U.S. hospitals saw overall decline in health care-associated infections from 2011 to 2015

Surgical-site and urinary tract infections decreased, while rates of pneumonia and Clostridium difficile in the hospital held steady, according to data gathered by the CDC.

Between 2011 and 2015, rates of surgical-site and health care-associated urinary tract infections decreased in U.S. hospitals, driving a decline in health care-associated infections overall, a recent CDC study found.

The study included data from hospitals participating in the Emerging Infections Program, using a random sample of patients on a single day chosen by each hospital to assess the prevalence of health care-associated infections. A total of 12,299 patients treated in 199 hospitals in 2015 were compared with 11,282 patients treated in 183 hospitals in 2011. Results were published in the Nov. 1 New England Journal of Medicine.

Fewer patients had health care-associated infections in 2015 than 2011: 394 patients (3.2% [95% CI, 2.9 to 3.5]) versus 452 patients (4.0% [95% CI, 3.7 to 4.4]; P<0.001). This was largely due to reductions in the prevalence of surgical-site and urinary tract infections. The percentages of patients with pneumonia, gastrointestinal infection (including and mostly comprising C. difficile infection), or bloodstream infection did not differ significantly between 2015 and 2011. Pneumonia, gastrointestinal infections, and surgical-site infections were the most common health care-associated infections.

After adjustment for age, presence of devices, days from admission to survey, and being in a large hospital, the risk of having a health care-associated infection was 16% lower in 2015 than in 2011 (risk ratio, 0.84 [95% CI, 0.74 to 0.95]; P=0.005). “These results provide evidence of national success in preventing health care-associated infections, particularly surgical-site and urinary tract infections,” the authors said. However, the lack of decline in pneumonia, C. difficile, and mortality from health care-associated infections “suggests that more work is needed.”

The decline in urinary tract infections might be due to reduced use of urinary catheters, and surgical-site infections might have been prevented by practices such as decolonization of patients with Staphylococcus aureus colonization or implementation of surgical prophylaxis guidelines, the authors speculated. It's possible that increaseed use of C. difficile nucleic acid amplification testing since 2011 masked reductions in prevalence in the study data, but regardless, there is room for improvement in antibiotic prescribing and infection control, they noted. The authors also pointed out that although most inpatient pneumonia prevention efforts focus on ventilated patients, the majority of pneumonia events found in the study were not ventilator-associated.

The generalizability of the results to hospitals not participating in the program is uncertain and limitations of the study include that fewer patients met the screening criteria in 2015 than in 2011, the authors said.