title: The spatial distribution of leprosy in four villages in Bangladesh: an observational study.
abstract: BACKGROUND
  There is a higher case-detection rate for leprosy among spatially proximate contacts such as household members and neighbors. Spatial information regarding the clustering of leprosy can be used to improve intervention strategies. Identifying high-risk areas within villages around known cases can be helpful in finding new cases.
  
  
  METHODS
  Using geographic information systems, we created digital maps of four villages in a highly endemic area in northwest Bangladesh. The villages were surveyed three times over four years. The spatial pattern of the compounds--a small group of houses--was analyzed, and we looked for spatial clusters of leprosy cases.
  
  
  RESULTS
  The four villages had a total population of 4,123. There were 14 previously treated patients and we identified 19 new leprosy patients during the observation period. However, we found no spatial clusters with a probability significantly different from the null hypothesis of random occurrence.
  
  
  CONCLUSIONS
  Spatial analysis at the microlevel of villages in highly endemic areas does not appear to be useful for identifying clusters of patients. The search for clustering should be extended to a higher aggregation level, such as the subdistrict or regional level. Additionally, in highly endemic areas, it appears to be more effective to target complete villages for contact tracing, rather than narrowly defined contact groups such as households.
authors.affiliation: Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands. egil.fischer@wur.nl
authors.forename: Eaj
authors.initials: E
authors.lastname: Fischer
authors.forename: D
authors.initials: D
authors.lastname: Pahan
authors.forename: Sk
authors.initials: S
authors.lastname: Chowdhury
authors.forename: L
authors.initials: L
authors.lastname: Oskam
authors.forename: Jh
authors.initials: J
authors.lastname: Richardus
mesh_terms: D000328:Adult; D001459:Bangladesh / Q000453:epidemiology; D016000:Cluster Analysis; D016358:Contact Tracing; D003710:Demography; D019353:Endemic Diseases; D005260:Female; D040362:Geographic Information Systems; D006801:Humans; D015994:Incidence; D007918:Leprosy / Q000453:epidemiology* / Q000635:transmission; D008297:Male; D009166:Mycobacterium leprae / Q000302:isolation & purification; D011159:Population Surveillance; D015995:Prevalence; D012307:Risk Factors