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Biomedical subjects

G A Ayliffe

Publications and source records attributed to G A Ayliffe.

At least 19 recordsLinked to original sources
PubMed1991

Masks in surgery?

Explore the source record for details and available documents.

Clinical Trials as Topic↗
PubMed1991

A test procedure for evaluating surgical hand disinfection.

A technique for assessing the immediate and prolonged efficacy of surgical scrubs and alcoholic hand rubs is described. A mean baseline count is obtained from all volunteers and logarithmic reductions in resident skin flora immediately after one or more applications, and after wearing gloves for 3 h, are measured. Loose-fitting surgical gloves are used for sampling resident flora. Preparations were applied using a standard technique for 2 min, apart from one test with 70% isopropanol (IPA) in which the application time was 30 s. Two studies are described, one of which compared four chlorhexidine scrubs, and the second 70% IPA, 7.5% povidone-iodine scrub, 2% triclosan cleanser and unmedicated bar soap. In spite of their constituent similarity, the four chlorhexidine scrubs varied considerably in efficacy and user acceptability. A 2 min application of 70% IPA was the most effective treatment, and gave log10 reductions of 1.65 for immediate and 1.58 for prolonged effect. This was marginally more effective than a 30 s application, but the difference was not significant. 'Hibiscrub' was the most effective aqueous formulation and gave reductions of 1.01 for immediate effect and 1.16 for prolonged effect. The test described could be used by reference centres and manufacturers to assess the efficacy of new and existing surgical hand disinfection formulations.

Adolescent↗
PubMed1990

Acquired immune deficiency syndrome: recommendations of a Working Party of the Hospital Infection Society.

Unified procedures to control those infections that are transmitted by inoculation of blood are recommended. These should be applied to patients with acquired immune-deficiency syndrome (AIDS), AIDS-related complex, persistent generalized lymphadenopathy or hepatitis B, those with serological evidence of infection by human immunodeficiency virus or hepatitis B virus, and those in medical and social categories with a higher than average prevalence of such infections. When the identification of these categories of patient would be particularly difficult, the precautions should be applied to all patients, in situations of high risk for inoculation incidents. Rational infection-control measures, based on the known mode of spread, permit efficient management of infected patients, with satisfactory protection of staff and other patients.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Bacterial contamination and frequency of changing ventilator circuitry.

A questionnaire sent to 40 intensive care units showed that ventilator circuits were changed every 24 h in 62% and every 48 h in 20% of the units. A similar survey in 40 special-care baby units showed that only 9.7% changed circuits daily and the majority were changed weekly (38.7%) or between patients (38.7%). A prospective study of bacterial contamination of circuits in adult patients showed that when water humidification was used, 28/72 samples from inspiratory and 31/72 from expiratory tubing were contaminated with Gram-negative bacilli. None of 48 sets of tubing was contaminated when a heat-moisture exchanger was used and only one expiratory tube was contaminated in tubing from 45 neonates using a water humidifier. Gram-negative bacilli were isolated from the mouths of 21/36 adults and 6/12 neonates, and also from 6/17 hands of staff after changing circuits. It is suggested that circuits with water humidification may be changed every 48 h in adult patients, and between patients or weekly in neonatal units or between patients if a heat-moisture exchanger is used. Handwashing after removal of a circuit is of major importance in the prevention of spread of infection.

Bacterial Infections↗
PubMed1990

Hygienic hand disinfection tests in three laboratories.

A comparative study was made in three laboratories of a test for hygienic hand disinfection. Staphylococcus aureus was applied to the fingertips of a total of 74 volunteers (49 female and 25 male) and the effect of washing with three chlorhexidine preparations and one non-medicated soap was assessed after one and five applications. Fingertip inoculation is convenient and is a realistic representation of the in-use situation. Although significant differences were obtained between log10 reductions in test organisms using the same formulation in different centres, and different periods in the same centre, the maximum differences after a single application of a preparation were small, e.g. between centres 0.39 and between periods in the same centre 0.55, and after multiple applications the maximum difference between centres was 0.42 and between periods in the same centre it was 0.51. The differences between preparations were similar in all centres. This test compares well with other similar tests and products can be placed in rank order of effectiveness. It is concluded that this test, if carried out under the controlled conditions described, is sufficiently reproducible between laboratories and repeatable within laboratories to be used as a standard test.

Chlorhexidine↗
PubMed1990

Virucidal activity of disinfectants: studies with the poliovirus.

