title: Molecular epidemiology of tuberculosis in a rural area of high prevalence in South India: implications for disease control and prevention.
abstract: Molecular and conventional epidemiologic techniques were used to study the mechanisms and risk factors for tuberculosis transmission in a rural area with high prevalence in south India. Restriction fragment length polymorphism analysis with IS6110 and direct repeat probes was performed with 378 Mycobacterium tuberculosis isolates from patients. Forty-one percent of M. tuberculosis isolates harbored a single copy of IS6110. Of 378 patients, 236 had distinct strains; 142 (38%) shared a strain with other patients, indicating recent infection. Older patients, those detected by a house-to-house community survey, and those hospitalized in a sanatorium were more likely to have had a recent infection. These findings suggest that the majority of the tuberculosis cases in south India were due to reactivation; therefore, efforts to control tuberculosis should be sustained.
authors.affiliation: Tuberculosis Research Centre, Chetput, Chennai, India.
authors.forename: Sujatha
authors.initials: S
authors.lastname: Narayanan
authors.forename: Sulochana
authors.initials: S
authors.lastname: Das
authors.forename: Renu
authors.initials: R
authors.lastname: Garg
authors.forename: Lalitha
authors.initials: L
authors.lastname: Hari
authors.forename: Vijay Bhaskara
authors.initials: VB
authors.lastname: Rao
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Frieden
authors.forename: P R
authors.initials: PR
authors.lastname: Narayanan
mesh_terms: D000328:Adult; D004251:DNA Transposable Elements / Q000235:genetics; D005260:Female; D006801:Humans; D007194:India / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000302:isolation & purification; D012150:Polymorphism, Restriction Fragment Length; D015995:Prevalence; D012307:Risk Factors; D012424:Rural Population; D014397:Tuberculosis, Pulmonary / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control*
chemical_list: D004251:DNA Transposable Elements