Hygienic hand disinfection for the removal of epidemic vancomycin-resistant Enterococcus faecium and gentamicin-resistant Enterobacter cloacae

An outbreak strain of Enterococcus faecium, bearing plasmid-mediated vancomycin resistance, and an epidemic gentamicin-resistant, multiply-resistant strain of Enterobacter cloacae, both survived well on fingertips of three volunteers for up to 30 minutes after inoculation. Hand disinfection of inoculated fingers with 60% isopropyl alcohol, or with alcoholic chlorhexidine, reliably gave a 4 log10 reduction of both test organisms. Enterobacter cloacae could not be detected in any finger washings, even by enrichment culture. Chlorhexidine digluconate and povidone-iodine were also effective against E. faecium and Ent. cloacae, giving 4 log10 reductions, but finger washings taken after disinfection yielded low counts of the test strains, e.g. less than 45 recoverable colony forming units (cfu) per finger. Handwashing with soap and water was the least reliable method. The epidemicity, serious antimicrobial multiple resistance and survival on finger-tips of these two strains justifies the use of handwashing agents which have maximum effect. The rapid bactericidal (and residual) activity of alcoholic chlorhexidine suggests that, on the basis of present evidence, it is the preferred agent for hygienic hand disinfection against such strains.

Microprocessors for auditing the surveillance activity of the Infection Control Nurse

An important part of the Infection Control Nurse's activity in the UK is the laboratory-based surveillance of patients with infections that are known to be transmissible, i.e. of 'alert' organisms. We have replaced a manual 'T-card' system in which relevant patient information, microbiology and nursing notes are held on all patients yielding 'alert' organisms. The programme is menu driven, requires minimal coding and runs on a microprocessor with a hard disc. The programme enables surveillance patient information to be entered, edited, archived and recorded. Instant retrieval on screen or hard copy includes summarized or full displays of all patients on all wards, sorted by wards, organism, date or risk category. Archived data may be retrieved within minutes and this avoids having to interrogate the whole laboratory database overnight. To illustrate an additional use of the data stored, we analysed the surveillance activities of the Control of Infection Nurse for one year. Of 203 laboratory diagnoses requiring patient surveillance, 30% were viral infections, of which more than two-thirds were caused by hepatitis B virus; of the 142 bacterial isolates, 27% were multiply antibiotic-resistant Enterobacteriaceae, 25% Pseudomonas spp, 12% Salmonella spp., 9% methicillin-resistant Staphylococcus aureus (MRSA), 7% Group A streptococci and 8% meningococci. These isolates resulted in only four outbreaks involving nine patients or staff. This information has proved useful for auditing the nurse's activity and provides evidence for the cost-effectiveness of infection control.

Visual status of industrial workers

Two hundred and eighty four industrial workers were screened to determine their visual acuity. Significant visual impairment was observed in 21.8% individuals and moderate impairment in 34.5% of cases. Convergence insufficiency was a problem in 9.86% of the workers. Since uncorrected refractive errors are a prelude to disastrous workplace related eye injuries, it is recommended that prior to job placement all workers undergo visual acuity screening and get their refractive errors rectified.

The survival of Acinetobacter calcoaceticus inoculated on fingertips and on formica

When inoculated on the fingers of three volunteers, strains of Acinetobacter calcoaceticus var. anitratus survived better than strains of var. lwoffii; 60 min after an inoculum of 10(4) cfu/finger, washings yielded between 2.6 x 10(1) (for a sporadic strain of var. lwoffii) and 7.2 x 10(2) cfu/finger (for an epidemic strain of var. anitratus). All five test strains survived better on formica than on skin, and from an inoculum of 10(4) cfu, between 6.4 x 10(2) and 2.2 x 10(3) cfu/finger were recoverable 60 min later. After inoculation of formica sheets, both strains of var. lwoffii could still be recovered in low numbers 24 h later, and two of the three strains of var. anitratus 60 h later. These findings suggest the presence of hitherto unrecognized antibacterial activity of skin against Acinetobacter calcoaceticus and suggest that outbreaks may be sustained by hand transmission. The ability of these organisms to survive desiccation on formica supports the proposal that transmission by air, dust or fomites may hitherto have been underestimated for this species.

