Q. What is Methicillin-resistant Staphylococcus aureus (MRSA)?
A. MRSA is the abbreviation for a specific type of bacteria (called “Staphylococcus aureus”) that is resistant to a class of antibiotics in the penicillin family including “methicillin.” The full name is Methicillin-resistant Staphylococcus aureus.
Q. Why is MRSA resistant to treatment?
A. When penicillin was first used in the 1940's, it could seemingly treat nearly any infection. As the use of penicillin increased over time (including some overuse and misuse) bacteria (including Staphylococcus aureus) became resistant. As newer antibiotics were developed and used, bacteria became resistant to them as well, over time. Thus, there are a group of bacteria that are no longer sensitive to older antibiotics and a few bacteria that are resistant to nearly all of our current antibiotics. MRSA is often referred to as a “super bug” because it is resistant to many antibiotics and can cause severe disease. There are, however, effective treatments for MRSA, and it is important to begin treatment as early as possible.
Q. What are the symptoms of MRSA?
A. An MRSA infection usually begins when the resistant bacteria enter through the skin but MRSA can also invade the body in other areas such as the lungs. When entering through the skin, MRSA usually uses a small cut or a scratch for entry. In this case, early MRSA symptoms may include:
- A painful red bump or boil that may look similar to a “spider bite”
- A cluster of pimples
- A cut that begins to leak pus from it
If the infection progresses, the bump may become larger and more painful or be accompanied by spreading redness or tenderness. The bacteria can invade deeper into tissue and the blood stream causing fevers and chills, tiredness, cough or shortness of breath, rash, headache or worsening pain at infection site, and may cause more serious health problems and even death. People should seek medical attention as soon as they note any symptom that is unusual so that the infection can be evaluated and treatment started early, if needed.
Q. How is MRSA spread?
A. About 10% to 40% of healthy people have some form of the Staphylococcus aureus bacteria living on their body. This is part of the normal bacteria in our nose and, armpits, groin and other areas of skin. Skin-to-skin contact between people and contact between shared equipment can spread the bacteria. The bacteria can live on surfaces that come in contact with skin in common areas such as locker rooms, military barracks, and day care centers. The bacteria can also live on surfaces such as door handles, equipment, computer keyboards, and tabletops. Most people who come in contact with MRSA do not become infected and have no problem with it at all. It is only when the bacteria invade through the outer layer of skin or into our lungs that issues can arise.
Q. What are the two types of MRSA (HA-MRSA and CA-MRSA)?
A. Until the 1990s, MRSA was found mostly in hospitals and healthcare facilities, including nursing homes, dialysis units, and wound-care units. This type of MRSA is called healthcare associated MRSA (HA-MRSA). For the most part, HA-MRSA caused infections in people with weakened immune systems, older individuals, and also in people who had recently undergone surgery.
In the 1990’s healthy people with no connection to hospitals or healthcare facilities also started getting MRSA infections. Some people at risk are athletes on sports teams, children in daycare, army recruits, and people in prisons. This type of MRSA is called community acquired MRSA (CA-MRSA).
Q. What can be done to help stop the spread of MRSA?
A. Prevention of any exposure is very difficult, short of living in a plastic bubble. But you can reduce your risk of becoming infected by doing a few simple things:
- Wash your hands often. Use an alcohol-based hand sanitizer when soap and water are not available
- Keep cuts and scrapes clean and bandaged until the skin heals
- Avoid touching other people’s scrapes and wounds or bandages without washing hands afterwards
- Do not share personal items, such as razors, towels, athletic equipment
- Shower with soap and water after all athletic events
- Clean high-touch surfaces regularly
Q. If someone suspects that they may be infected with MRSA, what should they do?
A. If you think you have a significant infection, seek medical help right away. Health-care professionals can work to determine what type of bacteria is involved and provide the right treatment. Certain antibiotics can be used to control CA-MRSA and HA-MRSA. The more an infection advances, the harder it becomes to treat. Depending on the type and severity of the MRSA infection, in-hospital treatment may be needed. Getting treatment early may help stop a MRSA from becoming a serious or life-threatening infection.
Jay Purdy, MD, PhD is Senior Director in anti-infectives at Pfizer.