News Scan for Apr 27, 2020

News brief

H7N3 avian flu in US turkey outbreaks related to wild bird strains

The US Department of Agriculture (USDA) last week shared new details about its investigation into H7N3 avian flu outbreaks at turkey farms in North Carolina and South Carolina, one of them involving a highly pathogenic version of the virus.

The outbreaks initially involved low-pathogenic H7N3, occurring earlier this spring at a few commercial turkey farms in both of the states. One of the later events at a South Carolina farm, however, involved highly pathogenic H7N3.

In an Apr 24 update to the World Organization for Animal Health (OIE), the USDA's Animal and Plant Health Inspection Service (APHIS) said genetic sequencing of the viruses suggested a single introduction followed by secondary spread. Mutation of the virus from a low-pathogenic to highly pathogenic virus occurred in one barn at one of the facilities. The sequencing study also found that the H7 virus was distinct from other poultry H7 viruses, but was similar to wild bird H7 viruses, with the hemagglutinin protein similar to those found in North American wild birds from 2016 to 2018.

Scientists said the virus isn't related to the H7N3 strain found in Mexican poultry outbreaks or to H7N9 lineage viruses from China.
Apr 24 OIE report on H7N3 in US turkeys
Apr 10 CIDRAP news scan "High-path H7N3 avian flu strikes South Carolina turkey farm"

Mexico confirms 124 measles cases, with other cases being probed

Public health officials in Mexico have so far identified 1,364 probable cases of measles, 124 of them lab-confirmed, most of them in unvaccinated people, according to a notice from the World Health Organization (WHO).

Of the 1,240 probable but unconfirmed cases identified from Jan 1 to Apr 2, however, 991 were discarded, and 328 are still being investigated. Of the 124 confirmed cases, 105 were in Mexico City, 18 in Mexico state, and 1 in Campeche state. The median age of patients with confirmed measles was 20 years (range, 3 months to 68 years); 59% were male.

"Under vaccination may be linked with missed opportunities for vaccination, a lack of access to vaccination services, scheduling limitations impacting [parents'] abilities to take their children to get vaccinated, or lack of vaccine stocks," the WHO said.

The WHO Region of the Americas was declared measles-free in September 2016 but lost that status after outbreaks occurred in Venezuela and Brazil in 2018 and 2019. In 2019, Brazil reported 19,326 cases, including 15 deaths, while the United States confirmed 1,282 cases.

From Jan 1 to Apr 4 this year, measles outbreaks have been reported in seven countries in the region, leading with Brazil, at 2,194 cases, including 4 deaths. The United States has reported 12 cases so far this year.
Apr 24 WHO measles report

Stewardship / Resistance Scan for Apr 27, 2020

News brief

Australian study: Antibiotics likely overprescribed for older adults

Priority antibiotics with a high potential for developing resistance are commonly prescribed to older adults in Australia, particularly those with chronic respiratory conditions, but fewer than one fifth of those prescriptions are accompanied by microbiologic tests, researchers reported in BMC Infectious Diseases.

In the study, Australian researchers looked at data on a cohort of older adults (mean age 69 years) that were linked to records of community-based antibiotic prescribing and microbiologic testing. Their aim was to examine the incidence rate of World Health Organization (WHO)-defined Access and Watch antibiotic dispensing among older adults and compare it to the rate of microbiologic testing for bacterial infections. Access antibiotics are first-line options for common infections, while Watch antibiotics are those the WHO considers at greater risk for developing resistance. The WHO recommends that microbiologic assessment accompany use of Watch drugs.

In 2015, among 244,299 participants, there were 63,306 Watch antibiotic prescriptions dispensed and 149,182 microbiology tests conducted; the incidence rate was 0.26 per person-year for Watch group antibiotic dispensing and 0.62 for microbiology testing. Of those antibiotic prescriptions, only 19% were accompanied by microbiology testing within − 14 to + 7 days.

