Clinical and Geographical Analysis of Rocky Mountain Spotted Fever in Children: Implications for Outbreak Response

Abstract Background Rocky Mountain Spotted Fever (RMSF) is a bacterial disease transmitted by infected ticks, with Northern Mexico experiencing a concerning rise in cases, particularly among children. Elevated inflammatory markers, such as C-reactive protein (CRP) and procalcitonin (PCT), indicate an acute inflammatory response but are not specific to RMSF. Monitoring these markers can guide management. A key challenge during the outbreak was delayed diagnosis, highlighting the importance of laboratory test results, clinical data, and georeferencing in outbreak response. Methods Clinical geographical data of patients under 16 with confirmed RMSF diagnosed at the Pediatric Reference Hospital (HRMI) in NL, Mexico, from August 2022 to September 2023, were analyzed. HRMI admitted most affected children during the outbreak. A descriptive analysis of clinical and laboratory tests was conducted, and QGIS® was employed to map case distribution, incorporating regional marginalization indices from official sources. Results Total of 23 subjects included, with a mean age 8 years (± 3.3). Most (82%) had positive contact with ticks. Time from symptom onset was 4.9 ± 1.8 days. There was high mortality (65.2%) despite in-hospital treatment. Laboratory test results showed CBC: lymphopenia (8,000/mm3) in 47%, and thrombocytopenia (0.5 mg/dL) in 100%, hyperferritinemia (>1,000 ng/dL) in 74%, D-dimer elevation (>2,000 mg/dL) in 95%, and hypoalbuminemia (