Mendez, Julio

Abstract Objectives: Community-acquired intra-abdominal infections (CA-IAIs) are a leading cause of US hospitalizations. Piperacillin-tazobactam is often used to empirically treat CA-IAIs, despite national guidelines recommending narrower-spectrum antibiotics for these infections. The overuse of broad-spectrum agents such as piperacillin-tazobactam contributes to antibiotic resistance, which poses serious public health challenges. This resident-led quality improvement initiative aimed to reduce unnecessary piperacillin-tazobactam use for treating CA-IAIs measured as DOT/1,000 patient-days by 10% without adversely affecting hospital length of stay (LOS). Methods: Using the DMAIC (define, measure, analyze, improve, control) framework, we identified barriers to appropriate antibiotic use and developed a treatment algorithm for CA-IAIs that included clear guidelines and exclusion criteria. This algorithm was disseminated to internal medicine residents and emergency department physicians along with educational sessions to highlight updated CA-IAI treatment recommendations, antibiotic resistance, and appropriate antibiotic ordering via the electronic health record. Antimicrobial stewardship pharmacists provided overnight support to assist with de-escalation. Data were collected over a 10-month period spanning 2 intervention phases. The primary outcome was piperacillin-tazobactam use, measured as days of therapy (DOT) per 1,000 patient-days and DOT per patient LOS. Mean LOS served as the balancing measure. Results: Piperacillin-tazobactam use was significantly reduced ( P < .001) after the interventions without increasing the mean LOS. Conclusion: This project raised awareness of antibiotic resistance and led to lasting improvements in reducing the inappropriate use of piperacillin-tazobactam to treat CA-IAIs, without affecting the mean LOS. This was attributed to the strong collaboration among a multidisciplinary team of infectious disease physicians, antimicrobial stewardship team members, residents, emergency department physicians, and faculty.

Background: Piperacillin-Tazobactam (PTZ) is often used to treat community-acquired intra-abdominal infections (CA-IAIs) despite common causative pathogens being susceptible to more narrow-spectrum agents. However, susceptibility to PTZ among these predominant pathogens has been declining. Antibiotic de-escalation to non-antipseudomonal beta-lactams whenever possible is an important strategy to prevent the development of resistance to PTZ. Objective: The purpose of this study is to assess PTZ length of therapy in patients with CA-IAI, by comparing patients who received a pharmacist-led intervention involving the de-escalation of PTZ to narrow-spectrum regimens with those who did not receive the intervention. Methods: A retrospective analysis was conducted among patients >18 years old and admitted with CA-IAI empirically placed on PTZ between January 1, 2022, through June 30, 2022 (pre-intervention group), and January 1, 2024, through June 30, 2024 (post-intervention group). A total of 246 patients were included in the pre-intervention group and 129 patients in the post-intervention group. The utilization of PTZ, hospital length of stay (LOS), and treatment-associated complications were assessed using linear and logistic regression model, respectively. Results: Compared with patients in the pre-intervention group, those in the post-intervention group had a mean 1.2-day reduction in PTZ length of therapy (2.3 vs 1.2 days, P < 0.001). There was no difference in LOS, (β = 0.001, 98% confidence interval [CI] −1.29 to 1.29; P = 0.477), hospital readmission within 30 days due to IAI (odds ratio [OR] = 0.85, 98% CI = 0.51 to 1.44; P = 0.56), treatment-associated complications during current hospitalization (OR = 0.77, 98% CI = 0.45 to 1.32; P = 0.35), development of Clostridium difficile -associated diarrhea (OR = 3.29, 98% CI = 0.77 to 22.4; P = 0.14), or medication toxicity (OR = 2.07, 98% CI = 0.79 to 6.08; P = 0.15). Conclusion and relevance: The use of narrow-spectrum antibiotics for the empiric treatment of CA-IAI-reduced PTZ length of therapy and did not result in adverse clinical outcomes.

