Stewardship / Resistance Scan for Apr 12, 2022

News brief

Trial supports shorter antimicrobial prophylaxis for orthopedic surgery

A randomized clinical trial found that a shorter antimicrobial prophylaxis (AMP) duration for "clean" orthopedic surgery (scheduled procedures not involving complications like open wounds) was non-inferior to a longer duration in preventing healthcare-associated infections (HAIs), Japanese researchers reported today in JAMA Network Open.

In the multicenter, cluster randomized trial, 1,211 participants undergoing clean orthopedic surgery were divided into two groups: one had AMP discontinued within 24 hours of wound closure (group 24), and the other had AMP discontinued within 24 to 48 hours (group 48). Group allocation was switched every 2 to 4 months according to the facility-based cluster rule. The primary outcome was incidence of HAIs requiring antibiotic therapies within 30 days of surgery. The non-inferiority margin was 4%.

There were 633 participants (median age, 73; 60.5% women) in group 24 and 578 participants (median age, 74; 64.7% women) in group 48. HAIs occurred in 29 patients (4.6%) in group 24 and 38 patients (6.6%) in group 48. Intention-to-treat analyses showed a difference in the risk of HAIs of −1.99 percentage points (95% confidence interval [CI], −5.05 to 1.06 percentage points; P < .001 for non-inferiority) between groups, indicating non-inferiority. Results of adjusted intention-to-treat, per-protocol, and per designated procedure population analyses supported this result, without a risk of antibiotic resistance and prolonged hospitalization.

The findings are noteworthy because several studies have shown that AMP is still routinely continued for several days after orthopedic surgery, despite concerns that prolonged AMP may increase the risk of antimicrobial resistance.

"To our knowledge, this is the first large size clinical trial to elucidate the effect of AMP duration on postoperative HAI in the field of orthopedic surgery," the study authors wrote. "Our results support the global notion against antimicrobial resistance and may encourage surgeons to shorten AMP duration and reduce the antibiotic load in clean orthopedic surgeries."
Apr 12 JAMA Netw Open study

Remote stewardship in rural nurseries tied to fewer infant antibiotics

Implementation of a remote antibiotic stewardship program (ASP) in medically underserved newborn nurseries was associated with a decline in the number of infants exposed to antibiotics and total antibiotic use, researchers reported today in Pediatrics.

The remote ASP, implemented at eight rural nurseries in Texas, included 24/7 provider-to-provider phone consultation with a neonatal infectious diseases specialist, on-site and virtual education sessions on topics such as early-onset sepsis and the risks and benefits of antibiotic exposure in newborns, and prospective audit and feedback of prescribing practices. Using a cluster-randomized, stepped-wedge design, researchers evaluated the impact of the program over 3 years, including a 15-month baseline period, a 9-month step-in period using random nursery order, and a 12-month post-intervention period.

During the study period, there were 9,277 infants born, 4,586 of them preintervention and 4,691 postintervention. The proportion of infants exposed to antibiotics declined from 6.2% pre-ASP to 4.2% post-ASP (absolute risk reduction, 25%; relative risk 0.68; 95% CI, 0.63 to 0.75). Similarly, total antibiotic use declined from 117 to 84.1 days of therapy per 1,000 patient-days (-28%; 95% CI, −22% to −34%). No safety signals were observed; the mean length of stay was unchanged (1.84 days preintervention, 1.83 days postintervention), as was the frequency of infant transport to a higher level of care (0.26% preintervention, 0.23% postintervention).

The ASP also proved feasible for staff. There were 451 provider-to-provider phone consultations during the study period, and most were less than 5 minutes and occurred during normal business hours.

The study authors say that while the sample size is small, the findings suggest that remote ASPs could be a viable strategy for rural or medically underserved nurseries.

"A 2% absolute reduction in antibiotic exposure is a small decrease; however, if applied to the approximately 1.7 million births in rural or medically underserved areas in 2020, this reduction would equate to over 30,000 less antibiotic courses, which in turn could reduce the risk of obesity, asthma, eczema, diabetes, metabolic syndrome, multidrug resistant organisms, and other adverse consequences of early antibiotic exposure," they wrote.
Apr 12 Pediatrics abstract

News Scan for Apr 12, 2022

News brief

Study shows COVID-19–induced myocarditis rare, linked to severe cases

Approximately 2.4 out of every 1,000 patients hospitalized with COVID-19 developed myocarditis, an inflammation of the heart muscle that typically follows viral infections, according to an international study published yesterday in the American Heart Association (AHA) journal Circulation.

