Tick Borne Encephalitis (TBE)FINtickNCT07897825
FINtick - a Prospective Multicenter Study on Tick-borne Infections in Finland
An observational study of Tick Borne Encephalitis (TBE) and Lyme Borreliosis, run by Turku University Hospital at 3 sites in Finland.
Trial summary
Ticks in Finland can carry several microbes that may infect humans. The best known tick-borne diseases are Lyme borreliosis and tick-borne encephalitis (TBE). In recent years, scientists have also found other microbes in Finnish ticks, such as Anaplasma, Rickettsia, Neoehrlichia, Borrelia miyamotoi, and Babesia. Read more about this study
- Who is it for?
- Ages 1 year and older
- Conditions the study is for
- Tick Borne Encephalitis (TBE), Lyme Borreliosis, Neoehrlichiosis
- How many people
- 850 participants
- Where
- 3 sitesFinland
- Study dates
- 23 Apr 2025to 31 Dec 2034
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 1 year and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: Medical history: tick exposure, tick bite, splenectomy, immunosuppressive treatment (e.g. anti-CD20 or other biological/immunomodulatory drugs, cortisone corresponding to >10 mg prednisolone/day, chemotherapy, hematologic malignancy, other malignancy, rheumatologic disease) Symptoms/clinical signs: fever after tick bite, fever of unknown origin, skin rashes (single/multiple erythema migrans, lymphocytoma, acrodermatitis chronica atrophicans or other), venous thrombosis, repeated thrombophlebitis, vasculitis, meningitis, encephalitis, myelitis, cranial nerve palsy, radiculitis, peripheral nerve involvement, mono-/oligoarthritis, carditis, ocular or otogenic disturbances of uncertain origin where medical history includes recent tick bite. Laboratory findings in combination with suspicion of tick-borne disease: leukopenia, thrombocytopenia, anemia, elevated liver enzymes, slightly elevated erythrocyte sedimentation rate and/or C-reactive protein, pleocytosis in CSF or synovial fluid.
Who may be able to join
- Clinical suspicion of tick-borne disease.
Who cannot join
- Prisoners
- Adults who are unable to decide, unless next of kin gives consent.
- Patients, who cannot attend the first follow-up visit or phone call.
- Patients, who are not willing to give a blood sample at the initiation.
Trial locations and contacts
3 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Finland3 sites, 3 recruiting
- Recruiting
Helsinki University Central Hospital
Helsinki, 00029
Elisa Kortela, MD, PhD, +358504271507, elisa.kortela@hus.fi
- Not yet recruiting
Ålands hälso- och sjukcård ÅHS
Mariehamn, 22111
Marika Nordberg, MD, PhD, +358185355, marika.nordberg@ahs.ax
- Recruiting
Turku University Hospital
Turku, 20521
Ulla Hohenthal, MD, PhD, +3582 3130500, ulla.hohenthal@varha.fi
Eeva Feuth, MD, PhD
About this study
Ticks in Finland can carry several microbes that may infect humans. The best known tick-borne diseases are Lyme borreliosis and tick-borne encephalitis (TBE). In recent years, scientists have also found other microbes in Finnish ticks, such as Anaplasma, Rickettsia, Neoehrlichia, Borrelia miyamotoi, and Babesia. Infections caused by these microbes are called emerging tick-borne diseases. Climate change may also increase the number of ticks and expand their range further north. This could lead to more tick-borne diseases in the future.
The public health impact of these emerging infections is still unclear. Some of them may cause severe illness, especially in people with weakened immune systems or without a spleen. However, we still know little about how common these infections are, how they develop in the body, and what symptoms they cause. Some people may have no symptoms, while others may become seriously ill. Good diagnostic tests are also lacking.
Read more
More knowledge is also needed about Lyme borreliosis and TBE. Some forms of Lyme disease, such as arthritis, heart inflammation, or eye problems, may be underdiagnosed. In addition, TBE cases have increased in Finland in recent years. This study will examine the symptoms, recovery, and quality of life of patients with these infections.
Another goal is to improve laboratory diagnostics. Current tests for Lyme disease and TBE mainly detect antibodies. These tests cannot always tell when the infection occurred or distinguish a past Lyme borreliosis infection from a current one. This also makes it difficult to detect reinfections in Lyme borreliosis or TBE-infections in vaccinated individuals. By collecting samples from patients, we aim to develop better diagnostic methods.
The main goal of the study is to improve knowledge about tick-borne diseases in Finland. We will study how common emerging infections are, what symptoms they cause, and whether people can have more than one tick-borne infection at the same time. We will also examine how the immune system responds to these infections and how this relates to disease severity and recovery.
This study includes both children and adults who are being examined for a suspected tick-borne disease. Participants will be followed for six months using questionnaires at initiation, one, three, and six months. Blood samples and other samples, depending on the patient's symptoms, will be collected together with routine clinical samples. The samples will be analyzed to detect tick-borne pathogens and antibodies against them. Molecular tests (PCR) will look for the genetic material of the microbes. Researchers will also search for new biological markers of these diseases and study the immune response using advanced laboratory methods.
The study will be conducted in collaboration with the SWETICK study.
