Surveillance of life-long antibiotics: a review of antibiotic prescribing practices in an Australian Healthcare Network

The Use of Long-term Antibiotics for Suppression of Bacterial Infections

Suppressive antibiotic therapy is prescribed when a patient has an infection that is presumed to be incurable by a defined course of therapy or source control. The cohort receiving suppressive antibiotic therapy is typically highly comorbid and the infections often involve retained prosthetic material. In part due to a lack of clear guidelines regarding the use of suppressive antibiotics, and in part due to the complex nature of the infections in question, patients are often prescribed suppressive antibiotics for extremely long, if not indefinite, courses. The risks of prolonged antibiotic exposure in this context are not fully characterized, but they include adverse drug effects ranging from mild to severe, the development of antibiotic-resistant organisms, and perturbations of the gastrointestinal microbiome. In this narrative review we present the available evidence for the use of suppressive antibiotic therapy in 4 common indications, examine the gaps in the current literature, and explore the known and potential risks of this therapy. We also make suggestions for improving the quality of evidence in future studies, particularly by highlighting the need for a standardized term to describe the use of long courses of antibiotics to suppress hard-to-treat infections.

Oral Staphylococcus Species and MRSA Strains in Patients with Orofacial Clefts Undergoing Surgical Rehabilitation Diagnosed by MALDI-TOF MS

This study investigated the occurrence and dynamics of oral Staphylococcus species in patients with orofacial clefts undergoing surgical rehabilitation treatment. Patients (n = 59) were statistically stratified and analyzed (age, gender, types of orofacial clefts, surgical history, and types of previous surgical rehabilitation). Salivary samples were obtained between hospitalization and the return to the specialized medical center. Microbiological diagnosis was performed by classical methods, and MALDI-TOF MS. MRSA strains (SCCmec type II, III, and IV) were characterized by the Decision Tree method. A total of 33 (55.9%) patients showed oral staphylococcal colonization in one, two, or three sampling steps. A high prevalence has been reported for S. aureus (including HA-, MRSA and CA-MRSA), followed by S. saprophyticus, S. epidermidis, S. sciuri, S. haemolyticus, S. lentus, S. arlettae, and S. warneri. The dynamics of oral colonization throughout surgical treatment and medical follow-up may be influenced by (i) imbalances in staphylococcal maintenance, (ii) efficiency of surgical asepsis or break of the aseptic chain, (iii) staphylococcal neocolonization in newly rehabilitated anatomical oral sites, and (iv) total or partial maintenance of staphylococcal species. The highly frequent clinical periodicity in specialized medical and dental centers may contribute to the acquisition of MRSA in these patients.

Association between antihyperlipidemic agents and the risk of chronic periodontitis in patients with hyperlipidemia: A population-based retrospective cohort study in Taiwan

BACKGROUND

The lipid-lowering and anti-inflammatory effects of statins and fibrates may ameliorate periodontitis. Patients with hyperlipidemia tend to have a worse periodontal status. This study assessed the association between the use of statins/fibrates and the incidence of chronic periodontitis in patients with hyperlipidemia in Taiwan.

METHODS

This retrospective cohort study enrolled patients newly diagnosed with hyperlipidemia between 2001 and 2012 from the 2000 Longitudinal Generation Tracking Database and followed them for 5 years. The study population was divided into four groups: statin monotherapy, fibrate monotherapy, combination therapy (both statins and fibrates), and control (neither statins nor fibrates). Each patient in the treatment group was matched at a ratio of 1:1 with a control. Chronic periodontitis risk was compared in the three study arms by using a Cox proportional hazard model.

RESULTS

Chronic periodontitis risk was reduced by 25.7% in the combination therapy group compared with the control group (adjusted hazard ratio [aHR], 0.743; 95% confidence interval (CI), 0.678-0.815). Low dose (<360 cumulative defined daily dose [cDDD]) and shorter duration (<2 years) of statin monotherapy seem to be associated with an increased risk of chronic periodontitis; high dose (≥720 cDDD/≥1080 cDDD) and longer duration (≥3 years) of statin/fibrate monotherapy may be correlated with a lower risk of periodontitis. Hydrophobic statin users had a lower chronic periodontitis risk than hydrophilic statin users.

