ASP Scan (Weekly) for Dec 08, 2017

MRSA surveillance limits
;
ESBL prevention
;
Beta-lactamase outbreak
;
Improper therapy for Enterobacteriaceae
;
Candida auris case study
;
Treatment for Candida infections
;
C diff vaccine axed

Study highlights limits of mandated MRSA surveillance

A 2007 state law in Illinois mandating active surveillance of methicillin-resistant Staphylococcus aureus (MRSA) in intensive care unit (ICU) patients failed to reduce MRSA prevalence, according to a study yesterday in Clinical Infectious Diseases.

The Illinois law, the first of several passed in the United States, requires hospitals to screen ICU patients for MRSA colonization and place those who test positive for MRSA in contact precautions. While the "search and isolate" strategy has been used to control MRSA during outbreaks, its role in controlling MRSA in non-outbreak settings is more controversial. To evaluate the law's impact, researchers from the US Centers for Disease Control and Prevention and three Chicago hospital systems invited all hospitals in Chicago with more than 10 ICU beds to participate in regional point prevalence surveys for MRSA colonization.

In total, 25 hospitals and 3,909 adult ICU patients participated in the point prevalence surveys over eight survey periods (2008 to 2013). Of the 3,909 patients, 432 (11.1%) were found to be colonized with MRSA, and the prevalence of MRSA colonization prevalence did not change significantly from year 1 to year 5 of the study period; year-over-year relative risk for MRSA colonization was 0.97. In addition, roughly 4 in 10 MRSA-colonized ICU patients were not in contact precautions at the time of cross-sectional surveys.

"Our findings highlight the limits of legislated MRSA active surveillance as a strategy to reduce MRSA colonization burden among ICU patients," the authors write.
Dec 7 Clin Infect Dis study

 

Controlling ESBL carriage on hospital wards

An analysis of two studies demonstrated a low acquisition rate of extended-spectrum beta-lactamase–producing Enterobacteriaceae (ESBL-E) in 14 Dutch hospitals after contact precautions were used for all ESBL-E carriers.

Writing in Infection Control and Hospital Epidemiology, Dutch investigators detailed their analysis of data from 2011 through 2014 involving perianal cultures. In both studies, staff employed contact precautions for all ESBL-E carriers. The analysis involved patients hospitalized for more than 2 days.

The team determined that the absolute risk acquiring ESBL-E rectal carriage ranged from 2.4% to 2.9%, with an ESBL-E acquisition rate of 2.8 to 3.8 acquisitions per 1,000 patient-days. In addition, 28% of acquisitions were attributable to patient-dependent transmission.

The authors conclude, "The low ESBL-E acquisition rate in this study demonstrates that it is possible to control the nosocomial transmission of ESBL in a low-endemic, non-ICU setting where Escherichia coli is the most prevalent ESBL-E and standard and contact precautions are applied for known ESBL-E carriers."
Dec 7 Infect Control Hosp Epidemiol study

 

Report details first European outbreak involving certain resistance gene

The first report of a certain drug-resistant strain of beta-lactamase–producing bacteria in Europe points to endoscope contamination, according to a study yesterday in Eurosurveillance.

Researchers examined 29 isolates of OXA-48–like beta-lactamase–producing bacteria from 23 patients collected in France from October 2012 through May 2014, 21 of which remained susceptible to imipenem and meropenem, which complicated their detection. Of those 21 isolates (12 from Escherichia coli and 9 from Klebsiella pneumoniae), all co-produced the cephalosporinase CMY-4 resistance gene, and 60% of them co-produced the extended-spectrum beta-lactamase resistance gene CTX-M-15.

"The results of this analysis led us to do an epidemiologically investigation of this dual outbreak," the authors wrote. "An endoscope was identified as the possible source of the outbreak in that the investigation showed that 17 patients had direct contact with the endoscope, while five (Patients 10, 11, 13, 14 and 16) were considered as secondary cases through patient-to-patient transmission on a clinical ward."
Dec 7 Eurosurveill report

 

Inappropriate antibiotics shown costly for Enterobacteriaceae infections

Originally published by CIDRAP News Dec 7

A nationwide study of US patients with Enterobacteriaceae infections suggests that inappropriate empiric therapy (IET) is associated with higher 30-day readmission rates and is costlier than adequate treatment.

The retrospective cohort study, published yesterday in Antimicrobial Resistance & Infection Control, looked at all adult patients admitted to 175 US hospitals from 2009 through 2013 with urinary tract infection (UTI), pneumonia, or sepsis as the principal diagnosis. IET was defined as failure to administer an antibiotic therapy active in vitro against the culture-confirmed pathogen within 2 days of admission.

To understand the full economic impact of IET among patients with Enterobacteriaceae infections, the researchers sought to explore the direct costs associated with antibiotics prescribed and those attributable to delaying adequate treatment, and to examine rates of hospital readmission at 30 days.

Among the 40,137 patients diagnosed as having Enterobacteriaceae infections, 4,984 (13.2%) received IET. Carbapenem-resistant Enterobacteriaceae (CRE) was more frequent in patients given IET (13%) than non-IET patients (1.6%). While the proportion of total hospital costs represented by antibiotics were similar among IET and non-IET patients (3.3% vs. 3.4%), each additional day of inadequate therapy added $766 to the total cost of hospitalization. And while 30-day readmission rates were above 20% in both groups, they were significantly higher in the IET patients compared with the non-IET patients (25.6% vs. 21.1%).

