Our weekly wrap-up of antimicrobial stewardship & antimicrobial resistance scans
FAO antimicrobial resistance report calls for more research
A new report from the United Nations Food and Agriculture Organization (FAO) says that while antimicrobial use in livestock production is widely acknowledged as contributing to antimicrobial resistance (AMR), large gaps in knowledge still remain, and more research is needed into how and why resistance emerges and spreads among humans and animals.
The 67-page report summarizes the extent of antimicrobial use in food production, particularly livestock production but also aquaculture, and what is known about the role that such use is playing in the emergence of AMR strains in animals. Understanding this link is critical, the authors note, because food-producing animals are expected to account for two thirds of the predicted global increase in antimicrobial use.
But what is less understood is how both pathogenic and non-pathogenic resistant bacteria are being transmitted from livestock to humans. Is it through food consumption? Via direct contact with animals or their waste in the environment? Or is transmission occurring through contact with soil and water laced with antimicrobial residue from livestock production?
While there is some evidence for all these potential transmission routes, the authors write, "The vast majority of AMR spread is not monitored or studied and thus the importance of transmission pathways and the magnitude of spread is largely unknown."
The report concludes with several recommendations, including regular monitoring of antimicrobial residues in the environment and more research into the factors that influence how and why resistant bacteria become incorporated into human and animal gut microbiomes. The authors also urge the phasing out the use of antimicrobials solely to promote animal growth.
Nov 15 FAO report
Nov 15 FAO news story on the report
Commentary calls for global stewardship collaboration
A commentary today in The Lancet Infectious Diseases urges more international collaboration in the fight against antimicrobial resistance.
The letter by Debra Goff, PharmD, et al highlights antibiotic stewardship efforts in five countries—the United States, South Africa, Colombia, Australia, and the United Kingdom—that have taken different approaches to the problem but have all adopted national strategies that emphasize government involvement, multidisciplinary approaches, education, and support. Each of these countries has had some success, the authors note, emphasizing the significance of gains made in the two limited-resource countries, Colombia and South Africa.
But these efforts can have an even greater impact, they argue, if stewardship experts reach out to their international partners to share knowledge. "Efforts to mitigate overuse will be unsustainable without learning and coordinating activities globally," they write.
An example they cite is a mentoring program that brings together infectious disease pharmacists at The Ohio State University Wexner Medical Center (where Goff teaches) with pharmacists from South Africa. This program allows South African pharmacist trainees to pass what they've learned from their American mentors to other colleagues.
This example of so-called "paying it forward," Goff and her colleagues write, is just one way in which international collaboration can enhance local and national antimicrobial stewardship programs. But it's not the only way. Individual stewards from different countries can collaborate on research and publication, offer their expertise for publicly available online stewardship courses, and reach out to other experts on social media platforms to share what they've learned from their successes and failures. The authors also argue that stewardship models need to evolve beyond infection specialist–based teams to include other healthcare professional.
"All healthcare providers who prescribe antibiotics need to take ownership, engage in stewardship, and understand the societal burden of inappropriate antibiotic use," the authors write.
Nov 18 Lancet Infect Dis commentary
Study: Discontinuing contact precautions did not lead to CDI outbreaks
Originally published by CIDRAP News on Nov 16.
A study yesterday in Clinical Infectious Diseases suggests that contact isolation may not be necessary to prevent outbreaks of Clostridium difficile infection (CDI) in hospitals.
The single-center study was conducted at the University Hospital Basel, Switzerland, a 735-bed tertiary care center that, in contrast to American and European guidelines, has discontinued contact precautions for CDI patients as a standard of care—except in cases where patients have hypervirulent strains of CDI such as PCR ribotype 027 or 078 or are suffering from incontinence. Contact precautions generally include assignment to a single room and the use of gloves and gowns at entrance. Instead, CDI patients at the hospital share rooms with other patients, are treated with adherence to standard precautions, and use dedicated toilets.
For the study, investigators screened the contacts of all index CDI cases recorded at the hospital between January 2004 and December 2013 by culturing rectal swabs. CDI transmission from an index to a contact patient was defined as possible if toxigenic C difficile was detected in contacts, as probable if the identical PCR-ribotype was identified in index-contact pairs, and as confirmed in next-generation sequencing revealed clonality of strains.
