Staphylococcus aureus

Staphylococcus aureus

Staphylococcus aureus (staph), is a type of bacteria that about 30% of people carry in their noses. Most of the time, staph does not cause any harm; however, sometimes staph causes infections. In healthcare settings, these infections can be serious or fatal. Staph bacteria can also become resistant to certain antibiotics.


What types of infections does Staphylococcus aureus cause?

Staphylococcus aureus can cause bacteremia or sepsis when bacteria spread to the bloodstream; pneumonia, which predominantly affects people with underlying lung disease including those on mechanical ventilators; endocarditis (infection of the heart valves), which can lead to heart failure or stroke; and osteomyelitis (bone infection), which can be caused by staph bacteria traveling in the bloodstream or put there by direct contact such as following trauma (puncture wound of foot or intravenous (IV) drug abuse).

Who is at risk for infection?

Anyone can develop a staph infection, although certain groups of people are at greater risk, including people with chronic conditions such as diabetes, cancer, vascular disease, eczema, and lung disease. In a healthcare setting, the risk of more serious staph infection is higher because patients often have weakened immune systems or have undergone procedures such as surgery or have intravenous catheters. 

How is Staphylococcus aureus spread?

Staph infections are usually spread by having contact with someone’s skin infection or personal items they have used, like towels, bandages, or razors that touched their infected skin. These infections are most likely to be spread in places where people are in close contact with others—for instance, schools and locker rooms where athletes might share razors or towels. Healthcare procedures can leave patients vulnerable to staph, which is typically spread in healthcare settings from patient to patient on unclean hands of healthcare personnel or through the improper use or reuse of equipment. Staph is found on people and not naturally found in the environment (e.g., soil, the ocean, lakes). Staph could get on objects and surfaces outside the body if someone touches infected skin or certain areas of the body where these bacteria can live (like the nose) and then touches the object or surface. Another way that items can be contaminated with staph and MRSA is if they have direct contact with a person’s skin infection. Keeping skin infections covered with bandages is the best way to reduce the chance that surfaces will be contaminated with MRSA.

How are staph infections treated?

Some staph infections can be treated with antibiotics, however, certain strains of staph are becoming more and more antibiotic-resistant and getting more difficult to effectively treat.  Drug-resistant staph infections include Methicillin-resistant Staphylococcus Aureus (MRSA), Vancomycin-resistant Staphylococcus Aureus (VRSA), and Vancomycin-intermediate Staphylococcus Aureus (VISA).


Source: Centers for Disease Control and Prevention,