 4 days (0-90 days). The condition resolved following discontinuation of treatment; spontaneously in 5 patients and with dermocorticoid therapy in 5 others. The results of this study give a precise idea of how the antiseptics are used by French dermatologists in clinical practice in outpatients and how often their use is complicated by the occurrence of adverse cutaneous reactions. The low rate of such reactions (2.9 per thousand) in our study is thus in contrast with the impression given by the large number of publications related to this complication. It also tempers the high rates of sensitisation to various antiseptics found in selected at-risk patients. The most common adverse event observed was contact dermatitis and a history of this condition conferred a significant risk of cutaneous reaction. Although cutaneous antiseptics are well tolerated with a low prevalence of adverse reactions, generally mild, they should nevertheless be prescribed with caution in patients with a history of contact dermatitis.

Effectiveness of a calcium hydroxide and chlorhexidine digluconate mixture as disinfectant during retreatment of failed endodontic cases

The purpose of this in vivo investigation is to compare the effect of a slurry of Ca(OH)2 mixed in aqueous 2% chlorhexidine (CHX) versus aqueous Ca(OH)2 slurry alone on the disinfection of the pulp space of failed root-filled teeth during endodontic retreatment. Forty single-rooted previously root-filled teeth with associated periradicular lesions were included. The teeth were nonsurgically retreated and medicated over 3 treatment visits with 7-10-day intervals with either Ca(OH)2 in water or Ca(OH)2 in 2% aqueous CHX. Root canal cultures were collected in fluid thioglycollate, and bacterial growth was assessed by turbidity daily for 1 week, then weekly for an additional 3 weeks. The presence of enterococci in the root canals at the initial treatment session was determined. Of the total sample population, 12 of 40 (30%) were positive for bacteria before root filling. The control medication disinfected 12 of 20 (60%) teeth including 2 of 4 teeth originally diagnosed with enterococci. The experimental medication resulted in disinfected 16 of 20 (80%) teeth at the beginning of the third appointment. None of the teeth originally containing enterococci showed remaining growth. This difference between the overall positive cultures was not statistically significant (P > .05). Canal dressing with a mixture of 2% CHX and Ca(OH)2 slurry is as efficacious as aqueous Ca(OH)2 on the disinfection of failed root-filled teeth.

Prospective evaluation of a multi-factorial prevention strategy on the impact of nosocomial infection in very-low-birthweight infants

The aim of this study was to examine the impact of a multi-factorial intervention on nosocomial infection in very-low-birthweight infants. Consecutive infants with a birth weight less than 1500 g, born between February 2002 and February 2003, were included in this prospective study. The first six-month period (control) included surveillance of current practice. The intervention began in the seventh month and included: (i) changes to handwashing solutions with hand hygiene education; (ii) standardization of intravascular device (IV) insertion with specialized packs; (iii) changes to skin antiseptic solutions (2% aqueous chlorhexidine and 1% chlorhexidine in ethanol); and (iv) mandatory removal or replacement of peripheral IV after 48 hours and removal once enteral intake was > 120 mL/kg/day. Demographic data and details of every device were collected prospectively. Bloodstream infections (BSIs), length of stay (LOS), length of ventilation (LOV) and death were recorded and the rate of nosocomial BSI was calculated. Overall, 174 newborns required 1359 devices. The two cohorts were similar for birth weight and gestation. There was a reduction in nosocomial BSIs from 21% to 9% (control vs. intervention) (P = 0.05, confidence intervals 0.19-1.0). There was no significant difference in LOS, LOV, or mortality. Four infants had complications from 2% chlorhexidine. In conclusion, implementation of the multi-factorial prevention strategy reduced nosocomial BSIs. Alternative antiseptic solutions are needed to reduce the complications caused by 2% aqueous chlorhexidine.

