Kathryn Chu and colleagues discuss the impact of high-income country investigators conducting research in low- and middle-income countries and explore lessons from the effective and equitable relationships that exist. Please see later in the article for the Editors' Summary

BackgroundThe diagnosis of periprosthetic joint infection (PJI) remains a serious clinical challenge. There is a pressing need for improved diagnostic testing methods; biomarkers offer one potentially promising approach.Questions/purposesWe evaluated the diagnostic characteristics of 16 promising synovial fluid biomarkers for the diagnosis of PJI.MethodsSynovial fluid was collected from 95 patients meeting the inclusion criteria of this prospective diagnostic study. All patients were being evaluated for a revision hip or knee arthroplasty, including patients with systemic inflammatory disease and those already receiving antibiotic treatment. The Musculoskeletal Infection Society (MSIS) definition was used to classify 29 PJIs and 66 aseptic joints. Synovial fluid samples were tested by immunoassay for 16 biomarkers optimized for use in synovial fluid. Sensitivity, specificity, and receiver operating characteristic curve analysis were performed to assess for diagnostic performance.ResultsFive biomarkers, including human α-defensin 1-3, neutrophil elastase 2, bactericidal/permeability-increasing protein, neutrophil gelatinase-associated lipocalin, and lactoferrin, correctly predicted the MSIS classification of all patients in this study, with 100% sensitivity and specificity for the diagnosis of PJI. An additional eight biomarkers demonstrated excellent diagnostic strength, with an area under the curve of greater than 0.9.ConclusionsSynovial fluid biomarkers exhibit a high accuracy in diagnosing PJI, even when including patients with systemic inflammatory disease and those receiving antibiotic treatment. Considering that these biomarkers match the results of the more complex MSIS definition of PJI, we believe that synovial fluid biomarkers can be a valuable addition to the methods utilized for the diagnosis of infection.Level of EvidenceLevel II, diagnostic study. See Instructions for Authors for a complete description of levels of evidence.

s pe c i a l r e p o r t T h e ne w e ngl a nd jou r na l o f m e dicine n engl j med 369;21 nejm.org november 21, 2013

Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Two decades ago, the genocide against the Tutsis in Rwanda led to the deaths of 1 million people, and the displacement of millions more. Injury and trauma were followed by the effects of a devastated health system and economy. In the years that followed, a new course set by a new government set into motion equity-oriented national policies focusing on social cohesion and people-centred development. Premature mortality rates have fallen precipitously in recent years, and life expectancy has doubled since the mid-1990s. Here we reflect on the lessons learned in rebuilding Rwanda’s health sector during the past two decades, as the country now prepares itself to take on new challenges in health-care delivery.