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Physicians Dedicated to Battling Emerging and Resistant Pathogens

In the past few years, physicians and patients alike have become more alarmed by the increasing number of emerging and resistant pathogens – organisms that do not respond to conventional treatment.

“There are several pathogens we are quite concerned about on a routine basis in the hospitals that we work in,” said Dr. Mark Dougherty, co-founder, with Dr. John Meek, of Lexington Infectious Disease Consultants. These hospitals include Central Baptist, Saint Joseph, Saint Joseph East and Cardinal Hill Rehabilitation Hospital. Lexington Infectious Disease Consultants is the hospital epidemiologist at each of those hospitals.

Methicillin-resistant Staphylococcus aureus (MRSA) has been in the headlines recently, but the news about it has taken a different twist.

“Most people know about MRSA, but there are some things that are changing with it,” Dougherty said. “MRSA, which has traditionally been sensitive to vancomycin, is now becoming slowly more resistant to vancomycin. One of the big issues that we’ve seen with MRSA now is it’s actually coming from the community and family units and sports teams and schools, rather than from the hospital.”

In some communities, up to 4 percent to 5 percent of inhabitants will have MRSA colonization. “The organism is just sitting there, waiting for a break, waiting for an opening, a cut, surgery or something,” Dougherty said. Because of MRSA’s aggressiveness, it requires very little for someone to go from being colonized to being infected.

“Community-acquired MRSA is a much more virulent and aggressive organism, so if you get colonized with it, you’re much more likely to get infected with it,” Dougherty said.

A deceptively simple mechanism for containing staph infections – improved hand hygiene – has made a huge difference in incidences of MSRA in hospitals, Dougherty said.

“We have a much bigger emphasis on hand washing than we used to,” he said. “It’s not just hand washing after you see the patient; it’s the hand washing before you see the patient, and it should happen every time regardless – when you walk in the room, when you walk out of the room and sometimes (even) in the middle of the exam. Hand hygiene is an effective control measure to reduce incidences of all these organisms.”

Vaccination is another key means of battling infectious diseases.

“I personally think influenza vaccine should be mandatory for all health-care workers,” Dougherty said. “I don’t think health-care workers have a right to expose patients to infectious diseases. Last year at Central Baptist Hospital, we made the influenza vaccine mandatory. If someone didn’t want the vaccine, they had to sign a note declining it.”

Some bacteria require more stringent methods of prevention and treatment. A new strain of clostridium difficile (C. difficile or C. diff) has emerged that is much more potent than the older strain, producing higher levels of toxins. C. difficile infections have become more frequent, more severe and more difficult to treat.

According to the Mayo Clinic, C. difficile most commonly affects older adults in hospitals or long-term-care facilities and typically develops during or shortly after a course of antibiotics. Sometimes antibiotics can destroy normal, helpful bacteria, and in these instances, C. difficile can quickly grow out of control. But this new strain has shown up in people who haven’t been in the hospital or taken antibiotics.

“In the past we used to think C. difficile was mostly a nuisance,” Dougherty said. “We made steady progress in reducing the risk in patients of most of these resistant organisms, but C. diff in particular was on the rise. Now we know it can be a very serious problem that can lead to not only sepsis but sometimes overwhelming illness to the point where the patient requires removal of the colon or even dies. That’s become an emergent phenomenon across the country.”

C. difficile can produce toxins that attack the lining of the intestine. Precise contact precautions need to be in place for patients with C. difficile, including washing hands with soap and water, because alcohol-based hand sanitizers may not effectively destroy the spores, and using double-terminal cleaning with bleach-containing products, which does kill the spores.

“We’ve finally made some inroads in lowering the incidence of C. diff through these methods,” Dougherty said. “We’re not fighting a losing battle, but we still have work to do.”

Overuse of antibiotics is a contributing factor in the increase of incidences of C. difficile as well as some other pathogens. (Ironically, the standard treatment for C. difficile is another antibiotic.) The Infectious Diseases Society of America (IDSA) says the more widely antibiotics and antivirals are used, the more likely it is that antimicrobial-resistant strains of microorganisms will emerge. Although antibiotics, antivirals and other antimicrobials have saved millions of lives, these drugs are losing their effectiveness because of antimicrobial resistance, according to the IDSA. Antimicrobial resistance refers to microbes’ natural ability to evolve genetically to counter the drugs. It may be either chromosomally mediated or plasmid mediated. Some of this is inevitable, but over-prescription and improper use of antimicrobials plays a big role. The IDSA maintains that up to half of antibiotic use is unnecessary or inappropriate.

Dougherty, who is a member of the IDSA, agrees antibiotics should be used with caution.

“Most people don’t acquire C. difficile unless their flora are depleted by antibiotics, so we want to make sure that when we use antibiotics in this day and time, the antibiotics are truly indicated,” he said. “We should not be giving any antibiotics for viral infections. We should be trying to give shorter courses of antibiotics. We should be highly selective in the types of antibiotics that we use. We need to engage in critical thinking and not just do things the way we’ve done in the past or do things by rote. We need to think about the risk versus the benefits of everything we’re doing.”

By Tanya J. Tyler, Associate Editor, Kentucky Doc Magazine



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