Source: DGNews  |  Posted 2 years ago

By Ed Susman

SAN FRANCISCO -- September 15, 2009 -- Researchers said that hospital-acquired infections with methicillin-resistant Staphylococcus aureus (MRSA) can be largely prevented by identifying carriers of the organism when patients are admitted to the hospital and then initiating aggressive isolation procedures, even if patients are not experiencing disease symptoms but are colonised by the bacteria.

Lance Peterson, MD, Microbiology and Infectious Diseases Research, NorthShore University HealthSystem, Chicago, Illinois, said if hospital staff is not aggressive in conducting isolation programs with persons carrying MRSA, the infection control program is doomed to fail.

The aggressive program initiated at his hospitals in 2005 resulted in a 70% reduction in MRSA infections rates, and even though the costs associated with the program added to the hospital budget, the resulting savings in preventing infections was triple the cost, Dr. Peterson said here on September 12 at the 49th Annual Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC).

The study at the 3 NorthShore system hospitals in Evanston, Illinois, revealed that about 7 of every 100 individuals who had MRSA colonisation developed a symptomatic infection. “The biggest risk factor for MRSA infection is to be colonised,” he said. The 3 hospitals used real-time polymerase chain reaction testing to screen incoming patients for colonisation with MRSA.

Upon presentation at the hospital, patients had their nostrils swabbed for pathogens. If MRSA was detected the patients were isolated and treated with mupirocin for 5 days. Staff treating these patients wore gowns and gloves for contact precautions, he said. Patients were also given 2 antiseptic baths.

The polymerase chain reaction test is more expensive than traditional tests, and additional nursing care precautions also added costs to the program, Dr. Peterson said.

“The bottom line for us is that if you want to have a successful MRSA reduction program,” he said, “you have to have a very aggressive, very rapid, and broad MRSA screening program.”

Dr. Peterson and colleagues studied 37,179 consecutive patients who underwent MRSA-testing at admission. The prevalence of MRSA was 8.5%, but two-thirds of the individuals were not aware they were carriers of MRSA.

“Successful control of any epidemic relies on detection of those harbouring the pathogen and limiting further spread,” he said. “The approach to control of the MRSA pandemic is no different. Most persons harbouring MRSA do not exhibit signs of infection and thus to detect all spreaders some surveillance must be done.”

[Presentation title: Debate: Is Molecular Screening for MRSA Colonization Worth the Cost? Case in Favour. Abstract 408]