Stewardship / Resistance Scan for Nov 11, 2019

News brief

Study shows decline in C difficile incidence at VA hospitals

A retrospective analysis of Veterans Administration (VA) patients who had stool testing for Clostridiodes difficile shows an overall decrease in C difficile infection (CDI) over the course of a decade, with temporal increases linked to implementation of molecular testing methods, researchers reported today in Infection Control and Hospital Epidemiology.

From 2006 through 2016, 472,346 VA patients were tested for C difficile and 68,995 new cases of CDI were reported. The incidence of total inpatient CDI per 10,000 patient-days decreased from 16.81 in 2006 to 13.66 in 2016, and incidence of hospital-onset healthcare facility-associated (HO-HCFA) CDI fell from 10.87 to 6.41. For both CDI and HO-HCFA CDI, temporal increases in incidence observed in 2011 were associated with increased use of molecular-based testing methods such as polymerase chain reaction (PCR) tests (P < .0001). Decreases for both CDI and HO-HCFA CDI were associated with reduced use of fluoroquinolones (P < .0001), clindamycin (P = .0006), and third-generation cephalosporins (P < .0002). Implementation of VA mandatory reporting of HO-HCFA CDI in 2012 did not influence overall CDI rates (P = .24) or HO-HCFA CDI rates (P = .72).

The analysis also found that the overall crude 30-day mortality rate for CDI fell from 2.17 deaths per 10,000 patient-days in 2006 to 1.41 in 2016. The decrease in mortality correlated with PCR testing (P = .0003) but not with decreased antibiotic use or with mandatory VA reporting.

The authors of the study conclude, "Controlling CDI is likely multifactorial. Although the VA initiative to report cases of hospital-acquired CDI was not significant in our model, the advent of stewardship programs throughout the VA and reductions in the use of third-generation cephalosporins, fluoroquinolones, and clindamycin were significantly associated with reduced rates of CDI."
Nov 11 Infect Control Hosp Epidemiol abstract


UK antibiotic development group to work on metallo-beta-lactamase inhibitor

UK-based antibiotic and diagnostic development group the AMR Centre announced today that is has selected a preclinical candidate from its program to address antibiotic resistance caused by metallo-beta-lactamase (MBL) enzymes.

According to an AMR Centre press release, the MBL inhibitor program is focused on a novel small molecule that inhibits a range of MBL enzymes—including NDM-1, IMP, and VIM—and has been shown in lab studies to restore the function of existing beta-lactam antibiotics, which are inactivated by MBLs. The goal is to combine the molecule with carbapenems to treat serious, multidrug-resistant infections caused by gram-negative, MBL-harboring bacteria.

"Our mission is to overcome resistance mechanisms and develop new treatments for serious infections," AMR Centre Executive Director Peter Jackson, PhD, said. "Our MBL inhibitor will be one of the first and, we hope, most effective broad-spectrum therapies against the emerging class of superbugs coming out of India and China."

Clinical trials are scheduled to begin in late 2020.
Nov 11 AMR Centre press release


Dutch study measures ESBL carriage in dogs, cats, and their owners

A nationwide study by Dutch researchers has found that more than 10% of dogs in the Netherlands carry extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E). The findings appear today in the Journal of Antimicrobial Chemotherapy.

For the cross-sectional study, which aimed to identify the prevalence, risk factors, molecular characteristics, persistence, and acquisition of ESBL-E in dogs and cats, the researchers randomly invited Dutch residents to fill out a web-based questionnaire and provide a fecal sample from their dog or cat. Participants were also invited to provide a fecal sample so researchers could investigate co-carriage in human-pet pairs belonging to the same household.

Overall, 550 pairs of fecal samples from humans and dogs and 282 pairs of fecal samples from humans and cats were submitted. The prevalence of ESBL-E carriage in these cohorts was 3.8% for human participants, 10.7% for dogs, and 1.4% for cats. Among the dogs and the cats, the most abundant ESBL gene were blaCTX-M-1 and blaCTX-M-15. The persistence of ESBL-E carriage in dogs was 57.1% at 1 month and 42.9% at 6 months. The primary risk factors for ESBL-E carriage in dogs was eating raw meat (odds ratio, 8.8; 95% confidence interval [CI], 4.7 to 16.4). Risk factors could not be determined for cats.

No ESBL-E co-carriage was found between cats and their owners, but in five households, both the human and dog fecal samples were positive for the same ESBL gene, which was more than expected based on chance. Whole-genome sequencing in three of the human-dog pairs found that the isolates were nearly identical.

The authors of the study say the observed ESBL-E co-carriage between humans and their dogs suggests either clonal transmission between humans and pets within the same household, or exposure to the same source.
Nov 11 J Antimicrob Chemother study

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MERS infects 2 more in Saudi Arabia, 1 fatally

In updates yesterday and today, Saudi Arabia's Ministry of Health (MOH) reported two more MERS-CoV cases, one of them fatal and both from Riyadh.