CONCLUSION

Chronic periodontitis risk was lower in patients with hyperlipidemia on combination treatment with statins and fibrates, and the risk decreased when patients used statins or fibrates for >3 years.

Management of Refractory Post-operative Osteomyelitis and Discitis: A Case Report

Vertebral osteomyelitis/discitis is a relatively rare disease but is a known potential complication of spinal surgical intervention. In general, the first-line treatment for this condition is targeted antibiotic therapy with surgical intervention only utilized in refractory cases with evidence of extensive damage, structural instability, or abscess formation. However, surgical best practices have not been established for osteomyelitis, including indications for anterior lateral interbody fusion (ALIF), posterior lateral interbody fusion (PLIF), or direct lateral interbody fusion (DLIF). This case provides a discussion of the indications that led to a direct lateral approach in the setting of refractory osteomyelitis/discitis, supporting factors that led to its success, and the efficacy of utilizing intraoperative neuromonitoring in cases of infection.

Long-term antibiotic prescribing in the community: 6 years of Australian national data

BACKGROUND

Prolonged or indefinite courses of antibiotics are sometimes prescribed for suppression of chronic infection, prophylaxis, and noninfective indications. Little is known about long-term prescribing practices in the community. In Australia, 75% of outpatient prescribing is funded through the Pharmaceutical Benefits Scheme (PBS), a government program for subsidized medications.

OBJECTIVES

To describe the landscape of outpatient prescribing of long-term antibiotics in Australia.

METHODS

We descriptively analyzed a randomized 10% sample of PBS prescription data from 2014 to 2020. "Long term" was defined as continuous prescribing 12 months or more. Patients were identified using a rolling window algorithm with 12-month look-back from each script provided.

RESULTS

Prolonged continuous antibiotics (> 12 months) were prescribed to 339/100,000 population; 50% of patients were aged more than 65 years and prescribing increased with age (1440/100,000 population in patients > 75 years). Frequently prescribed antibiotic classes were tetracyclines (43% of all long-term antibiotics), sulfonamides/trimethoprim (21%, predominantly cotrimoxazole), cephalosporins (15%, predominantly cefalexin), and penicillins (13%). Prophylaxis of infection and immunomodulatory indications were most common. Patients were co-prescribed analgesics (30%), antidepressants (30%), corticosteroids (20%), and immunosuppressive drugs (6%).

CONCLUSION

Prolonged community prescribing of antibiotics is an important target for antibiotic stewardship, particularly in older adults.

Long-Term Outcomes in Patients on Life-Long Antibiotics: A Five-Year Cohort Study

BACKGROUND

Little is known about the impacts at an individual level of long-term antibiotic consumption. We explored health outcomes of long-term antibiotic therapy prescribed to a cohort of patients to suppress infections deemed incurable.

METHODS

We conducted a 5-year longitudinal study of patients on long-term antibiotics at Monash Health, a metropolitan tertiary-level hospital network in Australia. Adults prescribed antibiotics for >12 months to suppress chronic infection or prevent recurrent infection were included. A retrospective review of medical records and a descriptive analysis was conducted.

RESULTS

Twenty-seven patients were followed up during the study period, from 29 patients originally identified in Monash Health in 2014. Seven of the 27 patients (26%) died from causes unrelated to the suppressed infection, six (22%) ceased long-term antibiotic therapy and two (7%) required treatment modification. Fifteen (56%) were colonised with multiresistant microorganisms, including vancomycin resistant Enterococci, methicillin resistant Staphylococcus aureus, and carbapenem resistant Enterobacteriaciae.

CONCLUSIONS

This work highlights the potential pitfalls of long-term antibiotic therapy, and the frailty of this cohort, who are often ineligible for definitive curative therapy.

PET/CT Imaging for Personalized Management of Infectious Diseases

Positron emission tomography combined with computed tomography (PET/CT) is a nuclear imaging technique which is increasingly being used in infectious diseases. Because infection foci often consume more glucose than surrounding tissue, most infections can be diagnosed with PET/CT using 2-deoxy-2-[18F]fluoro-D-glucose (FDG), an analogue of glucose labeled with Fluorine-18. In this review, we discuss common infectious diseases in which FDG-PET/CT is currently applied including bloodstream infection of unknown origin, infective endocarditis, vascular graft infection, spondylodiscitis, and cyst infections. Next, we highlight the latest developments within the field of PET/CT, including total body PET/CT, use of novel PET radiotracers, and potential future applications of PET/CT that will likely lead to increased capabilities for patient-tailored treatment of infectious diseases.

