Our weekly wrap-up of antimicrobial stewardship & antimicrobial resistance scans

Study: Toilet flushing could aid spread of pathogens in hospitals

A pilot study by researchers with the University of Iowa has found that bioaerosols from flushed toilets in the rooms of patients with Clostridioides difficile infection (CDI) may contribute to the spread of healthcare-associated bacteria in hospitals. The research was published today in Infection Control and Hospital Epidemiology.

In the study, which was conducted at the University of Iowa Hospitals and Clinics, researchers collected bioaerosols on plates placed 0.15 meters (m), 0.5 m, and 1.0 m from the rims of toilets in 24 rooms of patients hospitalized with CDI and collected bathroom air continuously with a bioaerosol sampler before and after toilet flushing. They then cultured and identified bacteria on the plates (focusing on C difficile), measured bacterial density, and calculated the difference in bioaerosol production before and after flushing.

Bacteria were positively cultured from 8 of 24 rooms (33%). In total, 72 preflush and 72 postflush samples were collected, with healthcare-associated bacteria found in 9 of the preflush samples (12.5%) and 19 of the postflush samples (26.4%); postflush plates had a significantly higher probability of culturing positive than preflush plates (P = .0309). The predominant species cultured were Enterococcus faecalis, E faecium, and C difficile. Compared with the preflush air samples, the postflush samples showed significant increases in the concentrations of the two large particle-size categories: 5.0 micrometers (P = .0095) and 10.0 micrometers (P = .0082).

The authors conclude, "This study potentially supports the hypothesis that toilet flushing may lead to the spread of clinically significant pathogens in healthcare settings. More information is needed to determine the risk factors associated with toilet flushing and environmental contamination by pathogens."
Jan 31 Infect Control Hosp Epidemiol abstract

Prenatal antibiotics linked to childhood asthma in Tennessee study

Originally published by CIDRAP News Jan 29

In a large retrospective cohort study, increasing number of antibiotics courses, early timing, and broad-spectrum prenatal antibiotic exposure were associated with increased risk for childhood asthma, researchers reported today in Clinical Infectious Diseases.

In the population-based cohort study, which involved 84,212 mother-child pairs enrolled in Tennessee's Medicaid program from 1995 to 2003, researchers from Vanderbilt University and Louisiana State University looked at prenatal antibiotic exposure and the development of asthma in the children by the age of 6 to fully understand the relationship between the two, and to investigate whether any association was modified by a familial disposition to asthma. A total of 54,141 children (64%) were exposed to antibiotics prenatally. 

Compared with never-exposed children, exposure to prenatal antibiotics increased the odds of childhood asthma by 23% after adjusting for covariates (adjusted odds ratio [aOR], 1.23; 95% confidence interval [CI], 1.18 to 1.28). Prenatal antibiotic exposure was also associated dose-dependently with increased odds of childhood asthma (aOR for interquartile increase of 2 courses [0, 2], 1.26; 95% CI, 1.20 to 1.33). 

Among children exposed to at least one course in utero, the effect of timing at the first course was moderated by total maternal courses. Among women receiving a single antibiotic course, timing of exposure had no effect on childhood asthma risk. Among women receiving more than one course, early exposure of the first course was associated with greater childhood asthma risk. Compared with the use of narrow-spectrum antibiotics only, broad-spectrum-only antibiotic exposure was associated with increased odds of asthma (aOR: 1.14; 95% CI, 1.05 to 1.24).

Although children with asthmatic mothers were more likely to be prenatally exposed to antibiotics, the number of courses and timing of the first course were not significantly associated with childhood asthma development. The significant dose-dependent relationship between the number of prenatal antibiotic courses and childhood asthma persisted only in children whose mothers did not have asthma, as did the significant timing effect of first prenatal antibiotic exposure on childhood asthma.
Jan 29 Clin Infect Dis abstract

Report: Some UK supermarkets still allowing routine antibiotics on farms

Originally published by CIDRAP News Jan 29

A report today from the UK-based Alliance to Save Our Antibiotics has found that a handful of British supermarket chains are still allowing suppliers to use antibiotics routinely in food-animal production.

The Alliance's assessment of the publicly available antibiotics policies of the 10 leading British supermarkets found that 3—Aldi, Asda, and Iceland—have no restrictions on their meat, dairy, and egg suppliers using antibiotics routinely, other than minimum legal requirements.

"It's completely unacceptable that Aldi, Asda and Iceland are putting their customers' health at risk by failing to ban routine antibiotic use," Alliance campaign manager Suzi Shingler said in a press release. "We know that antibiotic-resistant bacteria can pass to people from food produced with high levels of antibiotics and can end up causing infections which are much more difficult to treat. This is why the [World Health Organization] and the [United Nations] are calling for urgent action."

The assessment also found that Iceland was the only supermarket with no publicly available policies and no antibiotic-reduction strategy in place, and the only one not to collect data on its suppliers' antibiotic use. Six of the supermarkets have published some antibiotic use data, but none publish good data antibiotic use by farming system, the report says. 

"If supermarkets are really committed to reducing farm antibiotic use, they should publish antibiotic data viewed by farming system, as this would help all farmers to learn from best practice," said Cóilín Nunan, scientific adviser for the Alliance.

Only two supermarkets—Waitrose and M&S—prohibit their suppliers from using the last-resort antibiotic colistin. The supermarkets covered by the assessment are Aldi, Asda, Co-op, Iceland, Lidl, M&S, Morrisons, Sainsbury's, Tesco, and Waitrose.
Jan 29 Alliance to Save Our Antibiotics 2019 supermarket assessment
Jan 29 Alliance news release

FDA approves fidaxomicin for treating C difficile in children

Originally published by CIDRAP News Jan 27

Merck announced today that the US Food and Drug Administration (FDA) has approved the macrolide antibiotic fidaxomicin (Dificid) for the treatment of C difficile in children.

According to a company press release, the FDA has approved the company's New Drug Application (NDA) for fidaxomicin for oral suspension and a supplemental NDA for the use of fidaxomicin tablets and oral suspension in children aged 6 months and older. The approval is based on results of the SUNSHINE study, a phase 3 clinical trial evaluating the safety and efficacy of fidaxomicin in children from 6 months and older. It was the first randomized controlled trial of C difficile treatment in children.

The trial randomized 142 patients to receive either fidaxomicin (suspension or tablets, twice daily) or vancomycin (suspension or tablets, four times daily) in a 2:1 ratio. The results showed that the clinical response in the overall pediatric population was similar between fidaxomicin and vancomycin (77.6% vs. 70.5%), while the sustained clinical response—defined as confirmed clinical response and no C difficile–associated diarrhea recurrence through 30 days after treatment—was higher for fidaxomicin (68.4% vs 50%).

Treatment discontinuation due to adverse reactions was reported in 7.9% of fidaxomicin patients in a phase 2, single-arm trial, and in 1% of patients in another phase 3 randomized trial.

"C. difficile is an important cause of health care- and community-associated diarrheal illness in children, and sustained cure is difficult to achieve in some patients," said Larry K. Kociolek, MD, associate medical director of infection prevention and control at Ann & Robert H. Lurie Children's Hospital of Chicago. "I am very excited to have a new C. difficile infection treatment option for my pediatric patients."

The FDA granted priority review for both applications in October 2019.
Jan 27 Merk press release