Study finds dramatic impact tied to stewardship at a small, rural hospital

Implementation of an antimicrobial stewardship program (ASP) at a rural community hospital in Georgia significantly reduced Clostridium difficile infections (CDIs), antimicrobial use, and overall drug costs, researchers reported yesterday in the American Journal of Infection Control.

Researchers from the Mayo Clinic evaluated the performance of an ASP implemented at a small Georgia hospital with no previous ASP experience and an average occupied bed census of fewer than 100. The ASP was led by an infectious disease (ID) physician, used a prospective audit and feedback strategy with a targeted list of 12 antimicrobial agents, and included an educational grand rounds lecture series and algorithms to aid the selection of empirical antibiotics for specific infectious disease syndromes.

The targeted agents were amikacin, aztreonam, cefepime, ceftaroline, daptomycin, doripenem, ertapenem, fosfomycin, imipenem, linezolid, meropenem, and tigecycline. The researchers calculated rates of C difficile infection (CDI), total targeted antimicrobial costs, and drug usage rates prior to ASP implementation (January 2013 through September 2014) and after implementation (October 2014 through December 2015).

They found that nosocomial CDI rate declined from 3.35 cases per 1,000 occupied bed days (OBDs) at the end of the fourth quarter in 2013 to 1.35 cases per 1,000 OBDs at the end of the fourth quarter in 2015. Total targeted antimicrobial costs decreased by 50%, from $16.93 per patient day in 2013 to $8.44 per patient day in 2015, and annual savings in drug costs alone were estimated at $280,000, primarily because of the decreased use of 5 of the 12 targeted antimicrobials. Use of all antimicrobial agents decreased 10%.

"Our quality initiative shows that a new ASP can result in dramatic reduction in CDI rates, drug utilization rates, and antimicrobial cost savings within 1 year despite…perceived challenges in a small rural hospital," the authors write.
May 16 Am J Infect Control study

Researchers find rapid respiratory virus testing aids stewardship 

In another study in the American Journal of Infection Control yesterday, Canadian researchers found that integrating point-of-care respiratory virus testing with an ASP audit and feedback intervention was associated with a 32% reduction in antibiotic days per patient in patients with viral respiratory tract infections.

From December 2015 through April 2016, the researchers conducted a prospective audit and feedback intervention for all adult inpatients who had a positive polymerase chain reaction (PCR) finding for a respiratory virus at two acute care hospitals in Vancouver. Inclusion of patients for an ASP consult was based on two criteria: microbiology (no positive bacterial cultures) and chest imaging (absence of pneumonia). For patients who met the inclusion criteria, the ASP team reviewed the case with the treating physician to determine if antibiotics for community-acquired pneumonia were required and to assess the need for the antiviral drug oseltamivir (Tamiflu).

To assess the impact of the intervention, the researchers conducted a quasi-experimental before-and-after intervention study. The primary outcome of interest was duration of antimicrobial therapy after viral diagnosis. Secondary outcomes included intensive care unit admission, mechanical ventilation, re-prescription of antibiotics within 14 days, and readmission, mortality, and C difficile infection within 30 days.

Overall, 92 patients were included in the prospective cohort and 118 in the retrospective cohort, with 76% (70/92) of the prospective cohort and 83% (98/118) of the retrospective cohort on antibiotics at the time of PCR testing. The prospective cohort had an average of 1.3 fewer days on antibiotics than the retrospective cohort after the PCR results were reported, and within the prospective cohort, patients whose ASP recommendation was accepted versus rejected had on average 3.6 fewer days on antibiotics. ASP recommendations were accepted 77% of the time.

In addition, patients found to have a positive influenza result were more likely to start oseltamivir in the prospective cohort than the retrospective cohort (95% vs. 72%). No significant differences were identified in secondary outcomes.

"Virology testing has advanced rapidly over the last decade, but the full value of such testing may not be realized if the results do not change [clinical] management," the authors write. "Using antimicrobial stewardship as a bridge to connect virology reporting with the treating physician facilitated a reduction in duration of antibiotic treatment and optimized oseltamivir therapy."
May 16 Am J Infect Control study

Resistant Acinetobacter outbreak in long-term care facility detailed

Austrian researchers report the detection of an outbreak of two multidrug-resistant (MDR) Acinetobacter baumannii strains among patients at an Austrian long-term care facility in a study yesterday in Antimicrobial Resistance and Infection Control.

The researchers conducted the point-prevalence study in August 2015, taking inguinal and perianal swabs from 38 patients at two wards caring for patients with disorders of consciousness and screening them for asymptomatic colonization by MDR gram-negative bacteria. Microbiological sampling was repeated 6 months later.

In the initial survey, 50% of the patients (19/38) were found to harbor MDR gram-negative isolates, with 13 found to be colonized with A baumannii isolates that were resistant to three antimicrobial classes but susceptible to carbapenems. Five other patients were found to be colonized with A baumannii that was not characterized as MDR. Of the 18 patients initially colonized with any A baumannii isolate, 10 were still colonized after 6 months.

All but one of the MDR A baumannii isolates were found in patients from ward 2. In an attempt to isolate a source of the bacteria, swabs were taken from hospital items and surfaces in ward 2, and investigators found A baumannii isolates on a patient elevator into a bathtub and on a chair for visitors in a patient room. PCR testing indicated the A baumannii isolates belonged to two clusters (A and B), and that the isolate from the chair was identical to 15 patient isolates and was connected to cluster A, which was the larger of the two.

The authors of the study suggest that since the isolate on the chair was identical to 15 of the patient isolates, and the colonized patients had been at the ward longer before the study than the non-colonized patients, there is a good chance that cross-transmission between patients by staff had taken place.

In response to the outbreak, the facility has strengthened standard hygiene precautions and infection control practices and will screen all patients on both wards for MDR bacteria twice a year.
May 16 Antimicrob Resist Infect Control study