Mapping Potential Risks for the Transmission of Spotted Fever Rickettsiosis after Environmental Changes in an Atlantic Forest Region in Brazil
Abstract
Brazilian Spotted Fever (BSF), caused by Rickettsia rickettsii, is a fatal tick-borne disease endemic to southeastern Brazil. This study evaluates the eco-epidemiology of BSF in Santa Cruz do Escalvado, Minas Gerais, a region impacted by significant environmental changes following the 2015 Fundão dam collapse. We conducted serological and molecular surveys of mammals (n = 97) and ticks (n = 1,123) to assess pathogen circulation. Serological analysis revealed a 27.5% prevalence of anti-R. rickettsii antibodies in dogs, a marked increase compared to historical data (2% in 2009) from the same region. Conversely, wildlife sentinels (opossums, capybaras) showed minimal seroreactivity. Molecular screening of ticks identified Rickettsia bellii and a Rickettsia tamurae/Rickettsia monacensis-like genotype in Amblyomma dubitatum and Amblyomma sculptum, respectively; however, R. rickettsii DNA was not detected in any vector. These findings suggest a dichotomy in transmission cycles: a peri-urban cycle with high canine exposure driven by A. sculptum, and a riparian cycle involving A. dubitatum harboring non-R. rickettsii agents. The discrepancy between high canine seropositivity and the absence of R. rickettsii in vectors suggests that cross-reactivity with emerging SFG rickettsiae may be confounding surveillance signals, highlighting the need for specific molecular diagnostics in risk assessment.
Read the paper
Related studies
- eggNOG 5.0: a hierarchical, functionally and phylogenetically annotated orthology resource based on 5090 organisms and 2502 viruses
- Online Survival Analysis Software to Assess the Prognostic Value of Biomarkers Using Transcriptomic Data in Non-Small-Cell Lung Cancer
- OptiType: precision HLA typing from next-generation sequencing data
- Nicotinic Cholinergic System and COVID-19: In Silico Identification of an Interaction between SARS-CoV-2 and Nicotinic Receptors with Potential Therapeutic Targeting Implications
- Saccharomyces cerevisiae cells have three Omega class glutathione S-transferases acting as 1-Cys thiol transferases
- Hemolysis at low blood flow rates: in-vitro and in-silico evaluation of a centrifugal blood pump
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.