A new system for the measurement of ocular motility using a personal computer

A new system (automated Hess screen, AHS) for the measurement of ocular motility using a personal computer is described. The subject is seated with his/her head restrained at a fixed distance from a colour monitor and views the screen through red/green goggles. A red target is displayed on the screen and the subject is instructed to move a green stimulus (using a joystick control) until the stimulus appears to be centred on the target. A button on the joystick is pressed and the computer registers the relative position of the target and stimulus. This procedure is repeated for a range of target locations (positions of gaze) and the entire routine is then repeated with the other eye fixing, by reversing the colour of the target and stimulus. The oculomotor fields may be displayed on the screen, printed, plotted or saved on a magnetic disc. A prototype system (based on an IBM AT with a 20 in monitor viewed from 25 cm) has been evaluated in a clinical environment on a sample of patients with a wide range of oculomotor problems, and compared with the electronic Hess screen (EHS). In general, the shapes of the oculomotor fields obtained using the two instruments were similar, but the AHS tended to measure a slightly converged displacement of the plots relative to the EHS and to record larger deviations, particularly in patients with incomitant fields. However, the test-retest reliability and the diagnostic value of the charts obtained were similar for both instruments. There was no significant difference between the durations of the examinations with the EHS and AHS. The AHS is a viable alternative to the EHS.

Heart rate and blood pressure changes during postural change and isometric handgrip exercise in patients with panic disorder and normal controls

Changes in heart rate (HR) and blood pressure (BP) were measured serially during postural changes and isometric hand grip exercise test (IHT) in 30 patients with panic disorder and 30 normal controls. Though there were no significant differences in the delta increase of HR or systolic or diastolic BP during these tests, the resting supine and standing diastolic BP were significantly higher in panic disorder patients than in controls. The standing mean BP was also significantly higher in panic disorder patients. These findings are suggestive of an increase in adrenergic tone in panic disorder patients.

Possible effect of lactational period on the milk-to-plasma drug concentration ratio in lactating women: results of an in vitro evaluation

The fat and protein composition of human milk changes dramatically in the first several weeks postpartum. In order to investigate the possible effect of this compositional change on the milk-to-plasma drug concentration ratio (M/P), the following experiment was performed. Milk samples were collected from five healthy lactating women on days 3, 5, 7, and 14 postpartum; blood samples were obtained on these days, as well as on day 1. Serum and skim milk unbound fractions (fp and fm, respectively) and the skim milk-to-whole milk drug concentration ratio (S/M) were determined in vitro in the above samples for diazepam, propranolol, and etretin, an aromatic retinoid. In addition, the composition of these milk and serum samples was also assessed. Using a previously proposed mathematical model for the distribution of drugs between milk and plasma, M/P was calculated from values for fm, fp, S/M, milk pH, and literature values for the pKa values of the compounds. The M/P was calculated for each subject on each day of sample collection. Total serum protein and alpha-1-acid glycoprotein (AAG) levels increased in the first two weeks postpartum. Mean diazepam fp values fell from 0.020 to 0.014 during this period, while propranolol fp values changed inversely with serum AAG levels. Milk whey and total proteins decreased as lactation progressed, but changes in fat levels were not statistically significant. Calculated propranolol M/P increased during the study period, predominately due to changes in milk pH and propranolol S/M.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased alpha-adrenergic responsiveness in idiopathic Raynaud's disease

In our study of 28 patients with idiopathic Raynaud's disease, the patients had significantly greater digital blood flow responses to intraarterial phenylephrine and clonidine than did normal control subjects. There were no group differences in finger blood flow responses to body heating, reflex cooling, digital ischemia, or to intraarterial tyramine or isoproterenol. There were also no group differences in blood pressure or heart rate during any procedure. These results suggest that patients with idiopathic Raynaud's disease have increased peripheral vascular alpha-adrenergic receptor sensitivity and/or density compared with normal persons.

A laboratory model for testing agents for hygienic hand disinfection: handwashing and chlorhexidine for the removal of klebsiella

A model for the laboratory assessment of hygienic hand disinfection is described which closely reproduces handwashing in a ward setting. The model uses a clinically relevant test organism and takes into account the natural antibacterial action of the skin. It also provides a means of measuring any residual antibacterial action after hand disinfection. Using an epidemic multiply-resistant strain of Klebsiella aerogenes K21, 0.5% chlorhexidine in iso-propyl alcohol yielded sterile post-disinfection finger washings more often than 4% chlorhexidine digluconate. Both preparations were more effective than soap and water, and with each residual action was demonstrable. The model is applicable to the laboratory evaluation of hygienic hand procedures and for agents of potential use in defined clinical settings.

