1. From the Projecto de Saúde de Bandim, Bissau, Guinea-Bissau; the Department of Epidemiology Research, Danish Epidemiology Science Centre, Statens Serum Institut, Copenhagen; the Center for International Health, University of Bergen, Norway; All India Institute of Medical Sciences, New Delhi; and Laboratorio Nacional de Saúde Publica, Bissau, Guinea-Bissau.