Stewardship / Resistance Scan for May 03, 2017

News brief

VA study identifies factors associated with antimicrobial utilization

A new study of antimicrobial stewardship efforts at Veterans Administration (VA) hospitals published in the Journal of Hospital Medicine has identified factors associated with positive and negative effects on antimicrobial utilization.

The study comes out of a 2012 survey of antimicrobial stewardship practices at 130 acute care VA facilities administered by the VA National Antimicrobial Stewardship Task Force (ASTF). From the survey results, investigators derived 57 facility characteristics considered relevant to antimicrobial utilization, then whittled that number down to 34 variables. The variables were entered into a multivariable model that was used to determine associations between the variables and four antibiotic utilization measures: aggregate acute care antimicrobial use, antimicrobial use in patients with noninfectious primary discharge diagnoses, missed opportunities to convert from parenteral to oral antimicrobial therapy, and missed opportunities to avoid double anaerobic coverage with metronidazole.

Variables associated with at least three favorable changes (ie, reduced overall or noninfectious antimicrobial use, fewer missed opportunities to convert from parenteral to oral therapy or avoid double anaerobic coverage) included the presence of postgraduate physician/pharmacy training programs, the number of antimicrobial-specific order sets, frequency of systematic de-escalation review, the presence of pharmacists and/or infectious disease (ID) attending physicians on acute care ward teams, and formal ID training of the lead antibiotic stewardship program pharmacist. Variables associated with two unfavorable changes (increases in noninfectious antimicrobial use and missed opportunities to switch from parenteral to oral therapy) included number of hospital beds, the degree to which the facility engaged with the online resources of the VA stewardship task force, and the presence of antimicrobial stop orders.

"In summary, the VA has made efforts to advance the practice of antimicrobial stewardship system-wide, including a 2014 directive that all VA facilities have an ASP," the authors of the study write. "Our study identifies areas of stewardship that may correlate with, positively or negatively, antimicrobial utilization measures that will require further investigation."
May J Hosp Med study

Drug-resistant hospital infections tied to higher death rates

Hospital-associated infections caused by multidrug-resistant organisms (MDROs) can increase mortality, readmission rates, and emergency department (ED) visits compared with those caused by susceptible strains, Spanish investigators reported yesterday in Clinical Infectious Diseases.

The team studied 324 patients with MDRO infections and 686 with drug-susceptible infections. The risk of all-cause and 30-day mortality after infection was 70% and 77% higher, respectively, in MDRO patients. Probability of readmission was more than double that of patients with susceptible infections. ED visits were significantly higher with methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli infections, in which case the risk was about triple and double the risk in patients with susceptible infections.

The authors noted the MDROs did not appear to influence length of hospital stay or the need for hospital admission, intensive care, surgery, or diagnostic tests.
May 2 Clin Infect Dis study

Study finds 6% resistance rate in hospital Enterobacteriaceae isolates

Scientists at a Malaysian teaching hospital found a 6% rate of carbapenem resistance among Enterobacteriaceae isolates obtained from patients and high rates of the resistance gene NDM-1, according to a study yesterday in Antimicrobial Resistance & Infection Control.

The team analyzed 8,306 Enterobacteriaceae isolates collected from August 2013 to December 2015 from patients at a 700-bed tertiary teaching hospital. Of those, 477 (5.7%) were carbapenem-resistant Enterobacteriaceae (CRE). About 86% of the CRE were Klebsiella pneumoniae, and 49.3% were isolated from rectal swabs, with urine (15.9%) and blood samples (9.6%) accounting for most of the rest.

Of the 136 organisms that were genotyped, 112 (82.4%) were positive for the New Delhi metallo-beta-lactamase 1 (NDM-1) gene, which was first reported in 2009.
May 2 Antimicrob Resist Infect Control report

News Scan for May 03, 2017

News brief

MERS patient in critical condition after indirect camel contact

The Saudi Arabian Ministry of Health (MOH) said there was a new case of MERS-CoV today linked to indirect camel exposure.

