A growing problem with carbapenam resistant infections
I am sometimes concerned that when I warn students about the dire situation in health care regarding infection control, what the typical students hear is
Blah, blah, blah, wash your hands–Yes, we get it, Singleton. This is going on Twitter
Consequently, I like to back up my assertions with case reports to show the reality of the situation. Here is an alert from the Centers for Disease Control and Prevention, which has had widespread exposure in the media over the past week. Carbapenems are a group of semi-synthetic β-lactam antibiotics. The ring structure in them makes them typically very resistant to most β-lactamases, and as a result they are considered an antibiotic of “last resort” in the treatment of many antibiotic resistant infections. Historically, very low resistance to carbapenems has been observed clinically, however increasing numbers of reports have been observed over the past 10 years in cases with high mortality rates.
The most clinically worrisome group of bacteria are those of family Enterobacteriaceae (Escherichia, Enterobacter, Klebsiella, Proteus, and Serratia), which generally have been susceptible to a variety of antibiotics, but can rapidly acquire resistance. Many members of Family Enterobacteriaceae are members of the normal human microbial flora, and are found on the body in the absence of disease. Transfer of these organisms accidentally during medical care to another body site can result in a hospital acquired, or nosocomial, infection. The CDC estimates that there are around 1.7 million nosocomial infections annually in the US, with up to 90,000 deaths.
The CDC has several mechanisms for collecting data regarding healthcare associated infections, including the National Nosocomial Infections Surveillance system (NNIS) and the National Healthcare Safety Network (NHSN). In 2001, just over 1% of Enterobacteriaceae isolates were reported as carbapenem-resistant (carbapenem resistant Enterobacteriaceae–CRE), however by 2011 this figure had increased to 4.2% of isolates. Significant risk factors for acquiring these infections included urinary tract catheters, indwelling catheters or central lines, or surgery. Nearly half of the patients were over age 65, and almost 25% of the cases were transferred to intensive care units due to the complications. In essentially all cases, the isolates were found to be community-acquired, or the result of an organism being picked up from the patient’s surroundings.
The CDC continues to monitor the spread of carbapenem resistant patient isolates throughout the country. Although the number of cases remains relatively low, currently about 4% of acute-care and 18% of long term care hospitals reported at least one case of CRE in the first half of 2o12, and essentially all of the patients with CRE were currently or had previously received treatment in a health care setting. These numbers have significantly increased over the past decade. The possibility remains that these isolates can spread out into the community into otherwise healthy individuals.
The CDC makes several essential recommendations for dealing with this increasing threat. First, active case detection and universal precautions are critical for identifying infected patients and preventing immediate transfer to uninfected individuals. Second, appropriate use of antibiotics (identifying those that will work, avoiding the use of those that are ineffective) can lead more rapidly to a favorable patient outcome and slow down further the development of further antibiotic resistance. Third, clear lines of communication between patients and their families, health caregivers, and infection control specialists, particularly when patients are moved in facilities, can help to keep the reservoirs of infection contained.