Long-Term Benzathine Penicillin Prophylaxis Lasting for Years Effectively Prevents Recurrence of Dermato-Lymphangio-Adenitis (Cellulitis) in Limb Lymphedema

Background: The lymphedema-affected limbs are predisposed to acute and, subsequently, chronic dermato-lymphangio-adenitis (DLA) episodes in around 40%-50% of cases, irrespective of what the primary etiological factor is for the development of this condition. DLA is of bacterial etiology, and it needs antibiotic control and prevention of recurrence. Aim: To follow the effects of years-long continuous no-break administration of benzathine penicillin on the recurrence of acute DLA episodes. Methods and Results: Two hundred thirty-one patients were affected with lymphedema of lower and upper limbs. The mean duration of lymphedema was 10.2 ± 7.3 (range 2-30) years, and the number of DLA attacks/patient was 3.3 ± 3.2 (range 1-10). The total number of DLA episodes was 805. Benzathine penicillin injections 1,200,000 units were given i.m. at 14-21 days intervals (mean 18 ± 9 days) with short accidental breaks only. The period of therapy was 39.2 ± 38.7 (median 32) months. Recurrence occurred in 23 out of 231 (10%) (p < 0.01). There were 42 DLA incidents compared with 805 before introduction of therapy (5.2%) patients (hazard ratio 0.05, 95% confidence interval 0.034-0.079) (p < 0.01). Among patients with recurrence, there was a decrease of DLA episodes from 6.2% ± 3.6% to 1.7% ± 1.0%/patient. There were no differences in effectiveness of penicillin prophylaxis between etiological groups, depending on stages of lymphedema. Conclusions: Long-term years-long benzathine penicillin prophylaxis is extremely effective in prevention of DLA recurrence. It can be applied for years with no breaks, without clinical side-effects, and raising resistance to antibiotics. Microbial colonization and evoked inflammatory reaction of hosts should be controlled from the first symptoms of lymph stasis, irrespective of the etiology of lymphedema.

Antimicrobial Resistance in the Context of the Sustainable Development Goals: A Brief Review

The reduction in infectious disease morbidity and mortality may be attributed to a variety of factors; however, improved sanitation and public health, and the introduction of vaccines and antibiotics are among the most significant. The development of antimicrobial resistance (AMR) in bacterial pathogens is an expected consequence of evolutionary adaptation to these noxious agents and the widespread use of these drugs has significantly sped up this process. Infections caused by multidrug resistant pathogens are directly associated with worse clinical outcomes, longer hospital stays, excess mortality in the affected patients and an increasing burden and costs on the healthcare infrastructure. The Sustainable Development Goals (SDGs) were published in 2015 by the United Nations to serve as a global blueprint for a better, more equitable, more sustainable life on our planet. The SDGs contextualize AMR as a global public health and societal issue; in addition, the continuing emergence of AMR may limit the attainment on many SDGs. The aim of this mini-review is to provide insight on the interface between attainment of SDGs and the clinical problem of drug resistance in bacteria.

Reconciling Hygiene and Cleanliness: A New Perspective from Human Microbiome

The term hygiene is deeply rooted with the concept of maintaining sound health and alertness towards cleanliness, while "hygiene hypothesis" depicts the protective role of microbial community exposure in development of early immunity and initial allergic and aesthetic reactions. The tug-of-war has now been pushed toward the literal term "hygiene" over the "hygiene hypothesis" and has continued with disinfection of all microbial loads from the related environments to avoid infections in humans. With the advancement in the microbiome studies, it became clear that humans possess warm, and significant relationships with diverse microbial community. With this opinion article, we have emphasized on the importance of hygiene hypothesis in immunological responses. We also propose the individual/targeted hygiene instead of application of unanimous hygiene hypothesis. This review also elaborates the common practices that should be employed to maintain hygiene along with the balanced microbiome.

