Our weekly wrap-up of antimicrobial stewardship & antimicrobial resistance scans
More than 1 in 3 urinary infections in nursing homes caused by resistant bacteria
An analysis of urinary tract infections (UTIs) in US nursing homes found that more than one in three were caused by antibiotic-resistant pathogens, researchers reported in Infection Control & Hospital Epidemiology.
In the study, researchers from the Centers for Disease Control and Prevention (CDC) Division of Healthcare Quality and Promotion analyzed data on UTI-causative pathogens and antibiotic susceptibility testing results reported to the National Healthcare Safety Network (NHSN) by US nursing homes. All nursing homes that reported at least 1 complete month of UTI surveillance data were included. The data have been reported to NHSN since 2012, but this is the first time they have been analyzed.
Overall, 243 nursing homes from 46 states reported at least 1 month of UTI surveillance data from January 2013 through December 2017. In total, 6,157 pathogens were reported from 5,485 UTIs, with 9 pathogens accounting for 90% of all UTIs.
The three most frequently identified pathogens were Escherichia coli (41%), Proteus species (14%), and Klebsiella pneumoniae/oxytoca (13%). Among E coli, fluoroquinolone resistance (49.9%) and extended-spectrum cephalosporin resistance were the most prevalent. Staphylococcus aureus (67.1% resistant to methicillin) and Enterococcus faecium (59.5% resistant to vancomycin) had the highest levels of resistance but accounted for less than 5% of pathogens reported.
Of the 5,485 UTIs reported, 36% were associated with a resistant pathogen.
"The levels of antibiotic resistance observed demonstrate the importance of monitoring nursing homes and implementing nursing-home specific antibiotic stewardship activities," the authors wrote.
Aug 12 Infect Control Hosp Epidemiol abstract
Israeli study finds high antibiotic use for asymptomatic bacteriuria
In another study in Infection Control & Hospital Epidemiology, Israel researchers reported a high rate of improper antibiotic use and a high rate of multidrug-resistant organisms (MDROs) in patients with asymptomatic bacteriuria (ASB), along with significantly worse outcomes in patients who received antibiotics.
The retrospective case-control and cohort analysis looked at adults patients at an Israeli tertiary medical center with a positive urine culture, defined as the growth of one or two pathogens in a single sample. Pregnant women, kidney transplant recipients, and patients who underwent urologic procedures were excluded.
The researchers constructed multivariable logistics regression models to analyze predictors and outcomes associated with antibiotic use in ASB patients. Despite efforts to reduce the practice, treatment of ASB—defined as the isolation of bacteria in an uncontaminated urine specimen in the absence of UTI symptoms—is prevalent across healthcare settings and frequently leads to inappropriate antibiotic prescribing.
Of the 1,530 patient-unique cultures collected in 2017, 610 (40%) had ASB, and antibiotic therapy was administered to 178 (29.2%) of those patients. Among the 696 pathogens isolated from the patients, 36% had at least one MDRO, most commonly extended-spectrum beta-lactamase–producing Enterobacteriaceae (23%) or Pseudomonas aeruginosa (5.4%).
Independent predictors of improper administration of antibiotics were dependent functional status (adjusted odds ratio [aOR], 2.3; 95% confidence interval [CI], 1.4 to 3.6) and male sex (aOR, 2.0; 95% CI, 1.25 to 2.6). Use of antibiotics was independently associated with re-hospitalization (aOR, 1.7; 95% CI, 1.1 to 2.6) and acute Clostridioides difficile infections in the following days (aOR, 4.5; 95% CI, 2 to 10.6).
"These findings should prompt practitioners and administrators to invest efforts in reducing antibiotic administration for ASB and to discourage the practice of obtaining urine cultures from certain high-risk groups with no signs or symptoms of UTI," the authors concluded.
Aug 13 Infect Control Hosp Epidemiol abstract
Unnecessary prescribing by Canadian physicians linked to antibiotic volume
Total antibiotic use among a cohort of family physicians in Ontario, Canada, was strongly correlated with unnecessary antibiotic prescribing, Canadian researchers reported earlier this week in Clinical Infectious Diseases.
To study the association between total and unnecessary antibiotic use among family physicians in Ontario, the researchers looked at 5 years of electronic medical records from a database that collects data from a sample of Ontario physicians.
They used predefined expected antibiotic prescribing rates for 23 common primary care conditions to calculate unnecessary prescribing rates and multilevel Poisson regression models to evaluate the association between total antibiotic volume, adjusted for multiple practice- and physician-level covariates, and unnecessary prescribing.
Over the study period, there were 499,570 patient encounters and 152,853 encounters that resulted in one or two antibiotic prescriptions. Substantial inter-physician variability in unnecessary prescribing was observed, but in the fully adjusted model, the only covariate that could explain the inter-physician variability was total antibiotic volume (adjusted rate ratio, 2.11; 95% CI, 2.05 to 2.17). No other practice- or physician-level variables were associated with unnecessary prescribing.
The authors of the study say the results strongly support community antibiotic stewardship teams using total antibiotic volume as a surrogate for unnecessary prescribing and a basis for providing feedback to family physicians.
Aug 12 Clin Infect Dis abstract
UK, South African scientists to collaborate on antibiotic discovery
Scientists in the United Kingdom and South Africa yesterday announced a collaborative effort to establish a hub for new antibiotic discovery.
The three-year, £1.9 million (US $2.5 million) project, led by the University of Plymouth in the United Kingdom and Rhodes University in South Africa, aims to discover novel compounds from natural sources that could be developed into new antibiotics. The focus of the effort will be on unexplored, biodiverse habitats, including deep sea and polar environments.
