Affiliation: | 1. London School of Hygiene and Tropical Medicine, Infectious Diseases Epidemiology Unit, Keppel Street, London WC1E 7HT, UK;2. Ministry of Health, Adult Infectious Diseases Care Centre, Princess Marina Hospital, Gaborone, Botswana;3. Primary Health Care, Independence Surgery, Gaborone, Botswana;4. London School of Hygiene and Tropical Medicine, Health Policy Unit, London, UK |