An estimated 4% of inpatients at U.S. acute care hospitals have at least one health care–associated infection on any given day, according to a report published online March 26 in the New England Journal of Medicine.
Moreover, in a prevalence survey involving 183 acute care hospitals across 10 geographically diverse states, device-associated infections, "which have been a major focus of infection prevention in recent decades," accounted for only 25.6% of all health care–associated infections, said Dr. Shelley S. Magill of the division of health care quality promotion, Centers for Disease Control and Prevention, and her associates (N. Engl. J. Med. 2014;370:1198-1208).
In contrast, Clostridium difficile and other gastrointestinal infections, as well as non–ventilator-associated pneumonia, accounted for approximately half of all health care–associated infections in the survey. Surgical site infections also are still very common, accounting for 21.8%.
Because it appears that ventilator-associated pneumonia, catheter-associated UTIs, and central catheter–associated bloodstream infections are no longer the primary threat that they used to be, the study findings should prompt experts to "expand the public health focus to include these other types of infections, identifying patients at risk and developing effective countermeasures," the report’s authors noted.
The report shows that as a nation, we’re moving in the right direction; but there’s a great deal of work still to be done," Dr. Michael Bell said in a media briefing. "On any given day, 1 out of 25 hospitalized patients has an infection. And of those people, as many as one out of nine go on to die. This is not a minor issue," said Dr. Bell, deputy director of the CDC’s division of health care quality promotion.
The investigators developed and conducted the survey in 2011 to address a serious knowledge gap: No single surveillance system can provide estimates of "the burden of all types of such infections across acute care patient populations." So, Dr. Magill and her colleagues studied health care–associated infections among inpatients of all ages at 93 small, 68 medium-sized, and 22 large hospitals.
They found 504 such infections in 452 patients out of 11,282 patients covered in the survey, for an overall incidence of 4%. Using a statistical modeling process that accounted for predictors of infection prevalence and then applying those results to a nationally representative sample of U.S. community hospital stays, the investigators estimated that 648,000 inpatients nationwide had approximately 721,800 health care–associated infections in 2011.
Those estimates are lower than previous ones, such as those derived from the Study on the Efficacy of Nosocomial Infection Control in the 1970s , which postulated 2.1 million health care–associated infections each year, and those derived from National Nosocomial Infections Surveillance system data from 1990 to 2002, which estimated 1.7 million each year.
However, "it is difficult to draw conclusions from these comparisons because of the differences in patient populations, surveillance definitions of health care–associated infections, and data collection and analytical methods among these CDC methods," Dr. Magill and her associates said.
The current survey showed that 42.9% of health care–associated infections developed during a stay in a critical care unit or within 48 hours after; another 42.4% developed after a stay in a nonnursery ward.
Most of the surgical site infections were related to colon surgeries (14.5%), hip arthroplasty (10.0%), and small-bowel procedures (6.4%).
The median length of time between hospital admission and the onset of infection symptoms was 6 days.
C. difficile was the most frequently identified pathogen, accounting for 70.9% of all nosocomial GI infections and 12.1% of all health care–associated infections. Other common pathogens included Staphylococcus aureus (10.7% of all health care–associated infections), Klebsiella pneumoniae and Klebsiella oxytoca (9.9%), and Escherichia coli (9.3%).
The report’s investigators noted that their estimates "are remarkably similar to estimates from other data sources," such as the National Healthcare Safety Network and the Emerging Infections Program. That "bolsters our confidence in the overall estimates of health care–associated infections that we have generated," they said.
Sounding the alarm
The report "sounds the alarm" about infectious threats to hospitalized patients that need addressing, especially lung and gut infections and infections related to surgery or urinary catheters, Dr. Bell said. It also sheds light on several important pathogens, especially C. difficile, Staphylococci, and the family of Enterobacter organisms.
Those pathogens are at the center of President Barack Obama’s request for $30 million as part of his proposed $6.6 billion budget for 2015 for a new initiative to halve infections by those organisms within 5 years, Dr. Bell said.
The $30 million would be used to improve tracking of infections, the nation’s capacity for lab testing to determine which pathogens are most problematic, and "boots on the ground" to help hospitals implement best practices, Dr. Bell said.
