Health Break | Published November 20, 2006 | Written by Marlene Stetson, RN, CIC, director of infection prevention and control, Mount Nittany Medical Center

MRSA Infections: Hospital Or Community?

Before antibiotics many infections were fatal. When antibiotics were introduced in the 1940s, many believed they were the definitive answer to curing bacterial infections. But within a few years some microbes had begun to develop resistance to these life-saving medicines. To some extent, developing resistance was an evolutionary survival response the microbes had to adapt to new their environment, one with antibiotics.

Over the next couple of decades the problem with antibiotic-resistance continued to grow. With the discovery of more antibiotic types and greater use, more resistance developed.

Staphylococcus aureus, referred to as staph, is a type of bacteria with which most people are familiar. Staph is also a bacteria that has developed resistance to some antibiotics. Although commonly carried on the skin or in the nose of healthy people, staph can also cause infection. The staph bacteria can cause simple skin infections (such as pimples or boils) but can also cause more serious infections (such as wound infections or pneumonia). Antibiotic-resistant Staphylococcus aureus is referred to as methicillin-resistant Staphylococcus aureus or MRSA. Methicillin is one of a group of antibiotics that is no longer effective when treating infections caused by MRSA

Until recent years, infections caused by antibiotic-resistant organisms, including MRSA, were mostly associated with infections resulting from care in hospitals and other health care facilities (such as nursing homes and dialysis centers), and are referred to as hospital-acquired MRSA (HA-MRSA) infections. Despite their growing prevalence, however, these strains have been uncommon in the community. But just as bacteria adapted to antibiotics by developing resistance, MRSA changed again in another way. People outside of hospitals now get a strain of MRSA referred to as community-acquired MRSA (CA-MRSA). CA-MRSA has emerged as a growing public health concern.

CA-MRSA infections occur in persons who have not been recently (within the past year) hospitalized or had a medical procedure. They usually involve infections of the skin or soft tissue (such as pimples, boils and abscesses) and occur in otherwise healthy people.
So how can you tell if the infection is caused by the community- or hospital-acquired version of MRSA? You cant without some very specialized genetic testing of the bacteria. However, there are some clues that help distinguish between CA-MRSA and HA-MRSA. Persons with

MRSA that meet all of the following criteria likely have CA-MRSA infection:

  • No medical history of MRSA

  • No medical history in the past year of:
    • Hospitalization
    • Admission to a nursing home, skilled nursing facility or hospice
    • Dialysis
    • Surgery

  • Diagnosis of MRSA was made in the outpatient setting or within 48 hours of admission to the hospital

  • No permanent catheters or medical devices that pass through the skin

In addition to these clues, other factors have been linked to the spread of CA-MRSA infections. Factors include close skin-to-skin contact, openings in the skin such as cuts or abrasions, crowded living conditions and poor hygiene. Related to these risk factors, clusters of CA-MRSA infections have occurred among athletes, military recruits, children, prisoners and other groups.

Although methicillin and other antibiotics wont be effective, others will. Wound care alone may adequately treat some simple skin infections and antibiotics may not be necessary. Its important to not over-treat infections, contributing to further development of microbial resistance.

Prevention is always the best medicine against infection. The following tips will help decrease the chance of developing a Staph or MRSA skin infection.

  • Keep your hands clean by washing thoroughly with soap and water or using an alcohol-based hand sanitizer.

  • Keep cuts and scrapes clean and covered with a bandage until healed.

  • Avoid contact with other peoples wounds, bandages or other items that may have had contact with the wound.

  • Avoid sharing personal items such as towels or razors.

Marlene Stetson is the infection control coordinator at Mount Nittany Medical Center.