Oral Suppressive Antibiotic Research Articles

Peri-Prosthetic Joint Infection in Patients Prescribed Suppressive Antibiotic Therapy Undergoing Primary Total Joint Arthroplasty: A 1:4 Case Control Matched Study.

Background: Oral suppressive antibiotic therapy (SAT) has emerged as a potential means to increase rates of infection-free survival in many complex peri-prosthetic joint infection (PJI) cases after total joint arthroplasty (TJA). The purpose of the present study is to evaluate the risk of PJI of a new primary TJA in patients on oral SAT. Patients and Methods: A retrospective matched cohort study from five hospitals in a 20-year period within a large hospital network was performed. Inclusion criteria consisted of patients over age 18 undergoing primary TJA, with any order for oral long-term (>6 months duration) SAT, and minimum of one-year clinical follow-up. Patients were matched 1:4 on age, gender, body mass index (BMI), hip or knee surgery, diabetes mellitus, smoking status, and indication for primary TJA. Student t-test, Fisher exact, and χ2 tests were utilized for group comparisons. Our study was powered to detect a 10.5% increase in PJI incidence compared with a 1% baseline rate of PJI. Results: We identified 45 TJA in 33 patients receiving SAT, which were matched to 180 control cases. There was no difference in the rate of development of PJI at any time point within follow-up between the SAT cohort and control group (2.22% vs. 1.11%; p = 0.561). Conclusions: We found a 2.22% rate of PJI in a cohort of patients receiving SAT identified over a 20-year period. As the clinical scenario of primary TJA while on SAT is rare but likely to become more prevalent, future large-scale studies can be performed to better clarify rates and risk of PJI in this population.

LONG-TERM ORAL SUPPRESSIVE ANTIBIOTIC THERAPY FOR PROSTHETIC VALVE ENDOCARDITIS WITH PERIVALVULAR EXTENSION

LONG-TERM ORAL SUPPRESSIVE ANTIBIOTIC THERAPY FOR PROSTHETIC VALVE ENDOCARDITIS WITH PERIVALVULAR EXTENSION

196. Increasing Bacteremia and Endovascular Infections due to Serratia marcescens: Implications for Evaluation and Treatment

Abstract Background While Serratia marcescens can cause bloodstream infections (BSI), endocarditis or other endovascular infections are historically rare and typically due to injection drug use (IDU). Given the rise in IDU nationwide, and limited evidence for managing non-HACEK gram-negative endocarditis, we examined trends in the epidemiology of Serratia BSI and characterized management strategies. Methods Our study was a retrospective analysis of adults admitted to UNC Health, a hospital network in North Carolina, from Apr 2014 to Mar 2021 with Serratia bacteremia. We used EMERSE, a program that searches free text in clinical notes, to identify those with ‘Serratia’ and either ‘bacteremia’ or ‘endocarditis’. This helped identify patients with microbiology obtained at outside hospitals. We performed chart review to confirm the Serratia BSI and collect demographic and clinical data. We tabulated yearly hospitalizations (Apr 1 to Mar 31), proportions of endovascular infections (endocarditis, cardiac device, vascular grafts), and described demographics and treatment approaches. Results We identified 97 patients by EMERSE and included 66 in analysis (Fig 1). 21 (32%) had endovascular infections and 21 (32%) overall were due to IDU (Table). Endovascular infections and BSIs increased over the period (Fig 2). Until 2018-2019, there were 0-10 Serratia BSIs yearly. In the final year, there were 37, 13 (37%) of which were endovascular infections. While we did not limit to S. marcescens, no other species were seen. 59/61 (97%) isolates with 3rd generation cephalosporin susceptibility reported were sensitive. 17/21 endovascular infections were endocarditis. 10/17 (59%) patients underwent valve replacement and 8/21 (38%) received dual antibiotic therapy for ≥ 6 weeks. Of the 10 attending infectious diseases follow-up visit, 6 were prescribed oral suppressive antibiotics after parenteral therapy. Figure 2. Serratia bloodstream infections (2014-2021) Table 1. Characteristics of Serratia bloodstream infections Conclusion Serratia BSI and endovascular infections are markedly increasing, with a large component due to IDU. Given the high proportion of endocarditis, echocardiography may be considered for patients with Serratia BSI, particularly those with IDU or prosthetic material. Further studies are needed to confirm this phenomenon and to establish evidence for optimal management of Serratia endocarditis. Disclosures Asher J. Schranz, MD, United HealthCare (Other Financial or Material Support, Spouse provides scientific review)

