1. Centre MURAZ, National Institute of Public Health, Bobo-Dioulasso 390, Burkina Faso
2. Heidelberg Institute of Global Health, Medical Faculty and University Hospital, University of Heidelberg, 69120 Heidelberg, Germany
3. UFR Exact and Applied Sciences, Nazi Boni University, Bobo-Dioulasso BP 1091, Burkina Faso
4. Department of Global Health and Development, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
5. The World Bank Group, 1818 H St. NW, Washington, DC 20433, USA