Our weekly wrap-up of antimicrobial stewardship & antimicrobial resistance scans
Nebraska issues alert about highly resistant Enterobacteriaceae
The Nebraska Department of Health and Human Services (NDHHS) yesterday issued a health alert about an increase in carbapenemase-producing carbapenem-resistant Enterobacteriaceae (CP-CRE) cases this year. After detecting 7 each year in 2017 and 2018, officials have already confirmed 12 CP-CRE infections so far this year.
"Some of these are due to a particular type of carbapenemase referred to as NDM or New Delhi Metallo-beta-lactamase that have rarely been seen in Nebraska," the NDHHS said in the advisory. "Infections with this organism have a higher rate of morbidity and mortality than with less resistant organisms."
The carbapenem class of antibiotics includes the common drugs meropenem, imipenem, and ertapenem.
The increase in CP-CRE cases has been especially evident in southeast Nebraska, and long hospital stays, high antibiotic use, and being immunocompromised seem to increase the risk.
The NDHHS said, "At this time we are alerting hospitals, rehabilitation centers and long term care facilities of the recent increase so that facilities can expand their surveillance efforts, detect these organisms early and forward organisms suspected of this type of resistance to the NPHL [Nebraska Public Health Laboratory]."
Officials added, "Although all multidrug resistant organisms (MDROs) are difficult to treat and need to be contained, there are some especially concerning patterns of resistance."
Jun 13 NDHHS advisory
High urine culture rates in nursing homes tied to more antibiotics, C diff
A Public Health Ontario study today in Clinical Infectious Diseases found that nursing homes in the province have highly divergent urine culturing rates, and this variability is associated with higher antibiotic use and higher rates of Clostridioides difficile infection.
The investigators analyzed data from quarterly nursing home assessments from April 2014 through January 2017 at 591 Ontario nursing homes—representing 91% of the nursing homes in the province. They tracked urine culturing as the proportion of nursing home residents who had a urine culture taken in the preceding 14 days, and the study included data on 131,218 residents.
Overall, 7.9% of resident assessments had a urine culture (to test for pathogens) in the prior 14 days, but the rates varied widely, with 3.4% in the 10th percentile and 14.3% in the 90th percentile. The mean culturing rate was 6.5 per 1,000 resident-days, varying from 2.1 in the 10th percentile to 9.2 in the 90th percentile.
The researchers also determined that obtaining a doubling of the rate of urine culture was associated with a 21% increase in antibiotic use for urinary tract infection and an 18% higher rate of C difficile infection. The most common antibiotics prescribed were ciprofloxacin (2.7%), cephalexin (2.6%), trimethoprim and/or sulfonamides (2.5%), nitrofurantoin (2.2%), and amoxicillin (2.1%).
Jun 14 Clin Infect Dis abstract
Colombia Candida auris outbreak in 2015-16 tied to high death rates
An investigation into 40 cases of Candida auris illness in Colombia primarily in 2016 revealed a 43% 30-day mortality rate and evidence of person-to-person spread, according to a study yesterday in Emerging Infectious Diseases. C auris is a worrisome resistant fungus that is spreading worldwide.
The investigation, led by US Centers for Disease Control and Prevention scientists, involved four hospitals in three Colombian cities. Median patient age was 23 years, but 12 patients (30%) were less than 1 year old. Twenty-four (60%) were male. Cases were clustered in May through July 2016 in three hospitals but ranged from January 2015 through September in the fourth.
Seventeen patients (43%) died within 30 days. Five of the babies (42%) died within 30 days, but a sixth died later in the hospital, for a 50% death rate. Isolates showed resistance to multiple antimicrobial drugs.
Spatial and temporal analysis of samples taken from outbreak patients "showed a high degree of relatedness on whole-genome sequencing within hospitals and regional clustering, supporting in-hospital and person-to-person transmission," the scientists wrote. C auris skin colonization was common, especially in armpit and groin regions, which the authors said likely increases the risk of disease spread.
