Methicillin-Resistant Staphylococcus Aureus (MRSA) - Overview
What is methicillin-resistant Staphylococcus aureus (MRSA)?
Methicillin-resistant Staphylococcus aureus (MRSA)
is a type of staphylococcus or "staph" bacterium that is resistant to many
antibiotics. Staph bacteria, like other kinds of
bacteria, normally live on your skin and in your nose, usually without causing
problems. But if these bacteria become resistant to antibiotics, they can cause serious infections, especially in people who are ill or weak. MRSA is different from other types of staph because it cannot be
treated with certain antibiotics such as methicillin.
MRSA infections are more difficult to treat than ordinary
staph infections. This is because the strains of staph known as MRSA
do not respond well to many common antibiotics used to kill bacteria. When methicillin and other antibiotics do not kill the bacteria causing an infection, it
becomes harder to get rid of the infection.
MRSA bacteria are
more likely to develop when antibiotics are used too often or are not used
correctly. Given enough time, bacteria can change so that these
antibiotics no longer work well.
How is MRSA spread?
MRSA, like all staph bacteria, can be
spread from one person to another through casual contact or through
contaminated objects. It is commonly spread from the hands of someone who has
MRSA. This could be anyone in a health care setting or in the community. MRSA
is usually not spread through the air like the common cold or flu virus, unless
a person has MRSA
pneumonia and is coughing.
MRSA that is
acquired in a hospital or health care setting is called healthcare-associated
methicillin-resistant Staphylococcus aureus (HA-MRSA).
In most cases, a person who is already sick or who has a weakened
immune system becomes infected with HA-MRSA. These
infections can occur in wounds or skin, burns, and IV or other sites where
tubes enter the body, as well as in the eyes, bones, heart, or blood.
In the past, MRSA infected people who had chronic illnesses. But now MRSA has become more common in healthy people. These infections can occur among people
who have scratches, cuts, or wounds and who have close contact with one
another, such as members of sports teams. This type of MRSA is called
community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA).