Our weekly wrap-up of antimicrobial stewardship & antimicrobial resistance scans
Study finds MRSA associated with higher costs, longer hospital stays
A study yesterday in Antimicrobial Resistance and Infection Control found that patients with methicillin-resistant Staphylococcus aureus (MRSA) in Norway have longer hospital stays and incur higher costs than those without MRSA.
For the study, researchers examined data from the Norwegian Patient Registry and Norwegian Surveillance System for Communicable Diseases to identify all MRSA patients admitted to hospitals in 2012, then used a matched case-control method to compare those patients with non-MRSA patients in terms of length of stay (LOS), readmission within 30 days of discharge, and diagnosis-related group (DRG)–based costs. Cases were randomly matched, with one MRSA patients for every four control patients.
In total, 95 MRSA-positive patients were matched with 346 non-MRSA patients. The mean LOS for MRSA patients was 14 days, compared with 8 days for non-MRSA patients. A higher proportion of MRSA patients than controls were readmitted within 30 days (14% vs 10%), but the difference was not considered statistically significant. DRG-based hospital costs were 0.37 times higher for MRSA patients than for controls, with mean costs of 13,322 euros ($15,187) and 7,198 euros ($8,206), respectively.
The authors say the findings improve knowledge with regard to resistant bacteria, and may help Norwegian policy makers to make informed decisions about resource allocation, infection prevention programs, and guideline development.
Jul 6 Antimicrob Resist Infect Control study
C difficile found in kids' and dogs' sandboxes in Spain
An investigation by Spanish researchers has revealed that epidemic ribotypes of Clostridium difficile are widely distributed in children's and dogs' sandboxes in Madrid, according to a study today in Zoonoses and Public Health.
The researchers carried out sampling in 40 sandboxes in public playgrounds in Madrid (20 for children and 20 for dogs) over a 2-day period in July 2015. C difficile was isolated from 21 (52.5%) of the sand samples analyzed, with 12 of the samples coming from dogs' sandboxes and 9 coming from children's. Molecular testing showed that 8 of the 20 available C difficile isolates (one was lost during subculturing) were toxigenic and belonged to ribotypes 014 and 106, both of which are regarded as epidemic, and CD047. The rest belonged to nontoxigenic ribotypes 009, 039, 067, 151, and CD048. Further testing showed that isolates were genetically diverse and displayed resistance to several antibiotics, including high-level resistance to imipenem and levofloxacin.
Ribotype 014 is one of the most prevalent C difficile genotypes isolated from humans and animals in Europe. Other ribotypes identified in the study are also frequently isolated from human and animal fecal samples.
The authors say the presence of toxigenic C difficile in recreational sandboxes constitutes a major health risk. "Due to the zoonotic potential attributed to some ribotypes of C. difficile, the possible presence of this emerging pathogen should be considered in any environmental risk assessment," they write.
Jul 7 Zoonoses Public Health study
National guidelines in France tied to drop in ED antibiotic use
Originally published by CIDRAP News Jul 6
After France implemented national guidelines in 2011, antibiotic prescriptions for acute respiratory infections (ARIs) in children in emergency departments (EDs) dropped 31% over 3 years, representing more than 13,000 avoided antibiotic prescriptions, according to data presented yesterday in Clinical Infectious Diseases.
The multicenter, quasi-experimental, interrupted time series analysis of data from seven French pediatric EDs included all 242,534 patients with ARI from November 2009 to October 2014.
After national guidelines were implemented, antibiotic prescriptions for those cases fell 0.4% per 15-day period on average, for a cumulative drop of 30.9% by the end of the study period. This represented 13,136 antibiotic prescriptions avoided, the study authors said. They also noted that the relative percentage of broad-spectrum antibiotics prescribed dropped 62.7%; they were replaced with amoxicillin.
Jun 5 Clin Infect Dis abstract
UK researchers fine-tune diagnostic tool for serious bacterial infections
Originally published by CIDRAP News Jul 6
In a separate study involving children in the ED, UK researchers found that updating a published diagnostic model helped clinicians discriminate between pneumonia, serious bacterial infections (SBIs), and non-SBIs, representing a possible tool to bolster antibiotic stewardship.
