Our weekly wrap-up of antimicrobial stewardship & antimicrobial resistance scans

Study: Milder ventilator-related pneumonia may require fewer antibiotics
Patients treated for suspected ventilator-associated pneumonia (VAP) but with minimal and stable ventilator settings appear to have similar outcomes when treated with very short antibiotic courses compared with longer courses, according to a study yesterday in Clinical Infectious Diseases.

In the study, researchers retrospectively identified all adult patients who had been put on mechanical ventilation at Brigham and Women's Hospital in Boston from January 2006 to December 2014, then narrowed down the population to all patients started on antibiotics for possible VAP who had minimal or stable ventilator settings for at least 3 days. Minimal and stable ventilator settings can be an indication of less severe pneumonia.

The researchers then compared the outcomes of patients prescribed 1 to 3 days of antibiotics versus those prescribed more than 3 days of antibiotics. Results were adjusted for patients' demographics, comorbidities, severity of illness, clinical signs of infections, and pathogens.

Overall, 1,290 patients were identified, with 259 prescribed 1 to 3 days of antibiotics and 1,301 prescribed more than 3 days of antibiotics. When the outcomes were adjusted for possible confounders, the researchers found no statistically significant differences between the two groups in hazard ratios for time to extubation (HR, 1.16 for short versus long course), ventilator death (HR, 0.82), time to hospital discharge (HR, 1.07), or hospital death (HR, 0.99). In all cases, the authors note, the point estimates for the outcomes favored the shorter-course patients.

"These observations suggest the possibility that patients with suspected VAP but minimal and stable ventilator settings can be adequately managed with very short courses of antibiotics," the authors write, adding that if the findings are confirmed in a randomized controlled trial, serial ventilator settings surveillance could be a simple way for clinicians to identify candidates for early antibiotic discontinuation.
Dec 29 Clin Infect Dis abstract

Burger King, Tim Hortons to stop serving chicken raised on antibiotics

Originally published by CIDRAP News Dec 29

The company that owns fast-food chains Burger King and Tim Hortons announced yesterday its intention to switch to chickens raised without medically important antibiotics, Reuters reports.

Restaurant Brands International Inc said it plans to make the switch in US stores in 2017 and in Canadian stores in 2018.

The company becomes the latest major restaurant chain to stop serving chickens raised on antibiotics that are also used in human medicine. McDonalds made the move earlier this year, and Wendy's Co announced that its chicken would be antibiotic-free by 2017. Chik-fil-A says it will stop serving chicken raised with medically important antibiotics by the end of 2019.

"We believe that it is important to reduce the use of antibiotics important for human medicine in order to preserve the effectiveness of antibiotics in both veterinary and human medicine," the company told Reuters.

But a representative of the group As You Sow, which promotes corporate responsibility through shareholder activism, told Reuters that Restaurant Brands International isn't going quite as far as the other companies. Under the plan, the company will eliminate only those antibiotics that are "the most critical in human medicine," from their supply chain, Reuters reports.

Public health officials are concerned that the use of medically important antibiotics in food-producing animals is contributing to the emergence of antibiotic resistant infections, and have called on the agriculture industry to reduce their use. Approximately 70% of all medically important antibiotics sold in the United States are used in farm animals.

Last week, the FDA reported that the sales and distribution of medically important antibiotics for use in food animals rose by 2% from 2014 to 2015.
Dec 28 Reuters story
Dec 22 CIDRAP News story "FDA: Antibiotic use in food animals continues to rise"

Study: Personalized prescription feedback program had no impact on antibiotic prescribing

Originally published by CIDRAP News Dec 28

A study yesterday in JAMA Internal Medicine shows that a 2-year antibiotic prescription feedback program did not change antibiotic prescribing among Swiss physicians.

The randomized trial included 2,900 primary care physicians with the highest antibiotic prescription rates in Switzerland. For the study, the physicians were randomly split into two groups. In the intervention group, physicians received quarterly updates from October 2013 to October 2015 showing the rate of antibiotic prescriptions they had written per 100 consultations in preceding months compared to the adjusted average in peer physicians, along with evidence-based antibiotic prescribing guidelines. The control group received no material. None of the physicians in either group were aware of being part of a controlled trial, and the investigators didn't know which physicians were assigned to the intervention and control groups.

The primary outcome of the trial was the prescribed defined daily doses (DDD) of any type of antibiotics to any patient per 100 consultations. Investigators also assessed antibiotic prescriptions per age group and per type of antibiotic.

