An Antibiotic-Resistant Bacterium Worries Public Health Officials
Public Health Feature -- December 2003
By Ken Ortolon
When several inmates at the Bexar County jail in San Antonio developed skin eruptions last December, physicians originally diagnosed them as spider bites. But when the eruptions began to spread, eventually afflicting more than 150 prisoners, officials with the San Antonio Metropolitan Health District were brought in. They quickly determined the inmates had contracted an antibiotic-resistant strain of Staphylococcus bacteria known as methicillin-resistant Staphylococcus aureus (MRSA).
Significant outbreaks of MRSA in jails, day care centers, schools, and other facilities throughout Texas and the nation during the past 19 months have concerned public health officials. This potentially life-threatening disease once was considered a problem that mainly afflicted patients in hospitals or residents of long-term care facilities, says Neil Pascoe, RN, an epidemiologist with the Infectious Disease Division of the Texas Department of Health (TDH).
Officials aren't sure how MRSA spread to the community, but they say overprescribing of antibiotics may be a contributing factor. They warn physicians to be alert for these bacteria if they see staph infections that do not respond to the normal course of antibiotics. MRSA is resistant to penicillin and related antibiotics, but can be treated effectively with other drugs.
Hitting the Community
Mr. Pascoe says that around May 2002, public health officials began seeing a large jump in the number of cases of community-acquired MRSA in Texas.
"It has been going on a while, but that's really when I noticed a big increase in the number of reports," he said. "And they're coming from everywhere -- from jails, day care centers, schools, school football teams, athletic departments, volleyball players, wrestlers. It's getting to be ever-present in populations where we haven't seen these infections before."
In addition to the outbreak at the jail, several hundred MRSA cases have been reported in child care centers and among a variety of middle school and high school athletic teams in San Antonio, says Fernando Guerra, MD, director of the San Antonio Metropolitan Health District.
"It's hard at any given time to know what the cumulative numbers are, but certainly in the jail population we've probably had more than 150 cases during a period of about six months," he said. "In the schools, there are some campuses at which we've had 10 or 12 kids who have been identified by either the coaches or school nurses."
Dr. Guerra says calls to school officials, day care centers, and hospital emergency departments indicate that the community outbreak continues. In a recent three-month period, one of San Antonio's children's hospitals reported 105 cases of MRSA in preschool and school-age children, and one 20-month-old toddler died from MRSA septicemia.
In September, Pat Crocker, DO, chief of emergency medicine at Austin's Brackenridge and Children's hospitals, told the Austin American-Statesman that Brackenridge was seeing at least 10 people a day with MRSA infections. One day in August, a record 14 cultures were confirmed as MRSA.
Two years ago, only about one of every four staph infections seen at Brackenridge were resistant to penicillin and related antibiotics, but that has increased to 60 percent, Dr. Crocker says.
Mr. Pascoe says football teams have been especially hard hit by MRSA because of the large number of skin breaks that occur in that sport. "I know of at least 20 high school football teams around the state with this problem," he said. "We have one football team with 25 members with soft-tissue infections. Some of them are recurrent infections. Nine of the 25 have culture-confirmed MRSA."
While problems with MRSA have been particularly acute since last year, Corpus Christi pediatric infectious disease specialist Jaime E. Fergie, MD, chair of Texas Medical Association's Committee on Infectious Diseases, says the problem has been around for some time. In an article published in the Pediatric Infectious Disease Journal in September 2001, Dr. Fergie and Kevin Purcell, MD, PharmD, RPH, reported a significant jump in MRSA cases in Corpus Christi as early as 1997.
Drs. Fergie and Purcell reviewed all cases of Staphylococcus aureus at Driscoll Children's Hospital between Oct. 1, 1990, and Dec. 31, 2000, and identified 147 cases of MRSA. A review of the medical records of 128 patients confirmed 60 cases of community-acquired MRSA during that period. Of those 60 cases, 53 occurred since 1997 and 35 occurred in 2000 alone.