Life-long antimicrobial therapy: where is the evidence?

The decision to prescribe long-term or 'life-long' antibiotics in patients requires careful consideration by the treating clinician. While several guidelines exist to help assist in this decision, the long-term consequences are yet to be well studied. In this review, we aim to provide a summary of the available evidence for patient populations where long-term antibiotic therapy is currently recommended in clinical practice. We will also discuss the pitfalls of this approach, including medication adverse effects, economic cost and any possible contribution to the emerging epidemic of microbial resistance.

Surveillance of life-long antibiotics-A cross-sectional cohort study assessing patient attitudes and understanding of long-term antibiotic consumption

BACKGROUND

Some patients receive long-term or life-long antibiotics for suppression of infections deemed otherwise incurable. Little is known about the consequences of this strategy. We aimed to explore patients' attitudes towards and knowledge concerning prolonged antibiotic therapy.

METHODS

A cross-sectional cohort pilot study of outpatients on long-term antibiotics was performed. Surveys were conducted at our healthcare network in Victoria, Australia between April and December 2015. Microbiological screening for multi-resistant organisms (MRO) was also performed.

RESULTS

Heterogeneity was noted in the prescribed antibiotics and documented indications, with rifampicin and fusidic acid for suppression of prosthetic joint infection the most common regimen and indication. 41% (12/29) of participants reported side-effects attributed to their antibiotics, but 72% (21/29) still declared complete adherence to their prescribed regimen. 76% (22/29) of participants stated that they would cease their long-term antibiotics based on medical advice. 19/29 (66%) participants consented to microbiological screening and 4 were found to be colonised with MROs. They had spent more days as an inpatient in the preceding 12 months than the screened participants who were not colonised.

CONCLUSION

Participants in this study had a good understanding of their infection and the indications for their long-term antibiotic therapy, and were adherent to this therapy despite many experiencing side-effects attributed to their antibiotics. Patients who are prescribed life-long antibiotics can be carriers of multi-resistant organisms, but both the drivers of this resistance, and the broader impact of colonisation with MRO in this population is unclear.

Infectious diseases physician attitudes to long-term antibiotic use

Background In Australia, it is not known how much antibiotic prescribing by infectious diseases physicians is long-term, or how confident they are with the evidence behind this practice. Objective Survey Australian infectious diseases physicians to assess attitudes and prescribing practice prescribing prolonged courses of antibiotics. Methods An online questionnaire was distributed to the mailing group for the Australian Society of Infectious Diseases. Responses were collected from 29th October to 12th November 2015. Results The majority of respondents practiced in Australia as Infectious Diseases physicians, microbiologists, or trainees. 88% had prescribed long-term antibiotics. Heterogeneity was noted in the indications for prescription, including recurrent UTIs, cellulitis or chest infections, prosthetic joint infection and vascular graft infection. Beta-lactams antibiotics were prescribed most frequently. 22% of respondents had prescribed rifampicin/fusidic acid most frequently, while 11% could not identify a single antibiotic that they used most frequently, due to the heterogeneity of indications for prescribing. 95% stated that they would stop long-term antibiotic therapy if appropriate, and 74% were willing to enrol their patients into a randomised control trial looking at stopping long-term therapy. Conclusion Most infectious diseases physicians who responded to the survey prescribe long-term antibiotics, with great heterogeneity in the indications for which these antibiotics are prescribed.

The distribution of antibiotic use and its association with antibiotic resistance

Antibiotic use is a primary driver of antibiotic resistance. However, antibiotic use can be distributed in different ways in a population, and the association between the distribution of use and antibiotic resistance has not been explored. Here, we tested the hypothesis that repeated use of antibiotics has a stronger association with population-wide antibiotic resistance than broadly-distributed, low-intensity use. First, we characterized the distribution of outpatient antibiotic use across US states, finding that antibiotic use is uneven and that repeated use of antibiotics makes up a minority of antibiotic use. Second, we compared antibiotic use with resistance for 72 pathogen-antibiotic combinations across states. Finally, having partitioned total use into extensive and intensive margins, we found that intense use had a weaker association with resistance than extensive use. If the use-resistance relationship is causal, these results suggest that reducing total use and selection intensity will require reducing broadly distributed, low-intensity use.