SAN DIEGO – The incidence of septicemia due to antibiotic-resistant bacteria (referred to as the ESKAPE pathogens) increased in United States hospitals between 2008 and 2012, yet length of stay and in-hospital mortality both decreased over the same time period.
“We don’t know what’s going on here,” lead study author Dana R. Bowers, Pharm.D., said in an interview at the annual Interscience Conference on Antimicrobial Agents and Chemotherapy. “No new drugs [for septicemia] came out during that time frame. Maybe we’re getting better at identifying these patients and treating them earlier; maybe that’s impacting mortality.”
According to the Infectious Diseases Society of America, ESKAPE pathogens include Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp. “Septicemia caused by these pathogens is particularly concerning because of their propensity for antimicrobial resistance, limited treatment options, and elevated risk of death,” the researchers wrote in their abstract. “However, the burden of ESKAPE septicemia in the United States is relatively unknown.”
In an effort to provide national estimates for ESKAPE septicemia incidence over 5 years and to identify trends related to in-hospital mortality and hospital length of stay, Dr. Bowers, a clinical specialist in infectious diseases at Kingman (Ariz.) Regional Medical Center and her associates retrospectively evaluated the Nationwide Inpatient Sample between 2008 and 2012.
They used clinical classification software to identify patients with septicemia who were at least 18 years of age, and followed the International Classification of Diseases, Ninth Revision, Clinical Modification to identify codes for E. faecium [EF], Staphylococcus aureus [MRSA], Klebsiella pneumonia [KP], Acinetobacter baumannii [AB], Pseudomonas aeruginosa [PA] and Enterobacter spp. [EB].
In all, 7,668,636 patients acquired septicemia during the study period. Of these, 951,677 acquired septicemia due to ESKAPE pathogens. Patients in this cohort had a median age of 67 years, 47% were women, and 66% were white.
The researchers observed that the incidence for septicemia caused by ESKAPE pathogens increased over the time period, especially for MRSA (from 3.8 per 10,000 hospital discharges in 2008 to 14.6 per 10,000 discharges in 2012) and EF (from 6.2 per 10,000 discharges in 2008 to 10.4 per 10,000 discharges in 2012). They also observed a slight decline in median LOS for patients with MRSA (from 11 days in 2008 to 10 days in 2012), PA (from 10 days in 2008 to 9 days in 2012), as well as among those with KP/AB/EB (from 9 days in 2008 to 7 days in 2012).
In-hospital mortality declined over the study period among all pathogen groups and was greatest for those with KP/AB/EB septicemia (from 16.3% in 2008 to 12.1% in 2012).
The researchers concluded that additional research is needed to assess the clinical impact of these findings at the population level. They reported having no financial disclosures.