title: Detection and modelling of case clusters for urban leptospirosis.
abstract: OBJECTIVE
  To analyse the epidemiological profile of 488 cases of leptospirosis in Rio de Janeiro, Brazil between 1997 and 2002, using a variety of methods of spatial epidemiology, to establish alert guidelines in general hospitals, which might be a tool to improve diagnosis and treatment of leptospirosis to reduce lethality rates.
  
  
  METHODS
  Scan statistics identified six space-time clusters, which comprised a range of 2 to 28 cases per cluster. Generalized linear mixed models were used to evaluate risk factors for a cluster case which incorporated individual characteristics and spatial information on environmental and climactic factors in a single model frame.
  
  
  RESULTS
  Cluster case events were associated with heavy rainfall (OR 3.71; 95% CI 1.83-7.51). The model did not identify socioeconomic or environmental covariates that significantly influence the risk of developing a cluster rather than non-cluster case.
  
  
  CONCLUSIONS
  Clustering of leptospirosis in this urban setting appears to be due to transmission during heavy rainfall.
authors.affiliation: National School of Public Health, Oswaldo Cruz Foundation, Brazilian Ministry of Health, Rio de Janeiro, Brazil. tassinari@ufrrj.br
authors.forename: Wagner S
authors.initials: WS
authors.lastname: Tassinari
authors.forename: Debora C P
authors.initials: DC
authors.lastname: Pellegrini
authors.forename: Claudio B P
authors.initials: CB
authors.lastname: Sá
authors.forename: Renato B
authors.initials: RB
authors.lastname: Reis
authors.forename: Albert I
authors.initials: AI
authors.lastname: Ko
authors.forename: Marilia S
authors.initials: MS
authors.lastname: Carvalho
mesh_terms: D001938:Brazil / Q000453:epidemiology; D004196:Disease Outbreaks; D004777:Environment; D006801:Humans; D015994:Incidence; D007922:Leptospirosis / Q000453:epidemiology* / Q000635:transmission; D011891:Rain; D012307:Risk Factors; D013029:Space-Time Clustering; D014504:Urban Health