title: Clinical profile and predictors of fatal Rocky Mountain spotted fever in children from Sonora, Mexico.
abstract: BACKGROUND
  Rocky Mountain spotted fever (RMSF) is an increasingly important cause of preventable mortality in children in Sonora, Mexico. Although early treatment with tetracycline has shown to prevent fatal outcome, the disease remains a life-threatening condition, particularly for children. This study describes the clinical factors associated with pediatric mortality due to RMSF in Sonora, in order to guide healthcare practices.
  
  
  METHODS
  This is a retrospective analysis of 104 children consecutively hospitalized at the major pediatric hospital of Sonora, diagnosed with RMSF between January 2004 and December 2013. Descriptive statistics and multiple logistic regression were used to identify risk factors for fatal outcome.
  
  
  RESULTS
  The case fatality ratio in this cohort was 20.2%. Children were hospitalized after a median of 6 days from onset of symptoms including fever (100%), rash involving palms and soles (88.5%) and headache (79.8%); 90.4% of fatal cases had low platelet counts (<50,000/μL) and 33.3% showed serum creatinine concentrations above the normal value. Acute kidney injury increased mortality, odds ratio (OR(adj)) = 4.84, 95% confidence interval (CI): 1.2-16.2, as well as delay in treatment (≥ 5th day from onset) with doxycycline, OR(adj) = 2.62, 95% CI: 1.24-5.52 and hemorrhage, OR(adj) = 6.11, 95% CI: 1.89-19.69.
  
  
  CONCLUSIONS
  RMSF is a public health problem in Sonora. Clinically, fatal cases differ from non-fatal cases in renal function and hemorrhagic manifestations, although these findings may occur too late for a timely intervention. First-line providers must be educated to harbor a timely suspicion of RMSF, and should provide empiric treatment with doxycycline when febrile patients first present for care.
authors.affiliation: From the *Department of Medicine and Health Sciences, Universidad de Sonora, Hermosillo, Mexico; †School of Medicine and Health Sciences, Instituto Tecnológico y de Estudios Superiores de Monterrey, Monterrey, Mexico; and ‡Division of Comparative Medicine, Office of Research Infrastructure Programs, National Institutes of Health, Bethesda, Maryland.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Alvarez-Hernandez
authors.forename: Coral
authors.initials: C
authors.lastname: Murillo-Benitez
authors.forename: Maria del Carmen
authors.initials: Mdel C
authors.lastname: Candia-Plata
authors.forename: Manuel
authors.initials: M
authors.lastname: Moro
mesh_terms: D000293:Adolescent; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D004318:Doxycycline / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008800:Mexico; D009026:Mortality; D011379:Prognosis; D051437:Renal Insufficiency / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology*; D012189:Retrospective Studies; D012307:Risk Factors; D012373:Rocky Mountain Spotted Fever / Q000150:complications / Q000188:drug therapy / Q000401:mortality* / Q000473:pathology*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D004318:Doxycycline