Trends in clinical diagnoses of Rocky Mountain spotted fever among American Indians, 2001-2008.
American Indians are at greater risk for Rocky Mountain spotted fever (RMSF) than the general U.S. population. The epidemiology of RMSF among American Indians was examined by using Indian Health Service inpatient and outpatient records with an RMSF International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis. For 2001-2008, 958 American Indian patients with clinical diagnoses of RMSF were reported. The average annual RMSF incidence was 94.6 per 1,000,000 persons, with a significant increasing incidence trend from 24.2 in 2001 to 139.4 in 2008 (P = 0.006). Most (89%) RMSF hospital visits occurred in the Southern Plains and Southwest regions, where the average annual incidence rates were 277.2 and 49.4, respectively. Only the Southwest region had a significant increasing incidence trend (P = 0.005), likely linked to the emergence of brown dog ticks as an RMSF vector in eastern Arizona. It is important to continue monitoring RMSF infection to inform public health interventions that target RMSF reduction in high-risk populations.
Division of High-Consequence Pathogens and Pathology, and Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA. afolkema@cdc.gov
Arianne M
AM
Folkema
Robert C
RC
Holman
Jennifer H
JH
McQuiston
James E
JE
Cheek
D000293:Adolescent; D000328:Adult; D000368:Aged; D000818:Animals; D001130:Arizona / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004285:Dogs; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007198:Indians, North American; D007223:Infant; D007231:Infant, Newborn; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D009819:Office Visits / Q000706:statistics & numerical data; D048508:Rhipicephalus sanguineus; D012373:Rocky Mountain Spotted Fever / Q000175:diagnosis* / Q000453:epidemiology* / Q000635:transmission; D014481:United States / Q000453:epidemiology; D016549:United States Indian Health Service / Q000639:trends*; D055815:Young Adult