"What we have noticed since 1997 is that an organism that is usually seen only in the hospital is now becoming very common in the community," Dr. Fergie said. "That bacterium, that germ that in the past was just associated with infections acquired in the hospital, is now being seen in children who are otherwise perfectly healthy."
Mr. Pascoe says there are two theories about how MRSA jumped from hospitals to the community. One is that patients who originally acquired MRSA in the hospital have spread it to family members or friends.
Dr. Fergie says that may be only a minor part of the problem. "I think the major part of the problem is that these organisms are appearing new in the community at least in part because of the tremendous use of antibiotics that puts pressure on these organisms and selects the more resistant ones."
Mr. Pascoe agrees that overprescribing of antibiotics and patients' failure to complete prescribed courses of antibiotics could be producing new antibiotic-resistant strains. He says there is some epidemiologic basis and laboratory support for the theory "that this is a new problem in the community because of the overuse or abuse of antibiotics, both by the general public and on the part of practitioners toward prescribing antibiotics when they're not strictly indicated, when it's not supported by a culture, and perpetuated by people who stop taking their antibiotics after a couple of days because they start to feel better. And many times these are the very groups of common bacteria that we are seeing more frequently."
Recognizing the Right Bug
The key to dealing with MRSA is to recognize quickly that an infection is not responding to the antibiotics that physicians normally use to treat staph infections, Dr. Fergie says.
"The most common site of infection for staph is the skin," he said. "If you have an abscess, eventually it will drain by itself or the physician can open it up and drain it, and that's the end of the story. But if it's in more difficult places, such as the lungs, that's a major problem. And if the physician is treating for the common organism, he or she is not going to provide the right antibiotic, and the infection is going to get more severe. The patient may require surgery later on."
In fact, death is possible if the proper antibiotic is not administered in time. In 1999, the U.S. Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report cited four cases in which children in Minnesota and North Dakota died of community-acquired MRSA.
"These were previously normal, healthy children who died with this infection," Dr. Fergie said. "Part of the cause of death likely was that this problem was not recognized early on and the treatment with appropriate antibiotic was started a little later than what you would have wanted."
In their article, Drs. Fergie and Purcell conclude that the emergence of community-acquired MRSA might require a change in the initial selection of antibiotics. Dr. Crocker says Brackenridge Hospital is monitoring its MRSA culture rate and will change to a different antibiotic in the initial treatment for staph infections if the rate continues to increase.
While penicillin-related antibiotics are largely ineffective against MRSA, oral antibiotics such as trimethoprim-sulfamethoxazole and clindamycin work well against it, Dr. Fergie says. If a physician decides to hospitalize a patient, the intravenous antibiotic vancomycin also is effective, he adds.
Obtaining More Cultures
Mr. Pascoe says TDH would like to see more physicians order cultures of staph infections, particularly if the initial course of treatment fails. "I know physicians don't want to be told that they have to get a culture, but the fact of the matter is we're seeing more and more of this problem spread within families and in different settings because people are failing treatment and spreading it to others before they get reevaluated and on the right antibiotic regimen," he said.
TDH also is educating physicians, school officials, parents, and others about the prevalence of MRSA and how to combat it. The department has posted recommendations for school athletic departments, day care centers, and parents on its Web site. Recommendations for jails and information that physicians can give patients on caring for wounds to avoid contaminating others also are in the works, Mr. Pascoe says.
Hand-washing is at the top of TDH's recommendation for preventing the spread of MRSA because the infection is primarily spread through person-to-person contact.
"If you get the bacteria off your hands either through hand-washing or use of an alcohol-based hand sanitizer, you're 95 percent of the way there," Mr. Pascoe said. "If we practiced better personal hygiene, we wouldn't have as many communicable disease issues as we do today."
Ken Ortolon can be reached at (800) 880-1300, ext. 1392, or (512) 370-1392; or by email at Ken Ortolon.
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