Infected deep vein thrombophlebitis in people who inject drugs: missed opportunities and potential for alternative antimicrobial approaches

Infected deep vein thrombophlebitis (i-DVT) in people who inject drugs (PWID) is a clinically challenging but poorly characterised disease. We undertook a retrospective observational study of 70 PWID presenting acutely with i-DVT to improve the clinical and microbiological characterisation of this disease. i-DVT was frequently associated with bacteraemia (59.1% patients with blood cultures obtained), groin abscesses (in 34.3%; of which 54.2% required surgical drainage), and septic pulmonary emboli (38.6%) requiring anticoagulation. Network analysis identified a cluster of patients presenting with respiratory symptoms but lacking typical DVT symptoms, more likely to have septic pulmonary emboli. A microbiologic diagnosis was frequently achieved (70%). Causative pathogens were predominantly gram-positive (S. aureus and streptococci, especially anginosus group), whereas gram-negative pathogens were identified very infrequently (in 6.1% of microbiological diagnoses). This suggests routine empiric therapy against gram-negative bacteria, though commonly administered, is not required. High rates of clinical cure (88.6%) were observed despite the complex nature of infections and independently of the highly variable intravenous and total antimicrobial durations received. There exists a rationale to devise pragmatic approaches to implement novel individualised treatment plans utilising oral antimicrobial therapy for i-DVT. Despite frequent healthcare interactions, opportunities to address HCV treatment and opioid substitution therapy were frequently missed during these acute admissions.

Postoperative Endophthalmitis Caused by Cutibacterium (Formerly Propionibacterium) Acnes: Case Series and Review

We report the clinical features, treatment strategies and outcomes in a series of patients with infectious endophthalmitis after cataract surgery caused by <i>Cutibacterium acnes (C. acnes)</i>, formerly known as <i>Propionibacterium acnes (P. acnes)</i>. This retrospective case series includes six eyes of six patients with chronic postoperative endophthalmitis caused by culture-proven <i>C. acnes</i>from December 2010 to July 2019 at a University referral center. All patients underwent prior cataract extraction with intraocular lens (CE/IOL) implantation. The mean time between cataract surgery and the microbiologic diagnosis of endophthalmitis was 7.4 ± 5.2 months (range 1.5–17 months). The average time from obtaining the specimen to culture positivity was 7.7 ± 4.4 days (range 3–15 days). Three eyes (50%) presented with hypopyon and three eyes (50%) presented with prominent keratic precipitates without hypopyon. Presenting visual acuity ranged from 20/25 to 2/200. Initial treatments included intravitreal antibiotics alone (<i>n</i> = 2), pars plana vitrectomy (PPV) with partial capsulectomy and intravitreal antibiotics (<i>n</i> = 3), and pars plana vitrectomy with IOL removal and intravitreal antibiotics (<i>n</i> = 1). Follow-up treatments included IOL removal (<i>n</i> = 2), intravitreal antibiotics (<i>n</i> = 1), and topical antibiotics (<i>n</i> = 1). The best-corrected visual acuity at last follow-up was 20/70 or better in all patients. In a literature review, the clinical features and treatment outcomes for all case series of delayed-onset postoperative endophthalmitis caused by <i>C. acnes</i>(<i>n</i> = 120) are listed<i>.</i> A definitive cure (the absence of recurrent inflammation) was achieved in 100% of patients that underwent IOL removal, in 77% of those that underwent PPV/partial capsulectomy and intravitreal antibiotics, and in 18% of cases treated with intravitreal antibiotics alone. Endophthalmitis after CE/IOL caused by <i>C. acnes</i>is characterized by slowly progressive intraocular inflammation and has a protracted course from surgery to microbiologic diagnosis. Visual outcomes are generally favorable, but IOL explantation may be necessary for definitive cure.

Prevalence of Co-Infection at the Time of Hospital Admission in COVID-19 Patients, A Multicenter Study

Background Bacterial infections may complicate viral pneumonias. Recent reports suggest bacterial co-infection at time of presentation is uncommon in COVID-19; however, estimates were based on microbiology tests alone. We sought to develop and apply consensus definitions, incorporating clinical criteria to better understand the rate of co-infections and antibiotic use in COVID-19. Methods 1,016 adult patients admitted to five hospitals in the Johns Hopkins Health System between 3/1/2020-5/31/2020 with COVID-19 were evaluated. Adjudication of co-infection using definitions developed by a multidisciplinary team for this study were performed. Both respiratory and common non-respiratory co-infections were assessed. The definition of bacterial community-acquired pneumonia (bCAP) included proven (clinical, laboratory and radiographic criteria plus microbiologic diagnosis), probable (clinical, laboratory and radiographic criteria without microbiologic diagnosis), and possible (not all clinical, laboratory and radiographic criteria met) categories. Clinical characteristics and antimicrobial use were assessed in the context of the consensus definitions. Results Bacterial respiratory co-infections were infrequent (1.2%); 1 patient had proven bCAP, and 11 (1.1%) had probable bCAP. Two patients (0.2%) had viral respiratory co-infections. Although 69% of patients received antibiotics for pneumonia, the majority were stopped within 48 hours in patients with possible or no evidence of bCAP. The most common non-respiratory infection was urinary tract infection (present in 3% of the cohort). Conclusions Using multidisciplinary consensus definitions, proven or probable bCAP was uncommon in adults hospitalized due to COVID-19, as were other non-respiratory bacterial infections. Empiric antibiotic use was high, highlighting the need to enhance antibiotic stewardship in treatment of viral pneumonias.