They conclude, "The findings of our investigation highlight the necessity of adherence to infection control recommendations, especially aspects of careful central line care and maintenance, hand hygiene, proper disinfection of medical equipment, and use of standard and contact precautions. C. auris remains an emerging pathogen with the potential for high levels of resistance to a limited body of antifungal drugs."
Jun 13 Emerg Infect Dis study
Canada's public health chief offers prescription for preserving antibiotics
Originally published by CIDRAP News Jun 13.
Canada's chief public health officer, Theresa Tam, BMBS, issued a report this week aiming to raise awareness among both the public and healthcare professionals about the needless use of antibiotics and how to preserve the drugs' effectiveness.
The avowed goal of the "public health spotlight" report is "to describe why unnecessary antibiotic use sometimes happens and what we can do about it." The report is presented online in a single 24-page document and separately in a set of six chapters with larger type and graphics. The focus is on antibiotic use and prescribing in the community (non-hospital settings), where 92% of antibiotic prescriptions are written.
"When we better understand the many social and cultural reasons behind why unnecessary antibiotic use happens, we can begin to see some of the actions that each of us can take to help fight antibiotic resistance," Tam said in a statement about the report. "Canadians can help by keeping their vaccinations up to date, protecting themselves from infection, speaking to their health care providers before using antibiotics, and taking their antibiotics as prescribed."
Healthcare providers can help by talking with their patients about antibiotics, staying current on prescribing guidelines, and promoting appropriate use of antibiotics through tools like delayed prescriptions, meaning ones intended to be used only if symptoms don't improve within a few days, Tam added.
The report says that antibiotic resistance rates in Canada are lower than in many other countries, but not all is well. For two examples, cases of carbapenem-resistant bacteria in people without infections have quintupled, suggesting that those bacteria are becoming more common, and more than 50% of gonorrhea cases now involve bacteria with resistance to at least one antibiotic.
Included in the report are several real-life stories about patients' and providers' experiences with the prescribing and use of antibiotics.
In the conclusion, Tam says, "I look forward to using the findings from this Spotlight Report and the forthcoming Pan-Canadian Action Plan to work with leaders across the country" to preserve the effectiveness of antibiotics.
Jun 11 Tam statement
Full report in one document
First part of chapter-by-chapter version
Study reveals snapshot of carbapenem-resistant Pseudomonas burden
Originally published by CIDRAP News Jun 13.
A surveillance study based in five United States metropolitan areas to flesh out the epidemiology of carbapenem-resistant Pseudomonas aeruginosa (CRPA) in the United States found that the burden is high, but carbapenemase-producing CRPA were rare. A team from the Center for Disease Control and Prevention (CDC) Emerging Infections Programs (EIP) sites reported their findings yesterday in Emerging Infectious Diseases.
From July to October of 2015 they began lab surveillance for CRPA at sentinel sites in Georgia, New Mexico, Oregon, Tennessee, and Monroe County, N.Y. They defined a case as the first P aeruginosa isolate resistant to carbapenems in a patient in a 30-day period from any source except for the nares, rectum or perirectal area, or feces.
Overall, they found 384 (9.1%) CRPA cases among 4,243 P aeruginosa isolates. The team identified 294 incident cases among 274 patients, with isolates most commonly found in respiratory sites (40.8%) and urine (37.8%). CRPA—an opportunistic pathogen—was found mainly in patients with underlying health conditions. Nearly 80% occurred in patients who had been hospitalized in the previous year. They found genes encoding carbapenemases in only 2.3% of 129 isolated tested.
Of 280 cases with available healthcare exposure history, 91.8% were healthcare-associated and 8.2% were community linked. And of cultures collected in acute care settings, most (83.5%) were from short-stay hospitals and 16.5% were from long-term care facilities. Of 155 hospitalized patients with information available, 65.2% had received antimicrobial drugs within 14 days of culture collection, and of those, 82.2% had received one or more β-lactam antimicrobial drug.
