1. Eduardo Mondlane University, Faculty of Medicine, CIMed, P.O. Box 257, Maputo, Mozambique ; ;
2. Manhiça Health Research Centre (CISM), P.O. Box 08036, Manhiça, Mozambique
3. Barcelona Centre for International Heath Research (CRESIB), Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Universitat de Barcelona, P.O. Box 08036, Barcelona, Spain