Overview
Staph infections are caused by staphylococcus bacteria. These germs may be found on the skin or in the nose of many people and cause no harm.
If they do cause harm, staph bacteria most often cause a food poisoning or a skin infection that can be treated quickly and without complications.
But some staph infections can cause serious illness.
Staph infections can be deadly if the bacteria get into the bloodstream, joints, bones, lungs or heart. If the infection is in or near a medical device, such as a catheter, surgery may be needed to remove the device.
Medicine that kills bacteria, called antibiotics, is used to treat staph infections, but not food poisoning by staph bacteria. Infected tissue also may be removed to treat staph infection.
Symptoms
Staph infection symptoms vary depending on where the infection is in the body and how serious it is.
Staph skin infections
On the skin, a staph infection might be more common in areas where the skin is already damaged. These areas include eczema patches and places on the skin where insulin is injected or where you might have a bug bite.
Common skin infections caused by staph bacteria include:
- Impetigo. Sores on the face that burst and leave a yellow crust.
- Folliculitis. Pus-filled bumps around hair follicles that look like pimples. Unlike pimples, these staph infections are likely to be itchy and turn into a crusty sore.
- Boils, furuncles and carbuncles. Deep pockets of pus are called boils or furuncles. They are often found under the arms or around the groin or buttocks. Dockets of pus around the neck area are called carbuncles.
With these types of skin infections, people usually do not have a fever or symptoms of a more serious infection.
Staph infection
Staph infections can be minor, as shown in the image on the left, but can quickly turn serious, as shown in the image on the right.
A staph infection that starts on the skin but moves deeper may cause symptoms throughout the body, including:
- A change in skin color, called discolored. This may be a shade of red, purple or brown depending on your skin color.
- Skin that is discolored, swollen, warm painful and may feel hard.
- Skin that forms a blister that can break and leave a discolored, raw surface that looks like a burn.
- Fever and chills.
- A general feeling of being sick, called malaise.
- Serious pain.
These symptoms suggest that the infection is serious. Examples of serious staph infections include cellulitis, mastitis, necrotizing fasciitis, or staphylococcal scalded skin syndrome.
Food poisoning from staph bacteria
Staph bacteria can get into food from a person with a staph infection. The bacteria also can get into food from someone who has the bacteria on their skin or in the nose but who isn't ill. If food stays at room temperature for too long, the number of bacteria in the food grow and make toxins.
Symptoms you can expect with food poisoning from staph bacteria include:
- Upset stomach and vomiting.
- Stomach cramps.
- Loose stools, also called diarrhea.
Symptoms come on quickly, usually within hours of eating contaminated food. Food poisoning from staph bacteria usually doesn't cause a fever. And symptoms usually disappear quickly, too, often lasting less than a day.
Bloodstream infections, called bacteremia
Bacteremia is when staph bacteria enter the bloodstream. If it isn't treated, this type of infection can cause an overwhelming immune response, called sepsis. A bloodstream infection caused by staph bacteria can lead to a complication of sepsis called septic shock, where organs begin to fail.
Symptoms of bacteremia can include:
- Fever or chills.
- Fast breathing or not being able to catch your breath.
- Fast heart rate.
- New confusion or disorientation.
- Skin that feels cold or sweaty.
- Severe pain.
Toxic shock syndrome
Toxins made by some strains of staph bacteria cause the body's immune system to overreact. This life-threatening condition has been linked to certain types of tampons, skin wounds and surgery.
Toxic shock syndrome usually develops suddenly with:
- A high fever.
- Skin rash or color change in a pattern that mimics underwear.
- Stomach pain, feeling sick to the stomach or vomiting.
- Confusion.
- Muscle aches.
- Diarrhea.
Septic arthritis
Staph bacteria can infect the body's joints or artificial joints. The bacteria often target the knees, shoulders, hips, and fingers or toes.
Symptoms of septic arthritis may include:
- Joint swelling.
- Severe pain in a joint.
- Fever.
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When to see a doctor
If you have symptoms of sepsis or septic shock get emergency care right away. A staph infection can cause different types of sepsis, but symptoms may include:
- Fever or chills.
- Fast breathing or not being able to catch your breath.
- New confusion or disorientation.
- Skin that feels cold or sweaty.
- Severe pain.
- Skin rash or color change in a pattern that mimics underwear.
- Stomach pain, feeling sick to the stomach or throwing up.
- Muscle aches.
- Diarrhea.
- Joint swelling.
- Severe pain in a joint.
Make an appointment to see a healthcare professional for any skin infections or wounds that don't get better.
Also see a member of your healthcare team for:
- A change in skin color. This may be a shade of red, purple or brown depending on your skin color.
- Skin that is swollen, painful to touch or warm.
- Skin with pus-filled blisters.
- A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or greater.
If a skin infection is spreading between family members, talk to your healthcare professional. Also talk to a member of your healthcare team if two or more members of your family, sports team or gym have skin infections.
Causes
Staph infections are caused by contact with staph bacteria or toxins from the bacteria. Staph bacteria can spread from person to person. Or you may touch something with the bacteria on it and then touch your body.
