1. From the Cemubac Medical Team, Public Health School, Free University of Brussels; Communauté Evangélique de l'Ubangi-Mongala, Karawa, Zaire; Hôpital de Nyankunde and University of Kisangani, Zaire; Ecole de Santé Publique, Université de Kinshasa UNIKIN, Zaire: Division of Biochemistry, United Medical and Dental Schools, University of London; and Institut de Recherche Interdisciplinaire en Biologi