Community-Associated Antibiotic-Resistant Staph Infection (CA-MRSA)

What is antibiotic-resistant staph infection?

Antibiotic-resistant staph infection, also called methicillin-resistant staph infection, or MRSA, is an infection caused by a type of bacteria that is resistant to many commonly used antibiotics. Resistance means that some antibiotics (in this case, methicillin, oxacillin, penicillin, and amoxicillin) are not able to kill the bacteria and stop the infection. The bacteria causing these infections are a type of Staphylococcus aureus bacteria. They are often simply called staph.

How does it occur?

Staph bacteria are commonly carried on the skin or in the nose. They are one of the most common causes of skin infections in the US. Most of these skin infections are minor (such as pimples and boils) and heal on their own without antibiotics. However, staph bacteria can also infect the bloodstream, urinary tract, lungs, or surgical wounds, causing very serious illness. When an infection is caused by antibiotic-resistant bacteria, it can be hard to cure.

Resistant staph bacteria have developed in response to the widespread use of antibiotics. MRSA infections have been a problem in hospitals and nursing homes for about 20 years. Usually the people who get these infections are elderly or very sick or who have an open wound or a tube going into their body. But now these infections are being seen more often in healthy people in the community. MRSA infections that are acquired by people who have not recently been hospitalized (within the last year) or have not had a medical procedure (such as dialysis, surgery, or catheter placement) are called community-associated MRSA infections, or CA-MRSA. These infections in the community are usually skin infections, such as pimples and boils, and occur in otherwise healthy people.

The ways that community-associated MRSA skin infections may spread are:

• close skin-to-skin contact
• openings in the skin, like cuts or scrapes
• crowded living conditions
• poor hygiene
• sharing toys, towels, soap, or equipment, such as sports equipment.

CA-MRSA infections seem to be quite contagious. One study found that if one person carried the germ, there was a 30% chance that others in the family did, too.

What are the symptoms?

Skin infections may look like a pimple or boil. They may be red, swollen, painful, or have pus or other drainage. They can also look like a rash, with redness and oozing or crusting.

How is it diagnosed?

If there is an outbreak of CA-MRSA in the community, your healthcare provider will suspect that your infection may be MRSA. Pus from the infected wound will be sampled to see if bacteria can be grown in the lab from the sample. If bacteria do grow in the lab, the bacteria will be tested to see what antibiotics work against them.

How is it treated?

You may be treated with antibiotics. If you have a pimple or boil that needs to be opened, your treatment may be draining of the sore. Often antibiotics are not needed after the infection is drained.

Drainage of skin boils or abscesses should be done only by a healthcare provider. Serious complications as well as the spread of infection can result if you try to treat open sores at home.

If antibiotics are needed, an MRSA infection can usually be treated with antibiotics such as sulfamethoxazole/trimethoprim, doxycycline, and clindamycin. If you are given an antibiotic, take all of the doses, even if the infection is getting better, unless your provider tells you to stop taking it. Not finishing your antibiotic may cause more resistant bacteria to develop. Do not share antibiotics with other people or save them for another time.

If the infection does not get better within 2 to 3 days after you saw your provider, tell your provider. If other people you know or live with get the same infection, tell them to see their healthcare provider.

If lab tests show your bacteria are resistant to the antibiotic you were given, your provider will tell you and prescribe an antibiotic the tests show will work.

How long will the effects last?

The rash or sore usually goes away within a few days of starting the antibiotic. If the sore was treated with draining, it may take several days or a week to heal, depending on how deep the sore was.

How can I help take care of myself?

• Wash your hands thoroughly with soap and warm water for at least 15 seconds before and after you touch the infected area.
• Put a warm, moist cloth on the area for 10 to 15 minutes at least 3 times a day. Use a clean cloth each time. Wash the area with warm water and soap after soaking or applying the moist cloth. Rinse well. Keep the cloths used for this purpose in a separate laundry container and wash them in hot water separate from other laundry. If you throw the cloths away after use, put them in a sealed plastic bag to keep them separate from other trash.
• If the infection is in your groin or on your buttock, you can soak in a tub of warm water for 10 to 15 minutes. Be sure to clean the tub well before and after soaking so that the bacteria cannot be passed to others.
• If your healthcare provider put gauze inside the wound to help pull the drainage out, you should not remove it. If you have to remove the packing gauze, you may be instructed on how to put more gauze back in after soaking. This will help keep the skin from healing over the top of the wound before it is finished draining. (If this happens the area can get infected again.) Put the removed gauze in a closed plastic bag to keep it separate from other trash. Wash your hands well after handling the used gauze.
• Put a sterile gauze bandage over the area until it is healed. If drainage soaks through the bandage, you should change it as soon as possible. If the bandage sticks when you try to take it off, soak it off with warm water. If your bandage gets wet or dirty, put a clean one on as soon as you can. Put dirty bandages in a sealed plastic bag, keeping them separate from other trash. Wash your hands well after changing bandages.
• If you were given a prescription for antibiotics, be sure to get it filled right away. Follow the directions exactly. Take the medicine until it is completely gone. Do not stop taking it just because you feel better. The infection may not be completely gone.
• Acetaminophen may help decrease your pain.
• If you have an underlying illness, such as diabetes, your healthcare provider will want you to schedule regular appointments so your condition can be monitored.
• Call your healthcare provider right away if:
  • An infection does not begin to get better within 3 days after you started taking an antibiotic.
  • You have a fever of 101.5° F (38.6° C) or higher.
  • A wound is becoming more painful or has red lines leading away from it.
  • A wound or bandages smell bad or you have greenish or yellowish drainage.
  • You start to have chills, nausea, vomiting, or muscle aches.

How can I prevent CA-MRSA skin infections?

To help prevent skin infections, practice good hygiene:

• Keep your hands clean by washing thoroughly with soap and warm water or using an alcohol-based hand sanitizer.
• Keep cuts and scrapes clean and covered with a clean, dry bandage until healed.
• Avoid contact with other people's wounds or bandages.
• Avoid sharing personal items such as towels or razors.
• Shower after you work out at the gym or on the playing field. If you use shared athletic equipment, such as helmets or pads, use a barrier, such as clothing or a towel, between your skin and the equipment. Wipe surfaces of equipment before and after use. See if you can find a way to use the same equipment with each practice rather than sharing.

It is also important to take antibiotics only when necessary for infections. Finish all antibiotics as prescribed by your healthcare provider to help avoid creating resistant bacteria.

To prevent spreading a staph infection to others, follow these steps:

• Cover your wound. Keep wounds that are draining covered with clean, dry bandages. Follow your provider's instructions on wound care. Pus from infected wounds can contain the bacteria. Keeping wounds covered helps prevent spreading it to others. Dirty bandages or tape should be put into a plastic bag and sealed before they are thrown out with the regular trash.
• Clean your hands. You, your family, and others in close contact should wash their hands, including under the fingernails, often with soap and warm water or use an alcohol-based hand sanitizer, especially after changing the bandage or touching the wound.
• While you or a family member has a staph infection, keep your nails trimmed short to help prevent bacteria from living under the nails.
• Don't share personal items like towels, washcloths, razors, clothing, athletic equipment, or uniforms that may have had contact with the infected wounds or bandages. Wash sheets, towels, and soiled clothes with hot water and laundry detergent. After washing, drying clothes in a hot dryer helps kill bacteria in clothes, too.
• Talk to your healthcare provider. Tell any healthcare providers who treat you that you have or had a staph or MRSA skin infection.