Temporal and Spatial Analysis of Vector-Tick Borne Spotted Fever in the State of São Paulo

Brazilian spotted fever (BSF) is a tick-borne acute febrile disease that can be lethal to humans, caused by the bacterium Rickettsia rickettsii. In the State of São Paulo, transmission occurs mainly through two tick species: Amblyomma sculptum and Amblyomma aureolatum. We analyzed trends in BSF incidence and mortality in relation to the spatial distribution of these vector species in the State of São Paulo from 2007 to 2017 and evaluated clinical outcomes according to hospitalization location. In A. sculptum areas, incidence and mortality showed significant increasing trends between 2007 and 2015 (p-value < 0.05). In contrast, A. aureolatum areas exhibited a significant decrease in incidence (p-value < 0.05), while mortality remained stable throughout the study period. Lethality was substantially higher in cases associated with A. aureolatum than in those linked to A. sculptum (67.1% versus 55.0%, p-value = 0.037). Most patients received care in hospitals located near the probable site of infection. Incidence and mortality patterns differed sharply between vector-specific areas, with notably higher mortality in A. aureolatum-related cases. These findings highlight the importance of incorporating vector distribution into surveillance, prevention, and clinical management strategies to better address the distinct epidemiological contexts within the State of São Paulo.