6Cook S, Maw KL, Munsiff SS, et al. Prevalence of tuberculin skin test positivity and conversions among healthcare workers in New York City during 1994 to 2001. Infect Control Hosp Epidemiol, 2003, 24 (11): 807-813.
7Schablon A, Harling M, Diel R, et al. Risk of latent TB infection in individuals employed in the healthcare sector in Germany: a multicen- tre prevalence study. BMC Infect Dis, 2010, 30(10) :107.
8Keskiner R, Ergonul O, Demiroglu Z, et al. Risk of tuberculous in- fection among heahhcare workers in a tertiary-care hospital in Ankara, Turkey. Infect Control Hosp Epideminl, 2004, 25(12): 1067-1071.
9Escombe AR, Huaroto L, Ticona E, et al. Tuberculosis transmission risk and infection control in a hospital emergency department in Lima, Peru. Int J Tuberc Lumg Dis, 2010, 14(9): 1120-1126.