Temporal analysis of the relationship between leptospirosis and the occurrence of flooding due to rainfall in the city of Rio de Janeiro, Brazil, 2007-2012

The scope of this study is to examine the effect of the average monthly rainfall on the risk of contracting leptospirosis in the city of Rio de Janeiro between 2007 and 2012. It involves an analytical ecological study conducted in the city of Rio de Janeiro in the 2007-2012 period. The variable for the outcome was the number of leptospirosis cases per month, and the independent variable was the average monthly rainfall recorded by the 32 monitoring stations per year. It was decided to model the relationship between cases of leptospirosis and the effects of rain by building a generalized linear model using negative binomial distribution. The rainfall-lag per month was found to be a strong explanatory factor for the number of cases of leptospirosis. This study indicates that the average monthly rainfall may constitute an indicator that enables the execution of actions in order to prepare the health sector for the probable increase in cases of this disease. Therefore, it is necessary to implement the interaction between the work of epidemiological surveillance, especially by situation rooms in periods of crisis, and the risk management teams of environmental surveillance, to increase the response capacity to natural disasters in the municipality of Rio de Janeiro.