A major study in hospital intensive care units (ICUs) shows that bathing patients daily with an antimicrobial soap and applying antibiotic ointment in the nose reduced by 44 percent the bloodstream infections caused by dangerous pathogens, including the drug-resistant bacteria MRSA.
The effort to remove potentially harmful bacteria from ICUs also lowered by 37 percent the number of patients who harbored MRSA (methicillin-resistant Staphylococcus aureus) on their bodies. These patients were not sick from the bacteria but at risk for later illness and for spreading the germ to others.
The study’s findings will be presented Wednesday, Oct. 17, in San Diego at IDWeek, a meeting of specialists involved in treating or studying infectious diseases.
Hospitals must be continually on guard to prevent infections that occur in patients during their stays. These infections can spread quickly, and the sickest patients are most at risk. While vigilant hand washing among hospital staff is critical, many infections also occur from bacteria in patients’ noses and on their skin that they carry into the hospital.
The research involved nearly 75,000 patients who were treated at 43 mostly community hospitals, all part of the Hospital Corporation of America. Victoria Fraser, MD, head of the Department of Medicine and co-director of the division of infectious diseases at Washington University School of Medicine in St. Louis, helped design and oversee the study.
Of the strategies tested for reducing MRSA infections, the one that proved most effective was arguably the simplest and most straightforward. Rather than screening patients in intensive care units for MRSA and treating only the carriers, all ICU patients were bathed daily using a soap treated with an antiseptic, chlorhexidine, and all received an antibiotic ointment, mupirocin, applied in the nose for five days.
“Overall, the results are very encouraging and provocative,” said David Warren, MD, medical director for infection prevention at Barnes-Jewish Hospital and Washington University School of Medicine. “The results could potentially be applied to many critically ill patients in ICUs throughout the country to reduce the incidence of dangerous infections.”
At Barnes-Jewish Hospital, all ICU patients already are bathed daily with the chlorhexidine soap. That routine practice was implemented in 2009 after a study by Fraser, Warren and their colleagues showed that the antiseptic soap reduced hospital-associated infections by 25 percent among patients in the medical and surgical ICUs at Barnes-Jewish.
Mupirocin ointment is not used routinely in Barnes-Jewish ICUs or in most other hospital ICUs. There are a small number of bacteria that are already resistant to the antibiotic in the ointment and some concern about whether its broad use in ICUs could speed antibiotic resistance.
“Based on the new data, we’ll evaluate whether to incorporate mupirocin into routine use in our ICUs,” Warren said. “If we use the ointment, we will closely monitor patients for antibiotic resistance.”
In ICUs, antibiotic-resistant bacteria that usually live harmlessly on the body cause many infections. These infections can cause serious complications for patients, increasing the duration of their hospital stays, driving up costs and raising the risk of death. To address the problem, some states have mandated MRSA screening by hospitals, but experts in the field have questioned whether other measures would be more effective.
As part of the new study, patients in ICUs were randomly assigned to one of three approaches for reducing MRSA infections. Patients in the first group were screened for MRSA and isolated if they were found to be carrying the bacteria. Those in the second group were similarly screened and carriers were isolated, but they also were bathed daily with chlorhexidine soap and received nasal mupirocin ointment for five days to help remove MRSA from the body. All ICU patients in the third group, regardless of whether they harbored MRSA on their bodies, received daily chlorhexidine baths and five days of mupirocin.
The new research is being discussed at the inaugural IDWeek meeting, which brings together experts in the prevention, diagnosis, treatment and epidemiology of infectious diseases. It is a joint meeting of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association and the Pediatric Infectious Diseases Society.
*Information from Caroline Arbanas, Washington University.