Long-term antibiotic therapy in patients with surgery-indicated not undergoing surgery infective endocarditis.

To date, there is little information regarding management of patients with infective endocarditis (IE) that did not undergo an indicated surgery. Therefore, we aimed to evaluate prognosis of these patients treated with a long-term antibiotic treatment strategy, including oral long term suppressive antibiotic treatment in five referral centres with a multidisciplinary endocarditis team. This retrospective, multicenter study retrieved individual patient-level data from five referral centres in Spain. Among a total of 1797, 32 consecutive patients with IE were examined (median age 72 years; 78% males) who had not undergone an indicated surgery, but received long-term antibiotic treatment (LTAT) and were followed by a multidisciplinary endocarditis team, between 2011 and 2019. Primary outcomes were infection relapse and mortality during follow-up. Among 32 patients, 21 had IE associated with prostheses. Of the latter, 8 had an ascending aorta prosthetic graft. In 24 patients, a switch to long-term oral suppressive antibiotic treatment (LOSAT) was considered. The median duration of LOSAT was 277 days. Four patients experienced a relapse during follow-up. One patient died within 60 days, and 12 patients died between 60 days and 3 years. However, only 4 deaths were related to IE. The present study results suggest that a LTAT strategy, including LOSAT, might be considered for patients with IE that cannot undergo an indicated surgery. After hospitalization, they should be followed by a multidisciplinary endocarditis team.

Outcomes of Orthopedic Hardware-Related Infection Treated Via a Public Teaching Hospital Outpatient Parenteral Antimicrobial Therapy Program

Background Orthopedic hardware-related infection (OHRI) is associated with high morbidity and cost with limited published data describing outpatient parenteral antimicrobial therapy (OPAT) for its treatment. This study was conducted to evaluate clinical outcomes, complications, and risk factors for treatment failure in OHRI patients treated with OPAT. Methods Electronic medical records of adults receiving OPAT for OHRI between July 1, 2009 and March 1, 2015 were retrospectively reviewed. Demographic, medical, infection-specific, and drug-specific data were collected for each patient. Patients were categorized as cure or failure using standardized definitions. Safety was evaluated through adverse drug event and line complication monitoring; readmission rates were recorded. Results Fifty patients with OHRI (mean age, 51.5 ± 12.6 years; 56% male) received OPAT for a mean duration of 41.4 ± 6.9 days. Thirty-one patients received OPAT in the presence of retained hardware—15 (48%) achieved clinical cure and 16 (52%) experienced failure; 3 patients (10%) experienced early (within 4 weeks) failure requiring unanticipated surgery. Twenty-four patients with retained hardware received oral suppressive antibiotics after OPAT until hardware removal; 3 nonadherent patients experienced failure. Nineteen patients received OPAT after hardware removal—14 (74%) achieved clinical cure and 5 (26%) experienced failure. Five patients (10%) experienced adverse drug event and 4 patients (8%) developed line complications resulting in readmission for 3 patients (6%) and alternate therapy for 4 patients (8%). Conclusions Outpatient parenteral antimicrobial therapy is safe and effective for OHRI, especially after hardware removal. Retention of hardware and nonadherence to oral suppression were associated with failure.

Lead Extraction for Cardiovascular Implantable Electronic Device Infection in Patients With Left Ventricular Assist Devices.

