First UK trial of Xenex PX-UV, an automated ultraviolet room decontamination device in a clinical haematology and bone marrow transplantation unit.

BACKGROUND: There is growing interest in the use of no-touch automated room decontamination devices within healthcare settings. Xenex PX-UV is an automated room disinfection device using pulsed ultraviolet (UV) C radiation with a short cycle time. AIM: To investigate the microbiological efficacy of this device when deployed for terminal decontamination of isolation rooms within a clinical haematology unit. METHODS: The device was deployed in isolation rooms in a clinical haematology unit. Contact plates were applied to common touch points to determine aerobic total colony counts (TCCs) and samples collected using Polywipe™ sponges for detection of vancomycin-resistant enterococci (VRE). FINDINGS: The device was easy to transport, easy to use, and it disinfected rooms rapidly. There was a 76% reduction in the TCCs following manual cleaning, with an additional 14% reduction following UV disinfection, resulting in an overall reduction of 90% in TCCs. There was a 38% reduction in the number of sites where VRE was detected, from 26 of 80 sites following manual cleaning to 16 of 80 sites with additional UV disinfection. CONCLUSIONS: The Xenex PX-UV device can offer a simple and rapid additional decontamination step for terminal disinfection of patient rooms. However, the microbiological efficacy against VRE was somewhat limited.

Outbreak of invasive group A streptococcus infection: contaminated patient curtains and cross-infection on an ear, nose and throat ward.

BACKGROUND: Outbreaks of group A streptococcus (GAS) infections may occur in healthcare settings and have been documented in surgical, obstetrics and gynaecology, and burns units. The environment may serve as a reservoir and facilitate transmission via contaminated equipment. AIM: To describe the investigation and control of an outbreak of healthcare-associated GAS infection on an ear, nose and throat (ENT) ward in a tertiary referral centre. METHODS: Two patients with laryngeal cancer developed invasive GAS infection (bacteraemia) with associated tracheostomy wound cellulitis within a 48 h period. The outbreak team undertook an investigation involving a retrospective review of GAS cases, prospective case finding, healthcare worker screening and sampling of patient curtains. Immediate control measures included source isolation, a thorough rolling clean with a chlorine-based disinfectant and hydrogen peroxide decontamination of patient equipment. FINDINGS: Prospective patient screening identified one additional patient with carriage of GAS from a tracheostomy wound swab. Staff screening identified one healthcare worker who acquired GAS during the outbreak and who subsequently developed pharyngitis. Environmental sampling demonstrated that 10 out of 34 patient curtains on the ward were contaminated with GAS and all isolates were typed as emm-1. CONCLUSION: This is the first outbreak report to demonstrate patient curtains as potential source for GAS cross-transmission, with implications in relation to hand hygiene and frequency of laundering. Based on this report we recommend that during an outbreak of GAS infection all patient curtains should be changed as part of the enhanced decontamination procedures.

Sensitivity of markers of DNA stability and DNA repair activity to folate supplementation in healthy volunteers.

We have previously reported that supplementation with folic acid (1.2 mg day(-1) for 12 week) elicited a significant improvement in the folate status of 61 healthy volunteers. We have examined effects of this supplement on markers of genomic stability. Little is known about the effect of folate supplementation on DNA stability in a cohort, which is not folate deficient. Preintervention, there was a significant inverse association between uracil misincorporation in lymphocyte DNA and red cell folate (P < 0.05). In contrast, there were no associations between folate status and DNA strand breakage, global DNA methylation or DNA base excision repair (measured as the capacity of the lymphocyte extract to repair 8-oxoGua ex vivo). Folate supplementation elicited a significant reduction in uracil misincorporation (P < 0.05), while DNA strand breakage and global DNA methylation remained unchanged. Increasing folate status significantly decreased the base excision repair capacity in those volunteers with the lowest preintervention folate status (P < 0.05). Uracil misincorporation was more sensitive to changes in folate status than other measures of DNA stability and therefore could be considered a specific and functional marker of folate status, which may also be relevant to cancer risk in healthy people.

