Staphylococcus aureus, or "staph" as it is sometimes called, is a common bacterium found on the skin or in the nose of 25-30 percent of humans. While it is usually harmless, in certain instances it may cause moderate to severe skin infections. Less commonly, it causes more serious systemic infections such as those in the bloodstream, surgical wounds and pneumonia requiring hospitalization. One group of staph known as MRSA, (Methicillin-resistant Staphylococcus aureus) was first identified in the 1960s, and is now prevalent in most hospitals. The organisms are resistant to multiple antibiotics and are therefore cause for considerable concern. Because of resistance, Vancomycin has often been the only drug able to successfully treat these MRSA infections.

A newer form of staph infection, know as CA-MRSA (for community-acquired, or community-assoc-iated Staphylococcus aureus) has appeared with increasing frequency and is now epidemic within certain community populations. Whereas hospital MRSA is almost always found in person with established risk factors associated with prior medical treatment, these are not present in CA-MRSA. Today, in the U.S. a little more than 10 percent of all MRSA infections are CA-MRSA. This form causes serous skin and soft tissue infections in otherwise healthy person, who have not been recently hospitalized or undergone invasive medical procedures. Hospitalization is required in approximately one out of five cases. CA-MRSA has been identified most frequently among specific populations including prisoners, athletes, children, military recruits and Native Americans.

A major difference between the two types of MRSA is that the community form (CA-MRSA) possesses a potent toxin which attacks infection fighting white blood cells called leukocytes. The most serious form of CA-MRSA infection causes necrotizing fasciitis, a severe, rapidly progressing and life-threatening skin infection. The CA-MRSA are genetically distinguishable from the hospital associated MRSA.

Treatment of MRSA skin infections is challenging. In some patients, skin ointments containing antibiotics can be used, but resistance to these can develop. Beta-Lactam antibiotics, which are typically used to treat common Staph aureus infections such as abscesses and cellulitis, are ineffective. Unlike hospital MRSA, which is resistant to multiple classes of antibiotics, CA-MRSA is still susceptible to several antibiotic classes outside the Beta-Lactam group.

The spread of skin MRSA infections occurs most frequently through close, skin-to-skin contact (such as that found in contact sports), through contact with skin wounds (cuts, abrasions) and through contact with contaminated items, where staph can survive for 24 hours or more. The organism can enter healthy, intact skin. Crowded living conditions and poor hygiene are factors which play a role in its spread. Currently, the only known means of prevention is through the following:

-Prudent hygiene measures involving hand washing

--Proper wound care, including proper disposal of bandages, and

--Avoidance of sharing certain personal items such as towels and razors. Shared exercise equipment should be wiped down between users.

When we talk about the spread of an infection, we talk about sources of infection - where it starts, and the way or ways it spreads - Mode of transmission

In the case of MRSA, patients who already have a MRSA infection or who carry the bacteria on their bodies but do not have symptoms (colonized) are the most common sources of transmission.

The main mode of transmission to other patients is through human hands, especially healthcare workers' hands. Hands may become contaminated with MRSA bacteria by contact with infected or colonized patients. If appropriate hand hygiene such as washing with soap and water or using an alcohol-based hand sanitizer is not performed, the bacteria can be spread when the healthcare worker touches other patients.

The good news is that MRSA is preventable. The first step to prevent MRSA is to prevent healthcare infections in general. Infection control guidelines produced by the Centers for Disease Control (CDC) and the Healthcare Infection Control and Prevention Advisory Committee (HICPAC) are central to the prevention and control of healthcare infections and ultimately, MRSA in healthcare settings.

St. Andrews Hospital and Healthcare Center has strived to implement these recommendations and recently started an Active Surveillance program. This is a kind of "Search and Destroy" method where high risk patients have screening cultures obtained at admission in order to identify those that may be harboring the MRSA bacteria. By knowing which patients might be a point of contact, proper precautions are taken to reduce the risk of transmission. By adhering to this and other CDC recommendations we have been able to keep the risk of infections to a minimum and help keep our community healthy.

Reference:

Centers for Disease Control and Prevention. Campaign to Prevent Antimicrobial Resistance in Healthcare Settings.

Alliance for the Prudent Use of Antibiotics. Update on antibiotic-resistant Staph aureus