A 74-year-old Saudi man from Al Bukayriyah is in critical condition after presenting with symptoms of MERS-CoV (Middle East respiratory syndrome coronavirus). The man had indirect camel exposure, a known risk factor for contracting the coronavirus. Indirect camel exposure can mean exposure in a household or by visiting a site where animals are kept.

The new case brings Saudi Arabia's total to 1,600 MERS-CoV cases, 661 of them fatal, since the virus was first detected in humans in 2012. Seven people are still being treated for their infections, the MOH said.
May 3 MOH report

New Zika test streamlines detection, offers new outbreak response tool

A new test that doesn't require costly reagents can accurately and quickly detect Zika in human samples and in mosquitoes, an international team led by researchers from Colorado State University reported today in Science Translational Medicine.

The testing method uses a specialized technique called loop-mediated isothermal amplification (LAMP) assay to amplify Zika virus genomes, and tests on unprocessed human samples that included blood, saliva, and semen found that sensitivity was similar to the gold standard for testing, reverse-transcriptase polymerase chain reaction (RT-PCR).

Also, the test distinguishes between the African and Asian strains and is sensitive enough to identify one single infected mosquito from a collection pool of 50 uninfected insects. Another advantage was that the LAMP test did not deliver false-positives for closely related viruses such as chikungunya and dengue.

To validate the test, researchers used it to test samples from healthy people that had been spiked with Zika and to test samples from confirmed Zika cases.

Researchers said the minimal processing requirements and the streamlined turnaround time will be helpful for Zika virus surveillance and control.
May 3 Sci Transl Med abstract
May 3 American Association for the Advancement of Science press release

Study probes H9N2 and 2009 H1N1 reassortants in pigs

A study of an avian H9N2 and 2009 H1N1 flu virus reassortant in pigs found that after seven serial passages, it gained the ability to transmit more efficiently. Belgian scientists and US researchers from Kansas State University published their findings yesterday in Scientific Reports.

Both viruses can infect both pigs and people, so researchers have been assessing the characteristics of the reassortant. The team that conducted the latest experiments constructed and tested one that contained the hemagglutinin and neuraminidase of H9N2 and the internal proteins of 2009 H1N1.

The initial reassortant only infected cells of the pigs' nasal mucosa, with no virus found in the trachea or lungs. But after seven passages, the virus replicated in the entire respiratory tract. They also looked at transmissibility, comparing the original and seventh-passage reassortants with the 2009 H1N1 virus. For the original reassortant, nasal shedding was noted for only 2 of 6 direct-contact pigs. However, for the seventh passage of the reassortant, 4 of 6 direct-contact pigs showed nasal shedding of the virus, with virus titers similar to 2009 H1N1, which was passed to all six direct-contact pigs.

Genetic studies associated the expanded tissue tropism and increased transmission they saw after repeated passaging with the HA-D225G mutation, which the team said could be a marker for adaptation of H9N2 viruses to pigs. They concluded that the 2009 H1N1 internal genes combined with the serial passages support H9N2 adaptation in pigs.
May 2 Sci Rep abstract

CDC says 8-case raw milk cheese Listeria outbreak may be over

The Centers for Disease Control and Prevention (CDC) today called its investigation into a listeriosis outbreak over after it severely sickened eight people in four states, killing two.

The case total is two more than the CDC reported in its initial statement on the outbreak, on Mar 9. All eight patients who had Listeria monocytogenes infections required hospitalization, and raw (unpasteurized) milk cheeses made by Vulto Creamery of Walton, N.Y., were implicated in the outbreak. The company recalled eight types of soft cheese in March.

Specimens were collected from outbreak patients from Sep 1, 2016, to Mar 13. Case-patients range in age from less than 1 to 89 years, with a median of 52 years. Five patients are from New York, and Connecticut, Florida, and Vermont each reported a case. The patients in Connecticut and Florida died, and Connecticut public health workers identified the outbreak strain of L monocytogenes in leftover cheese in the deceased patient's home.

The CDC said, "This outbreak appears to be over. However, CDC recommends that consumers do not eat, restaurants do not serve, and retailers do not sell recalled raw milk cheeses made by Vulto Creamery."
May 3 CDC update