MSSA, or methicillin-susceptible Staphylococcus aureus, is an infection caused by a type of bacteria commonly found on the skin. You might have heard it called a staph infection.
Treatment for staph infections generally requires antibiotics. Staph infections are classified according to how they respond to this treatment:
- MSSA infections are treatable with antibiotics.
- Methicillin-resistant Staphylococcus aureus (MRSA) infections are resistant to certain antibiotics.
Both types can be serious and even life threatening. This article provides an overview of MSSA symptoms, causes, and treatment.
MSSA symptoms vary according to where the staph infection is located. MSSA can affect the skin, blood, organs, bones, and joints. Symptoms may range from mild to life threatening.
Some possible signs of an MSSA infection include:
- Skin infections. Staph infections that affect the skin may cause symptoms such as impetigo, abscesses, cellulitis, pus bumps, and boils.
- Fever. A fever signals that your body is fighting an infection. A fever may be accompanied by sweating, chills, confusion, and dehydration.
- Aches and pains. Staph infections can cause pain and swelling in the joints as well as headaches and muscle pain.
- Gastrointestinal symptoms. Staph bacteria can cause food poisoning. Common symptoms associated with staph food poisoning include nausea, abdominal pain, vomiting, diarrhea, and dehydration.
Staph bacteria are commonly found on the surface of the skin, such as the inside of the nose. The Centers for Disease Control and Prevention (CDC) estimates that
Staph is harmless some of the time. It’s possible to have it without showing any symptoms.
In other cases, staph causes minor and easily treatable skin, nose, mouth, and throat infections. Staph infections can even heal on their own.
A staph infection becomes serious if the infection is also present in the bloodstream, usually from an advanced and untreated infection. Staph infections can cause life threatening complications.
In healthcare settings, staph is especially dangerous, as it can easily transmit from person to person.
Staph is transmitted through skin-to-skin contact, most often from touching something that contains the bacteria and then spreading it to your hands.
In addition, staph bacteria are resilient. They can live on surfaces like doorknobs or bedding long enough for a person to develop an infection.
MSSA infections can affect children, adults, and older adults. The following can increase your chances of developing an MSSA infection:
A current or recent stay in a healthcare facility
Staph bacteria remain common in places where people with compromised immune systems may come into contact with people or surfaces carrying the bacteria. This includes:
- outpatient facilities
- nursing homes
Staph bacteria can enter your system via medical devices that enter the body, such as:
- intravenous (IV) devices
- tubes for kidney dialysis, breathing, or feeding
People with a weakened immune system or chronic condition
This includes people who have:
- HIV or AIDS
- kidney diseases
- lung diseases
- conditions that affect the skin, such as eczema
People who use injection drugs, such as insulin, also have an increased risk.
Having an uncovered or draining wound
Staph bacteria can enter the body through an open wound. This may occur among people who live or work in close quarters or play contact sports.
Sharing personal items
Sharing certain items can increase your risk for a staph infection. These items include:
- sports equipment
This tends to occur in locker rooms or shared housing.
Unhygienic food preparation
Staph can be transferred from skin to food if people handling food don’t properly wash their hands.
If your doctor suspects a staph infection, they’ll ask you questions about your symptoms and examine your skin for wounds or other signs of an infection.
Your doctor might ask you questions to try to determine whether you were exposed to staph bacteria.
Your doctor might run additional tests to confirm a suspected staph infection. These may include:
- Blood test. A blood test can identify a high white blood cell (WBC) count. A high WBC count is a sign that your body might be fighting an infection. A blood culture can also determine whether the infection is in your blood.
- Tissue culture. Your doctor might take a sample from the infected area and send it to a lab. In the lab, the sample is allowed to grow under controlled conditions and then gets tested. This is especially helpful in identifying whether the infection is MRSA or MSSA, and which medications should be used to treat it.
You should receive the results of these tests within 2 to 3 days, although the tissue culture can sometimes take longer. If a staph infection is confirmed, your doctor might run additional tests to check for complications.
Antibiotics are typically the first line of treatment for staph infections. Your doctor will identify which antibiotics are most likely to work on your infection based on how the infection was acquired.
Some antibiotics are taken orally, while others are administered through an IV. Examples of antibiotics currently prescribed for the treatment of MSSA infections include:
Some antibiotics currently prescribed for MRSA infections include:
Take the antibiotics exactly as prescribed by your doctor. Finish all the medication, even if you already feel better.
Additional treatments depend on your symptoms. For instance, if you have a skin infection, your doctor might make an incision to drain the fluid from the wound.
Your doctor might remove any medical devices believed to be contributing to the infection.
Staph infections can result in a number of medical problems, some of which are life threatening. Here are the most common complications:
- Bacteremia occurs when the bacteria infect the bloodstream.
- Pneumonia is more likely to affect people who have underlying lung conditions.
- Endocarditis occurs when bacteria infect the heart valves. It can cause stroke or heart problems.
- Osteomyelitis occurs when staph infects the bones. Staph can reach the bones via the bloodstream, or through wounds or drug injections.
- Toxic shock syndrome is a potentially fatal condition caused by toxins associated with certain types of staph bacteria.
- Septic arthritis affects the joints, causing pain and swelling.
Most people recover from staph infections. Your healing window will depend on the type of infection.
If staph enters the bloodstream, these infections can become serious and life threatening.
Recovery typically takes a few months.
Be sure to see your doctor right away if you suspect an MSSA infection.