Training general practitioners in psychiatry - a new venture

Formal training programmes in psychiatry for general practitioners (GPs) by Psychiatrists so far reported have involved MBBS graduates. But, a considerable proportion of registered medical practitioners who serve the community are non-MBBS about whose training needs, no experience is yet available. This paper describes a training programme in which an attempt was made to know the training needs of the non-MBBS GPs and also to assess the potential of the previously trained GPs to complementarily assist the psychiatrists in such training programmes.

Nonneural beta-adrenergic vasodilating mechanism in temperature biofeedback

Although finger temperature feedback has been used to produce digital vasodilation in normal persons and those with Raynaud's disease, the mechanism and site of this effect have not been studied. In the present investigation, feedback-induced vasodilation was attenuated by brachial artery infusions of propranolol in infused, but not contralateral, hands and was not affected by digital nerve blockade. Quantitative measurements of finger blood flow demonstrated that this vasodilation occurred in arteriovenous shunts in normal persons and in the finger capillary bed in those with Raynaud's disease. Raynaud's disease patients who received finger temperature feedback reported 80 fewer percent symptoms 1 and 2 years after treatment and retained the ability to increase finger temperature and capillary blood flow at these times. These effects were not shown by patients given autogenic training, a relaxation procedure.

Sex differences in peripheral vascular adrenergic receptors

Although the incidence of many vascular diseases differs in men and women, sex differences in vascular physiology have not been extensively examined in human in vivo studies. The present study compared finger blood flow responses of normal men and women with brachial artery infusions of adrenergic agonists and with other neurally and nonneurally mediated procedures. In response to phenylephrine and clonidine, men showed significant dose-related vasoconstriction while women did not. In response to isoproterenol, men showed significant dose-related vasodilation while women did not. There were no sex differences in response to intra-arterial nitroglycerin or digoxin or to reactive hyperemia, procedures that do not act through adrenergic receptors. These data show that the sensitivity and/or density of peripheral vascular adrenergic receptors is lower in women than in men. There were no sex differences in response to reflex vasoconstriction or to intra-arterial tyramine, suggesting that neurally released norepinephrine acts at alpha-adrenergic receptors that are spatially removed from those that respond to circulating catecholamines.

Clinical and biochemical variation and family studies in the multiple acyl-CoA dehydrogenation disorders

We report clinical and biochemical studies in patients with multiple acyl-CoA dehydrogenation disorders (MAD) and their parents. A severely affected (MAD:S) patient presented with neonatal acidosis leading to death and excreted a wide range of straight- and branched-chain acyl CoA derivatives. Two patients with mild variants of the same disorder (MAD:M) presented with neurologic abnormalities, acidotic coma, and/or poor growth; they primarily excreted ethylmalonate and variable amounts of adipate. Fibroblasts from the MAD:S patient demonstrated severely defective radiolabeled substrate oxidation, while the MAD:M cells had milder oxidative defects. Fibroblasts from two other MAD:M and six other MAD:S patients demonstrated analogous defects in substrate oxidation. As a group, MAD:S cells deficient in electron transfer flavoprotein:ubiquinone oxidoreductase had significantly lower residual oxidative activities than did MAD:S cells deficient in electron transfer flavoprotein. Fibroblasts from the parents of four MAD:S patients oxidized radiolabeled substrates significantly less effectively than did normal infant controls but were indistinguishable from normal adult cells. We found relatively higher residual oxidative activities in maternal than in paternal cells. Amniocytes from a fetus at risk for MAD:S catabolized labeled substrates normally; the infant has been clinically and biochemically normal up to 30 months of age.

