1. Instituto de Saude Coletiva Universidade Federal da Bahia Salvador Bahia Brazil
2. Colegio de Ciencias de la Salud Universidad San Francisco de Quito Quito Ecuador
3. Asthma and Allergic Diseases Center University of Virginia Charlottesville VA USA
4. Department of Epidemiology London School of Hygiene and Tropical Medicine London UK
5. Molecular and Biochemical Parasitology Liverpool School of Tropical Medicine Liverpool UK