Healthcare-Associated Infections
Peter Linden, MD

Discussion

Dr Kollef: Are you seeing more Klebsiella pneumoniae carbapenemase (KPC) producing Klebsiella? At St. Louis it just seems like we are seeing more, even in the community. More than 30% to 40% of the Klebsiella isolates now are KPC-positive. You mentioned Clostridium difficile and methicillin-resistant Staphylococcus aureus (MRSA), but maybe KPC Klebsiella is another that in the next 5 years could be a problem.
Dr Linden: This also gets back to the issue of knowing your local organisms and your local pathogens and incorporating that information into your decisions.
Dr Kollef: I do not think that there is a high level of awareness among clinicians in general about recognizing healthcare-associated risk factors, especially among the emergency department physicians and hospitalists, or even the surgeons, who are seeing these patients come in from the community.

Dr Linden: I think one of the unintended consequences of CMS (Centers for Medicare and Medicaid Services) reimbursement is that we are taking a very defensive posture in terms of documenting what these patients coming into our system have already. We have purchased an informatic system in which all patients will be swabbed at admission, and a centralized automated system will record all of their results and will recommend additional tests as needed. For example, if the patient has diarrhea, the system will recommend testing for C difficile. We will be able to show what was acquired in the community, in another hospital, or in a para-health setting.
Dr Kollef: The problem is that even for MRSA or C difficile, the sensitivity is not even close to 100%.
Dr Linden: But it can be helpful if the patient develops pneumonia 3 days later and you have the MRSA swab.
Dr Napolitano: One thing that I think is important is that in the past, surgeons have not really embraced the concept of appropriate or inappropriate antibiotics. The general understanding has been that surgical source control was more important than antimicrobial therapy. Yet now, there have been several studies that have identified antibiotic therapy as being as important as source control. In patients with intraabdominal infections, inadequate antibiotic selection is associated with poor outcomes even with good source control.¹
Dr Linden: Of the patients who come in with resistant organisms, can you identify something from their demographics that would help you to target therapy?
Dr Napolitano: Recent studies have shown that there is increasing worldwide resistance of Escherichia coli in patients with complicated intraabdominal infection, with 40% resistant to ampicillin/sulbactam. Risk factors for multidrug resistant infections included longer preoperative hospital stay and previous antimicrobial therapy.² But you do not find out who until after you operate on them.
Dr Owens: A recent paper examined antibiotic-resistant E coli in the urinary tract.³ In that study, individuals with complicated urinary tract infections admitted to the hospital were shown to have an increasing probability of having fluoroquinolone-resistant E coli strains resulting in inappropriate therapy. They illustrated that the pattern of increasing fluoroquinolone use correlated with increased isolation of fluoroquinolone resistant E coli over time.

References
1. Krobot K, Yin D, Zhang Q, et al. Effect of inappropriate initial empiric antibiotic therapy on outcome of patients with community-acquired intra-abdominal infections requiring surgery. Eur J Clin Microbiol Infect Dis. 2004;23:682-687.
2. Seguin P, Laviolle B, Chanavaz C, et al. Factors associated with multidrug-resistant bacteria in secondary peritonitis: impact on antibiotic therapy. Clin Microbiol Infect. 2006;12:980-985.
3. Johnson L, Sabel A, Burman WJ, et al. Emergence of fluoroquinolone resistance in outpatient urinary Escherichia coli isolates. Am J Med. 2008;121:876-884.