1. Institute of Infectious and Tropical Diseases, WHO Collaborating Centre for Tuberculosis Prevention, University of Brescia, Brescia, Italy;
2. London School of Hygiene & Tropical Medicine, London, UK;
3. Independent Consultant, Lucca, Italy;
4. Regional Office for Europe, WHO, Copenhagen, Denmark;
5. United States Agency for International Development, Washington DC, USA;
6. Global Tuberculosis Programme, WHO, Geneva, Switzerland