1 Academic Medical Center, Department of Infectious Diseases, University of Amsterdam, P.O. Box 227001100DE, Amsterdam, the Netherlands.
2 Public Health Service of Amsterdam, Department of Infectious Diseases, Research and Prevention, P.O. Box 22001000CE, Amsterdam, the Netherlands.
3 Academic Medical Center, Department of Infectious Diseases, University of Amsterdam, P.O. Box 227001100DE, Amsterdam, the Netherlands. g.j.debree@amc.nl.
4 Amsterdam Institute for Global Health and Development, University of Amsterdam, P.O. Box 227001100DE, Amsterdam, the Netherlands. g.j.debree@amc.nl.
5 Amsterdam Institute for Global Health and Development, University of Amsterdam, P.O. Box 227001100DE, Amsterdam, the Netherlands.
6 Kenya Medical Research Institute, Centre for Geographic Medicine Research -Coast, P.O. Box 230, Kilifi, Kenya.
7 Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7BN, UK.