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Volume 31, Number 11—November 2025

Dispatch

Two Autochthonous Cases of Anaplasmosis, Washington, USA, 2022–2023

Hannah Schnitzler1Comments to Author , Mary Chan1, Jeni Nybo, Kelley Palmer-McGee, Zachary Doobovsky, Ian Tracy, Siu-Kei Chow, Roumen B. Iordanov, Eugene H. Lee, Julianna R. Van Enk, Elizabeth A. Dykstra, Beth A. Lipton, and Hanna N. Oltean
Author affiliation: Washington State Department of Health, Olympia, Washington, USA (H. Schnitzler, M. Chan, E.A. Dykstra, B.A. Lipton, H.N. Oltean); Tacoma-Pierce County Health Department, Tacoma, Washington, USA (J. Nybo); Whatcom County Health and Community Services, Bellingham, Washington, USA (K. Palmer-McGee, Z. Doobovsky); Mason County Public Health and Human Services, Shelton, Washington, USA (I. Tracy); MultiCare Health System, Tacoma (S.-K. Chow, R.B. Iordanov, E.H. Lee, J.R. Van Enk)

Main Article

Figure

Geographic data from a study of 2 autochthonous cases of anaplasmosis, Washington, USA, 2022–2023. Blue indicates counties where health investigators have reported I. pacificus ticks (12); dark blue indicates counties of likely exposure for the 2 cases reported.

Figure. Geographic data from a study of 2 autochthonous cases of anaplasmosis, Washington, USA, 2022–2023. Blue indicates counties where health investigators have reported I. pacificus ticks (12); dark blue indicates counties of likely exposure for the 2 cases reported.

Main Article

References
  1. Chen  SM, Dumler  JS, Bakken  JS, Walker  DH. Identification of a granulocytotropic Ehrlichia species as the etiologic agent of human disease. J Clin Microbiol. 1994;32:589–95. DOIPubMedGoogle Scholar
  2. Dykstra  EA, Oltean  HN, Kangiser  D, Marsden-Haug  N, Rich  SM, Xu  G, et al. Ecology and epidemiology of tickborne pathogens, Washington, USA, 2011–2016. Emerg Infect Dis. 2020;26:648–57. DOIPubMedGoogle Scholar
  3. Bakken  JS, Krueth  J, Wilson-Nordskog  C, Tilden  RL, Asanovich  K, Dumler  JS. Clinical and laboratory characteristics of human granulocytic ehrlichiosis. JAMA. 1996;275:199–205. DOIPubMedGoogle Scholar
  4. Biggs  HM, Behravesh  CB, Bradley  KK, Dahlgren  FS, Drexler  NA, Dumler  JS, et al. Diagnosis and management of tickborne rickettsial diseases: Rocky Mountain spotted fever and other spotted fever group rickettsioses, ehrlichioses, and anaplasmosis—United States. MMWR Recomm Rep. 2016;65:1–44. DOIPubMedGoogle Scholar
  5. Bakken  JS, Krueth  J, Wilson-Nordskog  C, Tilden  RL, Asanovich  K, Dumler  JS. Clinical and laboratory characteristics of human granulocytic ehrlichiosis. JAMA. 1996;275:199–205. DOIPubMedGoogle Scholar
  6. Bakken  JS, Dumler  S. Human granulocytic anaplasmosis.[ [viii. ]. Infect Dis Clin North Am. 2008;22:433–48, viii. DOIPubMedGoogle Scholar
  7. Dahlgren  FS, Heitman  KN, Drexler  NA, Massung  RF, Behravesh  CB. Human granulocytic anaplasmosis in the United States from 2008 to 2012: a summary of national surveillance data. Am J Trop Med Hyg. 2015;93:66–72. DOIPubMedGoogle Scholar
  8. Schotthoefer  AM, Meece  JK, Ivacic  LC, Bertz  PD, Zhang  K, Weiler  T, et al. Comparison of a real-time PCR method with serology and blood smear analysis for diagnosis of human anaplasmosis: importance of infection time course for optimal test utilization. J Clin Microbiol. 2013;51:2147–53. DOIPubMedGoogle Scholar
  9. Centers for Disease Control and Prevention. Anaplasmosis—epidemiology and statistics [cited 2023 Oct 10]. https://www.cdc.gov/anaplasmosis/hcp/statistics/index.html
  10. Eisen  RJ, Eisen  L, Beard  CB. County-scale distribution of Ixodes scapularis and Ixodes pacificus (Acari: Ixodidae) in the continental United States. J Med Entomol. 2016;53:349–86. DOIPubMedGoogle Scholar
  11. Poitout  FM, Shinozaki  JK, Stockwell  PJ, Holland  CJ, Shukla  SK. Genetic variants of Anaplasma phagocytophilum infecting dogs in Western Washington State. J Clin Microbiol. 2005;43:796–801. DOIPubMedGoogle Scholar
  12. Centers for Disease Control and Prevention. CDC tick surveillance data sets. December 2023 [cited 2024 Jan 4]. https://www.cdc.gov/ticks/surveillance/TickSurveillanceData.html
  13. Washington State Department of Health. Washington tracking network—tick data dashboard. [cited 2023 Oct 10]. https://doh.wa.gov/data-and-statistical-reports/washington-tracking-network-wtn/tick-data/tick-dashboard

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1These authors contributed equally to this article.

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