The study, published yesterday in Pediatrics, involved 1,101 children younger than 16 years who had a fever and visited an ED, 264 of whom had an SBI. The investigators validated a published model for diagnosing pneumonia or other SBI in children, then updated it by including measures of procalcitonin and resistin.
In validating the published model, which incorporated various clinical symptoms, the authors reported that it discriminated well between pneumonia and no SBI (concordance statistic [CS], 0.85) and between other SBIs and no SBI (CS, 0.76). Refining the model with procalcitonin and resistin, however, led to even better results. In discrimination of pneumonia, CS increased from 0.88 to 0.90 (P = .03), and for other SBI models it increased from 0.82 to 0.84 (P = .03).
The researchers further reported that at a low-risk threshold for pneumonia, the extended pneumonia model had a sensitivity of 92% and a negative likelihood ratio of 0.12. For other SBIs, sensitivity was 92%, and negative likelihood ratio was 0.21. At a high-risk threshold, specificity was 89% for pneumonia and 86% for other SBIs.
The authors conclude, "Improvements in the classification of nonevents have the potential to reduce unnecessary hospital admissions and improve antibiotic prescribing. The benefits of this improved risk prediction should be further evaluated in robust impact studies."
Jul 5 Pediatrics study
Study finds high rate of MRSA in pediatric Staph infections in Taiwan
Originally published by CIDRAP News Jul 6
Almost two thirds of S aureus isolates from kids in northern Taiwan from 2004 to 2012 were MRSA, and the MRSA proportion rose significantly, according to a study yesterday in BMC Infectious Diseases.
Scientists analyzed 409 S aureus isolates collected from a university hospital from 2004 to 2012 from patients younger than 19 years old. Of the total, 260 (63.6%) were MRSA. The percentage of MRSA-positive isolates rose from 48.5% in 2004-05 to 63.6% in 2012, a statistically significant increase. The highest rate, 69.3%, was recorded in both 2007 and 2011.
In addition, 181 (70%) of the 260 MRSA isolates were community-associated. Among those 181 patients, 157 (86.8%) had skin or soft-tissue infections, 13 (7.2%) had urinary tract infections, and 6 (3.3%) had pneumonia.
Jul 5 BMC Infect Dis study
Study evaluates UTIs, antibiotic use among pregnant women in Uganda
Originally published by CIDRAP News Jul 3
A new study in Clinical Infectious Diseases found that 96% percent of pregnant women with urinary tract infection (UTI) symptoms in Uganda were erroneously given antibiotics, suggesting a need for better diagnostic methods in clinical settings with no access to laboratory service.
In a multi-part study conducted by researchers in Sweden and Uganda, investigators examined 2,562 urine samples to determine the prevalence of bacteriuria among pregnant women with and without UTI symptoms in at a hospital in Kampala, Uganda, and to evaluate different diagnostic methods—dipslide, urine microscopy, and nitrite and leukocyte esterase tests—for possible use in clinical settings without access to a microbiological laboratory and where no medical doctors are available. They also evaluated the susceptibility of Escherichia coli to antibiotics used for pregnant women with UTI in Uganda, where diagnosis of UTI is often based on clinical symptoms and midwives hand out antibiotics free of charge to pregnant women with suspected UTI.
The prevalence of culture-proven UTI among pregnant women with UTI symptoms, all of whom received antibiotics at the hospital's antenatal clinic, was 4%. Slightly more than half (52%) of these bacterial infections were caused by E coli. Susceptibility testing showed that 18% of the E coli strains were extended-spectrum beta-lactamase (ESBL)-producing and 36% were multidrug-resistant. While urine microscopy and nitrite and leukocyte esterase tests demonstrated insufficient diagnostic value, nurses with limited training were able to identify E coli UTI in nearly 80% of cases and no bacterial growth in nearly 100% of negative samples using dipslide testing.
"Compared to clinical diagnosis alone, the use of dipslide would imply substantially decreased antibiotic consumption and as a consequence decreased risk for development of resistance among bacterial pathogens," the authors write. "The massive amount of saved antibiotics might furthermore outweigh, at least in part, the costs associated with the increased diagnostic efforts."
Jun 30 Clin Infect Dis abstract