Minimally Symptomatic Infection in an Ebola 'Hotspot': A Cross-Sectional Serosurvey.

INTRODUCTION: Evidence for minimally symptomatic Ebola virus (EBOV) infection is limited. During the 2013-16 outbreak in West Africa, it was not considered epidemiologically relevant to published models or projections of intervention effects. In order to improve our understanding of the transmission dynamics of EBOV in humans, we investigated the occurrence of minimally symptomatic EBOV infection in quarantined contacts of reported Ebola virus disease cases in a recognized 'hotspot.' METHODOLOGY/PRINCIPAL FINDINGS: We conducted a cross-sectional serosurvey in Sukudu, Kono District, Sierra Leone, from October 2015 to January 2016. A blood sample was collected from 187 study participants, 132 negative controls (individuals with a low likelihood of previous exposure to Ebola virus), and 30 positive controls (Ebola virus disease survivors). IgG responses to Ebola glycoprotein and nucleoprotein were measured using Alpha Diagnostic International ELISA kits with plasma diluted at 1:200. Optical density was read at 450 nm (subtracting OD at 630nm to normalize well background) on a ChroMate 4300 microplate reader. A cutoff of 4.7 U/mL for the anti-GP ELISA yielded 96.7% sensitivity and 97.7% specificity in distinguishing positive and negative controls. We identified 14 seropositive individuals not known to have had Ebola virus disease. Two of the 14 seropositive individuals reported only fever during quarantine while the remaining 12 denied any signs or symptoms during quarantine. CONCLUSIONS/SIGNIFICANCE: By using ELISA to measure Zaire Ebola virus antibody concentrations, we identified a significant number of individuals with previously undetected EBOV infection in a 'hotspot' village in Sierra Leone, approximately one year after the village outbreak. The findings provide further evidence that Ebola, like many other viral infections, presents with a spectrum of clinical manifestations, including minimally symptomatic infection. These data also suggest that a significant portion of Ebola transmission events may have gone undetected during the outbreak. Further studies are needed to understand the potential risk of transmission and clinical sequelae in individuals with previously undetected EBOV infection.

Strengthening Health Systems While Responding to a Health Crisis: Lessons Learned by a Nongovernmental Organization During the Ebola Virus Disease Epidemic in Sierra Leone.

An epidemic of Ebola virus disease (EVD) beginning in 2013 has claimed an estimated 11 310 lives in West Africa. As the EVD epidemic subsides, it is important for all who participated in the emergency Ebola response to reflect on strengths and weaknesses of the response. Such reflections should take into account perspectives not usually included in peer-reviewed publications and after-action reports, including those from the public sector, nongovernmental organizations (NGOs), survivors of Ebola, and Ebola-affected households and communities. In this article, we first describe how the international NGO Partners In Health (PIH) partnered with the Government of Sierra Leone and Wellbody Alliance (a local NGO) to respond to the EVD epidemic in 4 of the country's most Ebola-affected districts. We then describe how, in the aftermath of the epidemic, PIH is partnering with the public sector to strengthen the health system and resume delivery of regular health services. PIH's experience in Sierra Leone is one of multiple partnerships with different stakeholders. It is also one of rapid deployment of expatriate clinicians and logistics personnel in health facilities largely deprived of health professionals, medical supplies, and physical infrastructure required to deliver health services effectively and safely. Lessons learned by PIH and its partners in Sierra Leone can contribute to the ongoing discussion within the international community on how to ensure emergency preparedness and build resilient health systems in settings without either.

Rapid isolation of bone marrow mesenchymal stromal cells using integrated centrifuge-based technology.

BACKGROUND AIMS: The use of bone marrow-derived mesenchymal stromal cells (MSCs) in cell-based therapies is currently being developed for a number of diseases. Thus far, the clinical results have been inconclusive and variable, in part because of the variety of cell isolation procedures and culture conditions used in each study. A new isolation technique that streamlines the method of concentration and demands less time and attention could provide clinical and economic advantages compared with current methodologies. In this study, we evaluated the concentrating capability of an integrated centrifuge-based technology compared with standard Ficoll isolation. METHODS: MSCs were concentrated from bone marrow aspirate using the new device and the Ficoll method. The isolation capabilities of the device and the growth characteristics, secretome production, and differentiation capacity of the derived cells were determined. RESULTS: The new MSC isolation device concentrated the bone marrow in 90 seconds and resulted in a mononuclear cell yield 10-fold higher and with a twofold increase in cell retention compared with Ficoll. The cells isolated using the device were shown to exhibit similar morphology and functional activity as assessed by growth curves and secretome production compared to the Ficoll-isolated cells. The surface marker and trilineage differentiation profile of the device-isolated cells was consistent with the known profile of MSCs. DISCUSSION: The faster time to isolation and greater cell yield of the integrated centrifuge-based technology may make this an improved approach for MSC isolation from bone marrow aspirates.

Clickable Amphiphilic Triblock Copolymers.

Amphiphilic polymers have recently garnered much attention due to their potential use in drug-delivery and other biomedical applications. A modular synthesis of these polymers is extremely desirable since it offers precise individual block characterization and increased yields. We present here for the first time a modular synthesis of poly(oxazoline)-poly(siloxane)-poly(oxazoline) block copolymers that have been clicked together using the copper-catalyzed azide-alkyne cycloaddition reaction. Various click methodologies for the synthesis of these polymers have been carefully evaluated and optimized. The approach using copper nanoparticles was found to be the most optimal among the methods evaluated. Furthermore, these results were extended to allow for a reactive Si-H group-based siloxane middle block to be successfully clicked. This enables the design of more complex amphiphilic block copolymers that have additional functionality, such as stimuli responsiveness, to be synthesized via a simple hydrosilylation reaction.