Relative to other health care-associated infections, the overall incidence of illnesses caused by Carbapenem-resistant Enterobacteriaceae (CRE) was relatively low in the United States during the period of 2012 through 2013, a new Centers for Disease Control and Prevention study indicated.

CRE infections are a worldwide menace. With limited treatment options, infections caused by these organisms often lead to death, so they are commonly referred to as "killer bacteria." Infections usually occur in hospitals, nursing homes, and other health care settings, according to the Centers for Disease Control and Prevention (CDC). Generally, people in good health are not at risk from these bacteria commonly transferred through touch. It is believed CRE spreads when a doctor touches first an infected patient and then another uninfected patient. These bacteria also contaminate the surfaces of medical instruments and hospital furniture, yet it's unclear how long they live.

To better understand these bacteria, a team of researchers from the CDC in Atlanta conducted an active surveillance of these deadly bacteria in seven metropolitan areas in Colorado, Georgia, Maryland, Minnesota, New Mexico, New York, and Oregon. The total population in the participating areas under surveillance was an estimated 13.2 million in 2013.

Nightmare Bacteria

Dr. Alexander J. Kallen and his colleagues examined cases of CRE recovered from sterile-site or urine cultures during 2012-2013. After identifying the specific strains, the research team performed an analysis.

“During this two-year surveillance period, 599 incident CRE cases were reported across seven emerging infectious program sites, resulting in an overall crude incidence of 2.93 per 100 000 population,” wrote the authors.

The average age of the patients was 66 years old. Death occurred in 51 cases (9 percent). Most cases (75 percent) occurred in people with prior hospitalizations or indwelling devices, such as urinary catheter or a central venous catheter (73 percent). About 56 percent of admitted cases resulted in a discharge to a long-term care setting.

The estimate of 2.98 per 100,000 people, the researchers say, is substantially lower than incidence rates for other infections associated with health care exposures, including methicillin-resistant Staphylococcus aureus (25.1 per 100,000), invasive candidiasis (13.3 to 26.2 per 100,000), and Clostridium difficile (147.2 per 100,000).

“The frequency with which individuals with CRE are transferred between facilities emphasizes the need for regional control efforts in all the facilities,” noted the researchers.

Source: Guy AY, Bulens SN, Mu Y, et al. Epidemiology of Carbapenem-Resistant Enterobacteriaceae in 7 US Communities, 2012-2013. JAMA. 2015.