Key Points Question In first-episode infective endocarditis in persons who inject drugs, what are the clinical differences between patients who receive surgery vs those who are medically treated, and which factors are associated with mortality? Findings In this case series of 370 first-episode cases of infective endocarditis, the main significant differences between persons who inject drugs who received surgery and those who did not were the site of infection and cardiac complications. Decreased mortality was associated with surgery and referral to addiction treatment services, while higher mortality was associated with left-sided and bilateral infections. Meaning In selected persons who inject drugs with first-episode endocarditis, surgical management and referral to addiction treatment were associated with reduced mortality.

This algorithm will enable researchers to examine epidemiological trends in PWID-associated infective endocarditis.

Background: Historically, patients with HIV have been at the highest risk of infection with opportunistic protozoans such as Toxoplasma, Cryptosporidium, and Isospora. Among patients with HIV who are compliant with antiretroviral therapy, the likelihood of acquiring an opportunistic infection is low. The risk of infection is harder to mitigate in the growing number of HIV-negative immunodeficient patients, such as people with hematological malignancies or those who are post-transplantation. Methods: We conducted a retrospective case series of patients with documented Toxoplasma infections between 2008 and 2017 and with Cryptosporidium and Isospora infections between 2014 and 2017 at the Ottawa Hospital. Results: During the study period, there were 10 confirmed cases of toxoplasmosis, 20 cases of cryptosporidiosis, and 2 cases of isosporiasis. Cryptosporidiosis (95%) and toxoplasmosis (60%) occurred more frequently among HIV-negative patients, whereas isosporiasis cases were limited to HIV-positive patients. Among patients with cryptosporidiosis, the most common underlying cause of immunosuppression in HIV-negative individuals was solid organ transplantation (15.79%), followed by diabetes (10.53%), end-stage renal disease (5.26%), and hematologic malignancy (5.26%). Seventy percent of patients had no known cause of immunosuppression. The most common underlying condition associated with toxoplasmosis was hematological malignancy (50%), followed by solid organ transplantation (33.33%), and solid tumours (16.66%). Conclusions: This study’s results suggest that Cryptosporidium infections are more common among immunocompetent patients in Ottawa, whereas Toxoplasma infections are more common among HIV-negative patients with acquired immunodeficiencies. As the demographics of immunocompromised individuals continue to evolve, screening for protozoal infections in high-risk populations may become clinically important.

Importance The role of systemic antibiotics in the treatment of bacterial endophthalmitis remains controversial. While penicillin is a highly effective antibiotic against bacteria that frequently cause endophthalmitis, the ability of systemically administered Penicillin G to penetrate into the vitreous at adequate therapeutic concentrations has not been studied. Its role in the treatment of endophthalmitis, particularly for bacteria for which it is the antibiotic of choice, therefore remains unknown. Objective We sought to determine whether intravenous administration of Penicillin G leads to adequate therapeutic concentrations in the vitreous for the treatment of bacterial endophthalmitis. Design and setting This study was conducted in an ambulatory setting, at the Ottawa Hospital Eye Institute, a university-affiliated tertiary care center, where a 77-year old gentleman with chronic post-cataract surgery Actinomyces neuii endophathalmitis was treated with intravenous Penicillin G (4 × 106 units every 4 h) and intravitreal ampicillin (5000μg/0.1 m1). Main outcomes and measures Intravitreal concentration of Penicillin G and ampicillin were obtained at the time of intraocular lens removal, measured by high-performance liquid chromatography. Results The intravitreal concentration of penicillin and ampicillin was 3.5μg/ml and 0.3μg/ml, respectively. Both the concentration of penicillin and ampicillin were within the level of detection of their respective assays (penicillin 0.06-5μg/ml, ampicillin 0.12–2.5μg/ml). Conclusion and relevance This study shows that intravenous Penicillin G administered every four-hours allows for adequate intravitreal concentrations of penicillin. Future studies are required to determine if the results of this study translate into improved clinical outcomes.

Introduction During the last ten years there have been two notable studies within vessel preparation for peripheral vascular disease; the DEFINITIVE AR prospective multi-centre randomised study (evaluating the use of atherectomy prior to drug-eluting balloon catheters (DCB)) and the DISRUPT PAD III randomized control trial (evaluating the use of intravascular lithotripsy (IVL)). This study aimed to analyse a true cohort of vascular patients who underwent vessel prep and whether this reflects those included in the studies. Methods Data were collected on patients with SFA disease in 14 countries across 17 centres. We applied the inclusion criteria for the DEFINITIVE AR and DISRUPT PAD III studies to our cohort. Results Data were collected on n=974 patients who received at least one form of vessel prep. Of these patients, 202 (20.7%) underwent atherectomy and 22 (2.26%) underwent lithotripsy. 50.1% (n=103) of those who underwent atherectomy would have been eligible to participate in the DEFINITVE AR study. 18% (n=4) of patients who underwent lithotripsy would have been eligible to participate in the DISRUPT PAD III trial. Conclusion Both the DEFINITIVE AR and DISRUPT PAD III trials have shown promising results however in this large multicentre study we have shown that the study participants reflect only a small percentage of the patients seen within a real vascular ward. We would advise caution when interpreting the results from these studies considering the disparity we have shown between the study cohorts and the real life vascular population.