title: Transmission of tuberculosis in an endemic urban setting in Brazil.
abstract: METHODS
  Two out-patient facilities in São Paulo, Brazil.
  
  
  OBJECTIVE
  To study the transmission pattern of tuberculosis (TB) among human immunodeficiency virus (HIV) infected and uninfected persons in a setting endemic for TB.
  
  
  METHODS
  A prospective study comparing HIV-seropositive and -seronegative TB patients identified consecutively between 1 March 1995 and 1 April 1997. The patients were stratified according to their Mycobacterium tuberculosis isolate IS6110 RFLP patterns. Risk factors were sought for infection with an RFLP cluster pattern strain, inferred to represent recent transmission.
  
  
  RESULTS
  Fifty-eight (38%) of 151 HIV-seropositive patients and 36 (25%) of 142 HIV-seronegative patients were infected with M. tuberculosis isolates that belonged to cluster patterns (OR 1.84, 95% CI 1.08-3.13). Multidrug-resistant (MDR) strains were isolated from 19 patients, all of whom were HIV seropositive; 12 (63%) of these, and 46 (35%) of 132 drug-susceptible isolates had cluster patterns (OR 3.20, 95% CI 1.08-9.77).
  
  
  CONCLUSIONS
  In a TB-endemic urban setting in Brazil, the proportion of cases resulting from recent transmission appears to be greater among HIV-seropositive than among HIV-seronegative patients. A large proportion of MDR-TB (63%) cases was caused by strains that had cluster RFLP patterns, suggesting recent transmission of already resistant organisms. This type of knowledge regarding TB transmission may help to improve locally appropriate TB control programs.
authors.affiliation: Instituto Adolfo Lutz, Divisão de Biologia Médica, São Paulo, Brazil. lucilafe@usp.br
authors.forename: L
authors.initials: L
authors.lastname: Ferrazoli
authors.forename: M
authors.initials: M
authors.lastname: Palaci
authors.forename: L R
authors.initials: LR
authors.lastname: Marques
authors.forename: L F
authors.initials: LF
authors.lastname: Jamal
authors.forename: J B
authors.initials: JB
authors.lastname: Afiune
authors.forename: E
authors.initials: E
authors.lastname: Chimara
authors.forename: M C
authors.initials: MC
authors.lastname: Martins
authors.forename: M A
authors.initials: MA
authors.lastname: Silva Telles
authors.forename: C A
authors.initials: CA
authors.lastname: Oliveira
authors.forename: M C
authors.initials: MC
authors.lastname: Palhares
authors.forename: D T
authors.initials: DT
authors.lastname: Spada
authors.forename: L W
authors.initials: LW
authors.lastname: Riley
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D000293:Adolescent; D000328:Adult; D000368:Aged; D001938:Brazil / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D012150:Polymorphism, Restriction Fragment Length; D011446:Prospective Studies; D012307:Risk Factors; D018088:Tuberculosis, Multidrug-Resistant / Q000453:epidemiology* / Q000635:transmission*; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology* / Q000635:transmission*; D014504:Urban Health