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Volume 31, Number 11—November 2025

Dispatch

Neoehrlichia mikurensis in Ticks and Tick-Bitten Persons, Sweden and Finland, 2008–2009

Emilia Hero, Malin Lager, Pia Forsberg, Per-Eric Lindgren, Anna J. Henningsson, and Peter WilhelmssonComments to Author 
Author affiliation: Linköping University, Linköping, Sweden (E. Hero, P. Forsberg, P.-E. Lindgren, A.J. Henningsson, P. Wilhelmsson); Region Jönköping County, Jönköping, Sweden (M. Lager, P.-E. Lindgren, A.J. Henningsson, P. Wilhelmsson)

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Figure

Schematic overview of the Tick-Borne Diseases STING study during 2008–2009 in Sweden and Finland (6), in which tick-bitten persons >18 years of age gave written informed consent to participate, submitted removed tick(s), provided a blood sample, and completed a questionnaire. At a follow-up visit 3 months later, they provided a second blood sample and completed a second questionnaire. Any additional tick(s) found attached during the study period were also submitted and available medical records were reviewed.

Figure. Schematic overview of the Tick-Borne Diseases STING study during 2008–2009 in Sweden and Finland (6), in which tick-bitten persons >18 years of age gave written informed consent to participate, submitted removed tick(s), provided a blood sample, and completed a questionnaire. At a follow-up visit 3 months later, they provided a second blood sample and completed a second questionnaire. Any additional tick(s) found attached during the study period were also submitted and available medical records were reviewed.

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References
  1. Welinder-Olsson  C, Kjellin  E, Vaht  K, Jacobsson  S, Wennerås  C. First case of human “Candidatus Neoehrlichia mikurensis” infection in a febrile patient with chronic lymphocytic leukemia. J Clin Microbiol. 2010;48:19569. DOIPubMedGoogle Scholar
  2. Portillo  A, Santibáñez  P, Palomar  AM, Santibáñez  S, Oteo  JA. Candidatus Neoehrlichia mikurensis’ in Europe. New Microbes New Infect. 2018;22:306. DOIPubMedGoogle Scholar
  3. Höper  L, Skoog  E, Stenson  M, Grankvist  A, Wass  L, Olsen  B, et al. Vasculitis due to Candidatus Neoehrlichia mikurensis: a cohort study of 40 Swedish patients. Clin Infect Dis. 2021;73:e23728. DOIPubMedGoogle Scholar
  4. Markowicz  M, Schötta  AM, Höss  D, Kundi  M, Schray  C, Stockinger  H, et al. Infections with tickborne pathogens after tick bite, Austria, 2015–2018. Emerg Infect Dis. 2021;27:104856. DOIPubMedGoogle Scholar
  5. Jahfari  S, Hofhuis  A, Fonville  M, van der Giessen  J, van Pelt  W, Sprong  H. Molecular detection of tick-borne pathogens in humans with tick bites and erythema migrans, in the Netherlands. PLoS Negl Trop Dis. 2016;10:e0005042. DOIPubMedGoogle Scholar
  6. Wilhelmsson  P, Fryland  L, Lindblom  P, Sjöwall  J, Ahlm  C, Berglund  J, et al. A prospective study on the incidence of Borrelia burgdorferi sensu lato infection after a tick bite in Sweden and on the Åland Islands, Finland (2008-2009). Ticks Tick Borne Dis. 2016;7:719. DOIPubMedGoogle Scholar
  7. Wilhelmsson  P, Lindblom  P, Fryland  L, Ernerudh  J, Forsberg  P, Lindgren  PE. Prevalence, diversity, and load of Borrelia species in ticks that have fed on humans in regions of Sweden and Åland Islands, Finland with different Lyme borreliosis incidences. PLoS One. 2013;8:e81433. DOIPubMedGoogle Scholar
  8. Wilhelmsson  P, Lindblom  P, Fryland  L, Nyman  D, Jaenson  TG, Forsberg  P, et al. Ixodes ricinus ticks removed from humans in Northern Europe: seasonal pattern of infestation, attachment sites and duration of feeding. Parasit Vectors. 2013;6:362. DOIPubMedGoogle Scholar
  9. Gray  J, Stanek  G, Kundi  M, Kocianova  E. Dimensions of engorging Ixodes ricinus as a measure of feeding duration. Int J Med Microbiol. 2005;295:56772. DOIPubMedGoogle Scholar
  10. Labbé Sandelin  L, Tolf  C, Larsson  S, Wilhelmsson  P, Salaneck  E, Jaenson  TG, et al. Candidatus Neoehrlichia mikurensis in ticks from migrating birds in Sweden. PLoS One. 2015;10:e0133250. DOIPubMedGoogle Scholar
  11. Grankvist  A, Sandelin  LL, Andersson  J, Fryland  L, Wilhelmsson  P, Lindgren  PE, et al. Infections with Candidatus Neoehrlichia mikurensis and cytokine responses in 2 persons bitten by ticks, Sweden. Emerg Infect Dis. 2015;21:14625. DOIPubMedGoogle Scholar
  12. Andersson  M, Bartkova  S, Lindestad  O, Råberg  L. Co-infection with ‘Candidatus Neoehrlichia Mikurensis’ and Borrelia afzelii in Ixodes ricinus ticks in southern Sweden. Vector Borne Zoonotic Dis. 2013;13:43842. DOIPubMedGoogle Scholar
  13. Wass  L, Grankvist  A, Bell-Sakyi  L, Bergström  M, Ulfhammer  E, Lingblom  C, et al. Cultivation of the causative agent of human neoehrlichiosis from clinical isolates identifies vascular endothelium as a target of infection. Emerg Microbes Infect. 2019;8:41325. DOIPubMedGoogle Scholar
  14. Grankvist  A, Jaén-Luchoro  D, Wass  L, Sikora  P, Wennerås  C. Comparative genomics of clinical isolates of the emerging tick-borne pathogen Neoehrlichia mikurensis. Microorganisms. 2021;9:1488. DOIPubMedGoogle Scholar
  15. Jahfari  S, Fonville  M, Hengeveld  P, Reusken  C, Scholte  EJ, Takken  W, et al. Prevalence of Neoehrlichia mikurensis in ticks and rodents from North-west Europe. Parasit Vectors. 2012;5:74. DOIPubMedGoogle Scholar

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