Staph infection (non-MRSA)
Staphylococcus is a group of bacteria that are referred to collectively as “staph.” While staph infections are usually associated with the skin, staphylococcus bacteria can also cause food poisoning and infections of the heart, lungs, blood, and bones. Most infections are caused by Staphylococcus aureus bacteria.
About a third of the population naturally carries staph bacteria on their skin or in their nose without developing an infection. However, if staph gets into a cut or wound, it can cause an infection. The result is usually a mild skin infection that gets better on its own or with antibiotics. Unfortunately, an increasing number of staph infections are resistant to common antibiotics like methicillin, leading to more severe infections that are hard to treat.
Because staphylococcus bacteria can cause a range of infections, symptoms depend largely on the type of tissue affected. These may include:
Staphylococcal infection of the skin
Abscess: Most staph infections occur on the skin as small red bumps that look like pimples. These bumps are called an abscess or boil. They are usually filled with pus, which will drain if the boil breaks open.
Cellulitis: Cellulitis most commonly occurs on the lower parts of the legs. It is usually a red, tender area. Rather than being localized, like a boil, cellulitis tends to expand. In some instances, cellulitis may look like an open wound. In others, there may be no break in the skin. Other symptoms include:
- Skin that is warm to the touch.
Impetigo: Impetigo is a contagious skin infection common among infants and children. Symptoms include:
- Red sores.
- Sores that leak clear fluid and then eventually develop a honey-colored crust.
Staphylococcal scalded skin syndrome: This condition is also more common among infants and children. It occurs as the result of toxins produced by staphylococcal aureus bacteria. These toxins have an exfoliative effect and cause the top layer of skin to peel away. Symptoms include:
- Blisters that may break or have a wrinkled appearance.
- Pain in the affected area.
Staph is also commonly associated with food poisoning. Staphylococcal food poisoning is not a true staph infection. Rather, it is caused when the toxins produced by the bacteria contaminate food, which can happen as a result of poor food handling and hand hygiene. Symptoms usually appear rapidly and may include:
Toxic shock syndrome
This life-threatening condition occurs because of the toxins secreted by Staphylococcus aureus growing in a low-oxygen environment. It is associated with some surgical wounds and tampon usage. Symptoms include:
- Sudden onset of fever.
- Muscle aches.
- Sunburn-like rash, usually on the palms and feet.
Staph from an infected wound on the skin can also get into the bloodstream and cause a serious condition known as sepsis. When this happens, it can spread to internal organs, like the lungs and the endocardial sac around the heart, or to internally-implanted devices like pacemakers. It can also cause bone infections. Common symptoms of sepsis include:
- Low blood pressure.
Other symptoms may develop, depending on which internal organs become infected.
Staph infections of the lungs leads to pneumonia. Symptoms may start suddenly and may include:
- High fever.
- Shortness of breath.
- A cough that brings up mucus, which may be rust-colored.
How does staph spread?
Staph is a contagious infection. It spreads through skin-to-skin contact with an infected person.
It also spreads through contact with contaminated objects, such as shared towels, household items, or athletic equipment. A person with a staph infection can spread it for as long as they are infected.
Who is at risk for a staph infection?
Anyone can get a staph infection. Certain risk factors make it more likely, including:
- A current or recent hospitalization, or having a recent surgery.
- Having a catheter, feeding tube, or port.
- Having an open wound or sore.
- Kidney dialysis.
- Living or having close contact with someone who has staph.
- Living in a long-term care facility.
- Playing contact sports.
- Poor food handling.
- Sharing towels or athletic equipment
- Taking injection drugs.
Other health-related factors can also increase your risk for developing a staph infection or having a severe infection. These include:
- Cancer, especially if undergoing chemotherapy.
- Having a weakened or suppressed immune system.
How is a staph infection diagnosed?
When it comes to a staph skin infection, your doctor can usually diagnose based on appearance alone.
For more serious infections, or infections of internal organs, other testing may be needed. These may include collecting a sample of blood, pus, or mucus from the lungs (sputum) and testing it in a lab. Lab tests will be used to diagnose the infection and to figure out which antibiotics will be effective treatment.
How is a staph infection treated?
A minor skin infection is often treated with warm soaks and basic wound care, including a bandage. For more serious staph skin infection, antibiotic treatment may be prescribed, either as ointment or a pill. In some instances, your doctor may drain your abscess of pus to help it heal.
For a severe or widespread infection, you may need a more powerful antibiotic, given through an IV. These antibiotics travel through the bloodstream to kill bacteria throughout the body.
If staph has infected an implanted device, it may need to be removed. This may involve surgery.
Increasingly, staph infections are resistant to common antibiotics like methicillin and penicillin. Resistant staphylococcus are referred to as methicillin resistant staphylococcus aureus (MRSA), and they are often harder to treat.
Staph infection prevention
While there is no vaccine for staph, there are several ways you can lower your risk for infection. These include:
- Washing your hands frequently with soap and water.
- If soap and water aren’t available, clean hands with an alcohol based hand sanitizer.
- Keeping wounds clean and covered until they heal.
- Don’t share personal items like towels, razors, or sports equipment.
- Practice good food hygiene by always washing your hands before eating. Additionally, make sure to refrigerate leftovers as soon as possible.
- Reduce tampon usage, use low-absorbency tampons, or alternate tampon and sanitary pad usage.
Taking antibiotics correctly
Bacteria like staphylococcus evolve rapidly. Decades of antibiotic overuse and misuse has led some staph bacteria to evolve and become resistant. Given this, one of the best ways you can also help combat MRSA (methicillin-resistant Staphylococcus aureus) is by taking your antibiotics correctly.
- Don’t take antibiotics when they’re not needed. Antibiotics are ineffective against colds, flus, and other infections caused by viruses.
- Don’t skip doses.
- Follow all of your doctor’s instructions regarding taking the prescription.
- Always finish the entire prescription, even if you start feeling better.
Centers for Disease Control and Prevention. Methicillin-resistant Staphylococcus aureus (MRSA) (https://www.cdc.gov/mrsa/community/index.html)
MedlinePlus: National Library of Medicine. Staphylococcal Infections (https://medlineplus.gov/staphylococcalinfections.html)
National Center for Biotechnology Information (NCBI): National Library of Medicine. Staphylococcus Aureus (https://www.ncbi.nlm.nih.gov/books/NBK441868/)