title: Determinants of multidrug-resistant tuberculosis clusters, California, USA, 2004-2007.
abstract: Laboratory and epidemiologic evidence suggests that pathogen-specific factors may affect multidrug-resistant (MDR) tuberculosis (TB) transmission and pathogenesis. To identify demographic and clinical characteristics of MDR TB case clustering and to estimate the effect of specific isoniazid resistance-conferring mutations and strain lineage on genotypic clustering, we conducted a population-based cohort study of all MDR TB cases reported in California from January 1, 2004, through December 31, 2007. Of 8,899 incident culture-positive cases for which drug susceptibility information was available, 141 (2%) were MDR. Of 123 (87%) strains with genotype data, 25 (20%) were aggregated in 8 clusters; 113 (92%) of all MDR TB cases and 21 (84%) of clustered MDR TB cases occurred among foreign-born patients. In multivariate analysis, the katG S315T mutation (odds ratio 11.2, 95% confidence interval 2.2-Yen; p = 0.004), but not strain lineage, was independently associated with case clustering.
authors.affiliation: University of California, San Francisco, California, USA. john.metcalfe@ucsf.edu
authors.forename: John Z
authors.initials: JZ
authors.lastname: Metcalfe
authors.forename: Elizabeth Y
authors.initials: EY
authors.lastname: Kim
authors.forename: S-Y Grace
authors.initials: SY
authors.lastname: Lin
authors.forename: Adithya
authors.initials: A
authors.lastname: Cattamanchi
authors.forename: Peter
authors.initials: P
authors.lastname: Oh
authors.forename: Jennifer
authors.initials: J
authors.lastname: Flood
authors.forename: Philip C
authors.initials: PC
authors.lastname: Hopewell
authors.forename: Midori
authors.initials: M
authors.lastname: Kato-Maeda
mesh_terms: D000293:Adolescent; D000328:Adult; D000995:Antitubercular Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D002140:California / Q000453:epidemiology; D002374:Catalase / Q000235:genetics; D016000:Cluster Analysis; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005260:Female; D005798:Genes, Bacterial; D005838:Genotype; D006801:Humans; D007538:Isoniazid / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D015999:Multivariate Analysis; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics; D017354:Point Mutation; D012293:Rifampin / Q000494:pharmacology; D018088:Tuberculosis, Multidrug-Resistant / Q000453:epidemiology* / Q000382:microbiology; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; D002374:Catalase; C480353:katG protein, Mycobacterium tuberculosis; D007538:Isoniazid; D012293:Rifampin