Performance of power assisted respirators during simulated asbestos removal.

Protection factors were measured on full face mask power assisted respirators when worn by experienced asbestos removal operatives under simulated asbestos removal work conditions. The sulfur hexafluoride test method as defined in European Standards was employed to determine the leakage into the respirators. Protection factors were measured on a total of 21 test volunteers. The test method allowed protection factors to be related to wearer activities and practices. Poor fitting techniques and simulated reduction in the respirator's performance resulted in a reduction in the protection factor. Visual inspection of the RPE usually worn by the volunteers identified inadequate maintenance. This study re-emphasises that careful selection, facepiece fit testing and correct use and maintenance of RPE are essential to ensure optimum protection to the wearer.

Magnetic resonance guided general surgery.

Image guided surgery can be defined as the intraoperative use of a radiologicai technique to give the surgeon information not available from direct inspection or palpation of the surgical field. This information may then be used to change the course of an operative procedure. Magnetic resonance (MR) imaging has the potential to be the most useful radiologicai technique in the developing field of image guided surgery.

Pituitary Cushing's disease arising from a previously non-functional corticotrophic chromophobe adenoma.

Severe pituitary Cushing's disease of sudden onset after 18 years of unsuccessful treatment for a previously non-functioning chromophobe adenoma is described in a middle-aged woman. Initial presentation with symptoms of optic nerve compression had been preceded by two years of amenorrhoea. Transfrontal resection of a chromophobe adenoma followed by radiotherapy, performed both at this time and again after a recurrence eight years later, failed to eradicate the tumour. Ten more years elapsed before she rapidly developed florid features of Cushing's syndrome. Plasma ACTH levels were markedly elevated and were only partially reduced by further transfrontal surgery, complete removal of the tumour proving impossible. Subsequent bilateral adrenalectomy was performed to control her hypercortisolism and a course of cytotoxic chemotherapy was administered in an attempt to treat the tumour recurrence. Immunocytochemical staining of tumour obtained at surgery demonstrated ACTH immunoreactivity both before and after the development of Cushing's disease. Although silent corticotrophic adenomas of the human pituitary, including chromophobic tumours, have been previously described, this is the first report of such a tumour becoming functional, sufficient to cause clinically evident Cushing's disease.

The effect of selective and non-selective beta-adrenoceptor blockade, and of naloxone infusion, on the hormonal mechanisms of recovery from insulin-induced hypoglycaemia in man.

The rise in plasma adenosine-3',5'-monophosphate occurring in response to insulin induced hypoglycaemia in normal human subjects, was abolished by non-selective beta-adrenoceptor blockade but unaffected by selective beta 1-adrenoceptor blockade. This implies that the rise is secondary to beta 2-adrenoceptor stimulation. The abolition of this rise by non-selective beta-adrenoceptor blockade had no pronounced effect on the recovery from hypoglycaemia. Endogenous opiate receptor blockade with naloxone had no significant effect on the recovery from insulin induced hypoglycaemia, or the hormonal mechanisms involved.

The diagnosis of primary hyperaldosteronism.

An aldosterone-suppression test based on a simple method of extracellular-fluid volume expansion over three days reliably discriminated between patients with aldosterone-producing adenomas, idiopathic adrenal hyperplasia, and essential benign hypertension. In patients with primary hyperaldosteronism adrenal-vein plasma aldosterone/cortisol concentration ratios successfully lateralised all 21 adenomas. In patients with an adenoma the contralateral adrenal gland was always suppressed, as indicated by a ratio which was less than that seen in the lower inferior vena cava, whereas in patients with hyperplasia the adrenal-vein aldosterone/cortisol concentration ratio from each adrenal was always greater than that seen in the lower inferior vena cava. Thus adrenal-vein sampling not only lateralises solitary adenomas but also discriminates between patients with an adenoma or hyperplasia. However, in view of the diagnostic reliability of the suppression test, it is suggested that adrenal-vein sampling is unnecessary in hyperaldosteronism due to adrenal hyperplasia.