Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

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.

Scrub typhus is caused by the obligate intracellular bacterium Orientia tsutsugamushi and is endemic to many countries in the Asia-Pacific region, including tropical Australia. We describe a recent large outbreak amongst military personnel in north Queensland. A total of 45 clinical cases were identified (36% of all potentially exposed individuals). This occurred despite existing military protocols stipulating the provision of doxycycline prophylaxis. Doxycycline resistance in O. tsutsugamushi has been described in South-East Asia, but not Australia. In one case, O. tsutsugamushi was cultured from eschar tissue and blood. Using quantitative real-time PCR to determine susceptibility to doxycycline for the outbreak strain, a minimum inhibitory concentration (MIC) of ≤0.04 μg/mL was found, indicating susceptibility to this agent. It seems most probable that failure to adhere to adequate prophylaxis over the duration of the military exercise accounted for the large number of cases encountered rather than doxycycline resistance.

A prospective cohort study was undertaken to describe the natural history of the cubital fossa peripherally inserted central catheter (PICC), determine which factors influenced the hazard of complication and develop a standard methodology for evaluation of a PICC service. A total of 4349 patient days of PICC observation were analysed using survival analysis techniques. The median time to PICC removal for a complication was 60 days. The most common complications were phlebitis, malposition and tip migration. Complications usually occurred during the first week. There was only one episode of line-related sepsis. Size 3 French gauge catheters had a complication rate of 7.3 per 1000 line days compared to 14.2 for 4 French catheters (hazard rate 1.26 90% CI 1.02 to 1.55). PICCs requiring two or more attempts at insertion were more likely to develop complications than those inserted at the first attempt: 20 per 1000 line days vs 10.5 but the confidence intervals were wide (hazard rate 1.91, 90% CI 0.90 to 4.05). Operator (amongst the four experienced operators who inserted all PICCs), arm of placement, or medial or lateral placement in the cubital fossa did not influence PICC survival.