Staph bacteria can live on the human body without making you sick. The bacteria live on skin as well as in the nose and the back of the mouth. Many people have staph bacteria and never develop staph infections.
Risk factors
A serious staph infection may be more likely for some people than others. For example, the risk goes up as you age. People with a weakened immune system are at higher risk. And skin diseases may raise the risk of staph infections.
Some health conditions, treatments and medical devices raise the risk of a serious staph infection, including:
- Diabetes.
- HIV infection.
- Kidney failure, also called end-stage renal disease.
- Treatment with chemotherapy.
- Medical devices inside the body, such as an artificial joint, or that travel from outside to inside the body, such as a catheter.
- Use of dialysis.
- Treatment with systemic steroids.
Higher risk of staph infection also may be linked to broken skin, including:
- Chronic skin disease.
- Burns.
- Minor or serious skin damage, trauma or wounds.
- Surgical procedures.
- Injections.
- Acupuncture.
Some staph bacteria can't be killed by standard antibiotics. One example is methicillin-resistant staphylococcus aureus, also called MRSA. People in the hospital are at risk of MRSA infection. But it also can affect people in the general public.
People at high risk of MRSA that spreads in the community include:
- People who live in crowded conditions. This could include people in college dorms, nursing homes, military facilities or correctional facilities. It also can include people living in shelters.
- People with a high chance of skin damage. This could include people who use injected illicit drugs and people managing chronic skin disorders.
- People who have a weakened immune system. This may include children younger than age 2, people over age 65, and people with HIV infection.
- People who work with or handle animals. People who work with farm animals have a higher risk of getting some strains of MRSA. This includes vets, people who work on or around farms, and meat-processing workers.
- Some population groups. Some groups of people have higher rates of MRSA infection. This includes Native American and Alaska Native people, and African Americans.
- Regular skin-to-skin contact. Athletes in some contact sports, such as football or wrestling, are at higher risk.
Contact sports
The risk of a staph infection may be higher if you're involved in contact sports, including wrestling or mixed martial arts. Staph bacteria can spread easily through cuts, scrapes and skin-to-skin contact. Staph infections also may happen if people share items such as lotions, razors, towels, uniforms or equipment.
Food contaminated with staph bacteria
Food handlers may have staph bacteria on their hands or in their nose but don't get sick. If they don't wash their hands, the bacteria can get into the food being prepared.
Food that isn't cooked before you eat it, such as potato salad, has a higher risk of causing food poisoning than food cooked to order.
Following the guidelines for safe food handling helps control bacteria growth in food. But once a food has toxins in it, cooling it or heating it to the right temperature doesn't get rid of the toxins.
Complications
Skin infections from staph bacteria often heal without complication, but some may leave a scar.
Staph infections that spread to the bloodstream, organs or medical devices can cause serious illness, such as pneumonia or sepsis, and even death.
Medical devices infected with staph bacteria may need to be removed. If a staph infection happens after surgery, you may need another surgery to treat it.
Prevention
You can lower the risk of staph infections by taking actions to keep the bacteria off your skin.
Wash your hands to prevent staph infection
Wash your hands well and often with soap and water for at least 20 seconds. Or use an alcohol-based hand sanitizer with at least 60% alcohol.
Wash your hands before, during and after making food, especially after touching raw animal products. Always wash your hands before you eat.
It's important to wash your hands after you use the bathroom, change diapers, clean up waste from animals or handle trash.
Other times to wash your hands include:
- After touching animals or animal feed.
- Before and after you clean a cut.
- Before and after helping someone who is sick.
- After you sneeze, cough or blow your nose.
Care for cuts, scrapes and wounds
If you get a scrape, cut or other skin wound that isn't serious, first wash your hands. Then wash the area using soap and water. Use a dry, clean bandage to cover the skin damage. For deep wounds, see a healthcare professional.
As your skin heals, don't get the area wet in pools, hot tubs or natural bodies of water such as lakes.
If you have a skin wound or scab, don't pick at it or pop it.
Clean common items and laundry
Clean things you touch often, such as keyboards or remote controls. Also, regularly clean items touched by many people. This includes light switches, gym equipment or lockers.
Follow the cleaning instructions that come with these items, and make sure the disinfectant you use can kill staph bacteria.
For laundry, you don't need bleach to kill staph bacteria. Use laundry detergent and follow the instructions for use.
Don't share personal items
Don't share items such as razors or athletic equipment. And don't share skin products that are already open and have been used.
Use tampons safely
Rarely tampon use can lead to toxic shock syndrome. This illness is caused by toxins made by some strains of staph bacteria. Wash your hands before and after placing a tampon. Change the tampon at least every eight hours and use the lowest absorbency tampon you can.
Take food safety precautions
Wash your hands before handling food. If food will be out for a while, make sure that hot foods stay hot — above 140 degrees Fahrenheit (60 degrees Celsius). Make sure that cold foods stay at 40 degrees Fahrenheit (4.4 degrees Celsius) or below. Refrigerate leftovers as soon as possible. Wash cutting boards and counters with soap and water.
