Analysis of time series of cattle rabies cases in Minas Gerais, Brazil, 2006-2013

Abstract

Vampire bats are potential transmitters of rabies in rural areas. Cattle rabies is relevant in the state of Minas Gerais due to the increasing cattle herds and geographical features of the area, which are favorable to bat populations. This study evaluated the occurrence of rabies in state cattle by analyzing the time series of monthly values, 2006-2012, describing some aspects of the areas and species affected. The study also pointed out the disease prediction for January-December 2013. We used monthly data of cases reported to the Continental Epidemiological Surveillance System (SIVCONT) of the Ministry of Agriculture, Livestock, and Supply (MAPA), January 2006-March 2013. We also collected data on municipalities and other animal species affected by rabies for a descriptive analysis of the disease. The results indicate that cattle rabies is endemic in the State, with different intensities in different regions. The variables frequency of notifications and bat shelters had a positive and regular correlation (P = 0.035; r = 0.567) between them. With respect to data series, there was a fluctuation of the number of cases (5 to 29 cases per month) over 2006 and 2013, without trend or seasonality, although there would visually appear to be a downward trend. The results also suggest that the forecasting method is suitable for predicting future cases. Bovine species had the highest number of reporting, with 1007 cases (88.88 %), followed by equine species with 112 (9.89 %). The information provided by this study may help understand disease occurrence and find the most effective measures for rabies control in endemic areas.