The effect of a polyhexamethylene biguanide mouthrinse compared with a triclosan rinse and a chlorhexidine rinse on bacterial counts and 4‐day plaque re‐growth

For various clinical applications, polyhexamethylene biguanide hydrochloride (PHMB) has been used for many years as an antiseptic in medicine. Recently, a 0.04% and a 0.12% PHMB mouthwash were shown to inhibit plaque re-growth and to reduce oral bacterial counts. In this study, a 0.2% PHMB mouthrinse (A) was compared with a positive control 0.12% aqueous chlorhexidine solution (B), a commercially available 0.3% triclosan/2.0% polyvinyl methyl ether maleic acid copolymer mouthrinse (Colgate Total Plax) (C), and a negative control placebo rinse (10% ethanol, flavour) (D). The controlled clinical study was a double blind, randomized, four replicate cross - over design. Plaque re-growth was assessed with the Turesky et al. (1970) modification of the Quigley & Hein (1962) plaque index. The antibacterial effect was assessed by taking bacterial counts on the tooth surface (smears from the buccal surface of 16/26) and mucosa (smears from the buccal mucosa in opposite of area 16/26) after the professional prophylaxis and after the first rinse with the preparations on day 1 and prior to the clinical examination on day 5. Sixteen volunteers participated and, on day 1 of each study period were rendered plaque-free, ceased toothcleaning, and rinsed twice daily with the allocated mouthrinse. On day 5, plaque was scored and smears were collected according to the protocol. A 10-day wash-out period was carried out between each rinse evaluation. Data were analysed using ancova with Bonferroni HSD adjustment for multiple comparisons (colony forming units per sample) with a significance level alpha=0.05. The 0.2% PHMB mouthrinse (A) was significantly better at inhibiting plaque than the placebo (D), but significant less effective than the 0.12% aqueous chlorhexidine solution (B). There is no significant difference between A and the 0.3% triclosan/2.0% copolymer mouthrinse (C). Bacterial count reductions (tooth surface and mucosa) with PHMB (A) were significantly greater compared with the placebo (D) and triclosan (C), but significantly lower compared with chlorhexidine (B) (tooth surface) and equally effective compared with chlorhexidine (B) (mucosa). Consistent with previous studies, a PHMB mouthrinse was shown to inhibit plaque re-growth and to reduce oral bacterial counts, indicating that PHMB could be an alternative to established mouthrinses in preventive applications.

Applied physiology: the newborn skin

The most important function of the skin is to provide a protective barrier between the body and the environment. It limits loss of body water, prevents absorption of noxious agents and protects against physical trauma. The epidermal barrier begins to develop in mid-gestation and is fully formed by about 32 weeks gestation. In the extremely preterm infant, it is poorly formed and functionally weak. Exposure to air after birth accelerates epidermal development. Transepidermal water loss is high in the immature infant, causing difficulties in fluid balance and temperature control. The percutaneous absorption of topically applied agents may lead to accidental poisoning. Adhesive trauma strips the epidermis, predisposing to infection. These problems can be minimized by limiting the use of skin probes and adhesive tape, nursing the infant in a high ambient humidity and sparing use of aqueous chlorhexidine as an antiseptic. The routine use of emollients or skin coverings is not recommended.

Evaluation of chlorhexidine and povidone iodine activity against methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus faecalis using a surface test

Most published studies of the activity of biocides against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) have been based on suspension tests. This study was undertaken to provide information on the effect of chlorhexidine and povidone iodine on bacteria dried on to surfaces, a situation in which biocide activity is known to be reduced. The inactivation of MRSA (10 strains), methicillin-sensitive Staphylococcus aureus (MSSA, 10 strains), VRE (nine strains) and vancomycin-sensitive Enterococcus faecalis (VSE, 10 strains) by 0.5% aqueous chlorhexidine gluconate or 10% povidone iodine was evaluated by applying the European surface test method. Povidone iodine was equally active against resistant and sensitive strains of both species with microbicidal effects (ME), i.e. the log10concentration of micro-organisms compared with controls treated with distilled water, after 1.5 min of 3.14 and 3.49 for VRE and VSE respectively, and 3.47 and 3.78 for MRSA and MSSA. Chlorhexidine was equally active against VRE and VSE (ME 3.37 vs. 3.56 after 7 min, respectively), but was significantly less active against MRSA as opposed to MSSA (ME 3.07 vs. 3.83 after 10 min, P= 0.017).

Chlorhexidine and chondrolysis in the knee.