The authors of the study, which was co-authored by two employees and two consultants of primary sponsor The Medicines Company, say the findings are significant because they suggest the additional costs and worsened outcomes associated with IET may outweigh concerns about using newer, more expensive broad-spectrum antibiotics. "Given the known improvement in the chances of survival with immediate appropriate treatment, this serves as further compelling evidence to start broadly and de-escalate as necessary," they write.  
Dec 6 Antimicrob Resist Infect Control study

 

Study evaluates quick response to Candida auris infection

Originally published by CIDRAP News Dec 7

A small quasi-experimental study yesterday in Infection Control and Hospital Epidemiology describes efforts to limit dissemination of Candida auris at a New York hospital after the fungal pathogen was identified in a patient.

The patient, a 59-year-old woman with metastatic colon cancer, was found to have C auris in her bloodstream 6 days after admission to the hospital and remained colonized until her death on day 21 of hospitalization. On day 7, the patient and her roommate were placed on enhanced contact precautions and moved to private rooms, and their former room was terminally cleaned with peracetic acid–hydrogen peroxide (PA-HP) and ultraviolet (UV) light. In addition, hospital staff moved all patients in the oncology ward to terminally cleaned rooms.

Sampling of the index patient and other patients on the ward, along with environmental sampling, was conducted, and 180 samples (48 from 18 different patients, and 132 from 32 different surfaces) were collected. C auris was isolated from 3 of 132 surface samples on days 8, 9, and 15 of ward occupancy but from no patient samples. Isolates from the environment and the case-patient were genetically identical and most closely related to the 2013 India CA-6684 strain, indicating the source of the environmental contamination was the case-patient, who likely acquired the pathogen from another New York hospital.

Although the authors can't say whether the timely feedback from the referral laboratories, cleaning with PA-HP and UV, and high hand hygiene compliance on the ward limited the spread of C auris, the pathogen was isolated from fewer surfaces and patients than noted in prior reports. They say the response is noteworthy for the multifaceted interagency approach taken and for the extensive attempt at environmental assessment.
Dec 6 Infect Control Hosp Epidemiol study

 

Improper antifungal prescribing not tied to death in Candida blood infections

Originally published by CIDRAP News Dec 7

Inappropriate antifungal therapy did not have an impact on mortality in patients with Candida bloodstream infection (CBSIs), according to a study yesterday in BMC Infectious Diseases.

Researchers in Mexico looked at patients admitted to two referral tertiary centers in Mexico City from June 2008 to July 2014 with a blood culture positive for Candida. CBSIs represent 10% of all bloodstream infections, and mortality is high (46% to 75%). The purpose was to evaluate the impact on mortality of the Clinical and Laboratory Standards Institute's (CLSI's) updated clinical breakpoints for antifungal therapy for the most common Candida species. The breakpoints were updated in 2012.

Overall, 149 episodes of CBSI were included for analysis. The most frequent species identified were C albicans (40%), C tropicalis (23%), and C glabrata complex (20%). According to the 2012 CLSI breakpoints, 8.7% of the patients received inappropriate antifungal therapy. The 30-day mortality among CBSI patients was 38%.

In multivariate analysis, severe sepsis (odds ratio [OR], 3.4) and cirrhosis (OR, 36) were independently associated increased 30-day mortality, while early central venous catheter removal and previous antifungal therapy were associated with decreased 30-day mortality. Inappropriate antifungal therapy, as defined by the 2012 CLSI breakpoints, was not associated with 30-day mortality (OR, 0.19).

"Mortality in CBSI remains high due to disease severity and comorbidities such as cirrhosis at the time of diagnosis," the authors conclude. 
Dec 6 BMC Infect Dis study

 

Sanofi ends development of experimental C difficile vaccine

Originally published by CIDRAP News Dec 4

Drugmaker Sanofi Pasteur says it's discontinuing clinical development of an experimental vaccine for Clostridium difficile infection (CDI).

In a Dec 1 press release, the company announced that, following a planned interim analysis of early results from the phase 3 Cdiffense clinical trial, an independent data monitoring committee concluded that the study was unlikely to meet its primary objective. The trial was designed to test the efficacy and safety of a toxoid vaccine in a subpopulation at risk of CDI. The vaccine stimulates the immune system to fight toxins generated by C difficile bacteria.

The company said data from all vaccinated volunteers in the trial will continue to be analyzed for more information and shared with the scientific community.

CDI is a leading cause of diarrhea in hospital patients and one of the most common healthcare-associated infections. According to the CDC's most recent estimates, C difficile is responsible for nearly half a million infections among US hospital patients annually, with approximately 29,000 patients dying within 30 days of infection.
Dec 1 Sanofi press release      

Newsletter Sign-up

Get CIDRAP news and other free newsletters.

Sign up now»

OUR UNDERWRITERS

Unrestricted financial support provided by

Bentson Foundation 3MAccelerate DiagnosticsGilead 
Grant support for ASP provided by

  Become an underwriter»