Test Your Knowledge

Staph bacteria are often present on the skin or within the nose of healthy people. The bacteria are most often spread through direct skin-to-skin contact with a bacteria carrier. This can occur if someone touches an area of the body with the bacteria then touches another person. Staph bacteria may also be transmitted via contaminated objects or surfaces (e.g., shared towels, eating utensils) or through the air (e.g., when a person carrying the bacteria sneezes or coughs). By late childhood, most people develop some immunity against infection because the body develops antibodies as a result of repeat exposure to the bacteria.

Many cases of staph infections result from medical procedures or stays in hospitals or other healthcare facilities. These hospital-acquired (nosocomial) infections may result from an immunosuppressed patient being exposed to the bacteria of healthcare workers or other patients. The bacteria may also invade the body during certain dental or surgical procedures.

Factors that may increase a person’s risk of developing a staph infection include:

• Immunosuppression (e.g., due to certain illnesses or disease, or due to use of certain medications such as antibiotics or corticosteroids)
  
  
• Open wounds (e.g., cuts, burns)
  
  
• Existing skin conditions or disease
  
  
• Implantation of foreign objects (e.g., shunt, intravascular catheter, dialysis graft) into the body
  
  
• Being in close physical proximity to others (e.g., daycare, college dormitories)
  
  
• Newborns and nursing mothers
  
  
• Heart conditions such as heart murmurs or mitral valve prolapse

People at greater risk for serious cases of methicillin-resistant Staphylococcus aureus (MRSA) include those who are male, black or older than 65, according to the U.S. Centers for Disease Control and Prevention.

Additional risk factors for various conditions caused by staph infections may vary, depending on the condition. These include: