title: Identifying locations of recent TB transmission in rural Uganda: a multidisciplinary approach.
abstract: OBJECTIVE
  Targeting high Tuberculosis (TB) transmission sites may offer a novel approach to TB prevention in sub-Saharan Africa. We sought to characterise TB transmission sites in a rural Ugandan township.
  
  
  METHODS
  We recruited adults starting TB treatment in Tororo, Uganda, over 1 year. Fifty four TB cases provided names of frequent contacts, sites of residence, health care, work and social activities, and two sputum samples. Mycobacterium tuberculosis (MTB) culture-positive specimens underwent spoligotyping to identify strains with shared genotypes. We visualised TB case social networks, and obtained, mapped and geo-coded global positioning system measures for every location that cases reported frequenting 1 month before treatment. Locations of spatial overlap among genotype-clustered cases were considered potential transmission sites.
  
  
  RESULTS
  Six distinct genotypic clusters were identified involving 21 of 33 (64%) MTB culture-positive, genotyped cases; none shared a home. Although 18 of 54 (33%) TB cases shared social network ties, none of the genotype-clustered cases shared social ties. Using spatial analysis, we identified potential sites of within-cluster TB transmission for five of six genotypic clusters. All sites but one were healthcare and social venues, including sites of drinking, worship and marketplaces. Cases reported spending the largest proportion of pre-treatment person-time (22.4%) at drinking venues.
  
  
  CONCLUSIONS
  Using molecular epidemiology, geospatial and social network data from adult TB cases identified at clinics, we quantified person-time spent at high-risk locations across a rural Ugandan community and determined the most likely sites of recent TB transmission to be healthcare and social venues. These sites may not have been identified using contact investigation alone.
authors.affiliation: HIV/AIDS Division, Department of Medicine, San Francisco General Hospital, University of California, San Francisco, CA, USA; Makerere University-University of California, San Francisco (MU-UCSF) Research Collaboration, Kampala, Uganda.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Chamie
authors.forename: Bonnie
authors.initials: B
authors.lastname: Wandera
authors.forename: Carina
authors.initials: C
authors.lastname: Marquez
authors.forename: Midori
authors.initials: M
authors.lastname: Kato-Maeda
authors.forename: Moses R
authors.initials: MR
authors.lastname: Kamya
authors.forename: Diane V
authors.initials: DV
authors.lastname: Havlir
authors.forename: Edwin D
authors.initials: ED
authors.lastname: Charlebois
mesh_terms: D000328:Adult; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology; D009169:Mycobacterium tuberculosis / Q000235:genetics; D012111:Residence Characteristics; D012424:Rural Population; D014376:Tuberculosis / Q000453:epidemiology / Q000635:transmission*; D014454:Uganda / Q000453:epidemiology
keywords: dinámicas de transmisión; dynamiques de la transmission; epidemiología molecular; molecular epidemiology; rural Africa; transmission dynamics; tuberculose; tuberculosis; zone rurale d'Afrique; África rural; épidémiologie moléculaire