Staphylococcus aureus: Methicillin- Resistant Invasive Disease

Infectious agent:  methicillin-resistant Staphylococcus aureus (MRSA)

Description of illness:  About one-third of people in the world have Staphylococcus aureus bacteria on their bodies at any given time, primarily in the nose and on the skin. When the bacteria/organism is present but the individual shows no clinical signs or symptoms of an active infection they are said to be “colonized”.  The most common body site colonized is the nose. Most MRSA infections are skin infections that may appear as pustules or boils which often are red, swollen, painful, or have pus or other drainage. These skin infections commonly occur at sites of visible skin trauma, such as cuts and abrasions, and areas of the body covered by hair (e.g., back of neck, groin, buttock, armpit, beard area of men). Recognizing the signs and receiving treatment for MRSA skin infections in the early stages reduces the chances of the infection becoming severe. MRSA infections that are neglected or insufficiently treated may develop into serious infections in bones, joints affecting deeper underlying tissue (e.g., osteomyelitis), spread to the bloodstream (e.g., bacteremia, sepsis), or involve internal organs (e.g., pneumonia, endocarditis). The signs and symptoms of more severe and potentially life-threatening infections will vary by the type and stage of the infection. Fever, chills, low blood pressure, joint pains, severe headaches, shortness of breath, and "rash over most of the body" are symptoms that need immediate medical attention, especially when associated with skin infections.