One Health Approach to Brazilian Spotted Fever: Capybaras, Horses, and Rural Areas as Predictors for Human Disease

(1) Background: Brazilian spotted fever (BSF) is a tick-borne disease that has occurred in several Brazilian regions, caused by <i>Rickettsia</i> spp. bacteria and mainly transmitted by <i>Amblyomma</i> ticks. Despite the high BSF lethality in several Brazilian endemic areas, predictors and associated risk factors remain to be fully established. Accordingly, the retrospective study herein aimed to assess BSF cases and associated factors in an endemic area of western São Paulo state. (2) Methods: Notified cases identified by the System for Epidemiological Surveillance of São Paulo (CVE), from January 2007 to December 2021, were gathered and analyzed by Logistic Multivariate Regression (LMR) to assess potential risk factors for BSF. (3) Results: Overall, 74/1121 (6.6%; 95% CI: 5.29-8.21) individuals were considered positive for BSF. Univariate analysis showed previous contact with capybaras (OR: 1.89; 95% CI: 1.0-3.55; <i>p</i> < 0.001) and raising horses (OR = 1.4; 95% CI: 0.66-2.67; <i>p</i> = 0.45), while LMR revealed living in rural areas (OR = 2.0; 95% CI: 1.02-3.73; <i>p</i> = 0.037) as an associated risk factor for BSF. (4) Conclusions: The results herein show that the geographically studied area still shows high occurrence of BSF, mostly for individuals living or visiting areas overlapping free-ranging capybaras.