December 18, 2007 - BD Diagnostics, a segment of BD (Becton, Dickinson and Co.), today announced a major study published in the British Journal of Surgery demonstrates that rapid screening for Methicillin-resistant Staphylococcus aureus (MRSA) could help reduce hospital infection rates by almost 40 percent.
Led by researchers at the University College London Hospital National health Service Foundation Trust (UCLH), the study investigated whether using a two-hour rapid screening test to identify MRSA carriers could effect a significant reduction in infection rates. The researchers who conducted the trial of approximately 19,000 surgical patients at University College Hospital concluded that use of the rapid molecular test is cost-effective and reduces MRSA infection rates.
“MRSA has a devastating impact on patients and their families,” said Peter Wilson, consultant microbiologist, UCLH, who led the research study. “To win the war on MRSA, hospitals need to consider effective new technologies, such as rapid tests which can help speed the selection of appropriate interventions. It is important to identify methods, which can be demonstrated to be effective in reducing hospital infection rates. Our research shows rapid molecular screening to identify carriers prior to elective or emergency surgery is an important tool toward that goal.”
The authors tested 18,810 surgery patients admitted to the hospital between January and December 2006 with the BD GeneOhm MRSA Assay, a rapid, two-hour molecular test for the detection of MRSA from nasal specimens. The rapid test revealed that 4.5 percent of screened patients were carrying MRSA when they were admitted to the hospital. Patients who tested positive as carriers of MRSA were treated with a topical suppression in order to reduce the risk of infection and potential transmission to others. The overall rate of MRSA bloodstream infections fell by 38.6 per cent compared with 2005 rates. When compared with the mean of the preceding six years, the rate fell by 38.5 per cent.
The annual cost for the active screening program at UCLH was equal to about $551,000. Cost savings were measured in terms of sending a patient home earlier as an infection was avoided. Using the 2005 MRSA infection rates, the cost savings in 2006 were nearly $1 million, translating to a net savings of about $442,000 for the year.
Based upon the success of the active screening study, UCLH plans to expand its screening program to include medical (nonpresurgical) patients. The rapid screening program is just one avenue UCLH has pursued to reduce its MRSA rates. Prior to the screening study, the trust had already introduced intensive hand hygiene campaigns and improved infection control around intravenous line procedures. UCLH recently became the first institution in the country to introduce “infection-resistant” keyboards.
There is a 23 percent mortality rate among patients with MRSA bacteraemia (bacterial infections of the bloodstream). In the early 1990s, 2 percent of Staphylococcus aureus bacteraemias were due to MRSA in the UK; the mean figure is now about 45 percent and UK rates of MRSA bloodstream infections are among the highest in Europe. The UK government has set a target that by 2008 all hospitals must reduce infection rates by 50 percent in comparison to 2003-2004 base rates. However, recent official figures from the Health Protection Agency showed that there has only been a reduction of 20 percent across all UK hospitals.
The “Health Act 2006: Code of practice for the prevention and control of healthcare-associated infections,” published by the Department of Health (DOH), states hospitals should make provisions for preadmission MRSA screening in addition to decontamination and isolation of colonized patients. While the DOH does not specify the type of screening that should be used, it does suggest decolonization of emergency orthopedic patients and all critical care patients should begin immediately upon admission, unless a rapid screening method is used, owing to the fact that the results for culture-screening will not be known until after the critical period for these patients.
The BD GeneOhm MRSA assay is performed on a nasal swab specimen with a real-time polymerase chain reaction instrument that rapidly identifies patients who are carriers of MRSA. It was used in the study because it provides results in two hours, thereby enabling UCLH to swiftly implement appropriate interventions. In contrast, traditional culture screening methods can take up to 72 hours. UCLH was the first NHS Trust to introduce this rapid molecular technique for routine screening. The rapid test is quicker and easier to read because it is based on the presence of MRSA-specific DNA. Traditional methods take longer because they rely on growing bacteria and subsequent testing for antibiotic resistance on culture plates.
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