News Scan for Jun 17, 2020

News brief

Face masks allow virus-containing droplets to escape, study finds

In a study with implications for COVID-19 transmission, mild coughing can expel small saliva droplets through and around a face mask and travel as far as 1 meter (3.3 feet), according to a study published yesterday in Physics of Fluids.

Researchers from the University of Nicosia in Cyprus simulated airborne droplet transmission for a person with and without a mask using computer models and found that, while masks may reduce airborne droplet transmission and protect the wearer from other people's saliva droplets, they provide incomplete protection against the many droplets that spread around and away from them.

Mask certification standards define a surgical mask's effectiveness as a constant value and don't take into account fluid flow dynamics, droplet leakage through mask openings, or the effects of repeated coughing, which can saturate the masks and reduce their efficiency, the authors said.

The study showed that 10 cough cycles reduced mask efficiency about 8%, and severe coughing and longer mask-wearing time would reduce it even further.

The researchers found that saliva droplet sizes change constantly during cyclic coughing because of interactions between the face and the mask, which typically have gaps of 4 millimeters (0.16 inches) to 1.4 centimeters (0.55 inches).

"Masks decrease the droplet accumulation during repeated cough cycles," lead author Talib Dbouk, PhD, aid in an American Institute of Physics press release. "However, it remains unclear whether large droplets or small ones are more infectious."

The authors called for physical distancing, new criteria for assessing mask performance and assessment that consider flow physics and cough dynamics, and provision of more complete personal protective equipment to healthcare workers, such as helmets with built-in filters, face shields, disposable gowns, and double sets of gloves.

"The implications of the reduced mask efficiency and respiratory droplet transmission away from the mask are even more critical for healthcare workers," they wrote.
Jun 16 Phys Fluids study
Jun 16 American Institute of Physics press release

 

Study shows 5% rate of COVID-19 among symptomatic healthcare workers

Seattle emerged as the first hot spot of novel coronavirus infections in the United States in February, and new data on testing of symptomatic healthcare workers (HCWs) shows 5.3% tested positive for SARS-CoV-2, the virus that causes COVID-19. The study is published in Clinical Infectious Diseases.

To conduct the study, Seattle-area investigators tested 3,477 symptomatic healthcare workers in March and April at drive-through and walk-through sites for employees in the University of Washington Medicine system. A total of 185 employees (5.3%) tested positive for SARS-CoV-2. The prevalence was similar between frontline healthcare workers (5.2%) and medical staff (5.5%).

Symptomatic employees also filled out a survey prior to testing. Of employees who tested positive, 61.6% said they were experiencing fatigue, 59.5% had headaches, 58.4% reported a cough, and 38.4% complained of fever. Only six healthcare workers required hospitalization, and none died.

"Rapid and high throughput testing of HCWs for COVID-19 is feasible using drive-through and walk-through testing clinic models and facilitated the rapid return of SARS-CoV-2 negative HCWs to work," the authors concluded.
Jun 16 Clin Infect Dis study

Stewardship / Resistance Scan for Jun 17, 2020

News brief

Wording change tied to fewer unneeded antibiotics for neonatal sepsis

A change in the wording of antibiotic duration orders for neonatal sepsis led to a substantial decrease in the number of infants who received extra unnecessary antibiotic orders, pharmacists at a hospital in British Columbia reported today in the American Journal of Infection Control.

The intervention implemented at Surrey Memorial Hospital in British Columbia in April 2016 involved a change in the way that clinicians wrote the orders for antibiotic duration in infants with sepsis, from "antibiotics for 48h if blood culture negative" to "antibiotics for 48h unless blood culture positive."

The change in the wording allowed infants to stop receiving antibiotics after they received 48 hours of therapy if the healthcare team had not received notification of a positive culture. The change was made because delays in receiving notification of a negative blood culture can lead to infants receiving extra, unnecessary antibiotic doses.

A medical review of 523 charts (268 prior to the change and 255 after the change) found that unnecessary antibiotic orders (doses beyond 48 hours) were administered to 50% (82 of 164) of infants prior the change and only 7.2% (12/167) after the change. None of the patients included in the review had a blood culture come back positive after the 48 hours of antibiotics were completed. Reductions in pharmacy time and medication waste were also observed.

"The wording and interpretation of antibiotic duration orders, as well as fostering the desired culture shift amongst staff, should be considered as strategies to reduce unnecessary antibiotic administration," the authors of the study wrote.
Jun 17 Am J Infect Control abstract

 

CARB-X funds rapid test for resistant urinary tract infections

CARB-X today announced that it is awarding India-based Module Innovations a contract worth $702,000 and up to $2.5 million more if it meets certain milestones to develop a rapid diagnostic test for drug-resistant urinary tract infections (UTIs). In a press release, CARB-X said the test would also provide information on which antibiotics would be most useful against the resistant organisms, including common ones such as Escherichia coli, Klebsiella, Pseudomonas aeruginosa, and Enterococci faecalis.

The test has the capacity to take days off the time needed to diagnose a UTI and can detect an infection and provide an antibiotic-resistance profile of the pathogen in about 2 hours. The current process requires advanced microbiology laboratories and personnel, and doctors often prescribe patients broad-spectrum antibiotics while waiting days for a test result. The approach doesn't often work, leading to sepsis, kidney damage, and other complications. CARB-X said the affordable and data-driven approach will be useful, especially in middle- and low-income countries.

Erin Duffy, PhD, chief of research and development at CARB-X, said, "This technology, if successful, could provide health professionals with fast, accurate, and affordable AST [antibiotic susceptibility testing] information for UTIs, accelerating the delivery of effective therapeutics to patients, saving lives, and reducing the risk of contributing to drug resistance."

Since its launch in 2016, CARB-X (the Combating Antibiotic Resistant Bacteria Biopharmaceutical Accelerator) has awarded more than $232.1 million to companies developing new treatments and diagnostics for drug-resistant pathogens.
Jun 17 CARB-X press release

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