Superbugs are resistant to all antibiotic treatments
Professor Kaltreider in Biology sent me this link from USA Today, detailing a truly alarming report out of the University of Virginia Medical Center. This story of antibiotic resistance will make MRSA seem like a walk in the park. Full disclosure: I worked as a researcher at the UVa Medical Center for about 14 years, and spent about 8 years or so working with fungal pathogens with the director of Clinical Microbiology. My youngest daughter was born at this hospital, so I know and respect the facility well.
The case study reports a middle aged man with an infection due to one of our enteric bacteria, Klebsiella pneumonia. The patient had a bloodstream infection with this organism. Treatment with the antibiotic carbapenem, considered to be an antibiotic of “last resort,” did not resolve the infection and the patient died. Over the course of the next few months, additional patients became infected with carbapenem-resistant isolates of K. pneumoniae, with similar outcomes. This outbreak marked the largest number of patients with this infection seen to date at UVa. A similar outbreak also occurred this summer at the National Institutes of Health clinical center in Washington, where 7 patients died with essentially untreatable infections.
The USA Today article indicates that thousands of carbapenem resistant infections have been noted throughout the country over the past several years, causing infections in the bloodstream as in this outbreak, urinary tract infections, gastroenteritis, as well as pneumonia. Death rates due to infection are around the 40% mark, however cases have only appeared sporadically so far. Part of the problem with assessing the scope of the issue is that many hospitcal clinical laboratories are unable to follow up infectious disease cases with molecular analysis, particularly if cases come out of facilities such as nursing homes or clinics.
The Centers for Disease Control and Prevention reports that there are significant issues with the emergence of carbapenem-resistant Enterobacteriaceae (CRE), and has offered guidelines for infection management and control. The goal of active surveillance is to identify undetected carriers of CRE, and include recommendations to clinical laboratories when performing disk diffusion antibiotic susceptibility tests, to ensure that proper interpretation of potential carbapenem-resistant Klebsiella isolates is done. Anytime a CRE case is suspected, a modified susceptibility test should be performed to prevent the possibility of a false negative occurring (failure to recognize CRE). Once a reservoir has been identified by molecular typing, acute infection control measures must be implemented. The CDC does not make any recommendations for when those measures should be lifted, so one can assume that once a reservoir is present it may be extremely difficult to eliminate. If a case of CRE is identified, surveillance measures should be extended out from the point where the organism was isolated in the hospital, due to the extremely rapid spread of this organism.