Overall, the investigators found that 451 contacts were exposed to 279 CDI index patients, with toxigenic C difficile being detected in 27 (6%) of those contact patients after a median contact time of 5 days. But probable transmission was only detected in six index-contact pairs, and next-generation sequencing performed on four of six pairs with identical PCR-ribotype strains confirmed transmission in only 2 contact patients.
"In conclusion, discontinuing contact precautions did not lead to CDI-outbreaks over a 10-year study period," the authors write. "The rate of transmission was low, challenging current guidelines for management of CDI. Contact isolation may lead to lower levels of care and additional costs."
Nov 15 Clin Infect Dis abstract
Hog workers may be at risk for Staph aureus skin infections, study finds
Originally published by CIDRAP News on Nov 16.
A study today in PLoS One provides new evidence of the potential risk posed by livestock-associated, drug-resistant Staphylococcus aureus to hog workers and their families.
The study, led by a team of investigators from the Johns Hopkins University Bloomberg School of Public Health, builds on their previous research into the emergence of livestock-associated S aureus in hog workers, which is believed to be linked to the widespread use of antibiotics in hog production. Their previous study found that employees of industrial hog farms, and their family members, may be more vulnerable to nasal carriage of S aureus, methicillin-resistant S aureus (MRSA), and multidrug-resistant S aureus (MDRSA). What they were unable to determine from that research was whether the nasal carriage prevalence of drug-resistant S aureus they found represented a risk for infection. That's what they wanted to find out in the current study.
To determine the risk for infection, the researchers enrolled 103 workers from an industrial hog operation in North Carolina, along with 26 adult household members and 54 minor children. All participants provided a baseline nasal swab and completed a questionnaire. They were also asked whether they had seen symptoms, or been diagnosed with, a soft-tissue skin infection (SSTI) in the 3 months prior to enrollment in the study.
Analysis of the nasal swabs found that 45 of the 103 hog workers (44%) and 31 of 80 household members (39%) carried S aureus in their noses. Nearly half of the strains carried by the hog workers, and nearly a third of those carried by the household members, were drug-resistant. But the researchers also found that 6% of the hog workers and 11% of the children who lived with them had reported a recent SSTI. Furthermore, hog workers who carried S aureus were five times as likely to have an SSTI as those who didn't carry the bacteria, and those who carried MDRSA were nearly nine times as likely to have an SSTI.
While the study was small and the overall number of SSTIs was low among the study participants, the researchers say their findings are the first to show a relation between nasal carriage of livestock-associated S aureus and SSTIs among workers with frequent and intense exposure to hog production.
"Before this study, we knew that many hog workers were carrying livestock-associated and multidrug-resistant Staphylococcus aureus strains in their noses, but we didn't know what that meant in terms of worker health," study leader Christopher D. Heaney, PhD, MS, said in a Johns Hopkins news release. "This study suggests that carrying these bacteria may not always be harmless to humans."
Nov 16 PLoS One study
Nov 16 Johns Hopkins news release
Experts call for surgeons to have a greater role in ASPs
Originally published by CIDRAP News on Nov 16.
An international collection of experts is calling on surgeons to play a greater role in antimicrobial stewardship programs (ASPs).
In an article published in the journal Surgical Infections, the authors wrote that surgeons, in their role as providers who actively engage in antimicrobial prescribing, must be aware that judicious use of antimicrobials is an integral part of any ASP and is necessary to minimize the emergence of antimicrobial resistance. Moreover, they argue that the direct involvement of surgeons in ASPs, in collaboration with other healthcare specialists, can be highly impactful.
One area where surgeons can play a greater role in ASPs is in enforcing compliance with standards for pre-operative antibiotic prophylaxis, which accounts for 15% of all antibiotic agents prescribed in hospitals. The authors write that surgeons should follow joint guidelines that call for narrow-spectrum antibiotics to be used in procedures that have high rates of surgical site infection (SSI) and administered not more than 30 to 60 minutes before surgery. Those guidelines also discourage the use of prolonged post-operative antibiotic therapy.
And because they commonly have to initiate antimicrobial therapy in their patients if a SSI is suspected, the authors argue that surgeons need to be aware that inappropriate prescribing, improper dosing, and incorrect duration can fuel drug-resistant pathogens and cause collateral damage (such as CDIs) in their patients.
"If surgeons around the world participate in this global fight and demonstrate awareness of the major problem of antimicrobial resistance, they will be pivotal leaders," the authors write. "If surgeons fail to actively engage and use antibiotics judiciously, they will find themselves deprived of the autonomy to treat their patients."
Nov 9 Surg Infect article