VRE isolates: They’re everywhere!
Environmental vectors frighteningly common
The presence of vancomycin-resistant enterococci (VRE) isolates in U.S. hospitals has increased 35-fold since 1989, according to the Centers for Disease Control and Prevention (CDC) in Atlanta. Now come reports that these pathogens can survive in the darndest places and for considerable periods of time.
According to a report in Infection Control and Hospital Epidemiology, "Role of Environmental Contamination in the Transmission of Vancomycin Resistant Enterococci," some VREs have been found to survive on countertops for as long as a week and telephone handsets for up to an hour. Clothing can stay infected for at least 18 hours, and bed rails remain contaminated for up to 24.
The report concludes that widespread environmental contamination is likely in the room of someone infected with a VRE, and that health care workers should pay assiduous attention to the use of disinfectants. On that score, the authors recommend avoiding hydrogen peroxide because it doesn’t work. Acceptable disinfectants include quaternary ammonium compounds, phenols, and alcohol. Even though some bacteria establish resistance to antibiotics, they remain susceptible to these disinfectants.
Other documented places where VRE was found thriving: doorknobs, IV pumps, floors, a blood pressure cuff, a computer table, a cabinet, a blood glucose monitor, several parts of an EKG machine (leads, knobs and wires), ventilator tubing and, most disturbing, on an automated medication cart serving an entire ICU.
New threats addressed at conference
VRE was a hot research topic this past year, as evidenced by presentations at this spring’s annual meeting of the Society for Healthcare Epidemiology of America in St. Louis, but other emerging threats were addressed as well. Here are some of the findings:
• Researchers at the Atlanta VA Hospital found that a CDC recommendation to test roommates of VRE-infected individuals may be overkill. Rectal swab testing of VRE and non-VRE roommates showed no difference in incidence between the groups.
• A CDC recommendation also was taken to task at the Albany (NY) Medical Center, but this time with more positive results for the agency. With the CDC advising "incidence surveillance" for VRE in high-risk populations, Albany Medical Center conducted a one-month surveillance program in its surgical intensive care unit. The researchers discovered that of 10 patients positive for VRE, only three provided samples that grew VRE on culture. Cost of the five-week program: $5,000.
• A Miriam Hospital study in Providence, RI, appears to confirm what’s long been suspected: that nursing home residents harbor VRE more often than elderly people in other environments. Most disturbing, the three VRE-infected nursing home residents all came to Miriam Hospital from separate nursing homes. A German study found nursing home patients were almost five times more likely to be carrying VRE than were a sample of university students.
• At the University of Nebraska Medical Center in Omaha, researchers found environmental contamination with VRE in an outpatient oncology suite. About a third of patients reporting to the clinic left behind the dangerous organisms, and a quick wash of patient rooms with a phenol solution didn’t kill the bugs.
• Many clinicians continue to use vancomycin inappropriately, according to an Oregon survey. The survey of 64 hospitals in that state found that in a three-week period in 1994, vancomycin was used inappropriately about 40% of the time. The most common misuse was failure to use a first- or second-line drug before moving to the big gun. Unnecessary prophylaxis accounted for about a third of the cases of misuse. Internists, neurosurgeons, and nephrologists were most likely to prescribe vancomycin in error, the survey found.
• Hospitals discharging patients home on IV antibiotics should keep an eye out for the development of neutropenia, researchers at Rush Medical College in Chicago say. They found that about 15% of patients in an 87-person sample had a neutropenic episode at home five became severely neutropenic (less than 500 Absolute Neutrophil Count). A potpourri of antibiotics caused the neutropenia, including vancomycin, ciprofloxacin, and a variety of beta-lactams.
• Wooden tongue depressors could be harboring dangerous molds. That’s the conclusion of a team of Dutch researchers who examined an "outbreak" of Rhizopus microsporus in a group of immunocompromised patients. Only there wasn’t an outbreak at all. It seems the depressors, used to obtain fecal samples, were contaminated with the mold in the first place, giving the false impression of a mass infection. However, the researchers note, wooden splints have caused infections in children. They recommend using only sterile wood products or switching to plastic.