MRSA Facts
Methicillin Resistant Staphylococcus aureus
What is Staphylococcus aureus?
Staphylococcus aureus, often referred to simply as "staph"are bacteria commonly carried on the skin or in the nose of healthy people. Occasionally, staph can cause an infection; staph bacteria are one of the most common causes of skin infections in the United States. Most of these infections are minor (such as pimples and boils) and most can be treated without antibiotics. However, staph bacteria can also cause serious infections (such as surgical wound infections and pneumonia). In the past most serious staph bacteria infections were treated with a certain type of antibiotic related to penicillin. Over the past 50 years, treatment of these infections has become more difficult because staph bacteria have become resistant to various antibiotics, including the commonly used penicillin-related antibiotics.
Where are staph and MRSA found?
Staph bacteria and MRSA can be found on the skin and in the nose of some people without causing illness.
What is the difference between colonization and infection?
Colonization occurs when the staph bacteria are present on or in the body without causing illness. Approximately 25-30% of the population have colonized staph bacteria in the nose at a given time.
Infection occurs when the staph bacteria causes disease in the person.
Who gets MRSA?
MRSA is a staph bacterium; it can cause the same kinds of infections as staph; however MRSA occurs more commonly among persons in hospitals and healthcare facilities. MRSA causes illness in persons outside of hospitals and healthcare facilities as well. Cases of MRSA diseases in the community have been associated with recent antibiotic use, sharing contaminated items, having active skin diseases, living in crowded settings, incarcerated persons, and players of close contact sports. Community-associated MRSA infections are typically skin infections, but also can cause severe illness. Most of the transmission in the above settings appeared to be from people with active MRSA skin infections.
How common is staph and MRSA?
Staph bacteria are one of the most common causes of skin infection in the United States, and are a common cause of pneumonia and bloodstream infections. Staph and MRSA infections are not routinely reported to public health authorities, so a precise number is not know. According to some estimates, as many as 100,000 persons are hospitalized each year with MRSA infections, although only a small proportion of these persons have disease onset occurring in the community (outside the hospital setting). Approximately 25-30% of the population has colonized staph bacteria in the nose at a given time.