title: Detection of Tuberculosis Infection Hotspots Using Activity Spaces Based Spatial Approach in an Urban Tokyo, from 2003 to 2011.
abstract: BACKGROUND
  Identifying ongoing tuberculosis infection sites is crucial for breaking chains of transmission in tuberculosis-prevalent urban areas. Previous studies have pointed out that detection of local accumulation of tuberculosis patients based on their residential addresses may be limited by a lack of matching between residences and tuberculosis infection sites. This study aimed to identify possible tuberculosis hotspots using TB genotype clustering statuses and a concept of "activity space", a place where patients spend most of their waking hours. We further compared the spatial distribution by different residential statuses and describe urban environmental features of the detected hotspots.
  
  
  METHODS
  Culture-positive tuberculosis patients notified to Shinjuku city from 2003 to 2011 were enrolled in this case-based cross-sectional study, and their demographic and clinical information, TB genotype clustering statuses, and activity space were collected. Spatial statistics (Global Moran's I and Getis-Ord Gi* statistics) identified significant hotspots in 152 census tracts, and urban environmental features and tuberculosis patients' characteristics in these hotspots were assessed.
  
  
  RESULTS
  Of the enrolled 643 culture-positive tuberculosis patients, 416 (64.2%) were general inhabitants, 42 (6.5%) were foreign-born people, and 184 were homeless people (28.6%). The percentage of overall genotype clustering was 43.7%. Genotype-clustered general inhabitants and homeless people formed significant hotspots around a major railway station, whereas the non-clustered general inhabitants formed no hotspots. This suggested the detected hotspots of activity spaces may reflect ongoing tuberculosis transmission sites and were characterized by smaller residential floor size and a higher proportion of non-working households.
  
  
  CONCLUSIONS
  Activity space-based spatial analysis suggested possible TB transmission sites around the major railway station and it can assist in further comprehension of TB transmission dynamics in an urban setting in Japan.
authors.affiliation: Department of Epidemiology and Clinical Research, the Research Institute of Tuberculosis, Japan Anti-tuberculosis Association (RIT/JATA), Kiyose city, Tokyo, Japan; Nagasaki University Graduate School of Biomedical Sciences, Nagasaki city, Nagasaki, Japan.
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Izumi
authors.affiliation: Department of Epidemiology and Clinical Research, the Research Institute of Tuberculosis, Japan Anti-tuberculosis Association (RIT/JATA), Kiyose city, Tokyo, Japan; Nagasaki University Graduate School of Biomedical Sciences, Nagasaki city, Nagasaki, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Ohkado
authors.affiliation: Department of Epidemiology and Clinical Research, the Research Institute of Tuberculosis, Japan Anti-tuberculosis Association (RIT/JATA), Kiyose city, Tokyo, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Uchimura
authors.affiliation: Department of Mycobacterium Reference and Research, the Research Institute of Tuberculosis, Japan Anti-tuberculosis Association (RIT/JATA), Kiyose city, Tokyo, Japan.
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Murase
authors.affiliation: Department of Epidemiology and Clinical Research, the Research Institute of Tuberculosis, Japan Anti-tuberculosis Association (RIT/JATA), Kiyose city, Tokyo, Japan.
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Tatsumi
authors.affiliation: Shinjuku City Public Health Center, Shinjuku city, Tokyo, Japan.
authors.forename: Aya
authors.initials: A
authors.lastname: Kayebeta
authors.affiliation: Shinjuku City Public Health Center, Shinjuku city, Tokyo, Japan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Watanabe
authors.affiliation: The Research Institute of Tuberculosis, Japan Anti-tuberculosis Association (RIT/JATA), Kiyose city, Tokyo, Japan.
authors.forename: Nobukatsu
authors.initials: N
authors.lastname: Ishikawa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016000:Cluster Analysis; D003430:Cross-Sectional Studies; D005260:Female; D006703:Ill-Housed Persons; D006801:Humans; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D011159:Population Surveillance; D014041:Tokyo; D014376:Tuberculosis / Q000175:diagnosis*; D014505:Urban Population; D055815:Young Adult