An emerging form of so-called "flesh-eating bacteria" is caused by a strain that is resistant to standard first-line antibiotics. The same type of bacteria, methicillin-resistant Staphylococcus aureus (MRSA) is causing record numbers of less-serious skin infections in children and also is emerging as a cause of pneumonia, which can be deadly.
- Physicians are seeing more and more infections caused by drug-resistant bacteria, including skin boils, pneumonia and even so-called "flesh-eating bacteria."
- Until recently, infections caused by methicillin-resistant Staphylococcus aureus (MRSA) were unusual in healthy people outside of the hospital.
- Infections caused by MRSA must be treated with different antibiotics.
- Infectious diseases experts are concerned the bacteria will soon become resistant to those antibiotics as well, and few new drugs are in the development pipeline.
Numerous studies on the rise in infections caused by MRSA among healthy people outside of the hospital - nearly unheard of a few years ago - are being presented at the 42nd Annual Meeting of the Infectious Diseases Society of America (IDSA).
"The rate of MRSA infections has risen to epidemic proportions in some places, and the curve isn't flattening out yet," said Kevin Purcell, MD, PharmD, principal investigator of a study on MRSA-caused skin infections at Driscoll Children's Hospital in Corpus Christi, Texas. "Staphylococcus aureus is a bad bug to begin with and this resistant form also is more potent, making it easier for people to become infected."
MRSA is a concern because antibiotics prescribed by physicians only a few years ago typically no longer work. Over time, bacteria can mutate and become resistant to specific antibiotics. Effective antibiotics are available to treat MRSA, but physicians are concerned that the bacteria will eventually become resistant to those as well. Drug-resistant infections have long been a problem in hospitals and among the elderly and chronically ill, but in recent years physicians are seeing these infections more and more in healthy people.
"These reports highlight our concern over the crisis of antibiotic resistance, a problem that is magnified because there simply aren't enough new drugs in the pharmaceutical pipeline to keep pace with the evolution of drug-resistant bacteria, the so-called 'superbugs,' " said Joseph R. Dalovisio, MD, IDSA president. "This crisis has the potential to touch us all because drug-resistant infections can strike anyone - young or old, healthy or chronically ill."
MRSA and "Flesh-Eating Bacteria"
One study being presented at the meeting documents 14 cases of necrotizing fasciitis (known colloquially as the "flesh-eating bacteria") in Los Angeles caused by MRSA, an uncommon cause of the illness. None of the patients died, but all had surgery to remove infected flesh, three needed reconstructive surgery (such as skin grafting) and 10 spent time in the intensive care unit, one for a month. Half originally were thought to have less-serious skin abscesses. Four patients initially were given antibiotics to which the bacteria were resistant, but all 14 patients were eventually successfully treated with the antibiotics vancomycin and/or clindamycin.
Necrotizing fasciitis infections can start in a small cut or trauma and spread throughout the body within hours or days if not treated with surgery and antibiotics. Most cases of necrotizing fasciitis are caused by a different type of bacteria called Group A streptococcus (the same type of bug that causes strep throat) and about a third are fatal.
"This is about as serious an infectious disease emergency as you can get," said Loren G. Miller, MD, MPH, principal investigator at the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center (LA BioMed) and assistant professor of the David Geffen School of Medicine at UCLA. "Thankfully no one died, but physicians need to be aware that if they see cases of necrotizing fasciitis, they should treat for this resistant bug (MRSA) in addition to the other known causes until they know the causative bacterial. This is a major shift in treatment approach.
"We don't know how these people got the infection - there doesn't seem to be a common thread," said Dr. Miller, who also is a staff physician at Harbor-UCLA Medical Center, Torrance, Calif. "Four of the people had absolutely no other medical conditions or risk factors."
MRSA-Caused Skin Infections in Children
From New York to Texas, Maryland to Missouri, researchers are presenting reports at IDSA on the exponentially increasing incidence of MRSA-caused skin boils in non-hospitalized children.
The boils - called abscesses - typically are red and raised, and can be gumball to golf-ball sized. The abscesses can appear anywhere on the body, often on the backs, legs, buttocks and arms, and are filled with pus. Treatment involves draining the abscess, cleaning the wound and prescribing appropriate antibiotics.
Although the infections are rarely fatal, treating physicians must recognize that they may be caused by the MRSA, and treat them with stronger antibiotics.