1. Hôpital Evangélique de Vanga, Vanga Mission , B.P. 4728 Kinshasa 2, Democratic Republic of the Congo
2. Department of Family Medicine and Primary Care, Protestant University of Congo , B.P. 4745, Kinshasa 2, Democratic Republic of the Congo
3. Kumasi Centre for Collaborative Research in Tropical Medicine, Kwame Nkrumah University of Science and Technology , Kumasi , Ghana
4. School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology , Kumasi , Ghana
5. Komfo Anokye Teaching Hospital , Kumasi , Ghana
6. Universite de Kinshasa, Centre Neuro-psycho-pathologie , Kinshasa, Democratic Republic of the Congo
7. Swiss Tropical and Public Health Institute , 4002 Basel , Switzerland
8. University of Basel , 4001 Basel , Switzerland
9. Department of Tropical Disease Biology, Liverpool School of Tropical Medicine , Liverpool , L3 5QA, UK