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. 2020 Mar;67(2):130-137.
doi: 10.1111/zph.12662. Epub 2019 Nov 9.

Distribution of Neoehrlichia mikurensis in Ixodes ricinus ticks along the coast of Norway: The western seaboard is a low-prevalence region

Benedikte N Pedersen  1 , Andrew Jenkins  1 , Katrine M Paulsen  2   3 , Yohannes B Okbaldet  3 , Kristin S Edgar  4 , Alaka Lamsal  1   3 , Arnulf Soleng  4 , Åshild K Andreassen  3
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Distribution of Neoehrlichia mikurensis in Ixodes ricinus ticks along the coast of Norway: The western seaboard is a low-prevalence region

Benedikte N Pedersen et al. Zoonoses Public Health. 2020 Mar.

Abstract

Neoehrlichia mikurensis is a tick-borne pathogen widespread among ticks and rodents in Europe and Asia. A previous study on Ixodes ricinus ticks in Norway suggested that N. mikurensis was scarce or absent on the south-west coast of Norway, but abundant elsewhere. The aim of this study was to further investigate the prevalence and distribution of N. mikurensis along the western seaboard of Norway in comparison with more eastern and northern areas. The second aim of the study was to examine seasonal variation of the bacterium in one specific location in the south-eastern part of Norway. Questing I. ricinus were collected from 13 locations along the coast of Norway, from Brønnøysund in Nordland County to Spjaerøy in Østfold County. In total, 11,113 nymphs in 1,113 pools and 718 individual adult ticks were analysed for N. mikurensis by real-time PCR. The mean prevalence of N. mikurensis in adult ticks was 7.9% while the estimated pooled prevalence in nymphs was 3.5%. The prevalence ranged from 0% to 25.5%, with the highest prevalence in the southernmost and the northernmost locations. The pathogen was absent, or present only at low prevalence (<5%), at eight locations, all located in the west, from 58.9°N to 64.9°N. The prevalence of N. mikurensis was significantly different between counties (p < .0001). No significant seasonal variation of N. mikurensis prevalence was observed in the period May to October 2015. Our results confirm earlier findings of a low prevalence of N. mikurensis in the western seaboard of Norway.

Keywords: Ixodes ricinus; Neoehrlichia mikurensis; pooled samples; real-time PCR; sequencing.

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References

REFERENCES

    1. Andersson, M., Bartkova, S., Lindestad, O., & Raberg, L. (2013). Co-infection with 'Candidatus Neoehrlichia mikurensis' and Borrelia afzelii in Ixodes ricinus ticks in southern Sweden. Vector-Borne and Zoonotic Diseases, 13(7), 438-442. https://doi.org/10.1089/vbz.2012.1118
    1. Andersson, M., & Raberg, L. (2011). Wild rodents and novel human pathogen candidatus Neoehrlichia mikurensis, Southern Sweden. Emerging Infectious Diseases, 17(9), 1716-1718. https://doi.org/10.3201/eid1709.101058
    1. Andersson, M., Scherman, K., & Raberg, L. (2014). Infection dynamics of the tick-borne pathogen "Candidatus Neoehrlichia mikurensis" and coinfections with Borrelia afzelii in bank voles in Southern Sweden. Applied and Environment Microbiology, 80(5), 1645-1649. https://doi.org/10.1128/aem.03469-13
    1. Andreassen, A., Jore, S., Cuber, P., Dudman, S., Tengs, T., Isaksen, K., … Vainio, K. (2012). Prevalence of tick borne encephalitis virus in tick nymphs in relation to climatic factors on the southern coast of Norway. Parasit Vectors, 5, 177. https://doi.org/10.1186/1756-3305-5-177
    1. Belperron, A. A., & Bockenstedt, L. K. (2001). Natural antibody affects survival of the spirochete Borrelia burgdorferi within feeding ticks. Infection and Immunity, 69(10), 6456-6462. https://doi.org/10.1128/iai.69.10.6456-6462.2001

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