Among the initial projects will be an exploration of the diversity of antimicrobial peptides in South Africa.
"Natural products and their synthetic analogues are the basis for the majority of antibiotics in clinical use today, and the hope is that this collaboration will go some way towards unlocking the potential resources contained in marine and terrestrial biota in South Africa, one of the world's most biodiverse places," Mat Upton, PhD, a professor in medical microbiology at the University of Plymouth and project leader, said in a university press release.
Aug 13 University of Plymouth press release
MDR-TB cases at Ohio food processing facility investigated
Originally published by CIDRAP News Aug 13
A case report today in the Centers for Disease Control and Prevention's (CDC's) Morbidity and Mortality Weekly Report describes three cases of multidrug-resistant tuberculosis (MDR-TB) among workers at an Ohio food-processing facility.
Investigation into the three cases by the CDC and Ohio Department of Health (ODH) began in February 2019 after whole-genome sequencing revealed that MDR-TB isolates from the three patients were genetically identical. The index patient was born in one of the 30 countries identified by the World Health Organization as having a high prevalence of MDR-TB. According to the available work schedules, the second and third patients had worked for at least 54 days and 7 days, respectively, on the same food production line as the index patient. The third patient also worked in a second facility, but that facility had closed by the time of the investigation.
All three patients recovered, and no other cases of MDR-TB related to the patients were identified, but testing of 160 high-priority workplace contacts (out of 448) found that 59 (37%) had positive results on tuberculin skin tests or interferon-y release assay tests, both of which test for TB infection. That's higher than the estimated percentage of non–US-born people in the United States who have a positive tuberculin skin test (21%) or a positive interferon-y assay result (16%) and is an indication of workplace transmission, the investigators concluded. Among those with positive results, 19 (32%) began latent TB treatment.
The authors say the low level of TB testing and treatment for infection among contacts is a concern, and is likely related to difficulties in communication, perceived barriers to care, and mistrust of government authorities.
They write, "Public health agencies need to facilitate engagement with communities with higher rates of TB to build trust, which is important for successful disease investigations. Activities might include communicating in a culturally sensitive manner with community members, offering patients incentives for getting tested or treated, providing transportation to clinics, using mobile clinics, and conducting communitywide education efforts."
ODH is continuing to work with local partners to facilitate TB testing and latent TB treatment for contacts and monitor for new cases.
Aug 13 MMWR Notes from the Field
CARB-X to fund development of new class of broad-spectrum antibiotics
Originally published by CIDRAP News Aug 12
CARB-X announced today that it is awarding $2.91 million to German drug developer Evotec SE to develop a new class of antibiotics to treat infections caused by multidrug-resistant bacteria.
Under the terms of the agreement, Evotec will in-license an antibiotics development program from US biotechnology company Resolute Therapeutics, and continue preclinical development using its proprietary drug discovery and development programs. The goal of the partnership is to develop a novel class of broad-spectrum antibiotics that cover gram-negative and gram-positive pathogens.
Evotec will be eligible for an additional $5.5 million in funding from CARB-X (the Combating Antibiotic-Resistant Bacteria Biopharmaceutical Accelerator) if certain project milestones are met.
"New antibiotics are urgently needed, particularly those that hold significant promise to overcome antimicrobial resistance," Evotec chief scientific officer Cord Dohrmann said in a CARB-X press release.
Since its launch in 2016, CARB-X has awarded $250 million to 67 projects targeting drug-resistant bacteria.
Aug 11 CARB-X press release
Study: High antibiotic prescribing linked to patients' future receipt of antibiotics
Originally published by CIDRAP News Aug 12
Patients who were treated by a high–antibiotic prescribing physician for an acute respiratory infection (ARI) were more likely to receive antibiotics for an ARI in the subsequent year, according to the results of a study published yesterday in Clinical Infectious Diseases.
In the study, a team led by researchers from Harvard Medical School examined encounter data from a US health insurer, looking specifically for patients under the age of 65 with a visit to an urgent care center for an ARI from January 2013 through Jun 10, 2016 and a prescription for an antibiotic filled the day before, the day of, or the 2 days after the visit. They then categorized clinicians within each urgent care center into quartiles based on their antibiotic prescribing rate and examined the association between the clinicians' antibiotic rate during the index visit and the patients' rate of ARI antibiotic receipt in the subsequent year. They also examined subsequent ARI antibiotic receipt among patients' spouses.
The hypothesis was that patients who saw high-prescribing doctors might be more likely to seek care for ARIs and receive an antibiotic in the subsequent year and that their spouses might be as well.
Across 232,256 visits at 736 urgent care centers, ARI antibiotic prescribing rates were 42.1% in the lowest quartile of clinicians and 80.2% in the highest quartile of clinicians. In the year after the index ARI visit, patients who saw the highest-prescribing clinicians received 3 more antibiotic fills per 100 people, or 14.6% more antibiotic fills, over the subsequent year compared with those who saw the lowest prescribers. The increase was also observed among the patients' spouses. The increase was largely driven by the increased number of ARI visits (+ 5.6 ARI visits per 100 patients) among patients who saw high-prescribing clinicians, rather than a higher prescribing rate during those subsequent visits.
"Our results emphasize the importance of how care in one encounter drives a patient to seek care for subsequent ARIs," the authors of the study wrote. "A reduction in antibiotic prescribing may create a feedback loop such that more judicious antibiotic use in one encounter may result in fewer future antibiotics. Thus, an additional benefit of greater antibiotic stewardship is the establishment of new norms for patients on when antibiotics are needed."
Aug 10 Clin Infect Dis abstract
