What Is MSSA Bacteremia?

Medically Reviewed by Stephanie S. Gardner, MD on April 20, 2023
4 min read

The bacteria Staphylococcus aureus (staph) lives on the skin and in the nose of many people. It usually only causes a problem such as MSSA bacteremia if it gets inside the body.

Staph infections can be either methicillin-resistant staph (MRSA) or methicillin-susceptible staph (MSSA). MSSA infections are usually treatable with antibiotics. However, MRSA infections are resistant to antibiotics. Many staph infections are mild, but they can also be serious and life-threatening.

MSSA Bacteremia occurs when the MSSA bacteria enter your bloodstream. This is a serious infection that has a high risk of complications and death. Once it's in the bloodstream, the infection often spreads to other organs and tissues within the body such as the heart, lungs, or brain. 

MSSA bacteremia often starts as an MSSA infection in another part of the body. Many staph infections start on the skin. Symptoms of skin infection can include: 

  • Cellulitis: This causes red, painful, and swollen tissue just under the skin. 
  • Impetigo: This causes fluid-filled blisters to form and burst, leaving behind a brown or yellow crust. 
  • Abscesses: These are also called boils and are painful, red sores under the skin. 
  • Folliculitis: This causes painful, pimple-like sores under the hair follicles. 
  • Staphylococcal scalded-skin syndrome (SSSS): This serious infection usually affects infants and young children. It causes the skin to peel off all over the body.  

Once staph bacteria have entered the bloodstream, symptoms usually become more severe. The Sepsis Alliance uses the acronym TIME to describe the symptoms:

  • T: Temperature that is either higher or lower than normal. 
  • I: Infection. There may be symptoms from an MSSA skin infection or other infection. 
  • M: Mental decline. People with bacteremia may be sleepy, confused, or difficult to wake up. 
  • E: Extremely ill. There may be severe pain, discomfort, or shortness of breath. 

Staph bacteremia occurs when MSSA enters the bloodstream. If you develop a staph infection, it is probably from staph bacteria that you've been carrying around for a while. Staph bacteria can also be spread from person to person.  

MSSA will survive on objects like pillowcases and towels long enough to infect the next person who touches them. It can also survive stomach acid, drying, and extreme temperatures.  

Several circumstances can increase your risk of developing MSSA infections.

Health conditions

Medical devices:

Contact sports. Staph bacteria can spread in several ways through contact sports, including:

  • Cuts and abrasions
  • Skin-to-skin contact
  • Shared razors
  • Shared towels and uniforms
  • Shared equipment

Unsanitary food preparation. Staph bacteria can be spread to food if the preparer doesn't wash their hands. Food that is contaminated with staph looks and smells normal. 

Bacteremia is diagnosed with physical findings including: 

  • Low blood pressure
  • Increased heart rate
  • Fever
  • Difficulty breathing

Doctors will also perform lab tests such as blood cultures to determine whether the bacteremia is caused by MSSA or another type of bacteria or virus. 

When a blood culture tests positive for MSSA bacteremia, a doctor will perform an initial evaluation that may include: 

  • Assessment identifying the source of infection
  • Consulting with an infectious disease specialist
  • Eliminating or debriding (remove damaged tissue) sites of infection
  • Ordering follow-up blood cultures in 2 to 4 days
  • Considering a transesophageal echocardiogram to check heart status
  • Removing any central lines, a type of catheter placed in a large vein, if possible

Intravenous (IV) antibiotics are given to fight the infection. These antibiotics may include: 

Further treatment may be needed, depending on how the bacteremia responds. 

You can use the following precautions to help prevent the spread of staph bacteria.  

Wash your hands. Using soap and water, wash your hands thoroughly before, during, and after making food, after touching animals, after handling raw meat, and after using the bathroom.

Change tampons often. Tampons can provide a breeding ground for staph. Use the lowest absorbency possible and change tampons every 4 to 8 hours. 

Keep wounds covered. Use sterile, dry bandages to cover cuts and abrasions. Pus from sores contains staph bacteria. Covering cuts will keep it from spreading. 

Follow food safety precautions. Handle and store food safely and clean up counters and cutting boards with soap and water. 

Use the hot setting. Wash clothing and bedding in hot water. Use bleach on those materials that are bleach-safe. 

Personal means personal. Don't share personal items. Keep your towels, sheets, razors, and other personal items separate from others since staph can spread on objects.