News Scan for May 20, 2020

News brief

CDC: Backyard poultry Salmonella outbreak sickens 97 in 28 states

The US Centers for Disease Control (CDC) today announced that it—along with local public health officials—is investigating an outbreak of Salmonella infections linked to contact with backyard chicks and ducklings that sickened 97 people in 28 states from Feb 26 to May 1.

About one third of the people who became ill are younger than 5 years. Seventeen people have been hospitalized, but no deaths have been reported, the CDC said.

In interviews, 38 (86%) of 44 ill people said that they had contact with chicks and ducklings, which they procured from farm stores, website, and hatcheries, in the week before they became sick. Whole-genome sequencing showed that bacteria isolated from infected people were closely related genetically, meaning that they likely shared a common source of infection.

The agency said that people can become infected by Salmonella by touching live poultry—even ones that appear healthy and clean—or their environment. Such infections are typically reported in spring and summer, when people tend to buy chicks, ducklings, and other live poultry for their backyard flocks.

The CDC advises owners of backyard flocks to always wash their hands thoroughly with soap and water after contact with poultry or their environment, not allow kids younger than 5 years to touch the poultry, keep a separate set of shoes outside to wear while tending to the birds, remain outdoors when cleaning cages or feed containers, not eat or drink around the poultry, and not let live poultry in the house or kiss or snuggle with them.

Salmonella can cause diarrhea, fever, and stomach cramps 6 hours to 6 days after exposure. Most people are ill for 4 to 7 days and recover without treatment. But children younger than 5 years, adults 65 and older, and those with compromised immune systems can have severe illness and require hospitalization.
May 20 CDC investigation notice
CDC's backyard poultry web page

Iraq and Taiwan report high-path avian flu outbreaks in poultry

In the latest avian flu developments, two countries recently reported new outbreaks involving highly pathogenic strains, Iraq with H5N8 and Taiwan with H5N5, according to recent notifications from the World Organization for Animal Health (OIE).

Iraq's outbreak, its first since March 2019, occurred at a commercial poultry farm in Nineveh, located on the outskirts of Mosul in the north. The event began on May 9, killing 21,700 of 59,700 birds. The survivors were slated for culling as one of the steps to curb the spread of the virus. The source of the outbreak isn't known, but it might be related to contact with wild birds.

Taiwan's H5N5 outbreak is part of sporadic events involving the strain that have been occurring since September 2019. The latest began Apr 27, striking a commercial farm housing native chickens in Yunlin County. The virus killed 1,780 of 14,734 birds, and the rest were destroyed as part of the outbreak response.
May 19 OIE report on H5N8 in Iraq
May 18 OIE report on H5N5 in Taiwan

Stewardship / Resistance Scan for May 20, 2020

News brief

Study finds high antibiotic use in US hospitals

A retrospective study of inpatients treated at 576 US hospitals in 2016 and 2017 found that nearly two-thirds received antibiotics, and that broad-spectrum antibiotic use was common, US researchers reported in Clinical Infectious Diseases.

To measure antibiotic use at the hospitals, researchers from the University of Maryland School of Medicine and other US institutions obtained daily antibiotic charge data for each adult inpatient encounter, along with patient clinical data, facility data, and ICD-10 diagnosis codes. Each antibiotic was mapped to one of 18 mutually exclusive antibiotic classes and to spectrum of activity categories. Antibiotic usage rates were reported as total inpatient days of therapy of therapy (DOT) per 1,000 patient-days, and relationships between DOTs and hospital, case-mix, and geographic variables were evaluated in negative binomial regression models.

The study included 11,701,326 across 576 hospitals during the study period. Overall, patients received antibiotics in 65% of hospitalizations, at a crude rate of 870 DOTs per 1,000 patient-days. By class, use was highest among beta-lactam/beta-lactamase inhibitor combinations (206 DOTs/1,000 patient-days), third- and fourth-generation cephalosporins (128 DOTs/1,000 patient-days), and glycopeptides (113 DOTs/1,000 patient-days). By spectrum of activity, agents with anti-pseudomonal activity had the highest usage (245 DOTs/1,000 patient-days).

Teaching hospitals averaged lower rates of total antibiotic use than non-teaching hospitals (834 versus 957 DOTs/1,000 patient-days; P < 0.001). In adjusted models, teaching hospitals remained associated with lower use of third- and fourth-generation cephalosporins and anti-pseudomonal agents (adjusted incident rate ratios, 0.92 [0.86 to 0.97] and 0.91 [0.85 to 0.98], respectively). Significant regional differences in total and class-specific antibiotic use also persisted in adjusted models. Compared to the South Atlantic, rates of total antibiotic use were 6%, 15%, and 18% lower on average in the Pacific, New England, and the Middle Atlantic, respectively.

The authors of the study say that, given the recent focus on antibiotic stewardship, they're surprised by the antibiotic usage rate, which is similar and in some cases higher than estimates from 5 to 8 years prior. They say that could be because reductions in some antibiotics are being offset by increases in other agents. They also say it's possible that while antibiotic stewardship programs are reducing antibiotic use in hospitals, their uptake remains too limited to drive national reductions.
May 18 Clin Infect Dis abstract

Communication training tied to reduced prescribing in German physicians

A short communication trainings session for primary care physicians was associated with an 11% drop in antibiotic prescribing, German and Austrian researchers reported yesterday in PLoS One.

The study included a total of 1,554 German primary care physicians who received two 2-hour communication training sessions in February and March of 2016. The training was based on MAAS-Global, an instrument used in the Netherlands to measure physicians' communication skills (the German version is called MAAS-Global-D). The researchers compared antibiotic prescribing among these physicians (the intervention group) with a control group formed from observational data.

To estimate intervention effects, the researchers applied a combination of difference-in-difference (DiD) and statistical matching based on entropy balancing. They estimated a corresponding multi-level logistic regression model for the antibiotic prescribing decisions of German primary care physicians for upper respiratory tract infections (URTIs).

The reduction in the overall prescribing rate of the intervention group between the pre-intervention and post-intervention period was 11.2%. The difference between both groups in the difference between the periods was -6.5% and statistically significant. The estimated effects were nearly identical to the effects estimated for the multi-level logistic regression model with applied matching. Furthermore, for the treatment of young women, the impact of the training on the reduction of antibiotic prescription was significantly stronger.

The authors conclude, "Our results suggest that communication skills implemented via MAAS-Global-D training lead to more prudent prescribing of antibiotics for URTIs. Therefore, the MAAS-Global-D training could not only avoid unnecessary side effects but could also help to reduce the emergence of drug resistant bacteria."
May 19 PLoS One study