The goal of this study was to assess the utility of transvenous lead extraction for cardiovascular implantable electronic device (CIED) infection in patients with a left ventricular assist device (LVAD). The use of transvenous lead extraction for the management CIED infection in patients with a durable LVAD has not been well described. Clinical and outcomes data were collected retrospectively among patients who underwent lead extraction for CIED infection after LVAD implantation at Duke University Hospital. Overall, 27 patients (n=6 HVAD; n=15 HeartMate II; n=6 Heartmate III) underwent lead extraction for infection. Median (interquartile range) time from LVAD implantation to infection was 6.1 (2.5 to 14.9) months. Indications included endocarditis (n=16), bacteremia (n=9), and pocket infection (n=2). Common pathogens were Staphylococcus aureus (n=10), coagulase-negative staphylococci (n=7), and Enterococcus faecalis (n=3). Sixty-eight leads were removed, with a median lead implant time of 5.7 (3.6 to 9.2) years. Laser sheaths were used in all procedures, with a median laser time of 35.0 s (17.5 to 85.5s). Mechanical cutting tools were required in 11 (40.7%) and femoral snaring in 4 (14.8%). Complete procedural success was achieved in 25 (93.6%) patients and clinical success in 27 (100%). No procedural failures or major adverse events occurred. Twenty-one patients (77.8%) were alive without persistent endovascular infection 1 year after lead extraction. Most were treated with oral suppressive antibiotics after extraction (n=23 [82.5%]). Persistent infection after extraction occurred in 4 patients and was associated with 50% 1-year mortality. Transvenous lead extraction for LVAD-associated CIED infection can be performed safely with low rates of persistent infection and 1-year mortality.

1087. Aortic Graft Infections Caused by Propionibacterium acnes at the Minneapolis Veterans Affairs Health Care System (MVAHCS) 2007–2017

Background Propionibacterium acnes is a Gram-positive microaerophilic bacterium and part of the human skin flora. The ability of P. acnes to cause infections has been recognized, particularly in the presence of hardware. We aimed to define the frequency of P. acnes infections, with a focus on aortic graft infection.MethodsWe used microbiology laboratory records at the Minneapolis Veterans Affairs Health Care System to identify all P. acnes cultures from January 2007 to January 2017. We retrospectively reviewed all adult (≥18 years) patient’s medical records to identify associated infectious syndromes. Case definitions by the management of Aortic Graft Infection Collaboration were used to classify aortic graft infection cases.ResultsWe identified 328 positive P. acnes cultures during the study period. P. acnes was classified as a pathogen in 48 (15%), a pathogen of undetermined significance in 70 (21%), and a contaminant in 210 (64%) cases. We identified three cases aortic graft infection which accounted for (2.5%) of infections caused by P. acnes. Median age (range) at presentation was 74 years (67–83). Symptoms included pain (n = 3), fever (n = 2), and altered mental status (n = 1). None were hypotensive. All patients had at least one revision for endoleak prior to presentation. Median time from symptom onset to diagnosis was 120 days (78–140). Microbiological diagnosis was obtained by blood cultures, percutaneous peri-graft tissue aspiration, and operative culture in each patient, respectively. Infection was complicated by metastatic abscess in one patient. All cultures grew on Day 7. All patients were treated with IV ceftriaxone, and two were transitioned to life-long oral suppressive antibiotic therapy. Two patients had complete removal of infected material. No relapse was documented and survival was 100% at 1 year follow-up.ConclusionAortic graft infection is an uncommon subset of infections caused P. acnes. Clinical course is indolent and diagnosis is delayed due to nonspecific clinical presentation. In contrast to endovascular graft infection caused by other organisms, mortality is low when treated with appropriate antibiotic therapy and removal of infected material. The current laboratory practice of holding blood cultures for 5 days may need to be altered when P. acnes is a potential cause of infection.Disclosures All authors: No reported disclosures.

