OBJECTIVE: To determine tuberculosis transmission dynamics in San Francisco and its association with country of birth and ethnicity. METHODS: Restriction fragment length polymorphism (RFLP) typing was performed on Mycobacterium tuberculosis isolates from culture-positive pulmonary tuberculosis patients in San Francisco (1991 through 1996), using IS6110 as a probe. Patients were assigned to clusters based on mycobacterial isolates with identical DNA fingerprints. Clusters were assumed to have arisen from recent transmission. A transmission index was defined as the average number of culture-positive pulmonary tuberculosis cases generated by a single source case and calculated for subgroups. RESULTS: The transmission index was higher in US-born (0.59) than in foreign-born groups (0.21), and was highest in blacks, in particular those aged under 35 years. The increased transmission index among blacks was not explained by smear-positivity, human immunodeficiency virus infection, or increased susceptibility to disease progression. CONCLUSION: US-born tuberculosis cases generated more secondary cases than immigrants. Young blacks appear to be a high-risk group for tuberculosis transmission. These results suggest the need to develop interventions targeted towards this risk group.
OBJECTIVE: To determine tuberculosis transmission dynamics in San Francisco and its association with country of birth and ethnicity. METHODS: Restriction fragment length polymorphism (RFLP) typing was performed on Mycobacterium tuberculosis isolates from culture-positive pulmonary tuberculosispatients in San Francisco (1991 through 1996), using IS6110 as a probe. Patients were assigned to clusters based on mycobacterial isolates with identical DNA fingerprints. Clusters were assumed to have arisen from recent transmission. A transmission index was defined as the average number of culture-positive pulmonary tuberculosis cases generated by a single source case and calculated for subgroups. RESULTS: The transmission index was higher in US-born (0.59) than in foreign-born groups (0.21), and was highest in blacks, in particular those aged under 35 years. The increased transmission index among blacks was not explained by smear-positivity, human immunodeficiency virus infection, or increased susceptibility to disease progression. CONCLUSION: US-born tuberculosis cases generated more secondary cases than immigrants. Young blacks appear to be a high-risk group for tuberculosis transmission. These results suggest the need to develop interventions targeted towards this risk group.
Authors: Scott A Weisenberg; Andrea L Gibson; Richard C Huard; Natalia Kurepina; Heejung Bang; Luiz C O Lazzarini; Yalin Chiu; Jiehui Li; Shama Ahuja; Jeff Driscoll; Barry N Kreiswirth; John L Ho Journal: Infect Genet Evol Date: 2011-08-02 Impact factor: 3.342
Authors: Benjamin P Linas; Angela Y Wong; Kenneth A Freedberg; C Robert Horsburgh Journal: Am J Respir Crit Care Med Date: 2011-09-01 Impact factor: 21.405
Authors: M A Pagaoa; R A Royce; M P Chen; J E Golub; A L Davidow; Y Hirsch-Moverman; S M Marks; L D Teeter; P M Thickstun; D J Katz Journal: Int J Tuberc Lung Dis Date: 2015-12 Impact factor: 2.373
Authors: Barbara A Ellis; Jack T Crawford; Christopher R Braden; Scott J N McNabb; Marisa Moore; Steve Kammerer Journal: Emerg Infect Dis Date: 2002-11 Impact factor: 6.883
Authors: Jeffrey R Driscoll; Pablo J Bifani; Barun Mathema; Michael A McGarry; Genét M Zickas; Barry N Kreiswirth; Harry W Taber Journal: Emerg Infect Dis Date: 2002-11 Impact factor: 6.883