University of Oxford, Worldwide Radiology, Institut Pasteur de Madagascar - Epidemiology and Clinical Research Unit, Institut Pasteur de Madagascar, University of Oxford, University of Oxford - Pandemic Sciences Institute, Worldwide Radiology, Institut Pasteur de Madagascar, Institut Pasteur de Madagascar, Institut Pasteur de Madagascar, Institut Pasteur de Madagascar, University of Antananarivo, University of Oxford, University of Oxford, Institut Pasteur de Madagascar, University of Antananarivo and University of Oxford - Nuffield Department of Medicine