Environmental decontamination of a hospital isolation room using high-intensity narrow-spectrum light.

The performance of a new decontamination technology, referred to as 'high-intensity narrow-spectrum light environmental decontamination system' (HINS-light EDS) was evaluated by a series of three studies carried out in a hospital isolation room used to treat burns patients. The ceiling-mounted HINS-light EDS emits high-intensity 405nm light which, although bactericidal, is harmless to patients and staff thereby permitting continuous environmental disinfection throughout the day. Performance efficacy was assessed by contact agar plate sampling and enumeration of staphylococcal bacteria on environmental surfaces within the room before, during and after HINS-light EDS treatment. When the room was unoccupied, use of HINS-light EDS resulted in ∼90% reduction of surface bacterial levels and when the room was occupied by an MRSA-infected burns patient, reductions between 56% and 86% were achieved, with the highest reduction (86%) measured following an extended period of HINS-light EDS operation. In an on/off intervention study, surface bacterial levels were reduced by 62% by HINS-light EDS treatment and returned to normal contamination levels two days after the system was switched off. These reductions of staphylococci, including Staphylococcus aureus and meticillin-resistant S. aureus, by HINS-light EDS treatment were greater than the reductions achieved by normal infection control and cleaning activities alone. The findings provide strong evidence that HINS-light EDS, used as a supplementary procedure, can make a significant contribution to bacterial decontamination in clinical environments.

Use of a temporary cohort ward as part of an intervention to reduce the incidence of meticillin-resistant Staphylococcus aureus in a vascular surgery ward.

This article describes the effect of introducing a cohort area into a vascular surgery ward where a sustained increase in new cases of meticillin-resistant Staphylococcus aureus (MRSA) made the implementation of standard MRSA infection control precautions untenable. A recent review of published reports concluded, 'that little evidence could be found to suggest that isolation measures recommended in the UK are effective'. The authors recommended a reporting format to enable the evidence for isolation to be gathered more systematically. This paper follows the recommended reporting format. The setting was a 30-bedded acute and subacute vascular surgery ward within a tertiary care hospital in Glasgow, UK. The data were analysed as an interrupted time series of 19 months pre-cohort, eight months with cohort and eight months post cohort. Following the instigation of the cohort area, there was a significant reduction in the number of nosocomial MRSA isolates from patients (P=0.0005). This reduction was sustained after the cohort area was discontinued. In conclusion, effective separation of MRSA-colonized/-infected patients from patients who are not colonized/infected with MRSA, using a cohort area, resulted in a significant reduction in MRSA cross-colonization and cross-infection. The resulting reduction in MRSA prevalence within the unit facilitated effective screening and isolation of subsequent patients once the cohort area had been discontinued.

Control of an outbreak of respiratory syncytial virus infection in immunocompromised adults.

Respiratory syncytial virus (RSV) is increasingly recognized as an important pathogen in immunocompromised adults, particularly those receiving bone marrow transplants, and, given the ease with which it spreads, represents a significant nosocomial problem. We describe an outbreak of RSV infection involving eight patients on a haematology/oncology ward which was controlled by early screening of patients and staff. Positive patients were cohort nursed on a separate ward and basic infection control measures including use of gowns and gloves were enforced. Children under age 12 were denied ward access. All patients with lower respiratory tract infection, and bone marrow transplant recipients with upper respiratory symptoms, were treated with nebulized ribavirin. There were no deaths. We conclude that awareness of the risk of RSV infection in immunocompromised patients coupled with rapid diagnosis and treatment, screening of symptomatic patients and staff, cohort nursing of cases and basic infection control procedures can prevent spread of RSV infection and reduce morbidity.