We have summarised the clinical and pathological changes in the knees of three patients in whom aqueous chlorhexidine 0.02% had been used as the irrigation solution during arthroscopically-assisted reconstruction of the anterior cruciate ligament. Even very dilute solutions of chlorhexidine can cause marked chondrolysis of articular cartilage leading to severe permanent damage to the knee. Irrigation solutions should be checked carefully to ensure that their composition is appropriate to the procedure being carried out. Exposure of articular cartilage to chlorhexidine should be avoided.

Chlorhexidine and chondrolysis in the knee

We have summarised the clinical and pathological changes in the knees of three patients in whom aqueous chlorhexidine 0.02% had been used as the irrigation solution during arthroscopically-assisted reconstruction of the anterior cruciate ligament. Even very dilute solutions of chlorhexidine can cause marked chondrolysis of articular cartilage leading to severe permanent damage to the knee. Irrigation solutions should be checked carefully to ensure that their composition is appropriate to the procedure being carried out. Exposure of articular cartilage to chlorhexidine should be avoided.

Treatment of HIV-associated periodontal diseases.

Three presentations of periodontal disease are associated with HIV infection: necrotising periodontal disease; forms of atypical gingivitis and exacerbated attachment loss. Necrotising disease resembling aggressive acute necrotising ulcerative gingivitis and is the most acute and painful of these. Response to treatment by debridement of lesions, irrigation with aqueous chlorhexidine solution and oral metronidazole 200 mg, tds is almost diagnostic of the condition. Affected individuals are prone to relapse. Prevention by meticulous home care and frequent hygiene recalls is advised. The forms of atypical gingivitis are classically not plaque related. This means that persistence of gingivitis in the absence of plaque is required to establish the diagnosis. There is a consensus that these diseases are related to candidiasis. Treatment with antifungals may be contraindicated due to the emergence of resistant strains of Candida spp. Exacerbated attachment loss may be the legacy of repeated episodes of necrotic disease or may be due to accelerated periodontitis. In either event the principles of treatment are to encourage and facilitate plaque removal.

Dissemination of Bacillus cereus in an intensive care unit.

To report the contamination of ventilator equipment with Bacillus cereus and to outline the measures taken to trace the source of the organism. A prospective survey of all intensive care unit patients who were culture-positive for B cereus and obtaining of environmental cultures of the cleaning and assembly area of the respiratory services division between October 1991 and September 1992. Ventilated patients from a 16-bed medical and surgical intensive care unit (ICU) in a 1,000-bed adult tertiary care hospital. From October 1991 to April 1992, B cereus colonized the ventilator circuitry of patients in the ICU. One of two washer/decontaminators in the cleaning and assembly area of the respiratory services division was found to yield the microorganism consistently from the water intake port. The design of the machine precluded easy decontamination of the port with 2% glutaraldehyde and a second outbreak occurred. Following the second outbreak, aqueous chlorhexidine in a final concentration of 0.05% was added to the first of two pasteurization cycles in an attempt to achieve sporicidal activity. This ended the outbreak. Sixty-two patients became colonized with the organism including two with nonfatal Bacillus sepsis and one death due to pneumonia associated with the organism. This experience emphasizes the importance of obtaining cultures of machine parts to identify the source of contamination and thereby direct control measures. Use of chlorhexidine gluconate at high temperatures effectively eradicated B cereus from ventilator circuitry in a practical and cost-effective manner.

Effects of chlorhexidine gluconate douche on normal vaginal flora.

The effects of a 0.5% aqueous chlorhexidine gluconate (CHG) douche on the normal vaginal flora of twenty healthy nonpregnant volunteers were investigated. The douche was applied in a premeasured 180-ml quantity daily for 7 consecutive days. Specimens for aerobic and anaerobic culture of the vaginal flora were obtained on 3 occasions from each volunteer, once before and twice after CHG use. The culture results were analyzed qualitatively and quantitatively. A blood sample was also collected within 24 h of the last CHG application to determine serum CHG concentration. Lactobacillus spp., Gardnerella vaginalis and Staphylococcus epidermidis were the most prevalent aerobic bacteria at all phases of the study and Bacteroides spp. were the most prevalent anaerobes. The composition of the normal flora was essentially the same 30 days after the last dose as the pretreatment flora. Small amounts of CHG were detected in the serum of all but one subject. No untoward effects on the participants were observed. Candida albicans counts were slightly higher, but prevalence was not significantly increased at the end of the study.