When including possible myocarditis cases, the rate increases to 4.1 per 1,000 hospitalized patients.

The international study was based on records from 23 hospitals in the United States and Europe that admitted COVID-19 patients from February 2020 to April 2021. A total of 56,963 patient records were examined.

In total, 54 COVID-19 patients were diagnosed as having definite or probable acute myocarditis as determined via biopsies of the heart muscles or magnetic resonance imaging (MRI), and another 43 were identified as possible myocarditis cases.

The patients who developed probable or definite myocarditis were typically male (61%), non-Hispanic white (76.5%), and the average age was 38. No patients in the study were vaccinated against COVID-19.

Chest pain and difficulty breathing were the most frequent symptoms reported by patients who developed myocarditis (in 55.5% and 53.7% of cases, respectively), and 21 patients required inotropic support (the use of drugs to improve heart contraction) or temporary mechanical circulatory support. Having concurrent pneumonia was associated with higher mortality at 120 days post-diagnosis.

"At 120 days, estimated mortality was 6.6%, 15.1% in patients with associated pneumonia versus 0% in patients without pneumonia (P=0.044)," the authors wrote.

"This analysis indicates that, although rare, hospitalized patients with acute myocarditis associated with COVID-19 infection have a much greater need for intensive care unit admission, in up to 70.5% of the cases, despite the average age of the individuals in the study being much younger than expected at 38 years old," said co-senior study author Marco Metra, MD, a cardiology professor at the University of Brescia in Brescia, Italy, in an AHA press release.
Apr 11 Circulation study
Apr 11 AHA press release

COVID-19 inflammation—not SARS-CoV-2—may be behind loss of smell

Local COVID-related inflammation, rather than the virus itself, may cause the common early symptom of loss of smell, according to a postmortem study published yesterday in JAMA Neurology.

Johns Hopkins researchers led the multicenter study, which involved examining the olfactory bulb at the base of the brain of 23 deceased COVID-19 patients and 14 matched controls who died of other causes from Apr 7, 2020, to Sep 11, 2021.

The researchers used light and electron microscopy to look for any SARS-CoV-2 genetic material and assess cell structures and characteristics and the blood vessels and neurons within them. They also measured the number of axons in the neurons, which inform sensory perception and movement. Information about sense of smell and taste was derived from the medical records of three patients and from family interviews for the remainder.

Three of the 23 COVID-19 patients lost their sense of smell, while 4 had an impaired ability to smell, and 2 lost both smell and taste. No controls lost either smell or taste.

In a Johns Hopkins news release, lead author Cheng-Ying Ho, MD, PhD, said that COVID-19 decedents had more severe vascular injury and far fewer axons in the olfactory bulb—particularly those with diminished or total loss of smell, "strongly suggesting that these effects aren't age related and therefore, are linked to SARS-CoV-2 infection."

Ho said she was surprised that, despite nerve and vascular damage in COVID-19 decedents, most had no detectable SARS-CoV-2 virus particles in the olfactory bulb. "Our findings suggest that SARS-CoV-2 infection of the olfactory epithelium leads to inflammation, which in turn, damages the neurons, reduces the numbers of axons available to send signals to the brain, and results in the olfactory bulb becoming dysfunctional," she said.

In a JAMA Neurology audio interview, Ho said that long-term loss of smell occurs in about 1% of people and may be preventable. "If inflammation is the major cause of the injury in olfactory structures, it is possible that we may be able to use anti-inflammatory agent as the treatment," she said.
Apr 11 JAMA Neurol study and audio interview
Apr 11 Johns Hopkins Medicine press release

Avian flu strikes more poultry flocks in the Dakotas

The US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) reported more highly pathogenic avian flu outbreaks in North Dakota and South Dakota poultry, according to its latest update, which also adds information on recently reported outbreaks from officials in various states, including Colorado, Indiana, and Minnesota.

The new report from North Dakota involves a flock of 38 backyard birds in Stutsman County in the southeast, which now has seven outbreaks.

South Dakota has 3 more outbreaks, raising its total to 35. Two of the new outbreaks involve commercial turkey farms, one in Yankton County in the southeast housing 25,000 birds and one in Edmunds County in the north central region that houses 36,000 birds.

The outbreaks are part of activity involving the Eurasian H5N1 strain, which has struck wild birds and poultry in multiple world regions, including the United States, where poultry producers have now lost at least 24 million birds across 26 states.
USDA APHIS poultry outbreak page