A methicillin-resistant Staphylococcus aureus (MRSA) screening is a medical test. It detects the presence of that particular strain of bacteria. MRSA is a type of staph infection that cannot be effectively cured with commonly-used antibiotics. Patients who suspect they may have this infection should be tested as soon as possible so they can begin treatment.
People who have been hospitalized, or those who work in a hospital, may also undergo a MRSA screening. The test can be run even if they display no symptoms. This is usually intended to control the spread of this bacteria in hospitals that have reported an outbreak. Large-scale testing may also be done in groups such as schools, clubs, and nursing homes, if an individual belonging to that group has developed the infection.
A person with MRSA often has a sore or lesion on his body that became infected with the bacteria. These lesions can develop into abscesses, with the accumulation of fluid. To collect a sample for testing, a nurse or doctor will apply a sterile cotton swab to the broken skin.
Patients that do not have lesions or display symptoms can have their nasal secretions collected for a MRSA screening. The nurse will insert a sterile cotton swab into a nostril. He will then rotate the swab gently to collect the sample. This process is repeated with the other nostril.
After the sample is collected from the patient, it is sent to a lab that performs the MRSA screening. The lab will transfer the sample to a Petri dish. A lab technician will then wait for the bacteria to grow. This typically takes 24 to 48 hours.
The sample will then be tested to see if it is Staphylococcus aureus bacteria. Should this test result be positive, the MRSA screening will then check to see if it is resistant to antibiotics. If it is, it can be identified as MRSA bacteria. This second test may take another 24 hours.
A drawback to the MRSA screening is the amount of time that it takes. This infection can be potentially life-threatening if it spreads into a person's bloodstream. Due to the time delay of proper testing, some doctors may occasionally begin treating for MRSA while waiting for the test results, if the patient displays the right symptoms.
More rapid MRSA screening techniques are being developed. One of these tests can detect the presence of the bacteria in a patient's blood within a few hours. As of 2010, however, the traditional MRSA screening is still the most commonly-used test.