Spatial and temporal evolution of malaria in the municipality of Sifontes, Bolivar State, Venezuela. 1980-2013

Malaria is endemo-epidemic in Bolivar state with frequent epidemic outbreaks occurring due to both natural and anthropic factors. The Sifontes municipality, located in the northeastern corner of the state, has reported a considerable increase in the number of cases over the last decade; with 46.610 cases registered during 2013. This represents 71% of the number of malaria cases reported for the state and 61% for the country in this same year. Sifontes municipality is a meso-endemic focus of unstable malaria, and transmission occurs throughout the year with epidemic outbreaks tightly linked to gold mining activities. Since 1988 the increase in the number of cases reported in Venezuela has been determined by the number of cases reported in Bolivar state which, in turn, is correlated with the number of cases reported in Sifontes. A review of malaria data between 1980 and 2013 reveals the existence of two epidemiological categories: a base level and an additional level, the latter associated with gold mining; nevertheless, there was not correlation whit the rainfall for basal (R = 0,41, P = 0,78) or additional level (R = 0,41; P = 0,32). In addition, a geographic plotting of the data revealed the focal nature of malaria in the municipality, which to gather all environmental, climatic, social and epidemiological factors that have produced conditions typical of a hot spot. The spatial and temporal characteristics of malaria in the Sifontes municipality demonstrates that this is the most important malaria focus in Venezuela, and must be prioritized when designing strategies for the control of this disease.