Stewardship / Resistance Scan for Sep 28, 2022

News brief

Trial supports protocol for reducing antibiotics in suspected sepsis cases

An opt-out protocol for antibiotic de-escalation in patients with suspected sepsis resulted in more antibiotic discontinuations and less exposure to broad-spectrum antibiotics, with no evidence of harm, according to the results of a randomized controlled trial published today in Clinical Infectious Diseases.

The trial, conducted in 10 US acute care hospitals from September 2018 through May 2020, aimed to quantify the effect of an antibiotic opt-out program targeting low-risk patients in whom systemic infection was not confirmed or who recovered quickly and were therefore candidates for antibiotic de-escalation.

Eligible patients were randomly assigned to the opt-out protocol versus usual care. In the intervention arm, the clinician responsible for antibiotic treatment was encouraged to stop antibiotics based on an initial safety screen that determined the patient was not likely to have sepsis. If the clinician decided to continue antibiotics, a study team member initiated a guided antibiotic de-escalation discussion. The primary outcome of the trial was 30-day post-enrollment antibacterial days of therapy (DOT).

Among 9,606 patients screened, 767 were enrolled. Patients in the intervention arm had 32% lower odds of antibiotic continuation (79% vs 84; odds ratio [OR], 0.68; 95% confidence interval [CI], 0.47 to 0.98). Among those who had antibiotics continued, DOT (mean, 10.4 vs 9.9; ratio of means, 1.06; 95% CI, 0.88 to 1.26) were not different. Fewer intervention patients were exposed to extended-spectrum antibiotics (36% vs 44%). Thirty-day safety events were similar in both arms.

The most common rationales for continuing antibiotics were treatment of localized infection (76%) and belief that stopping antibiotics was unsafe (31%).

The study authors suggest the screening tools and standardized opt-out language and questions were critical factors in the success of the intervention.

"The opt-out language set expectations for antibiotic discontinuation based on patient-specific review and screening criteria," they wrote. "Thus, it sped up decisions to stop antibiotics among patients who ultimately may have had antibiotics stopped at a later timepoint in the absence of an intervention."
Sep 28 Clin Infect Dis abstract

Report: Resistant Campylobacter common in UK chicken

A new report from the United Kingdom's Food Safety Agency (FSA) finds that antimicrobial resistance (AMR) in Campylobacter bacteria isolated from retail chicken meat and chicken at slaughter is common but appears to have plateaued since 2014.

The analysis of AMR trends in Campylobacter, which causes an estimated 500,000 cases of foodborne illness annually in the United Kingdom, found that resistance to quinolones (ciprofloxacin), nalidixic acid, and tetracycline is common in Campylobacter jejuni and Campylobacter coli in UK broiler chickens.

The prevalence of ciprofloxacin resistance in C jejuni rose from 13% in 2001 to 2005 to 47% in 2011 to 2018, while ciprofloxacin resistance in C coli rose from 18% in the years 2001 to 2005 to 48% in 2016 to 2018. But for both species, there has been no significant change in resistance to ciprofloxacin since 2014.

Similar trends were observed for resistance to tetracycline, with resistance climbing from 27% in 2001 to 66% in 2018 among C jejuni isolates and from 23% in 2001 to 55% post-2013 in C coli, but no significant changes were observed since 2014. Rates of resistance to nalidixic acid rose from 16% in 2001 to 52% in 2018 in C jejuni, and from 16% in 2001 to 50% in 2017 in C coli, but resistance has declined post-2014.

Rates of resistance to erythromycin, gentamicin, and streptomycin were low, as were multidrug-resistant phenotypes.

"It is possible that this is related to the significant reductions in usage of antimicrobials (AMU) undertaken by the poultry industry in the past decade," the report states. "However, more data is required to provide convincing evidence that historical increases in the prevalence of quinolone and tetracycline resistance have ceased."

The authors say monitoring of AMR in C jejuni and C coli from chicken should continue and that further research should investigate the impact of other variables, including the effect of production system and seasonality on the incidence of resistance in Campylobacter.
Sep 28 FSA report

News Scan for Sep 28, 2022

News brief

High-flow oxygen not better than standard O₂ in COVID respiratory failure

High-flow oxygen didn't significantly lower death rates beyond those of standard oxygen therapy in COVID-19 patients with respiratory failure, according to a multicenter randomized clinical trial published yesterday in JAMA.

As part of an ongoing trial, researchers enrolled 711 patients who had COVID-19 respiratory failure in 1 of 34 intensive care units (ICUs) in France from January to December 2021, with final follow-up on Mar 5, 2022.