One of the patients is a 33-year-old man whose contact with camels isn't known. He is not a health worker, and his exposure is listed as primary, meaning he probably didn't contract MERS-CoV (Middle East respiratory syndrome coronavirus) from another patient.

The other is a 38-year-old man who died from his infection. Like the first case, he wasn't a health worker and his case is classified as involving primary exposure.

Saudi Arabia has now reported seven MERS-CoV cases for November.

The World Health Organization (WHO) said in a recent update that since the virus was first detected in humans in 2012, it has received reports of 2,470 cases as of early October, at least 851 of them fatal. Most are from Saudi Arabia.
Nov 11 Saudi MOH report


Study adds more evidence that maternal flu vaccination protects babies

A study over two influenza seasons in England added more evidence that immunizing pregnant women helps reduce lab-confirmed flu and related hospitalizations in babies younger than 6 months old. A team from Public Health England reported their findings on Nov 9 in the Journal of Infectious Diseases.

For the study, they used information from a clinical practice database that included a newly available pregnancy registry, which allowed the researchers to more accurately assess pregnancy timing and maternal flu vaccine uptake. Their goal was to reassess the effectiveness of maternal flu vaccination in preventing flu and flu-related hospitalizations in infants younger than 6 months in England during the 2013-14 season and the 2014-15 season. The former was dominated by 2009 H1N1, and the latter by a drifted H3N2 strain.

They found overall vaccine effectiveness (VE) of 66% (95% confidence interval [CI], 18% to 84%) in the 2013-14 season and a VE of 50% (95% CI, 11% to 72%) for 2014-15. VE for flu-related hospitalization was similar. Against the dominant 2009 H1N1 strain in 2013-14, VE was higher at 78% (95% CI, 16% to 94%), and against the drifted H3N2 strain the following season, VE was 60% (95% CI, 16% to 81%).

The results provide further evidence that maternal flu vaccination is effective against lab-confirmed flu and flu hospitalizations in young babies, even against a drifted H3N2 strain. Researchers noted their findings were similar to earlier studies from Bangladesh and South Africa, were somewhat higher than results from Mali and Nepal, and in the midrange of two observational studies from the United States. "Maternal vaccination is a valuable approach to protect infants (for whom seasonal influenza vaccine is not currently licensed) from influenza-related morbidity," they wrote.
Nov 9 J Infect Dis abstract


Flu vaccination in kids not tied to season severity, vaccine effectiveness

A study that looked at flu season severity, vaccine effectiveness, and flu vaccination rates in children found no association between vaccination rates and severity of the current or prior season. A team based at Columbia University reported their findings today in JAMA Pediatrics.

They based their findings on their analysis of publicly available data from the US Centers for Disease Control and Prevention for 2010 to 2017 seasons, looking at vaccination rates for four different pediatric age groups, flu severity designations for pediatric patients, and flu VE.

Along with a lack of association between vaccination and flu season severity, they also found no significant link between uptake and current or prior year flu VE, which over the study period ranged from 19% to 60%. However, they did see a slight decline in vaccination rates in 2015 after a very low flu VE of 19% in 2014.

Researchers said it's possible that effects of season severity and VE may be cumulative, reducing uptake if trends persist for multiple years.

The general decline in flu vaccination rates across age groups over recent years is alarming, they wrote, adding that the pattern could reflect the antivaccine movement or a mix of factors, which could include misperceptions about flu risk and severity, and lack of confidence in vaccine effectiveness, vaccine safety, and healthcare authorities. More studies are needed to tease out the factors that drive vaccination decisions, the group said.
Nov 11 JAMA Pediatr abstract


Cholera tops infectious diseases in WHO African member states in 2018

A new survey of infectious disease outbreaks in WHO African member states in 2018 shows that cholera was the most commonly reported disease outbreak, accounting for 20.8% of outbreak events. The study appears today in Epidemiology & Infection.

The WHO African region carries the largest infectious disease burden in the world, and the study was a retrospective descriptive analysis using records of all infectious disease outbreaks formally reported to the WHO in 2018 by member states of the African region, the authors said.

A total of 96 new disease outbreaks were reported across 36 of the 47 member states in 2018, and a total of 107,167 people were directly affected including 1,221 deaths (mean case fatality rate, 1.14%; 95% CI, 1.07% to 1.20%).

In addition to cholera, measles and yellow fever accounted for a large proportion of outbreaks, 11.5% and 7.3%, respectively.

About 25% of all outbreaks were reported to the WHO by member states based on signals detected through media monitoring.
Nov 11 Epidemiol Infect study

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