Overall, the investigators found that while antibiotic prescription rates were lower in both groups of physicians during the 2-year intervention period compared to the baseline period (12 months prior to randomization), there was no difference in antibiotic prescribing between the intervention and control groups in either the first year of intervention (between-group difference 0.81%) or second year (between-group difference -1.73%). Quarterly feedback did reduce antibiotic prescribing to older children and adolescents (ages 6 to 18) by -8.6% in the first year and to young- and middle-age adults (ages 19 to 65) by -4.6% in the second year, but those findings were not consistent over the entire intervention period and the authors note that they should be cautiously interpreted.

Aside from fewer macrolide prescriptions in the intervention group in the second year, no impacts were observed on prescribing of specific antibiotic types.

Although their study found that quarterly feedback had no impact on antibiotic prescribing, the authors suggest that "more intense and better tailored" prescription feedback approaches merit further evaluation, since prescription feedback interventions are less resource intensive than other antibiotic stewardship approaches.
Dec 27 JAMA Intern Med study

Study: 25% of K pneumonia in long-term care resistant to carbapenems

Originally published by CIDRAP News Dec 27

A new study has found that a quarter of Klebsiella pneumoniae isolates from a nationwide network of hospitals are resistant to carbapenem antibiotics.

According to a Dec 24 study in Clinical Infectious Diseases, 946 of 3,846 K pneumoniae isolates collected at 64 geographically widespread long-term acute care hospitals from January 2014 to March 2015 were carbapenem resistant, for an overall carbapenem resistance rate of 24.6%. While carbapenem-resistant K pneumoniae (CRKP) rates varied widely across 16 states, the highest rates were observed in California (45.5%), South Carolina (35.7%), Kentucky (22.1%), and Indiana (20%).

Of the US census regions, the West had the highest proportion of CRKP isolates (42.2%), followed by the South (12.2%), the Northeast (9.9%), and the Midwest (7.3%).

The 946 CRKP isolates came from 821 patients with a median age of 73 years and several comorbidities, including respiratory failure, advanced stage decubitus ulcers, and severe end-stage kidney disease. More than half of the patients had either a central venous catheter or a urinary catheter. CRKP isolates were primarily from respiratory (58.9%) and urinary (37%) sources.

In addition to being carbapenem resistant, the CRKP isolates were also found to be highly resistant to other commonly used broad-spectrum antibiotic agents, with more than 97% showing resistance to ciprofloxacin, levofloxacin, gentamicin, and tobramycin, and 59.2% demonstrating resistance to amikacin. Of significant concern, 16.1% of 700 tested isolates showed resistance to the last-line antibiotics colistin or polymixin B.

The authors note that the 25% carbapenem resistance rate is substantially higher than the rate of 10.4% reported in a previous study of ICU-associated infections from acute care hospitals, and is likely under-reported because rectal cultures for detection of asymptomatic gastrointestinal colonization were not routinely performed.

"Along these lines, it is clear that the epidemiology of CRKP in the U.S. is rapidly evolving, and enhanced surveillance and reporting is needed across the healthcare continuum," the authors wrote.
Dec 24 Clin Infect Dis study 

Copper oxide-embedded textiles help reduce healthcare-related infections

Originally published by CIDRAP News Dec 27

A study yesterday in the American Journal of Infection Control suggests that using copper oxide-impregnated biocidal textiles in long-term care medical facilities can reduce healthcare-associated infections (HAIs).

The 7-month study involved all patients in two ventilator-dependent wards at a long-term care hospital. In the first intervention period, investigators replaced all the textiles (lines, patients' clothes, and towels) in one ward with copper-oxide impregnated textiles, while the other ward used regular hospital textiles. Previous studies have shown that embedding nonsoluble copper oxide in textiles permanently endows them with potent broad-spectrum antimicrobial properties.

After a 1-month washout period, in which both wards used regular textiles, the investigators then switched the textiles in the two wards for the second intervention period, with the ward that received the treated textiles in period one getting the control textiles, and vice versa. Hospital personnel were blinded to which ward received the treated textiles and which received the control textiles, and all standard infection control measures were observed in both wards. In addition, the characteristics of the patients in the two wards were roughly the same.

At the end of the study, investigators observed significant reductions in HAI indicators in the wards when copper-treated textiles were used, including a 29.3% reduction in antibiotic treatment initiation events, a 55.5% decrease in fever days, a 23% drop in days of antibiotic treatment, and a 27.5% decrease in antibiotic defined daily doses per 1,000 hospitalization days.

"Our study adds an important layer to the in vitro studies and the previous open-label studies supporting the effect of copper oxide–impregnated medical textiles as a possible supplement to other measures aimed at reducing the rate of HAIs," the authors wrote.
Dec 26 Am J Infect Control study