Objective: We evaluated the impact of a methicillin-resistant Staphylococcus aureus (MRSA) nasal polymerase chain reaction (PCR) protocol on the vancomycin length of therapy (LOT) for skin and soft tissue infections (SSTIs). Design: Retrospective quasi-experimental pre- and post- MRSA nasal PCR protocol implementation study. Setting: Tertiary-care academic medical center in Jacksonville, Florida. Patients: Eligible patients received empiric vancomycin for SSTIs from January 1st to September 30th 2020 (pre-implementation group) and from January 1st to September 30th 2022 (post-implementation group). Intervention: The electronic health system software was modified to provide a best-practice advisory (BPA) prompt to the pharmacist upon order verification of vancomycin for patients with SSTIs. Methods: We reviewed patient records to determine the time from vancomycin prescription to de-escalation. The secondary outcomes were incidence of acute kidney injury (AKI), number of vancomycin levels collected, and hospital length of stay (LOS). Results: The study included 131 patients (pre-implementation, n = 86 and post-implementation, n = 45). There was no significant difference in vancomycin length of therapy (LOT) between implementation groups: mean LOT in days and standard deviation (SD) were 2.7 (1.9) and 2.6 (1.3), respectively, p-value 0.493. Of significance, in the post-implementation group, vancomycin LOT between patients with a negative and positive MRSA PCR were 2.3 (1.1) and 3.9 (1.6), p-value 0.006. There was no difference in secondary outcomes. Conclusion: The utilization of the MRSA nasal PCR to guide vancomycin de-escalation did not significantly change the vancomycin LOT, however in the post-implementation group there was a significant difference in vancomycin LOT between negative and positive MRSA PCRs.

Abstract Background Implementing effective antimicrobial stewardship interventions is an important component of antimicrobial stewardship programs. Recently, stewardship research has shown that clinician characteristics may have an impact on antimicrobial stewardship intervention methods and acceptance rates. Methods A multisite health system antimicrobial stewardship prospective audit and feedback program interventions performed by stewardship staff using a standardized electronic medical record (EMR) tool were compared by stewardship clinician profession (pharmacist, physician, or advanced practice provider, APP) from 7/1/2017 to 6/30/2022. Outcomes assessed were intervention rates, communication methods, and intervention acceptance by patient age and intensive care unit (ICU) status of patient. Generalized estimating equations utilizing logistic regression were used to assess for associations between staff. Associations were assessed both univariately and after adjusting for other factors. Results Of 69,503 prospective audit and feedback EMR based rules, there were 14,699 rules associated with an intervention. The majority of rules were reviewed by pharmacists (90.7%) followed by physician (9.2%) and APP (&lt; 1%). Of 9,034 interventions with an outcome documented, 7326 (85.5%) pharmacist interventions were accepted and 360 (77.3%) physician interventions were accepted (adjusted p=0.047). Pharmacists intervened by direct action (ie, adjust a medication order) in 6.6% of interventions; whereas, physicians did so rarely (0.4%). Pharmacists were more likely to use synchronous communication than physicians in the adjusted model (pharmacist vs. physician: 63.8% vs 52.5%; p=0.004). Patients in the ICU had a significantly lower intervention acceptance rate (non-ICU vs. ICU: 86.6% vs. 78.0%; adjusted OR 0.57 [95% CI 0.46-0.70], p&lt; 0.001).Table 1.Intervention Rate by Baseline Demographics of Stewardship Clinicians and Patients. *% are reported as row % **Multivariable model was also adjusted for day of week and time of day APP-Advanced practice provider; ICU-intensive care unitTable 2.Intervention Acceptance. *% are reported as row % **Multivariable model was also adjusted for day of week and time of day APP-Advanced practice provider; ICU-intensive care unit Conclusion Antimicrobial stewardship pharmacists and physicians are both effective at prospective audit and feedback but used different intervention styles. Advanced practice providers were vastly underrepresented. Patients in the ICU may benefit from tailored ASP efforts. Disclosures Sara Ausman, PharmD, Gilead: Honoraria Caitlin Brown, PharmD, Alexion: Grant/Research Support|Trevena: Advisor/Consultant Christina G. Rivera (O'Connor), Pharm.D, Gilead Sciences: Advisor/Consultant|Gilead Sciences: Board Member|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria

Abstract Background The majority of human antimicrobial utilization occurs in the outpatient setting. Despite being mainly viral in etiology, upper respiratory tract infections (URIs) were the most common indication for outpatient antimicrobial prescriptions at our institution. Methods Through our electronic health record (EHR), we were able to determine our rate of antibiotic prescriptions for inappropriate URI diagnosis at our primary care practice sites. We selected staff volunteers from each our primary care practice sites to serve as stewardship champions. They were given training in stewardship best practices, and an URI stewardship toolkit which included viral URI prescription pad, EHR order panel, and patient education signage. They were tasked with providing education and feedback to their practice sites. We meet with them on a monthly basis to disseminate prescribing data and education. They also provided feedback from practice sites to the stewardship committee. Results Our decentralized model was put in place in November 2020. In the 6 months prior to the intervention, the average prescribing rate was 29.1%. In the 6 months after the intervention, the average prescribing rate decreased by 15% to 24.8%. During the intervention phase, there was an increase in number of non-COVID URIs diagnosed at our primary care sites. Temporal Trend in Inappropriate Antibiotics Prescribing Rates for Viral URIs Pre- and Post- Intervention Inappropriate antibiotic prescribing rate for viral upper respiratory tract infections from May 2020 until May 2021. Intervention started in December 2021 (arrow). Pre-intervention average was 29.1%. Post-intervention age was 24.8% which is a 15% decline in prescribing rate. Viral Upper Respiratory Infections Visits The total number of visits for presumed viral upper respiratory infections to primary care sites from May 2020 until May 2021. The majority of COVID-19 precautions in the area expired at the end of March 2021. Conclusion We have been able to lower our inappropriate prescriptions for URIs utilizing a decentralized model of stewardship champions. This result was especially notable as the intervention phase corresponded with the end of COVID-19 precautions and an increase in non-COVID URIs diagnosed. The advantage of this approach includes an advocate embedded at each practice site who is familiar with the opportunities and challenges of the site, and a two-way flow of information from practice sites to the stewardship committee. This model provided additional benefit during the COVID-19 pandemic as the ability of centralized staff to travel to off campus clinic sites was curtailed. Disclosures All Authors: No reported disclosures

