annual risk of tuberculous infection using different methods in communities with a high prevalence of tb and hiv in zambia and south africa年度结核性感染风险使用不同方法在社区盛行的结核病和艾滋病在赞比亚和南非.pdf

Annual Risk of Tuberculous Infection Using Different Methods in Communities with a High Prevalence of TB and HIV in Zambia and South Africa 1 2 1,2 3 1,2 Kwame Shanaube *, Charalambos Sismanidis , Helen Ayles , Nulda Beyers , Ab Schaap , Katherine- 3 3 2 Anne Lawrence , Annie Barker , Peter Godfrey-Faussett 1 ZAMBART Project, University Teaching Hospital, Lusaka, Zambia, 2 London School of Hygiene and Tropical Medicine, London, United Kingdom, 3 Desmond Tutu TB Centre, Stellenbosch University, South Africa Abstract Background: The annual risk of tuberculous infection (ARTI) is a key epidemiological indicator of the extent of transmission in a community. Several methods have been suggested to estimate the prevalence of tuberculous infection using tuberculin skin test data. This paper explores the implications of using different methods to estimate prevalence of infection and ARTI. The effect of BCG vaccination on these estimates is also investigated. Methodology/Principal Findings: Tuberculin surveys among school children in 16 communities in Zambia and 8 in South Africa (SA) were performed in 2005, as part of baseline data collection and for randomisation purposes of the ZAMSTAR study. Infection prevalence and ARTI estimates were calculated using five methods: different cut-offs with or without adjustments for sensitivity, the mirror method, and mixture analysis. A total of 49,835 children were registered for the surveys, of which 25,048 (50%) had skin tests done and 22,563 (90%) of those tested were read. Infection prevalence was higher in the combined SA than Zambian communities. The mir