Hospital-acquired infections by multidrug-resistant organisms, or MDROs, significantly increase mortality rates compared with infections by sensitive strains, researchers said.
MDROs also increase the chances of hospital readmission, they wrote in Clinical Infectious Diseases.
“The results confirm the need to control the spread of [MDRO] infections that threaten global public health, current treatments of bacterial infections and many medical advances,” the researchers wrote.
The retrospective cohort study included 324 patients with MDROs and 676 control patients with infections caused by sensitive organisms. The patients were admitted to the University Hospital of Zaragoza in Spain between 2011 and 2014.
The mean patient age was 71 years, and the average length of hospital stay was 29.8 days.
Altogether, 39.5% of infections involved the urinary tract, 33.8% surgical site, 18.4% respiratory tract and 8.3% bloodstream, the researchers said.
The most common organisms were Escherichia coli (39.4%), Staphylococcus aureus (25.6%) and Pseudomonas aeruginosa (18.2%)
The in-hospital rate of mortality from all causes was 24.1% in patients infected with MDROs and 15.4% in the control patients (HR = 1.7; 95% CI, 1.25-2.32). Similarly, 22.5% of patients with MDROs died within 30 days of infection, compared with 14.5% of control patients (HR = 1.77; 95% CI, 1.29-2.44).
Concerning specific microbes, extended-spectrum beta lactamase (ESBL)-producing Klebsiella pneumoniae had the highest mortality risk (HR = 2.22; 95% CI, 0.95-5.21), followed by P. aeruginosa (HR = 2.14; 95% CI, 1.10-4.17), MRSA (HR = 1.79; 95% CI, 0.02-3.14) and ESBL E. coli (HR = 1.18; 95% CI, 0.65-2.10).
In addition, bacteremia increased the overall hospital mortality rate in patients with MDROs (HR = 2.49; 95% CI, 1.64-3.81).
The researchers estimated that 20% of hospital-acquired infections are caused by MDROs and calculated the risk to patients. The researchers determined that antibiotic resistance could cause more than 40% of deaths in patients with MDROs and up to 12% of total deaths from hospital-acquired infections.
The probability of hospital readmission was also higher among patients with MDROs (OR = 2.17; 95% CI, 1.36-3.46), the researchers said.
After adjustment, only MRSA (OR =2.8; 95% CI, 1.65-4.74) and resistant E. coli (OR = 2.28; 95% CI, 1.32-3.96) were more likely than sensitive microbes to be responsible for a higher likelihood of a patient’s visit to the ED within 30 days of discharge. – by Joe Green
Disclosure: The researchers report no relevant financial disclosures.