Hanne Kloster

• Kloster, Hanne; Stormo, Camilla; Jenkins, Andrew; Soleng, Arnulf; Andreassen, Åshild Kristine & Kjelland, Vivian (2026). Distribution of Rickettsia spp. and Bartonella spp. in questing Ixodes ricinus ticks in Norway. International Journal for Parasitology: Parasites and Wildlife. 31. doi: 10.1016/j.ijppaw.2026.101271. Fulltekst i vitenarkiv Vis sammendrag

  Ticks are important vectors of zoonotic pathogens in Europe, but knowledge regarding the presence of Rickettsia spp. and Bartonella spp. in questing Ixodes ricinus in Norway remains limited. This study investigated the occurrence of these bacteria in ticks collected across the Norwegian distribution range of I. ricinus. A total of 564 adult ticks and 3930 nymphs (393 pools) collected in seven counties were analysed by real-time PCR. Rickettsia spp. were detected only in adult ticks, with an overall prevalence of 3.9 % (22/564). Infected ticks were identified in only two counties, Østfold and Agder, with a prevalence of 11.2 and 10.9 %, respectively. Species-specific analysis confirmed R. helvetica in 77.3 % (17/22) of the positive samples. Rickettsia spp. were not detected in any nymph pools. Bartonella spp. were detected in 0.5 % (3/564) of adult ticks, representing the first report of Bartonella spp. in questing I. ricinus in Norway. Infected ticks were found in three counties, Østfold, Telemark, and Nordland. Bartonella spp. were not detected in any nymph pools. These findings demonstrate that Rickettsia spp. and Bartonella spp. are present in questing adult ticks in Norway, highlighting the importance of continued surveillance of emerging tick-borne pathogens in northern Europe.

• Kloster, Hanne; Stormo, Camilla; Haaland, Anita Haug; Okstad, Wenche; Andreassen, Åshild Kristine & Stuen, Snorre [Vis alle 7 forfattere av denne artikkelen] (2026). Antibodies against tick-borne pathogens in domestic dogs in Norway: Borrelia burgdorferi sensu lato, tick-borne encephalitis virus, and Anaplasma phagocytophilum. Acta Veterinaria Scandinavica (AVS). ISSN 0044-605X. 68. doi: 10.1186/s13028-026-00863-8. Fulltekst i vitenarkiv Vis sammendrag

  Background Ticks are important vectors of zoonotic pathogens, posing a growing threat to animals and humans in Europe. In Norway, the tick species Ixodes ricinus is expanding its range, increasing the risk of tick-borne infections. This study aimed to estimate the seroprevalence of IgG antibodies against Borrelia burgdorferi sensu lato (s. l.), tick-borne encephalitis virus (TBEV), and Anaplasma phagocytophilum in domestic dogs residing in Norway, and to assess their potential role as sentinel species for tick-borne pathogen surveillance at the northernmost limit of I. ricinus’ geographical range. Serum samples (n = 433) from domestic dogs were collected across 15 counties between 2016 and 2023 and analysed using immunoblot assays. Results Overall, 38% of the dogs were seropositive for one or more tick-borne pathogens. The seroprevalence was 20% for B. burgdorferi s. l., 19% for TBEV, and 11% for A. phagocytophilum. Statistically significant regional differences were observed for the latter two pathogens. Conclusions The findings indicated widespread exposure of Norwegian dogs to tick-borne pathogens and support their role as sentinel species for assessing human risk. Continued surveillance and preventive measures are recommended to reduce tick infestation and pathogen transmission to both dogs and humans.

• Kloster, Hanne; Stormo, Camilla; Haaland, Anita Haug; Stuen, Snorre & Kjelland, Vivian (2025). Seroprevalence of IgG Antibodies Against Borrelia burgdorferi Sensu Lato, Anaplasma phagocytophilum, and Tick-Borne Encephalitis (TBE) Virus in Horses in Southern Norway. Microorganisms. 13(4). doi: 10.3390/microorganisms13040771. Fulltekst i vitenarkiv Vis sammendrag

  Ixodes ricinus ticks play a crucial role as carriers of diseases, transmitting pathogens to vertebrate hosts, including horses. This study aimed to investigate the seroprevalence of IgG antibodies against Borrelia burgdorferi sensu lato (s. l.), Anaplasma phagocytophilum, and tick-borne encephalitis virus (TBE-virus) in equine sera collected in southern Norway. In total, sera from 331 horses stabled in four counties (Agder, Vestfold and Telemark, Vestland, and Viken) were analyzed by immunoblot. In total, 66% of the horses were IgG-seropositive for antibodies against one or multiple tick-borne pathogens. The highest seroprevalence was detected against B. burgdorferi s. l. (47%), followed by A. phagocytophilum (34%) and TBE-virus (10%). A significant difference between the counties regarding IgG antibodies against A. phagocytophilum was found, with the highest seroprevalence in horses stabled in the coastal areas of Agder and Vestland. In conclusion, the study demonstrates that horses in southern Norway are at high risk of contracting tick-borne infections.

• Kjelland, Vivian; Stamberg, Paul; Andreassen, Åshild Kristine; Kloster, Hanne; Vikse, Rose & Csango, Peter A. (2021). Borrelia spp. i skogflått samlet fra katter og hunder i Norge. Norsk veterinærtidsskrift. ISSN 0332-5741. 5, s. 284–289. Fulltekst i vitenarkiv

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• Haaland, Anita Haug; Kloster, Hanne; Stormo, Camilla; Omvik, Katrine; Pétursdóttir, Vala & Mjelde, Hans Kristian [Vis alle 8 forfattere av denne artikkelen] (2026). Arctic Exposure Pathways: Tick-Borne Pathogens Detected in a Terrestrial Mammal on Svalbard. doi: https:/www.nordtick2026.se/. Fulltekst i vitenarkiv
• Kloster, Hanne; Nordli, Ine Emilie Olsen; Kjelland, Vivian & Stormo, Camilla (2024). Har årets harde vinter tatt knekken på flåtten? - fvn.no. Fulltekst i vitenarkiv Vis sammendrag

  Årets sørlandsvinter har vært preget av sprengkulde og meterhøy snø. Det er nok mange som ønsker at flåtten har strøket med under disse omstendighetene, men det korte svaret på spørsmålet er: Nei, de fleste flått har nok klart seg helt fint.

• Lien, Anne; Nygård, Malene Østreng; Laugen, Ane Timenes; Lie, Asbjørn; Slettan, Audun & Johansen, Beate Strøm [Vis alle 33 forfattere av denne artikkelen] (2023). Utbygging vil ødelegge for biologisk mangfold på campus Gimlemoen. NB! 34 forfattere totalt. s. 19–19. Fulltekst i vitenarkiv
• Kloster, Hanne; Stormo, Camilla; Haaland, Anita Haug; Okstad, Wenche; Andreassen, Åshild Kristine & Stuen, Snorre [Vis alle 7 forfattere av denne artikkelen] (2022). Seroprevalence of antibodies against Anaplasma phagocytophilum, Borrelia burgdorferi sensu lato and tick-borne encephalitis (TBE) virus in dogs in Norway. Fulltekst i vitenarkiv
• Kloster, Hanne (2021). Flått: Det er mange som påvirkes - Starter ny studie om flåttbitt på hest. [Internet]. Trav365.no. Fulltekst i vitenarkiv

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