After adjusting for sociodemographic factors and comorbidities, the researchers found that individuals with chronic respiratory diseases were more likely to receive Watch antibiotics than those without—for example, asthma (adjusted incident rate ratio [aIRR], 1.59; 95% confidence interval [CI], 1.52 to 1.66) and chronic obstructive pulmonary disease (COPD) (aIRR, 2.71; 95% CI, 2.48 to 2.95). The rate of microbiology testing, however, was not higher among them (with asthma aIRR, 1.03; 95% CI, 1.00 to 1.05; with COPD aIRR,1.00; 95% CI, 0.94 to 1.06).

The authors of the study say the findings are noteworthy because the use of microbiologic testing can be considered a proxy for assessing the appropriateness of antibiotic use.

"Since watch group antibiotics have high resistance potential, focusing antibiotic stewardship efforts might be needed among older populations with chronic respiratory diseases in the primary care setting," they concluded.
Apr 25 BMC Infect Dis study

Hong Kong study supports adherence to pneumonia treatment guidelines

Researchers in Hong Kong report that adherence to antibiotic treatment guidelines was associated with shorter hospitalization and improved survival in community-acquired pneumonia (CAP) patients, according to a new study in Open Forum Infectious Diseases.

The prospective observational cohort study, conducted by researchers at the Chinese University of Hong Kong, looked at 258 patients hospitalized with CAP in Hong Kong from February 2017 to July 2018. The investigators were interested in looking at clinician adherence to new treatment guidelines for common infectious diseases published in Hong Kong in 2017, particularly the recommendations on empiric antibiotic therapy. They documented disease severity, microbiologic results, antibiotic treatment, and outcomes and performed multivariable logistics regression and Cox proportional hazard models to determine independent factors associated with prolonged hospitalization and mortality.

The researchers identified pathogens in 45% of patients, with 20% having viral pneumonia, 15% having bacterial pneumonia, and 9% having polymicrobial pneumonia. Streptococcus pneumoniae (12%), influenza (12%), and Mycoplasma pneumoniae (1.2%) were the most common atypical viral pathogens. The strong majority of patients were prescribed empirical amoxicillin-clavulanate (79%) or ceftriaxone (8%) with or without doxycycline, which are the recommended regimens for CAP requiring hospitalization.

Non-adherence to local empirical antibiotic treatment guidelines was observed in 25% of patients and, after adjustment for age, underlying chronic illness, and disease severity, was independently associated with prolonged hospitalization (more than 7 days) and higher mortality (adjusted hazard ratio, 3.88; 95% CI, 1.60 to 9.41).

The authors of the study say non-adherence to local guidelines involved both overtreatment with broad-spectrum antibiotics and undertreatment with inadequate coverage for potential drug-resistant pathogens.

"The findings of our study supported our current treatment guidelines," they wrote.
Apr 24 Open Forum Infect Dis abstract

Biopharma start-up receives financing for novel antibiotic candidate

Biopharma start-up Bugworks, Inc., announced last week that it received $7.5 million in financing to complete early clinical studies on a novel broad-spectrum antibiotic targeting a broad range of antibiotic-resistant pathogens.

The funding from Japanese and South African investors will enable the company to complete phase 1 studies of its GYROX intravenous drug candidate, which targets gram-negative and gram-positive bacteria, including Acinetobacter baumannii, Pseudomonas Aeruginosa, Enterococcus faecium, and Staphylococcus aureus. GYROX is a Gyrase-topoisomerase inhibitor that, according to company officials, has a low risk of developing antimicrobial resistance (AMR) because it inhibits two essential targets in the bacterial replication machinery and has been designed to bypass the efflux-resistance mechanism of the bacteria.

The money will also help advance an oral version of the drug toward clinical development.

"This new financing is an endorsement of our team and differentiated AMR assets, as we bring reputed global investors to aid our mission of pandemic preparedness by defeating superbug infections," Bugworks CEO Anand Anandkumar, MD, said in a company press release.

Bugworks, which is based in Delaware and Bangalore, India, received preclinical funding and support for GYROX from CARB-X (the Combating Antibiotic Resistant Bacteria Biopharmaceutical Accelerator) in 2017.
Apr 23 Bugworks press release