Methicillin-Resistant Staphylococcus Aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a mutation of very common bacterium spread easily by direct person-to-person contact. Once limited to large teaching hospitals and tertiary care centers, MRSA is now endemic in nursing homes, long-term-care facilities, and even community hospitals. Patients most at risk for MRSA include immunosuppressed patients, bum patients, intubated patients, and those with central venous catheters, surgical wounds, or dermatitis.

Others at risk include those with prosthetic devices, heart valves, and postoperative wound infections. Other risk factors include prolonged hospital stays, extended therapy with multiple or broadspectrum antibiotics, and close proximity to those colonized or infected with MRSA. Also at risk are patients with acute endocarditis, bacteremia, cervicitis, meningitis, pericarditis, and pneumonia.

Causes

MRSA enters health care facilities through an infected or colonized patient or a colonized health care worker. Although MRSA has been recovered from environmental surfaces, it's transmitted mainly by health care workers' hands. Many colonized individuals become silent carriers. The most frequent site of colonization is the anterior nares (40% of adults and most children become transient nasal carriers). Other sites include the groin, axilla, and the gut, though these sites aren't as common. Typically, MRSA colonization is diagnosed by isolating bacteria from nasal secretions.

In individuals where the natural defense system breaks down, such as after an invasive procedure, trauma or chemotherapy, the normally benign bacteria can invade tissue, proliferate, and cause infection. Today up to 90% of S. aureus isolates or strains are penicillinresistant, and about 27% of all S. aureus isolates are resistant to methicillin, a penicillin derivative. These strains may also resist cephalosporins, aminoglycosides, erythromycin, tetracycline, and clindamycin.

MRSA has become prevalent with the overuse of antibiotics. Over the years, overuse has given once-susceptible bacteria the chance to develop defenses against antibiotics. This new capability allows resistant strains to flourish when antibiotics knock out their more sensitive cousins.

Signs and symptoms

Methicillin-resistant staphylococcus aureus produces symptoms no different from any other type of Staphylococcus aureus bacteria. The skin will appear red and inflamed around wound sites. Symptoms in serious cases may include fever, lethargy, and headache. MRSA can cause urinary tract infections, pneumonia, toxic shock syndrome, and even death.

Diagnosis

Treatment

If you are carrying MRSA in your nose or on your skin and you are healthy, you do not need treatment and you should continue with your normal activities. Although you do not pose a health risk to your family, co-workers, or to the public, it is important for you to wash your hands regularly using soap and water. Using an alcohol hand rub may help stop you from spreading MRSA when touching surfaces with your hands. You do not need to disclose to your workplace, school or daycare setting the fact that you carry MRSA.

Mild infections of the skin often may not need to be treated. If necessary, antibiotics will be prescribed by your doctor.

Prevention

Hand washing is the most important measure. Always wash hands carefully after using the toilet, using household hand soap for at least 15 seconds. If you require continued care at home, you, or whomever is caring for you, should wear gloves when handling body fluids (urine, wound drainage, etc.), when providing care, or contacting surfaces contaminated with body fluids. Disposable items soiled by body fluids (dressings, diapers, used gloves, etc) should be placed in the trash. Good cleaning with a household disinfectant such as bleach is adequate.

Bacteria can survive on surfaces like railings, faucets and handles for up to seven days. Routine cleaning of these surfaces with regular household cleaners can also help reduce spread of bacteria.