Resistance testing found one-third were not multidrug-resistant, and more than half were susceptible to ceftazidime or cefepime. The authors said the surveillance findings provide a snapshot of CRPA epidemiology and that based on the findings, surveillance at eight EIP sites began in 2016 to monitor changes in CRPA incidence and carbapenemase-producing CRPA strains.
Jun 12 Emerg Infect Dis report
In a related research development, researchers from California who looked at antimicrobial susceptibility test results from California hospitals between 2014 and 2017 found 3.2% of Enterobacteriaceae were resistant to carbapenems and 26.9% were resistant to cephalosporins. They reported their findings yesterday in Emerging Infectious Diseases.
Also, they found that the proportion of cephalosporin-resistant Escherichia coli increased 7% per year during the study period. They said some decreasing trends in carbapenem resistance, often the focus of containment efforts, affirm the potential effectiveness of prevention strategies. "Nonetheless, increases and regional variation in carbapenem-resistant and ESCR E. coli highlight the urgent need for ongoing, local infection prevention and antimicrobial stewardship efforts."
Jun 12 Emerg Infect Dis report
Study: Standard gonorrhea treatment superior to solithromycin
Originally published by CIDRAP News Jun 11.
Solithromycin, a novel fourth-generation macrolide, isn't a suitable alternative to standard therapy of ceftriaxone plus azithromycin for treating gonorrhea, according to a study yesterday by researchers from Australia and the United States in The Lancet Infectious Diseases.
Given growing concerns about antibiotic-resistant Neisseria gonorrhoeae, scientists are looking for new therapies. The study took place at two sites in Australia and one in the United States from September 2014 through August 2015. Patients with gonorrhea ages 15 and older were randomly assigned to receive a single 1,000-milligram (mg) dose of solithromycin or a 500-mg intramuscular dose of ceftriaxone plus a 1,000-mg dose of azithromycin. Of 261 participants, 130 were in the solithromycin group and 131 were in the standard-treatment group. Researchers also obtained Neisseria gonorrhoeae cultures at baseline and test day of cure.
Of patients in the solithromycin group, 80% showed evidence of cure on follow-up testing, compared with 84% of the standard-treatment group, suggesting that solithromycin did not show non-inferiority at the preset -10% criterion.
A secondary analysis limited to patients who had follow-up testing found that the eradication rate for solithromycin was 92%, compared with 100% for standard therapy. Also, the team found that adverse events such as diarrhea and nausea were higher in the solithromycin group.
The authors concluded that the solithromycin dose tested isn't a suitable alternative first-line treatment, and further trials of longer dosing will need to consider potential side-effect risks.
In a related commentary in the same issue, two infectious disease specialists from Amsterdam said the ceftriaxone cure rate for gonorrhea is still about 95%, but the number of N gonorrhoeae with decreased susceptibility is increasing, and alternative antibiotics are urgently needed. The authors are Henry de Vries, MD, PhD, and Maarten Schim-van der Loeff, MD, PhD.
They note that the study found that solithromycin treatment failures weren't due to reinfection, hinting that a single dose might not be sufficient. They wrote that more study is needed on the pharmacodynamics of solithromycin. They add that the novel drug's use might be threatened by emerging azithromycin-resistant gonorrhea strains and that future trials involving the drug should include azithromycin-resistant gonorrhea strains.
Jun 10 Lancet Infect Dis abstract
Jun 10 Lancet Infect Dis commentary
Amoxicillin prescribing tied to amoxicillin and ciprofloxacin resistance
Originally published by CIDRAP News Jun 11.
An analysis of UK national data has found that amoxicillin prescribing was not only associated with amoxicillin resistance but ciprofloxacin resistance, as well, whereas nitrofurantoin prescribing was associated with lower levels of resistance to amoxicillin, according to a study yesterday in PLOS One.
