In late 2009 transplant organizations recommended that kidney recipients be vaccinated for pandemic H1N1 influenza (pH1N1); however, the vaccine efficacy was unknown. We had offered a monovalent non-adjuvanted pH1N1 vaccine to transplant recipients. Here we compared the pre- and post-vaccination seroresponses of 151 transplant recipients to that of 71 hemodialysis patients and 30 healthy controls. Baseline seroprotection was similar between groups but was significantly different at 1 month (44, 56, and 87%, respectively). Seroconversion was significantly less common for transplant recipients (32%) than dialysis patients (45%) and healthy controls (77%). After adjusting for age and gender, dialysis patients were significantly more likely (2.7-fold) to achieve new seroprotection than transplant recipients. The likelihood of seroprotection in transplant recipients was significantly reduced by mycophenolate use (adjusted odds ratio 0.24), in a dose-dependent manner, and by reduced eGFR (adjusted odds ratio 0.16 for worst to best). Seroprotection and geometric mean antibody titers increased substantially in 49 transplant recipients who subsequently received the 2010 seasonal influenza vaccine. Thus, patients requiring renal replacement therapy had reduced seroresponses to vaccination with the monovalent vaccine compared with healthy controls. Transplant recipient responses were further reduced if they were receiving mycophenolate or had significantly lower graft function.

Background Periprosthetic joint infection (PJI) is a devastating complication of joint replacement surgery. Most observational studies of PJI are retrospective or single-center, and reported management approaches and outcomes vary widely. We hypothesized that there would be substantial heterogeneity in PJI management and that most PJIs would present as late acute infections occurring as a consequence of bloodstream infections. Methods The Prosthetic joint Infection in Australia and New Zealand, Observational (PIANO) study is a prospective study at 27 hospitals. From July 2014 through December 2017, we enrolled all adults with a newly diagnosed PJI of a large joint. We collected data on demographics, microbiology, and surgical and antibiotic management over the first 3 months postpresentation. Results We enrolled 783 patients (427 knee, 323 hip, 25 shoulder, 6 elbow, and 2 ankle). The mode of presentation was late acute (>30 days postimplantation and <7 days of symptoms; 351, 45%), followed by early (≤30 days postimplantation; 196, 25%) and chronic (>30 days postimplantation with ≥30 days of symptoms; 148, 19%). Debridement, antibiotics, irrigation, and implant retention constituted the commonest initial management approach (565, 72%), but debridement was moderate or less in 142 (25%) and the polyethylene liner was not exchanged in 104 (23%). Conclusions In contrast to most studies, late acute infection was the most common mode of presentation, likely reflecting hematogenous seeding. Management was heterogeneous, reflecting the poor evidence base and the need for randomized controlled trials.

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Background Peri-prosthetic joint infection (PJI) is a devastating condition and there is a lack of evidence to guide its management. We hypothesised that treatment success is independently associated with modifiable variables in surgical and antibiotic management. Methods Prospective, observational study at 27 hospitals across Australia and New Zealand. Newly diagnosed large joint PJIs were eligible. Data were collected at baseline and at 3, 12 and 24 months. The main outcome measures at 24 months were clinical cure (defined as all of: alive, absence of clinical or microbiological evidence of infection and not requiring ongoing antibiotic therapy) and treatment success (clinical cure plus index prosthesis still in place). Findings 24-month outcome data were available for 653 patients. Overall, 449 (69%) experienced clinical cure and 350 (54%) treatment success. The most common treatment strategy was debridement and implant retention, with success rates highest in early post-implant infections (119/160; 74%) and lower in late acute (132/267, 49%) and chronic (63/142, 44%) infections. Selected comorbidities, knee joint and S.aureus infections were independently associated with treatment failure, but antibiotic choice and duration (including rifampicin use) and extent of debridement were not. Interpretation Treatment success in PJI is associated with selecting the appropriate treatment strategy, and with non-modifiable patient and infection factors. Interdisciplinary decision-making which matches an individual patient to an appropriate management strategy is a critical step for PJI management. Randomised controlled trials are needed to determine the role of rifampicin in patients managed with DAIR and the optimal surgical strategy for late-acute PJI.

Prototheca species are achlorophyllus algae. Prototheca wickerhamii and Prototheca zopfii cause human disease. In immunocompetent individuals, they cause soft tissue infections and olecranon bursitis, but in transplant recipients, these organisms can cause disseminated disease. We report a fatal case of disseminated P. zopfii infection in an hematopoietic stem cell transplant (HSCT) recipient with bloodstream infection and involvement of multiple soft tissue sites. We review all previous cases of protothecosis in HSCT reported in the literature. Protothecosis is uncommon after HSCT, but has a disseminated presentation that is frequently fatal. It is commonly misidentified as a yeast. Tumor necrosis factor-alpha inhibitors and contamination of central venous catheters may contribute to development of protothecosis. Optimal treatment approaches are yet to be defined. New agents such as miltefosine may be possible future therapies.