Patients were randomly assigned to receive either high-flow oxygen through a nasal cannula (357 patients) or standard oxygen therapy through a non-rebreathing mask (354) for a median of 4 days. Average patient age was 61 years, and 30% were women.

Death rates at 28 days were 10% in the high-flow oxygen group and 11% in standard oxygen recipients, a non-statistically significant difference. But the intubation rate was significantly lower in high-flow oxygen recipients than in those receiving standard oxygen (45% vs 53%).

The most common adverse event was ventilator-associated pneumonia (58% of the high-flow group vs 53% in standard oxygen recipients).

The authors said that although high-flow oxygen didn't significantly lower the death rate, the reduced risk of intubation and need for invasive mechanical ventilation may be an important outcome. "It may also help avoid the use of ICU ventilators in resource-constrained settings during a pandemic," they wrote.

In a related commentary, Alistair Nichol, PhD, of University College Dublin, and Cecilia O'Kane, PhD, and Daniel McAuley, MD, both of Queen's University Belfast, said that future trials should incorporate different types of COVID-19 patients to determine which subgroups are most likely to benefit or be harmed by the different oxygen therapies.

In the meantime, the results of this study "will provide some reassurance for clinicians in times of reduced availability of certain noninvasive respiratory support strategies during surges in COVID-19 hospitalizations," they wrote. "Particular attention should be given to the potential for complications with each approach, as well as patient preference and tolerance of the selected therapy."
Sep 27 JAMA study and commentary

New blood test aims to predict who will get long COVID

In a small study today in eBioMedicine, researchers from University College London show that a blood sample taken at the time of COVID-19 infection could predict who would develop persistent symptoms up to 1 year later by using precise measurements of proteins.

To conduct the study, the researchers looked at blood plasma samples from 54 British healthcare workers who had a confirmed COVID-19 infection, taken every week for 6 weeks in the spring of 2020. Those samples were compared to samples from 102 healthcare workers who were not infected during the same period.

Using targeted mass spectrometry, the researchers found abnormally elevated levels of 12 proteins out of the 91 studied among those infected by SARS-CoV-2. The degree of protein level elevation correlated to increased symptoms. They found that abnormal levels of 20 proteins, most related to anti-clotting and anti-inflammatory processes, were predictive of persistent symptoms 1 year after infection.

"Our study shows that even mild or asymptomatic Covid-19 disrupts the profile of proteins in our blood plasma," said first author Gabriella Captur, MD, PhD, in a university press release. "This means that even mild Covid-19 affects normal biological processes in a dramatic way, up to at least six weeks after infection."

The authors said a larger, independent study is needed to corroborate these findings. Senior author Wendy Heywood, PhD, said, "If we can identify people who are likely to develop long Covid, this opens the door to trialling treatments such as antivirals at this earlier, initial infection stage, to see if it can reduce the risk of later long Covid."
Sep 28 eBioMedicine study
Sep 28 University College London press release

Texas confirms CWD in Limestone County for first time

Texas officials have confirmed chronic wasting disease (CWD) in Limestone County for the first time, on a farm that breeds captive deer, according to a news release late last week from the Texas Animal Health Commission (TAHC).

Four deer at the facility tested positive for CWD on Sep 5 in tests conducted by the Texas A&M Veterinary Medical Diagnostic Laboratory in College Station. The National Veterinary Services Laboratory in Ames, Iowa, confirmed CWD in two of these samples on Sep 13 and will complete testing of the other two samples soon. Texas Parks and Wildlife Department (TPWD) and TAHC officials have taken steps to secure the facility and notify other breeding operations that received deer or shipped deer to this facility in the past 5 years, the TAHC said.

"TPWD and TAHC are taking this situation very seriously," said John Silovsky, TPWD wildlife director. "Fortunately, these positive cases were detected early, and we have a good sample distribution across the facility.

"At this time, CWD appears to be contained to one pen within the facility. Animal health and wildlife officials will continue to investigate to determine the extent of the disease within the facility and mitigate risks to Texas' CWD susceptible species."

TPWD officials are developing surveillance zone boundaries that may include portions of Limestone, Hill, Freestone, and Navarro counties.

CWD is a fatal prion disease spread between cervids such as deer, moose, and elk through contaminated environments, antler velvet, and body fluids and tissues. Though the disease isn't known to infect humans, some experts fear it one day could cause a disease similar to bovine spongiform encephalopathy ("mad cow disease"). Health officials warn against eating meat from infected animals. The disease has been detected in 30 US states.
Sep 23 TAHC news release