What is a staph infection?

Originally Published: April 5, 2002 - Last Updated / Reviewed On: March 10, 2014
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Dear Alice,

Please explain a staff infection and its symptoms.

Dear Reader,

A staff infection might be when all your employees call in sick on the same day to play hooky. But a Staph (pronounced "staff") infection is medical lingo for an infection caused by staphylococcus aureus bacteria. This pesky little bacterium is very common (many people have some living on their skin all the time), but when it enters the human body, usually through an open cut or break in the skin, it can cause infection and trouble anywhere in the body. Staph infections tend to be pus-producing. Common minor (or relatively minor) skin infections caused by staph include:

Folliculitis
Infections of hair follicles that cause itchy white pus-filled bumps on the skin (often where people shave or have irritations from skin rubbing against clothes)

Boils
Infections deeper within hair follicles that leave large, frequently red inflammations (often occur on the face or neck)

Styes
Infection of the follicle surrounding the eyelashes, causing a sore red bump in the eyelid

Impetigo
The infection kids often get around their mouths and noses that causes blisters and red scabby skin

Abscesses
Infection characterized by pus and swelling that can occur in the skin and in any other organ.

Staph infection is also the leading culprit behind cases of food poisoning, and can be to blame for larger life threatening conditions, such as Toxic Shock Syndrome (TSS), pneumonia, bone infections (osteomyelitis), mastitis in nursing mothers, endocarditis (infection of the inside of the heart), and bacteremia (blood infection). People who are otherwise healthy typically do not usually become severely ill from staph infections, but those at special risk, who have weakened immune systems, include:

  • persons with chronic illnesses, such as diabetes, cancer, lung disease, kidney disease, or HIV/AIDS
  • people with various skin conditions
  • the elderly
  • newborns
  • people recovering from major surgery
  • injection drug users (especially those who reuse needles)
  • people whose immune systems are weakened due to steroid use, radiation therapy, cancer treatment, immunosuppressive medications
  • women who are breastfeeding

Health care professionals can determine that staph (and not some other bacteria) is the cause of an infection by taking a culture (usually a swab from what looks like a giant Q-tip) from the infected site. Once staph has been diagnosed, the provider will prescribe antibiotics that are known to work on that specific strain of the bacteria. These antibiotics (usually either pills or creams applied to the infected body part) typically kill the bacteria and cure the infection within a week or two.

Hospitals are working to stamp out staph infections, in part because the majority of hospital patients fall into at least one "at-risk" category, but also because of drug-resistant strains of staph, including the particularly virulent MRSA (Methicillin-resistant Staphylococcus aureus) strain. Antibiotic-resistance means that strains of staph aren't killed by one or more of the antibiotics that are commonly used to treat staph infections. These strains of staph are becoming an increasingly common threat and while they do not always cause worse or different infections than non-resistant strains, they can be much harder to treat because the most common (and easiest to use) antibiotics may not be effective. People with resistant staph infections may require hospitalization to receive antibiotics through an IV or by injection. Unfortunately some staph infections can even be fatal. Check out the Centers for Disease Control and Prevention (CDC) for more information about MRSA.

Because improper use of antibiotics can help produce resistance to drugs, making future infections much harder to treat, the CDC recommends that patients:

  • follow the directions for any prescription exactly
  • take all of the medicine prescribed (even if one feels better after only a few days)
  • never save old, leftover prescriptions for future use
  • never take anyone else's prescription antibiotics

For a dose of the whys and wherefores of using and ensuring the effectiveness of antibiotics, check out the CDC's Get Smart: Know When Antibiotics Work page for more information.

Other preventative measures are careful treatment of all skin conditions, including wound care after trauma or surgery, IV drug users taking precautions when injecting, and people with special risk factors being attentive to early symptoms of staph. You can also reduce your risk by not sharing needles, razors, sheets, towels, and athletic equipment. Of course, general hygiene is also important; regular hand-washing and bathing (with soap) can help prevent many types of infections. If you have a skin wound that becomes infected, it's a good idea to visit a health care provider. They can test for staph infection, and give you any necessary treatment. Students at Columbia can contact Medical Services (Morningside) or the Student Health Service (CUMC)  to make an appointment.

Avoiding staph infections can help you save your sick days for times when you really are sick (which your employer is sure to appreciate!).

Alice