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Background: The envelope (E) protein of dengue virus (DENV) is the major target of neutralizing antibodies and vaccine development. While previous studies on domain III or domain I/II alone have reported several epitopes of monoclonal antibodies (mAbs) against DENV E protein, the possibility of interdomain epitopes and the relationship between epitopes and neutralizing potency remain largely unexplored. Methodology/Principal Findings: We developed a dot blot assay by using 67 alanine mutants of predicted surface-exposed E residues as a systematic approach to identify epitopes recognized by mAbs and polyclonal sera, and confirmed our findings using a capture-ELISA assay. Of the 12 mouse mAbs tested, three recognized a novel epitope involving residues (Q211, D215, P217) at the central interface of domain II, and three recognized residues at both domain III and the lateral ridge of domain II, suggesting a more frequent presence of interdomain epitopes than previously appreciated. Compared with mAbs generated by traditional protocols, the potent neutralizing mAbs generated by a new protocol recognized multiple residues in A strand or residues in C strand/CC9 loop of DENV2 and DENV1, and multiple residues in BC loop and residues in DE loop, EF loop/F strand or G strand of DENV1. The predominant epitopes of anti-E antibodies in polyclonal sera were found to include both fusion loop and non-fusion residues in the same or adjacent monomer. Conclusions/Significance: Our analyses have implications for epitope-specific diagnostics and epitope-based dengue vaccines. This high throughput method has tremendous application for mapping both intra and interdomain epitopes recognized by human mAbs and polyclonal sera, which would further our understanding of humoral immune responses to DENV at the epitope level. [ABSTRACT FROM AUTHOR]

Background: Long term retention of patients on antiretroviral therapy (ART) in Africa's rapidly expanding programmes is said to be 60% at 2 years. Many reports from African ART programmes make little mention of patients who are transferred out to another facility, yet Malawi's national figures show a transfer out of 9%. There is no published information about what happens to patients who transfer-out, but this is important because if they transfer-in and stay alive in these other facilities then national retention figures will be better than previously reported. Methodology/Principal Findings: Of all patients started on ART over a three year period in Mzuzu Central Hospital, North Region, Malawi, those who transferred out were identified from the ART register and master cards. Clinic staff attempted to trace these patients to determine whether they had transferred in to a new ART facility and their outcome status. There were 805 patients (19% of the total cohort) who transferred out, of whom 737 (92%) were traced as having transferred in to a new ART facility, with a median time of 1.3 months between transferring-out and transferring-in. Survival probability was superior and deaths were lower in the transfer-out patients compared with those who did not transfer. Conclusion/Significance: In Mzuzu Central Hospital, patients who transfer-out constitute a large proportion of patients not retained on ART at their original clinic of registration. Good documentation of transfer-outs and transfer-ins are needed to keep track of national outcomes. Furthermore, the current practice of regarding transfer-outs as being double counted in national cohorts and subtracting this number from the total national registrations to get the number of new patients started on ART is correct. [ABSTRACT FROM AUTHOR]