How Is MRSA Spread?
Methicillin-resistant Staphylococcus aureus
(or MRSA for short) is a strain of bacteria resistant to certain types of antibiotics. It is a less common, but potentially more serious, form of the common "staph" infection.
MRSA is categorized based on where the infection was first acquired -- either healthcare-associated MRSA (for those infections that were acquired in a hospital or healthcare facility) or community-associated MRSA.
Regardless of the type, transmission of MRSA occurs through direct contact with:
- Someone who has an active infection
- Someone who is a carrier of the infection (colonized)
- A contaminated object.
After a person comes into contact with a contaminated surface or object, he or she may become a carrier of the bacteria (colonized). An active infection with MRSA can develop when a person is colonized and the bacteria enter an opening, such as a cut or scrape in the skin.
Direct Contact, Colonization, and the Role in MRSA Transmission
Understanding how MRSA is spread through direct contact with someone that has an active infection is relatively straightforward. If a person has an active sore contaminated with MRSA and you touch it, you could become infected if you touch an opening on your skin.
The idea of colonization is often less clear. "Colonization," in the case of bacteria, means that a person is carrying a specific type of bacteria, but does not have any signs or symptoms of illness that this particular bacteria can cause.
In the case of MRSA, it is estimated that up to 7 percent of people in hospitals and up to 2 percent of people in the community are colonized with MRSA, either on the skin or within their nose (the two most common areas).
A person can become colonized with MRSA in a couple of different ways, such as:
- Touching the skin of another individual who is colonized with MRSA, or who has an active MRSA infection
- Breathing the tiny droplets that are expelled during breathing, coughing, or sneezing
- Touching a contaminated surface.
Once colonized with MRSA, a person can remain a carrier of the bacteria from a few days or weeks, up to several years. During this time period, people colonized with MRSA are not only at an increased risk for infecting others, but also themselves.
The process of transmission that occurs with colonized individuals is the same that occurs with direct contact with an active infection. The difference being, in the case of colonization, it is not apparent to either the person colonized or the person becoming infected that anything is wrong.