1 Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Amsterdam University Medical Centers, Location Amsterdam University, Meibergdreef 9, 1205 AZ, Amsterdam, The Netherlands.
2 Masanga Medical Research Unit, Masanga, Sierra Leone.
3 Center of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Amsterdam University Medical Centers, Location Amsterdam University, Meibergdreef 9, 1205 AZ, Amsterdam, The Netherlands. m.p.grobusch@amsterdamumc.nl.
4 Masanga Medical Research Unit, Masanga, Sierra Leone. m.p.grobusch@amsterdamumc.nl.