Point-of-care universal screening for meticillin-resistant Staphylococcus aureus: a cluster-randomized cross-over trial

BACKGROUND

Meticillin-resistant Staphylococcus aureus (MRSA) is frequently endemic in healthcare settings and may be transmitted by person-to-person spread. Asymptomatic MRSA carriers are potential, unsuspected sources for transmission and some of them may be identified by admission screening.

AIM

To assess whether rapid point-of-care screening (POCS) for MRSA at hospital admission may be associated with a reduction in MRSA acquisition rates when compared with slower laboratory-based methods.

METHODS

A cluster-randomized cross-over trial was conducted in four admission wards of an acute London tertiary care hospital. Polymerase chain reaction-based POCS screening was compared with conventional culture screening. Patients were screened on ward admission and discharge, and the MRSA acquisition rate on the admission wards was calculated as the primary outcome measure.

RESULTS

In all, 10,017 patients were included; 4978 in the control arm, 5039 in the POCS arm. The MRSA carriage rate on admission was 1.7%. POCS reduced the median reporting time from 40.4 to 3.7 h (P < 0.001). MRSA was acquired on the admission wards by 23 (0.46%) patients in the control arm and by 24 (0.48%) in the intervention arm, acquisition rates of 5.39 and 4.60 per 1000 days respectively. After taking account of predefined confounding factors, the adjusted incidence rate ratio (IRR) for change in trend for MRSA acquisition was 0.961 (95% confidence interval: 0.766-1.206). The adjusted IRR for step change for MRSA acquisition was 0.98 (0.304-3.162).

CONCLUSION

POCS produces a significantly faster result but has no effect on MRSA acquisition on admission wards compared with culture screening. Where compliance with infection prevention and control is high and MRSA carriage is low, POCS has no additional impact on MRSA acquisition rates over the first one to four days of admission compared with conventional culture screening.

Enhanced surveillance of meticillin-resistant Staphylococcus aureus bacteraemia in a London teaching hospital

In 2001, the UK Department of Health introduced mandatory surveillance of meticillin-resistant Staphylococcus aureus (MRSA) bacteraemias (blood-culture-positive episodes) in English hospitals. We performed enhanced surveillance in their hospital between April 2001 and March 2003 to determine the epidemiology of MRSA bacteraemia across different specialities. There were 267 MRSA-blood-culture-positive episodes, giving a rate of 0.37 per 1000 occupied bed-days (OBD). Thirty-three (12.4%) episodes were false positives due to contaminants and 15 (5.6%) originated in the community or at another institution. Thirty-one (11.6%) episodes were in outpatients or occurred after recent discharge and were designated 'hospital associated'. The remaining 188 cases were clinically significant hospital-acquired episodes in inpatients, with a rate of 0.26 per 1000 OBDs. The highest rates were in the intensive therapy unit (ITU; 2.74 per 1000 OBDs) and the high-dependency unit (HDU; 1.68 per 1000 OBDs). Fifty-five non-ITU, non-HDU episodes occurred in patients who had been discharged from ITU or HDU prior to the development of bacteraemia but during the same admission. The number of MRSA bacteraemias related to ITU/HDU suggests that these wards may be hubs of MRSA infection. Haematology, oncology and renal (HOR) patients had the greatest number of hospital-associated episodes. The most common source of MRSA bacteraemia was a vascular access device (VAD) (108 episodes, 57%, 64% of which were central lines). The high bacteraemia rates in ITU, HDU and HOR patients were associated with high usage of VADs. The majority of episodes occurred in patients who were newly colonized with MRSA after admission. Thus, in this hospital, VADs and stays in ITU or HDU are important risk factors for bacteraemia, and VAD care and prevention of cross-infection are priorities for intervention. We recommend that the mandatory national surveillance scheme should collect additional data on MRSA bacteraemia to provide information for a national strategy for MRSA control and to allow appropriate comparison between institutions.

Community associated MRSA: an alert to paediatricians

Community associated methicillin resistant Staphylococcus aureus (CA-MRSA) is an emerging pathogen typically associated with skin and soft tissue infection, with occasional reports of fatality in previously healthy children and young adults. We report a case of invasive CA-MRSA and highlight the potential impact of such infections on empirical treatment of staphylococcal infections.

Measles-associated encephalopathy in children with renal transplants

Two children, boys of 8 and 13 years, presented with measles-associated encephalopathy several years after kidney transplantation for congenital nephrotic syndrome. In the absence of prior clinical measles, the neurological symptoms initially eluded diagnosis, but retrospective analysis of stored samples facilitated the diagnosis of measles-associated encephalopathy without recourse to biopsy of deep cerebral lesions. Each had received a single dose of measles mumps and rubella vaccine before 12 months of age. Prior vaccination, reduction of immunosuppression and treatment with intravenous immunoglobulin and ribavirin may have contributed to their survival. Persistent measles virus RNA shedding, present in one child, was not controlled by treatment with i.v. ribavirin. Two years later, both patients continue to have functioning allografts with only minimal immunosuppression. These cases illustrate the difficulty in diagnosing measles-associated encephalopathy in the immunocompromised host, even in the era of molecular diagnostics, and highlight the renewed threat of neurological disease in communities with incomplete herd immunity.

Left anterior choroidal artery infarction and uncontrollable crying

Uncontrollable crying following a left anterior choroidal artery infarction and responding to fluoxetine is described. It is possible that this region has a role in the regulation of emotion.