November 7, 2007 > Drug-resistant Infections
New Test Speeds Diagnosis & Treatment of MRSA
Bacterial infections that are resistant to treatment with common antibiotics have been in the news a lot lately, particularly Methicillin-resistant Staphylococcus aureas - or MRSA. Treatment of these "staph" infections is becoming more complex and expensive. According to the Centers for Disease Control and Prevention (CDC), over $2.5 billion in excess health care costs are attributable to MRSA infections.
MRSA is an infection that can often occur in otherwise healthy people, generally showing up as skin infections that look like boils or pimples that can be swollen and painful with draining pus. But many people who carry the MRSA bacteria on their bodies do not have symptoms and can be "carriers" of the disease, spreading it to other people without realizing it. Fortunately, new testing technologies that provide fast results could dramatically reduce the transmission of MRSA infections.
"Until recently, the only way to test for MRSA was to perform a 'culture' test to see if the MRSA bacteria was present," says Washington Hospital Infection Control Coordinator Shabnam Hashemi, MT, RN, CIC. "Growing the bacteria in a culture takes at least two days to produce results.
"We now have a new test that gives results in under 90 minutes, adds Hashemi. "The rapid diagnosis enables us to identify the infected patients or the "carriers" right away and it also helps us ensure that all hospital staff members who come in contact with those patients take extra precautions to avoid the spread of infection."
Developed by the Sunnyvale-based company Cepheid, the Xpert MRSA test is a form of DNA testing. It involves swabbing inside the patient's nose and combining the sample in a small cartridge with chemical agents that produce a chain reaction process to rapidly produce copies of the microbes.
"Washington Hospital currently is the only hospital in the San Francisco Bay Area to use the Xpert MRSA test," says Director of Laboratory Services Mary Reynolds, MS, MPH.
"It's a completely painless test," Reynolds adds. "We take the nasal swab because MRSA germs can be present in the nose even in people who don't have any evidence of skin infection. It's essentially a sophisticated form of genetic testing that can now be done as a routine lab operation. The test is very specific for the MRSA gene. Other tests for MRSA aren't as sensitive or as accurate."
Washington Hospital currently is developing a plan to determine which groups of patients should automatically be tested with the Xpert MRSA test. "We know, for example, that MRSA occurs most frequently among patients who undergo invasive medical procedures." Reynolds explains. "Patients with suppressed immune systems also are more susceptible to MRSA infection."
Screening patients for MRSA is just the beginning of infection control.
"Even before we acquired the Xpert MRSA test, Washington Hospital had already lowered our rate of hospital-acquired MRSA infections by following strict policies in caring for patients with MRSA," says Hashemi.
"MRSA patients are kept in isolated rooms," she explains. "All staff members coming in contact with an MRSA patient must wear gowns and gloves for close patient contact - and face shields if the patient is coughing. The cleaning crew takes extra precautions, too, and disposes of cleaning materials such as mop heads and cloths that could be contaminated. And, of course, healthcare workers must always wash their hands before and after treating any patient."
Hashemi notes that people in the community can take various precautions to avoid contracting or spreading MRSA infections, too:
* Wash your hands frequently and thoroughly.
* Avoid touching your face.
* Don't handle other people's bandages or wounds without wearing latex gloves, or if you do, wash your hands right away.
* Carefully clean the surfaces in your home, such as countertops and bathroom fixtures, because the organisms can survive on surfaces.
* Don't share personal items such as razors, towels or eating utensils.
* Carry a liquid hand-sanitizer or sanitary wipes with you when going out in public places and handling items such as grocery carts.
"Following the precautions listed above can protect all of us from the complications associated with MRSA" she emphasizes.
If you have questions about MRSA, talk to your health care provider or visit the Center for Disease Control's website: www.cdc.gov
for more information related to MRSA.