The authors used primary care prescribing data from the National Health Service and records of 888,207 urine samples collected from April 2014 through January 2016 that were positive for Escherichia coli.
The researchers determined that amoxicillin prescribing, measured in defined daily doses per 1,000 inhabitants per day, was positively associated with amoxicillin resistance (relative risk [RR], 1.03; 95% confidence interval [CI], 1.01-1.04) and ciprofloxacin (RR, 1.09; 95% CI 1.04-1.17) resistance. In contrast to those findings, nitrofurantoin prescribing was associated with lower levels of resistance to amoxicillin (RR, 0.92; 95% CI 0.84-0.97). Clinical practices with higher levels of trimethoprim prescribing also had higher levels of ciprofloxacin resistance (RR, 1.34; 95% CI, 1.10-1.59).
The authors conclude, "Amoxicillin, which is mainly (and often unnecessarily) prescribed for respiratory tract infections is associated with increased resistance against various antibiotics among E. coli causing urinary tract infections. Our findings suggest that when predicting the potential impact of interventions on antibiotic resistances it is important to account for use of other antibiotics, including those typically used for other indications."
Jun 10 PLOS One study
Stewardship in Scotland tied to lower broad-spectrum prescribing
Originally published by CIDRAP News Jun 10.
Researchers in Scotland report in PLOS Medicine that implementation of an antimicrobial stewardship program (ASP) was associated with large, sustained reductions in the prescribing of three broad-spectrum antimicrobials and in a modest reduction of coliform bacteremia resistance rates.
The investigators analyzed data on all patients registered with a general practitioner in the Tayside region of east Scotland from Jan 1, 2005, through December 2015. A primary care ASP was implemented in 2009, and the authors measured prescribing rates for fluoroquinolones, cephalosporins, and co-amoxiclav, as well as resistance to the same three antimicrobials or classes among community-associated coliform bacteremia
Compared with pre-ASP prescribing, the relative reduction for fluoroquinolones was 68.8% and the absolute reduction was 6.3 people exposed per 1,000 population per quarter. For cephalosporins the reduction was 74.0% and 6.1, respectively, and for co-amoxiclav it was 62.3% and 6.8.
The researchers also found reductions in coliform bacteraemia resistance rates associated with the intervention that were significant for fluoroquinolones and cephalosporins 3.5 years after implementation of the ASP but not for co-amoxiclav. They note, "The reductions in resistance took much longer than reductions in prescribing to become evident, and relative reductions were more modest. The overall pattern was of flattening rather than reversal of previously rising resistance rates."
Jun 7 PLOS Med study
Study notes high resistance in Enterococcus in pigs at Thai-Laos border
Originally published by CIDRAP News Jun 10.
A new study has found high levels of antimicrobial resistance in Enterococcus faecium and Enterococcus faecalis from pigs, pork products, and humans in Thai-Laos border provinces.
Thai researchers, in the Journal of Global Antimicrobial Resistance, wrote that they analyzed 648 human, pork product, and swine swabs—359 from border provinces in Thailand and 289 from similar provinces in Laos. In all, 75% contained E faecium and 74% E faecalis. All isolates were resistant to all antimicrobials tested except vancomycin.
The occurrence of E faecium in pig, pig carcass, retail pork, and humans in Thailand was 80.6%, 73.8%, 77.6% and 67.0%, respectively. The prevalence of E faecium was higher in Laos (65.7%) than Thailand (47.1%), while E faecalis was more common in Thailand (24.2%) than Laos (12.8%).The scientists first observed high levels of resistance to tetracycline, erythromycin, and streptomycin, followed by gentamicin, ampicillin, and chloramphenicol.
The authors conclude, "These pathogens may serve as potential reservoirs for the maintenance and widespread dissemination of AMR and virulence determinants from animals to humans via the food chain."
Jun 8 J Glob Antimicrob Resist abstract