The Prevalence of Healthcare-Associated Infections in U.S. Hospitals in 2015: Defining Progress and Attention to the Future

Author: Joan Hebden, RN, MS, CIC, FAPIC, FSHEA

Categories: General Infection Prevention November 26, 2018

Point prevalence surveys of healthcare-associated infections (HAIs) provide for a national snapshot of this critical patient safety concern and complement the location- or infection-specific data that infection preventionists report to the National Healthcare Safety Network (NHSN). Utilizing 10 sites in the CDC Emerging Infections Program (EIP) which represents the major geographic sections of the U.S., an initial prevalence survey was conducted in 2011 of 11,282 patients in 183 hospitals and found that 4% of hospitalized patients had an HAI.

In order to assess changes in the HAI prevalence during a time period when intense national attention was placed on HAI reduction targets established by the Department of Health and Human Services (HHS), the survey was repeated in 2015 with 12,299 patients in 199 hospitals. The 10 EIP sites were used, prioritizing the hospitals that participated in the 2011 survey. Each hospital selected 1 day on which a random sample of patients were identified by trained staff utilizing the 2011 HAI definitions. The percentage of patients with HAIs were compared to evaluate the association of survey year with the risk of HAIs.1

In 2015, 3.2% of hospitalized patients experienced an HAI, a 16% decrease compared to the similarly derived estimate in 2011. The most common HAIs were pneumonia and Clostridium difficileinfections, with the biggest reductions in urinary tract and surgical site infections (SSIs)1. Of note, the percentages of patients with a urinary catheter or central line was significantly lower in 2015 than in 2011, reflecting [what can be assumed is] adoption of unnecessary invasive device removal emphasized in HAI prevention bundles. Further, in this survey, fewer patients met the criterion for review of HAI by receiving antimicrobial agents for the treatment of an infection or receiving antimicrobial agents for an undocumented reason than identified in the 2011 survey1. This finding suggests attention to and adoption of antimicrobial stewardship practices. Nearly 40% of HAIs, excluding SSIs, were attributed to critical care units. The most common pathogens reported were Clostridium difficile, S. aureus and E. coli. Among the S. aureus isolates, 45% were methicillin-resistant.1

Similar evidence in improvements in patient safety related to HAIs has been observed with the analysis of NHSN data, which has shown reductions in the standardized infection ratios for central line-associated bloodstream infections (CLABSI), selected SSIs and MRSA bacteremias between 2008 and 20141. Pneumonia, in both ventilated and non-ventilated patients, remains a significant concern with a stable prevalence. Although this survey did not evaluate practice changes, the authors state that the reduction in SSIs may reflect the adoption of perioperative infection prevention practices, such as decolonization of patients with S. aureus colonization or the use of updated surgical antimicrobial prophylaxis guidelines. In respect to C. difficile, the prevalence of infection was stable between 2011 and 2015 and continued focus on antimicrobial use and infection control measures to prevent transmission is needed.1

Looking to the future, focus on further reduction of all HAIs remains a national priority. In addition to monitoring HAI outcome metrics, compliance with process measures that have demonstrated value in HAI reduction efforts are receiving increased attention. Our industry partners in infection prevention are offering products and technologies, along with funded research, that contribute to the goal of HAI elimination. Examples include:

  • Heightened focus on the prevention of intraluminal contamination of intravascular devices to prevent bloodstream infections through disinfection of needleless connectors using chlorhexidine/alcohol (CHG/ALC), which was found to be superior to 70% alcohol alone and alcohol-impregnated caps.2 The immediate and sustained bactericidal activity of CHG/ALC makes it an attractive option for reducing culture contamination and improving the accuracy of BSI and UTI diagnosis.
  • SSI and MRSA bacteremia reduction, as noted by the authors, has been augmented with decolonization protocols. These protocols lower the microbial bio-burden on patient body sites to reduce endogenous colonization will can lead to infection when host defenses are altered e.g. surgery, insertion of invasive devices, and the risk of exogenous colonization from other patients and/or the environment e.g. poor hand hygiene practices by healthcare workers, contaminated equipment. Povidone-iodine is an attractive alternative to mupirocin with similar efficacy in eradicating S.aureus (a leading pathogen of SSIs), higher patient satisfaction and compliance and is cost-effective.3,4,5
  • C. difficile transmission reduction has been associated with the use of enhanced environmental cleaning practices6 along with antimicrobial stewardship efforts.

As healthcare facilities continue their efforts to eliminate HAIs, embracing the newer technologies and products that are supported by science in addition to process improvement activities should move the numbers in the right direction. The verdict will be clear when the next prevalence survey results are reported.

1Magill SS, et al. Changes in Prevalence of Health Care– Associated Infections in U.S. Hospitals. N Engl J Med 2018; 379:1732-44.DOI: 10.1056/NEJMoa1801550.

2Flynn JM, Rickard CM, Keogh S, Zhang L. Alcohol Caps or Alcohol Swabs With and Without Chlorhexidine: AnIn VitroStudy of 648 Episodes of Intravenous Device Needleless Connector Decontamination. Infect Control Hosp Epidemiol 2017; 38(5):617-18.

3Phillips M, Rosenberg A, Shopsin B, et al. Preventing surgical site infections: a randomized, open-label trial of nasal mupirocin ointment and nasal povidone-iodine solution. Infect Control Hosp Epidemiol 2014;35(7):826-32.

4Bebko SP, Green DM, Awad SS. Effect of a Preoperative Decontamination Protocol on Surgical Site Infections in Patients Undergoing Elective Orthopedic Surgery With Hardware Implantation. JAMA Surg 2015;150(5):390-395.

5Maslow J, Hutzler L, Cuff G et al. Patient Experience with Mupirocin or Povidone-Iodine Nasal Decolonization. Orthopedics 2014;37(6):e576-e581.

6Anderson, DJ et al. for the CDC Prevention Epicenters Program. Enhanced terminal room disinfection and acquisition and infection caused by multidrug-resistant organisms and Clostridium difficile (BETR-D study): a cluster-randomised, multicentre, crossover study. Lancet 2017


Joan Hebden RN, MS, CIC
Joan Hebden Independent infection prevention consultant and research coordinator


Joan received her baccalaureate and master’s degrees from the University of Maryland School of Nursing. She is currently the President of IPC Consulting Group LLC, a Maryland-based company providing infection prevention consultation and research coordination in acute and non-acute care settings. She served as the Director of Infection Prevention and Control for 28 years at the University of Maryland Medical Center in Baltimore, Maryland.

An accomplished practitioner, Ms. Hebden is an invited speaker at national epidemiology conferences, participates in research regarding the transmission of multi-drug resistant bacteria, and has multiple publications in medical and infection control journals. She is certified in infection control through the Certification Board of Infection Control and Epidemiology, is an active member of the Society for Healthcare Epidemiologists of America (SHEA) and the Association for Professionals in Infection Control (APIC), serves as a section editor and reviewer for the American Journal of Infection Control and is a fellow of APIC. She was the recipient of the 2018 SHEA Advanced Practice IP award.

Contact Information:

Email address:

More about Joan Hebden Less about Joan Hebden