title: Molecular epidemiology of tuberculosis in Prague: analysis by restriction fragment length polymorphism.
abstract: OBJECTIVE
  To characterize by restriction fragment length polymorphism (RFLP) patterns, the distribution of different Mycobacterium tuberculosis strains isolated consecutively from 75 tuberculosis patients who resided in Prague and had culture-confirmed cases during a 4-month period in 1995.
  
  
  METHODS
  The insertion sequence IS6110-based RFLP analysis of M. tuberculosis isolates was carried out.
  
  
  RESULTS
  There were a total of 75 patients with various forms of tuberculosis (54 males; 21 females). The sources of M. tuberculosis isolates were sputum (n = 64), pleura or lymph node drainage (n = 8), and urine (n = 3). Fifty-three of the patients (70.7%) had isolates with unique RFLP patterns, while 22 (29.3%) had isolates that belonged to seven clusters of related RFLP patterns. The seven clusters consisted of four groups of two patients, two groups of four patients, and one group of six patients. Most of the patients whose isolates fell within a clustered RFLP pattern lived in different quarters of the city and had no identifiable contacts with other patients whose isolates had the same pattern.
  
  
  CONCLUSIONS
  The finding that isolates from most patients (70.7%) had unique rather than clustered RFLP patterns suggests that endogenous reactivation rather than exogenous transmission is the major determinant of most of the tuberculosis cases in Prague. The occurrence of seven distinct clusters comprising 29.3% of the isolates suggests that approximately one third of cases developed active tuberculosis from recent exogenous transmission.
authors.affiliation: National Institute of Public Health, Prague, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Kubín
authors.forename: L W
authors.initials: LW
authors.lastname: Riley
authors.forename: M
authors.initials: M
authors.lastname: Havelková
authors.forename: N
authors.initials: N
authors.lastname: Poltoratskaia
authors.forename: A
authors.initials: A
authors.lastname: Kocová
mesh_terms: D000328:Adult; D000368:Aged; D018153:Czech Republic / Q000453:epidemiology; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000032:analysis*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000382:microbiology; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification; D012150:Polymorphism, Restriction Fragment Length; D013183:Sputum / Q000382:microbiology; D014376:Tuberculosis / Q000453:epidemiology* / Q000382:microbiology; D014556:Urine / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial