News Scan for Aug 13, 2019

News brief

Study adds more support for airborne avian flu spread in US outbreaks

A modeling study that incorporated air movement patterns from farms affected early in the highly pathogenic H5N2 avian influenza outbreak that hit US poultry in 2015 suggests that most affected farms in Iowa may have received airborne virus from farms within and outside the state. Using a model used for other animal pathogens such as foot-and-mouth disease virus, researchers published their findings today in Scientific Reports.

The outbreaks led to $3 billion in economic losses over 7 months, striking 232 farms in 15 states. A federal assessment of the outbreak found no one clear factor, but said the virus likely spread by multiple routes, including biosecurity gaps and possibly airborne transmission. There are also anecdotal reports that abnormal bird deaths began near air inlets of infected poultry barns.

In analyzing the model findings, researchers said the majority of infected farms in Iowa might have received airborne virus carried by fine particulate matter from farms within the state or infected farms in neighboring states. Though the modeled airborne virus concentrations never rose above the minimal infective dose for poultry, continuous exposure may have increased the risk, the group wrote.

They concluded that the probability of airborne highly pathogenic avian influenza infection could be affected by flock size and distance from earlier affected farms. "And more importantly, it can be markedly reduced by swift depopulation and inlet air filtration," the team added.
Aug 13 Sci Rep abstract


First clinical trial of chlamydia vaccine yields promising findings

The first phase 1 trial of a chlamydia vaccine found that it is safe and provokes an immune response. A team from Denmark and the United Kingdom reported their findings yesterday in The Lancet Infectious Diseases.

As the most common sexually transmitted bacterial infection, chlamydia causes about 131 million new cases each year, which experts say is likely an underestimate, because three out of four cases are asymptomatic. Vaccination has been eyed as a good way to curb the epidemic, but so far no other vaccine candidates have reached the clinical trial stage.

The vaccine, called CTH522, is based on the outer membrane protein of the Chlamydia trachomatis bacterium. The team analyzed two formulations, one with added CAF01 liposomes to boost cellular immunity and one with aluminum hydroxide to boost antibodies. Thirty five women not infected with chlamydia were randomly assigned to three different groups—two with the new vaccine combined with either CAF01 or aluminum hydroxide and one to placebo. The vaccine was given in three intramuscular injections and two intranasal boosts.

Researchers found that both formulations provoked an immune response in 15 of 15 women in both vaccine groups. However, the formulation combined with CAF01 produced 5.6 times more antibodies, suggesting that it should be evaluated for further study.

The team cautioned that though the vaccine prompted an immune response, it's still not clear if it translates into protection. In a Lancet press release, first author Helene Juel, PhD, with the Statens Serum Institute in Denmark, said both versions of the vaccine raised the concentrations of vaginal antibodies that in mouse studies were shown to be the first line of defense against chlamydia. She added that it will take many more years of research before a vaccine is available, but researchers are planning a phase 2a study of the CAF01 version of the vaccine.
Aug 12 Lancet Infect Dis abstract
Aug 12 Lancet press release


APHIS announces animal health activities funded by Farm Bill

Yesterday the U.S. Department of Agriculture's (USDA's) Animal and Plant Health Inspection Service (APHIS) announced plans for new animal health activities funded by the 2018 Farm Bill.

The 2018 Farm Bill established a three-part program to support animal disease prevention and management, through the creation of two new programs: the National Animal Vaccine and Veterinary Countermeasures Bank (vaccine bank) and the National Animal Disease Preparedness and Response Program (NADPRP), the USDA said in a press statement. The bill also expands funding opportunities for the existing National Animal Health Laboratory Network (NAHLN).

"For 2019, APHIS will also make available up to $10 million in funding to be divided between NADPRP and NAHLN based on the quality of proposed projects," the press statement said.  "Once fully implemented, these three programs will work together to protect and improve the health of our nation's livestock, helping farmers and ranchers provide high-quality agricultural products to consumers here and abroad."