Factors affecting the milk-to-plasma drug concentration ratio in lactating women: physical interactions with protein and fat

The factors that affect M/P (milk-to-plasma) ratios of several compounds were assessed in vitro using samples collected from four healthy lactating women. Three drugs were studied: diazepam, phenytoin, and propranolol. Serum and skim milk protein binding were determined by equilibrium dialysis at 37 degrees C. Skim-to-whole milk concentration ratios (S/M) were determined after incubation of whole milk at 37 degrees C for 1 h. Free fractions in serum and skim milk, respectively, were 0.013 and 0.334 for diazepam, 0.142 and 0.584 for phenytoin, and 0.107 and 0.699 for propranolol. The S/M values were 0.220, 0.727, and 0.610 for diazepam, phenytoin, and propranolol, respectively. An equation was derived which relates M/P to milk and plasma pH, unbound fractions of drug in skim milk and serum, and S/M. The M/P ratios calculated from in vitro data agreed with published in vivo M/P ratios. The results indicated that milk protein binding and fat partitioning can make a substantial contribution in determining M/P, and predictions of M/P made without considering these factors may be misleading.

The use of the Reuter centrifugal air sampler for the estimation of bacterial air counts in different hospital locations

The convenience and portability of the Reuter centrifugal air sampler (RCS) encouraged us to determine a range of 'expected values' for bacterial air counts in nine hospitals at 13 defined locations. Results were recorded as the number of cfu per strip per 4 min. Bacterial air counts were comparable from hospital to hospital; in operating theatres the overall median RCS counts for air-inlets and in empty operating rooms were 13 and 9.8 cfu per strip per 4 min respectively. For surgical wards the median value was 141 and 180 cfu per strip per 4 min with, and without, air conditioning. Increased counts were readily demonstrated during surgical operations, and during bedmaking in wards. Conversion of RCS counts to cfu m-3 of air usually yielded values higher than those established by other methods. Our findings, however, demonstrate that this instrument may replace some of the applications of the slit sampler and facilitate examination of epidemiological problems.

Pancreatic polypeptide in cystic fibrosis

Patients with cystic fibrosis (CF) and their normal siblings and parents were studied for protein meal-stimulated pancreatic polypeptide (PP) secretion. Patients with CF who had exocrine pancreatic insufficiency did not respond to a protein meal, whereas patients with CF and normal pancreatic function presented relatively well-preserved basal and elevated postmeal PP levels. The siblings responded with relatively lower PP levels compared with the control subjects. Plasma insulin levels were also investigated, and showed sluggish initial-phase but relatively well-preserved insulin responses in the patients with CF. Immunocytochemical and morphometric studies were made of pancreata obtained at autopsy from patients with CF. In the patients younger than 7 years of age, well-preserved islet tissue was disclosed by islet-area morphometry with normal and/or below-normal PP cell counts, whereas patients older than 9 years had relatively less insulin-containing islet tissue and scanty PP cells. Absent PP secretory response in patients with CF who had exocrine pancreatic insufficiency may suggest defects in the PP secretory mechanism. Abnormal PP secretion may be used as an indirect index of pancreatic damage in CF.

Optimisation of protein synthesis rates in reticulocyte lysates and reconstituted systems

Means of increasing the very low activity of a reconstituted protein synthesising system from rabbit reticulocytes were investigated. Increasing the concentration of labelled amino acid, addition of polyamines, use of Sepharose-filtered as opposed to centrifuged ribosomes, use of untreated as opposed to gel-filtered cytosol and an increase in ratio of cytosol to ribosomes all contributed to the increase in activity of the system to the point where activity was clearly consistent with initiation taking place. Similar activities could not be attained with rat liver cytosol though rat liver ribosomes incorporated well in reticulocyte cytosol. Incorporation by lysates was also found to be dependent on the concentration of the labelled amino acid added.

Cephalexin for the oral treatment of CAPD peritonitis

Sixteen episodes of peritonitis in 13 patients undergoing continuous ambulatory peritoneal dialysis (CAPD) were treated with oral cephalexin given at each 6-hourly dialysate exchange. Serial measurements of the antibiotic concentration in serum and dialysate were made in seven cases. Cephalexin levels increased rapidly and by 12 h exceeded 27 mg/l in serum and 20 mg/l in dialysate. Dialysate levels considerably exceeded the minimum bactericidal concentration for organisms considered cephalexin-sensitive and in patients with these the clinical response was usually good. Although dialysate concentrations sometimes reached the minimum inhibitory concentration for organisms considered cephalexin-resistant the clinical response in patients from whom resistant bacteria were cultured was unsatisfactory. Intra-peritoneal antibiotic administration would seem unnecessary in many CAPD patients with peritonitis.