Abstract Background Echinococcus multilocularis is a destructive zoonotic cestode with low human incidence. Hydatid disease classically presents with hepatic or lung involvement with infrequent extrahepatic bone destruction. Diagnosis is challenging due to its latency and mimicry. Fig.1: Case 1 - X-ray imaging of the pelvis shows osseous destruction of the iliac crest secondary to known osteomyelitis status post left ilium debridement. Fig.2: Case 1 - Magnetic resonance imaging demonstrates extensive osteomyelitis throughout left ilium. Stable scattered focal fluid collections seen throughout the left lower quadrant. Methods CASE 1: A 57 year-old Albanian male with diabetes, latent TB, and left iliac lytic lesion presented with 4 weeks of left flank pain and was treated with 6 weeks of IV Ceftriaxone and Flagyl. 2 years later he returned with flank pain and purulent lumbar drainage. Hip x-ray suggested chronic osteomyelitis, with left psoas fluid collections on CT. Bartonella, Q fever, Brucella, HIV, AFB and fungal serologies were negative. Hemipelvis debridement revealed structures concerning for hydatid disease. Echinococcus IgG was equivocal. Histopathology was consistent with Echinococcus multilocularis species, and albendazole was started. On follow-up, he presented with left hip tenderness and toe extensor weakness. Labs showed mild leukocytosis. CT revealed progressive destruction of the left iliac with sacroiliac extension concerning for abscess. CASE 2: A 36 year-old female presented with lung and liver cysts, progressive dyspnea, and non-productive cough. She lived in Africa, Asia, and Europe and consumed local street food and unpasteurized milk. Hobbies included spelunking and swimming in freshwater lakes. She had exposure to stray animals, but denied bites or scratches. Over 4 years dyspnea progressed to orthopnea. MR abdomen revealed a 10x6x12cm liver cyst and chest CT showed 2 fluid-attenuating lesions in the LLL and RLL, measuring 4.9 x 6.0 cm and 6.8 x 4.3 cm respectively. Echinococcus, Bartonella, Q fever, Brucella, HIV, AFB and fungal serologies were negative. Schistosomiasis serology was equivocal. Fig. 3: Case 2 - MRI abdomen demonstrating 10x6x12cm liver cyst Fig. 4: Case 2 - Chest CT showed 2 dominant fluid attenuating lesions within the LLL and RLL. The larger lesion in RLL measures 6.8 x 4.3 cm. The left lower lobe lesion measures 4.9 x 6.0 cm. Results Patient 1 underwent type I hemipelvectomy. Patient 2 underwent pulmonary segmentectomy and liver lobectomy. Both were continued on albendazole. Fig. 5: Case 1 - Photo taken during debridement of left ileac and hip. Note presence of white cysts discovered intraoperatively. Fig. 6: Case 1 - Histopathologic slides (H&E stain) demonstrating hooks and scolices consistent with Echinococcus multilocularis. A. Hooklet (100x magnification). B. Hydatid cyst with black-staining structures suggestive of degenerating hooklets. C. Zoomed detail of cyst wall. D. Degenerating hydatid cyst and hooklets. Conclusion Equivocal IgG serology does not exclude infection. History and clinical presentation are key to diagnosis, but histopathology remains the gold standard. Hydatid bone infection progresses insidiously and frequently recurs, depending upon excision and debridement. Finally, echinococcosis demands aggressive long-term therapy and surveillance. Disclosures Claudia R. Libertin, MD, Pfizer, Inc. (Grant/Research Support, Research Grant or Support)

Although uncommon, Brucella infection can occur outside the areas of high endemicity, such as the USA. In the southern USA, hunters of wild swine are at risk for brucellosis. We present a case of a patient with fever, headache and constitutional symptoms that were ongoing for 11 months. He was diagnosed with neurobrucellosis. The patient was treated successfully with intravenous ceftriaxone, oral doxycycline and oral rifampin therapy. He had persistent neurological sequelae after completing treatment. This case illustrates the high index of suspicion needed to diagnose neurobrucellosis in a non-endemic country because initial symptoms can be subtle. The disease can be treated successfully, but long-lasting neurological sequelae are common.

Group Milleri streptococci (GMS), a heterogeneous group of streptococci, are associated with purulent infections. This study was a retrospective analysis of all consecutive thoracic infections of GMS between 2001 and 2004. Of 246 surgical GMS infections, thoracic infections accounted for 4.5 per cent, including 10 pleural infections (eight empyemas and two infected pleural effusions) and one mediastinal infection. The etiology of pleural infection was parapneumonic (7), second to esophageal perforation (1), liver transplantation (1), and liver resection (1). Polymicrobial infections were present in 64 per cent. All patients underwent removal of the infected masses, including drainage (3), thoracoscopic decortication (5), thoracotomy with debridement (2), and incision with drainage (1). The case fatality rate was 9 per cent (there was one patient with congestive heart disease unfit to undergo surgical empyema evacuation) and the recurrence rate was 27.3 per cent (three patients). Combined antibiotic/surgical treatment was successful in all other cases. GMS isolates were susceptible to clindamycin and all β-lactam antibiotics except ceftazidime, but were resistant to aminoglycosides. If found intrathoracically, GMS frequently progress to severe empyema. Therefore, timely removal of pleural collection by percutaneous drainage or surgical intervention seems indicated. If surgery is required, thoracoscopic decortication may be the preferred approach.