Suppressive Oral Antibiotics in Orthopaedic Prosthetic Joint Infections

In orthopaedics, the use of oral suppressive antibiotics for the treatment of implant related infection was a treatment regimen that had been reserved only for patients who were unable to tolerate surgery. Recent literature has begun to demonstrate the benefits of utilizing suppressive antibiotics as an adjuvant treatment in addition to surgical debridement. The use of oral suppressive antibiotics carries with it inherent hurdles regarding dosing, tolerance, side effects, and cost that need to be considered. The purpose of this review is to act as a guide for orthopaedic surgeons and medical providers to allow them to safely utilize oral suppressive antibiotic regimens as part of their treatment algorithm.

Role of Suppressive Oral Antibiotics in Orthopedic Hardware Infections for Those Not Undergoing Two-Stage Replacement Surgery.

Background. The use of suppressive antibiotics in treatment of orthopedic hardware infections (OHIs), including spinal hardware infections, prosthetic joint infections, and infections of internal fixation devices, is controversial. Methods. Over a 4-year period at 2 academic medical centers, patients with OHI who were treated with debridement and retention of hardware components, with single-stage exchange, or without surgery were studied to determine whether use of oral antibiotics for at least 6 months after diagnosis impacts successful treatment of the infection at 1 year after diagnosis. Results. Of 89 patients in the study, 42 (47.2%) were free of clinical infection 1 year after initial diagnosis. Suppressive antibiotics used for at least 6 months after diagnosis was not associated with being free of clinical infection (adjusted odds ratio [aOR], 5.29; 95% confidence interval [CI], .74-37.80), but being on suppressive antibiotics at least 3 months after diagnosis was associated with being free of clinical infection (OR, 3.50; 95% CI, 1.30-9.43). Causative organisms impacted the likelihood of success; patients with methicillin-resistant Staphylococcus aureus as well as with Gram-negative rods were both less likely to have achieved clinical success at 1 year after surgery (aOR = 0.018, 95% CI = .0017-.19 and aOR = 0.20, 95% CI = .039-.99, respectively). Conclusions. Oral suppressive antibiotic therapy in treatment of OHI with retention of hardware for 3 months, but not 6 months, postdiagnosis increases the likelihood of treatment success. The organisms implicated in the infection directly impact the likelihood of treatment success.

Diagnosis of infected total hip arthroplasty.

Despite the battery of available tests, the diagnosis of periprosthetic joint infection (PJI) remains a challenge. A comprehensive medical history and physical examination with appropriate radiographs followed by erythrocyte sedimentation rate and serum C-reactive protein are the first-line screening test for patients with suspected hip PJI. The second line of investigation of patients with abnormal serology or a strong suspicion for PJI, is joint aspiration. Aspirates should be sent for assessment of white blood cell count, polymorphonuclear percentage, leukocyte esterase strip test, and microbiology. If the first attempt fails, the joint should be re-aspirated at a different time. The International Consensus recommends against infiltration of saline or other fluids into a "dry" joint. In patients not planned for surgery but need further evaluation for PJI, a nuclear imaging study may help. In others with a planned revision surgery, intraoperative samples for frozen section and culture study are the best measures available. Treatment strategies for PJI are well established in the literature. Poor surgical candidates receive oral suppressive antibiotic therapy alone. Acute PJI, presenting within 4 weeks of the index surgery, or as a result of bacteraemia, may be treated with irrigation and debridement and implant retention. Chronic PJI, occurring more than 4 weeks after initial surgery, is treated with 1-stage or 2-stage revision arthroplasty. In some persistent infections or patients who refuse to undergo revision surgery, salvage procedures may be needed.

Staphylococcus aureus osteitis of the dens: A rare location

An immunocompetent 84-year-old woman was admitted for severe neck pain with a fever. Magnetic resonance imaging showed osteitis of the dens. She had methicillin-susceptible Staphylococcus aureus bacteremia related to a dental extraction. She then developed an infection of a hip prosthesis due to the same organism. Her treatment consisted in intravenous antibiotics followed by oral suppressive antibiotic therapy for 2years. Exchange arthroplasty was not performed given the advanced age of the patient, her unwillingness to undergo the procedure, and the risk of neurological complications during endotracheal intubation. The outcome was favorable at last follow-up more than 2years after antibiotic treatment initiation.