324. Implant Sonication Improves Microbiologic Diagnosis of Elbow Prosthetic Joint Infection

Background With a reported incidence of up to 12%, periprosthetic joint infection (PJI) is a frequent complication of total elbow arthroplasty (TEA). Its microbiologic diagnosis is usually based on periprosthetic tissue culture (hereafter referred to as tissue culture), despite the poor sensitivity of this technique. Although implant sonication cultures have been shown to be superior to tissue cultures for hip and knee PJI diagnosis, only a single small study (including fewer than 10 infected implants) has assessed sonication of elbow arthroplasties. Methods We retrospectively analysed 116 sonicate fluid cultures from patients who underwent revision of a TEA at our Institution between 2007 and 2019, comparing results to tissue cultures. Nine elbows who had fewer than 2 tissue samples obtained during surgery were excluded. Using the IDSA guidelines to define PJI, there were 46 infected cases and 61 aseptic failures. We reviewed clinical characteristics and calculated the sensitivity and specificity of periprosthetic tissue culture compared to culture of samples obtained by implant sonication. In addition, we compared the sensitivity of tissue culture to the combination of tissue and sonicate fluid culture. Results A total of 107 elbows were included. Median ages in the aseptic failure and PJI groups were 60 and 67 years, respectively. Gender distribution was similar for both groups (PJI group 62% females; aseptic group 65% females). The most common pathogens were coagulase negative Staphylococcus species (66%), followed by Staphylococcus aureus (18%). The sensitivity of tissue culture was 63% and the sensitivity of sonicate fluid culture was 76% (p=0.14). The specificity of tissue culture was 86% and the specificity of sonicate fluid culture was 100%. Sensitivity of sonicate fluid culture in combination with tissue culture was 91% (p=0.045). Table. Comparison of tests for microbiologic diagnosis of PJI Conclusion The combination of sonicate fluid culture and tissue culture had a greater sensitivity than tissue culture alone for microbiologic diagnosis of elbow TEA infection. Disclosures Joachin Sanchez-Sotelo, M.D, PhD, Elsevier (Other Financial or Material Support, Publishing Royalties)Exactech (Consultant)Oxford Univerity Press (Other Financial or Material Support, Publishing Royalties)Stryker (Grant/Research Support)Wright (Consultant) Robin Patel, MD, Accelerate Diagnostics (Grant/Research Support)CD Diagnostics (Grant/Research Support)Contrafect (Grant/Research Support)Curetis (Consultant)GenMark Diagnostics (Consultant)Heraeus Medical (Consultant)Hutchison Biofilm Medical Solutions (Grant/Research Support)Merck (Grant/Research Support)Next Gen Diagnostics (Consultant)PathoQuest (Consultant)Qvella (Consultant)Samsung (Other Financial or Material Support, Dr. Patel has a patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic, and a patent on an anti-biofilm substance issued.)Selux Dx (Consultant)Shionogi (Grant/Research Support)Specific Technologies (Consultant)

105. Evaluation of a Multiplex PCR Panel for the Microbiologic Diagnosis of Pneumonia in Hospitalized Patients: A Retrospective Analysis from an Academic Medical Center

Background Pneumonia is a leading cause of hospitalization and mortality. Due to the low yield of available diagnostic tests, ATS/IDSA pneumonia guidelines recommend a microbiologic work-up only for hospitalized patients with severe pneumonia. Methods From 5/2019 to 1/2020, we selected adult patients with clinical and radiographic findings highly suggestive of pneumonia. The BioFire® FilmArray® pneumonia panel was performed on sputum specimens that met quality microbiologic criteria and the results were compared to those of sputum cultures and other tests sent per standard of care. A limit of 105 copies/mL was used for positivity in semi-quantitative bacterial targets. The empiric antimicrobial regimen was reviewed to quantify the potential for antimicrobial optimization. Results Seventy patients were included in the analysis. Median age was 70 (IQR 53.5–81.75), and the majority (43 patients, 61.4%) were classified as Class IV and V using the pneumonia severity index, indicating severe cases of pneumonia. Sixty-nine patients completed at least a 5-day course for pneumonia and 14.3% died during their hospitalization. The fifteen patients (21.4%) that submitted a sputum culture before the initiation of antimicrobial therapy, had a trend towards a positive sputum culture (60% (9/15) vs 36.4% (20/55)) (p=0.09). The BioFire® FilmArray® pneumonia Panel increased the number of patients who received a microbiologic diagnosis from 29 (41%) to 59 (84.3%) (p&lt; 0.001). The per isolate analysis revealed significantly more targets detected for Haemophilus influenzae (p=0.002) and Streptococcus pneumoniae (p=0.05). On review of empiric antimicrobial treatment, there was possibility for antimicrobial optimization in 80% of patients, including 9 cases of pathogens (4 MRSA, 3 Legionella pneumophila, 2 CTX-M gram-negative rods) where the pathogens were not covered and another 70 antimicrobials in 49 patients that could be stopped. Flow chart Bacterial Pathogens Detected in Standard of Care Alone Testing and with the Addition of Pneumonia Panel. Potential for Antimicrobial Optimization Using the Pneumonia Panel Conclusion Incorporation of the pneumonia panel in the diagnostic work-up of patients hospitalized with pneumonia substantially increased the rate of microbiologic diagnosis and had the potential to guide appropriate antimicrobial therapy. Future studies to quantify the effects on clinical outcomes and cost-effectiveness from tailored therapy are needed. Disclosures All Authors: No reported disclosures