1. Expanded Special Project for Elimination of NTDs, World Health Organization Regional Office for Africa, Cité du Djoué, P.O. Box 06 Brazzaville, Republic of Congo
2. Brighton and Sussex Centre for Global Health Research, Department of Global Health and Infection, Brighton and Sussex Medical School, Brighton, BN1 9PX, UK
3. University of Health and Allied Sciences, PMB 31, Ho, Volta Region, Ghana
4. Liverpool School of Tropical Medicine, Pembroke Pl, Liverpool L3 5QA, UK