Stent-Graft Treatment of Infected Aortic and Arterial Aneurysms

To evaluate the feasibility and effectiveness of endovascular stent-graft repair of infected aortic and arterial aneurysms. Eight patients (5 men; mean age 56.6 years, range 30-85) with infected saccular aneurysms in the brachiocephalic artery (n=1), proximal descending thoracic aorta (n=1), infrarenal abdominal aorta (n=3), common iliac artery (n=1), and common femoral artery (n=2) were treated with stent-graft placement and intravenous antibiotic treatment for at least 6 weeks followed by case-specific administration of oral suppressive antibiotics. All patients were considered to be in the high-surgical-risk group. Exclusion of the infected aneurysm was successful in all patients. However, 2 patients died within 30 days of uncontrolled sepsis, and 1 patient died at 6 months after rupture of a persistently infected aneurysm (37% mortality rate). Over a follow-up that ranged to 8 years, the 5 survivors showed complete resolution of the infected aneurysms; no stent-graft infection was observed during follow-up. The acceptable technical and clinical success of endovascular aneurysm repair makes this a promising treatment for infected aortic and arterial aneurysms. However, it is crucial that the infection is treated adequately prior to stent-graft placement.

Arthroscopic debridement of acute periprosthetic septic arthritis of the knee

To evaluate the efficacy of a treatment protocol including arthroscopic irrigation and debridement in resolving acute periprosthetic septic arthritis of the knee. Retrospective review. During a 1-year period, patients presenting with acute septic arthritis of the knee after total knee arthroplasty were screened for suitability for treatment with an arthroscopic debridement protocol consisting of (1) arthroscopic debridement and synovectomy with at least 12 L of antibiotic irrigant, (2) suction drainage until minimum output, (3) repeat arthroscopy for fever persisting beyond 48 hours, and (4) intravenous antibiotics for 6 weeks. Only previously well-functioning arthroplasties presenting within 7 days of symptom onset in patients without immunocompromising factors and with radiographically stable prosthetic components were selected for this treatment protocol. Five knees in 4 patients met the inclusion criteria and were examined clinically and radiographically at minimum 36-month follow-up. The mean follow-up interval was 41 months (range, 36 to 43 months). No knee had been revised or had revision planned for infection, although 1 had undergone tibial insert exchange for polyethylene wear. Follow-up radiographs showed no prosthetic loosening, and Knee Society scores averaged 88 (range, 75-95) in the 4 retained knees, 3 of which were subjectively thought to have returned to their preinfection level of functioning. All knees were infected with a single organism not considered highly virulent. No patients required oral suppressive antibiotics for their knees. Early aggressive arthroscopic debridement as part of a treatment protocol of acute periprosthetic knee septic arthritis with well-fixed and functioning implants can be an effective treatment option in selected cases. Level IV study (no, or historical control group).

Long-term suppression of infection in total joint arthroplasty.

Optimal treatment for a chronic infected prosthesis is the removal of infected and necrotic tissue and all the components of the prosthesis with staged revision in conjunction with systemic antibiotics. If this is not possible because of the poor general condition of the patient, because of unacceptable functional results secondary to removal of the prosthesis, or because the patient refuses surgery in an attempt to salvage the infected prosthesis, a reasonable alternative is long-term oral suppressive antibiotic therapy for maintenance of a functioning prosthesis. Prompt recognition with rapid debridement and initiation of antibiotic therapy seems crucial. Our study confirms a favorable outcome of maintenance of functioning prostheses in 86.2% of patients after a mean followup of 5 years. All patients had initial debridement with 4 to 6 weeks of systemic antibiotic therapy. Advanced age did not seem to predict poor outcome. Joint location, duration of symptoms, and the time of onset of infection did not predict success or failure. The overall success rate for Staphylococcus aureus prosthetic joint infection was 69% after a mean followup of 5 years. The ideal regimen and optimal duration of oral suppressive therapy for a favorable outcome is not well-established and needs additional data with prospective multicenter studies.