The activity of various disinfectants against poliovirus (Sabin 1 an) was assessed using surface and suspension tests. The surface test showed that 2% glutaraldehyde and high concentrations of hypochlorites (9200 ppm avCl2) were effective (i.e. greater than or equal to 4 log10 reduction) against a dried virus suspension in 1 min. Diluted aldehydes ('Sporicidin' and 'Gigasept'), lower hypochlorite concentrations (1000 ppm avCl2) and peroxides (3%) were less effective while 70% ethanol showed variable results; 70% isopropanol was ineffective in 10 min. In the suspension tests hydrogen peroxide (3% and 6%) and 70% ethanol were ineffective in 1 min.

Disinfectants↗
PubMed1989

An in vitro study of the antiviral properties of an alginate impression material impregnated with disinfectant.

The antiviral properties of a new alginate impression material impregnated with a disinfectant (didecyldimethyl ammonium chloride) were evaluated in vitro against herpes simplex virus type I and poliovirus type I. The material was exposed to the virus suspension for periods of up to 60 min. The impregnated alginate material showed no clinically acceptable effect against either virus, although log reductions of 1.0 and 1.7 plaque-forming units of herpes virus were obtained after exposure to the material containing the disinfectant for 5 and 60 min, respectively.

Alginates↗
PubMed1989

Bacteriological sampling of postmortem rooms.

Thirty hospital and coroners' postmortem rooms in the West Midlands were visited over two years. The design, environmental facilities, and hygienic practices were investigated and air exchange rates were measured. Microbiological samples were taken from the environment and from gloves, hands, and protective clothing of staff. Glove punctures were also recorded and a plastic isolator evaluated. Bacterial counts in the air were low and related more to the number of people in the room than to the air exchange rate. There was little evidence of the production of aerosol containing bacteria, although splashing occurred while intestines were being washed out. Surfaces often remained contaminated with Gram negative bacilli after cleaning but numbers were considerably reduced on drying. Decontamination of instruments was satisfactory. A wide range of disinfectants and concentrations was used, but none showed evidence of contamination. Gloves were heavily contaminated after use, and occasionally the hands of the wearer after removal of the gloves. Washing the hands effectively removed residual transient organisms, irrespective of the agent used. The incidence of glove punctures was higher among technicians (38%) than pathologists (12%). The plastic isolator reduced smells and limited environmental contamination but visibility and acceptability were poor. The results of the study suggest that there is little evidence of risk of infection to staff, providing basic hygienic precautions are taken, but consideration should be given to the prevention of glove punctures.

Air Microbiology↗
PubMed1988

Hand disinfection: a comparison of various agents in laboratory and ward studies.

The efficacy of 14 handwashing or disinfectant preparations was compared in laboratory tests on staff volunteers. The test organism, Escherichia coli, was applied to the fingertips and log reductions (LR) were measured following treatment with the test agent and control preparations (70% isopropanol and non-medicated bar soap). Alcoholic preparations, particularly n-propanol and isopropanol were the most effective showing LRs of 3.1-3.8. Chlorhexidine (LR 2.9) and povidone-iodine detergent preparations were significantly more effective than non-medicated soap (LR 2.1), but triclosan products were not. In addition the residual effect of several of these formulations was assessed after 10 applications by comparing the survival of E. coli on the fingertips over a 32-min period. This number of handwashes compares favourably with those recorded during an 8 h nursing shift. Chlorhexidine-detergent consistently showed the best residual activity. Alcoholic formulations showed little or no residual effect. The survival studies show that on the whole gram-positive organisms (Staphylococcus aureus and Candida albicans) survive better on the skin than Gram-negative bacilli (GNB). However, it would seem that GNB which are considered to be residents (Acinetobacter calcoaceticus and Enterobacter spp.) survive much better than many other GNB (Pseudomonas aeruginosa, E. coli and Proteus vulgaris). The Klebsiella species varied in survival times. Random sampling of ward staff hands showed that contamination with S. aureus and GNB was greater in dermatological and general wards than in an isolation unit, where handwashing or disinfection was carried out after every patient contact. No cross-infection occurred in the isolation ward during periods of study in which 70% alcohol, chlorhexidine-detergent and non-medicated soap were used.

Alcohols↗
PubMed1988

Infection control in the United Kingdom.

Most large acute hospitals have an infection control team, consisting of the infection control officier and nurse, which is responsible for day-to-day control of infection. The infection control officier is usually the medical microbiologist, a physician in charge of the microbiology laboratory, who is responsible to the Health Authority for control of infection. The team responsibilities usually include smaller hospitals, and long-term as well as acute-care facilities in each District. The infection control nurse is the only member of staff involved full-time in infection control. The infection control committee consists of managers of relevant departments, e.g. domestic, pharmacy, as well as infection control nursing and medical representatives, and usually meets 4-6 times a year. Advice or assistance is also available from national organisations, e.g. the Department of Health, the Communicable Diseases Surveillance Centre, reference laboratories and professional organisations such as the Hospital Infection Society, Infection Control Nurses Association and Central Sterilising Club.

Cross Infection↗