Detection and modelling of case clusters for urban leptospirosis.
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.
Tassinari
Wagner S
WS
National School of Public Health, Oswaldo Cruz Foundation, Brazilian Ministry of Health, Rio de Janeiro, Brazil. tassinari@ufrrj.br
Pellegrini
Debora C P
DC
Sá
Claudio B P
CB
Reis
Renato B
RB
Ko
Albert I
AI
Carvalho
Marilia S
MS
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