Both the vaccine bank and the NADPRP will help protect American livestock from outbreaks of foot-and-mouth disease or other high-impact foreign animal diseases.
Aug 12 USDA press release

Stewardship / Resistance Scan for Aug 13, 2019

News brief

Adding beta-lactam to daptomycin improves MRSA outcomes, study finds

The addition of a beta-lactam antibiotic to daptomycin is associated with improved clinical outcomes in patients with methicillin-resistant Staphylococcus aureus bloodstream infections (MRSA BSIs), researchers reported yesterday in Clinical Infectious Diseases.

In the retrospective observational study, conducted at two academic medical centers in Detroit from 2008 through 2018, researchers from Wayne State University compared two groups of adults who had MRSA BSIs; one group was treated with daptomycin plus a beta-lactam (DAP+BL), and the other group received daptomycin monotherapy. The primary outcome was composite clinical failure (60-day all-cause mortality and/or 60-day recurrence).

A total of 229 patients were included in the study, with 72 receiving DAP+BL and 157 receiving daptomycin monotherapy. Overall, 52 patients (22.7%) experienced clinical failure, including 43 (27.4%) in the daptomycin group and 9 (12.5%) in the DAP+BL group. In unadjusted and inverse probability of treatment weighted (IPTW)-adjusted analyses, DAP+BL was associated with significantly reduced odds of clinical failure (odds ratio [OR], 0.362; 95% confidence interval [CI], 0.164 to 0.801; adjusted OR, 0.386; 95% CI, 0.175 to 0.853). Lower clinical failure was also consistently demonstrated in all pre-specified subgroups across the spectrum of host and infection characteristics.

The authors of the study say the findings add to a growing body of evidence that beta-lactams, which are ineffective on their own against MRSA, can enhance the bactericidal activity of daptomycin against invasive MRSA infections.
Aug 12 Clin Infect Dis abstract


Study: Electronic medical records aid ICU stewardship program

The integration of electronic medical record (EMR) data with an intensive care unit antimicrobial stewardship (ICU-AMS) program was associated with high clinician compliance with recommendations and improved antibiotic appropriateness, Australian researchers reported today in Infection Control and Hospital Epidemiology.

The primary objective of the study was to examine the impact of an EMR-driven ICU-AMS program at Austin Health, a tertiary care referral hospital in Australia, on clinician compliance with a range of AMS recommendations. The service utilized EMR data coupled with face-to-face consultations with an infectious disease (ID) physician, an ID fellow, and an AMS pharmacist. The recommendations were defined by an internally developed "5 Moments of Antimicrobial Prescribing" metric: (1) escalation, (2) de-escalation, (3) discontinuation, (4) switch, and (5) optimization. The secondary objectives included measuring the impact of this service on antibiotic appropriateness and use of high-priority target antimicrobials.  The impact of the ICU-AMS round on antimicrobial appropriateness was evaluated using point-prevalence survey data.

For the 202 patients reviewed over 5 months (from implementation in August 2017 through December 2017), 412 recommendations were made in accordance with the "5 Moments" metric. The most common recommendation made by the ICU-AMS team was moment 3 (discontinuation), which comprised 173 of 412 recommendations (42.0%), with an acceptance rate of 83.8% (145 of 173). Data collected for point-prevalence surveys showed an increase in prescribing appropriateness from 21 of 45 (46.7%) recommendations pre-intervention (October 2016) to 30 of 39 (76.9%) during the study period (September 2017).

The ICU-AMS service was also associated with an immediate reduction in the use of several key target antibiotics, including meropenem (−40.5%; 95% CI, −52.9% to −24.8%), piperacillin-tazobactam (−39.8%; 95% CI, −50.8% to −26.6%), and vancomycin (−36.6%; 95% CI, −48.3% to −22.4%), and with a significant reduction in the monthly trend in use of vancomycin (−13.2%; 95% CI, −17.9%, −8.4%]).

"In conclusion, the use of an EMR-driven ICU-AMS model demonstrated a decrease in target antibiotic utilization as well as an increase in the appropriateness of antimicrobials," the authors of the study write. "ICU-AMS models that integrate the EMR should be encouraged in centers with appropriate digital resources to achieve subsequent positive impacts on antibiotic prescribing."
Aug 13 Infect Control Hosp Epidemiol abstract

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