- Conditions
- Tick Borne Encephalitis (TBE), Lyme Borreliosis, Neoehrlichiosis, Tick-Borne Diseases, Anaplasmosis, Babesiosis, Human
- Keywords
- tick-borne diseases, Lyme borreliosis, tick-borne encephalitis, neoehrlichiosis, anaplasmosis, babesiosis
- Medical subject headings
- Encephalitis, Tick-Borne, Lyme Disease, Tick-Borne Diseases, Anaplasmosis, Babesiosis, Rickettsia Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| TBD | Patients with confirmed tick-borne disease | |
| Possible TBD | Patients with possible but not confirmed tick-borne disease | |
| Non-TBD | Patients investigated for suspected tick-borne disease but diagnosed with another condition (tick-borne disease excluded) |
What is being measured
The primary outcome is the main question the study is designed to answer.
The number of diagnosed neoehrlichiosis cases
The number of patients in whose plasma (EDTA blood sample) Neoehrlichia mikurensis nucleic acid can be detected by a nucleic acid amplification test (NAAT).
Measured: From enrollment to the end of the follow-up at 6 months.
The number of diagnosed cases with Borrelia miyamotoi -infection
The number of patients in whose blood or cerebrospinal fluid sample Borrelia miyamotoi nucleic acid can be detected by a nucleic acid amplification test (NAAT).
Measured: From enrollment to the end of follow-up at 6 months
The number of diagnosed babesiosis cases
The number of patients with laboratory evidence of Babesia infection in a blood sample, detected by blood smear microscopy or nucleic acid amplification test.
Measured: From enrollment to the end of follow-up at 6 months
The number of diagnosed anaplasmosis cases
The number of patients with laboratory-confirmed Anaplasma phagocytophilum infection, demonstrated either by seroconversion in paired serum samples together with symptoms or by detection of nucleic acid in a blood sample using a nucleic acid amplification test (NAAT).
Measured: From enrollment to the end of follow-up at 6 months
The number of diagnosed rickettsiosis cases
The number of patients with laboratory-confirmed Rickettsia spp. infection, demonstrated either by seroconversion in paired serum samples together with symptoms or by detection of nucleic acid in a blood sample using a nucleic acid amplification test (NAAT).
Measured: From enrollment to the end of follow-up at 6 months
The number of diagnosed Lyme borreliosis cases
The number of patients diagnosed with Lyme borreliosis according to the European clinical case definitions (Stanek G, Fingerle V, Hunfeld K-P, et al. Lyme borreliosis: clinical case definitions for diagnosis and management in Europe. Clin Microbiol Infect. 2011;17(1):69-79).
Measured: From enrollment to the end of follow-up at 6 months
The number of diagnosed tick-borne encephalitis cases
The number of patients diagnosed with tick-borne encephalitis (TBE), confirmed either by serology or by a nucleic acid amplification test (NAAT).
Measured: From enrollment to the end of follow-up at 6 months
Secondary outcomes (2)
EuroQoL-5 Dimension Questionnaire (EQ-5D)
Difference in EQ-5D Health index between study inclusion and at the 6 month-follow-up
Measured: 6 months
Visual Analogue Scale for Health (VAS) from 0 to 100 (100 best)
Difference between the VAS units at study inclusion and at 6 month-follow-up.
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Oct 2026
- Study start23 Apr 2025
- Primary completion31 Dec 2034 (estimated)
- Study completion31 Dec 2034 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Tick Borne Encephalitis (TBE)Studies of the same condition, open and under way.
- More trials run by Turku University HospitalThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 850 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Turku University Hospital
- Sponsor type
- Other government
- Collaborators
- Helsinki University Central Hospital, Ålands hälso- och sjukvård ÅHS
- Responsible party
- Principal investigator, Jukka Hytonen, Turku University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07897825
- Sponsor's protocol ID
- VARHA/10387/13.02.02/2024
- Acronym
- FINtick
- Status last verified
- Oct 2026
- First submitted
- 10 Sep 2026
- Last updated
- 27 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Finnish legislation is very strict regarding the sharing of patient data, and reliable anonymisation of the data requires expertise. Although the patient data are collected without personal identifiers, patients may still be identifiable due to the rarity of their condition. For this reason, we do not share patient-level data.
Publications
Laaksonen M, Klemola T, Feuth E, Sormunen JJ, Puisto A, Makela S, Penttinen R, Ruohomaki K, Hanninen J, Saaksjarvi IE, Vuorinen I, Sprong H, Hytonen J, Vesterinen EJ. Tick-borne pathogens in Finland: comparison of Ixodes ricinus and I. persulcatus in sympatric and parapatric areas. Parasit Vectors. 2018 Oct 24;11(1):556. doi: 10.1186/s13071-018-3131-y.
PubMed 30355331Madison-Antenucci S, Kramer LD, Gebhardt LL, Kauffman E. Emerging Tick-Borne Diseases. Clin Microbiol Rev. 2020 Jan 2;33(2):e00083-18. doi: 10.1128/CMR.00083-18. Print 2020 Mar 18.
PubMed 31896541Sormunen JJ, Penttinen R, Klemola T, Hanninen J, Vuorinen I, Laaksonen M, Saaksjarvi IE, Ruohomaki K, Vesterinen EJ. Tick-borne bacterial pathogens in southwestern Finland. Parasit Vectors. 2016 Mar 22;9:168. doi: 10.1186/s13071-016-1449-x.
PubMed 27004834Quarsten H, Henningsson A, Krogfelt KA, Strube C, Wenneras C, Mavin S. Tick-borne diseases under the radar in the North Sea Region. Ticks Tick Borne Dis. 2023 Jul;14(4):102185. doi: 10.1016/j.ttbdis.2023.102185. Epub 2023 Apr 26.
PubMed 37116420Gilbert L. The Impacts of Climate Change on Ticks and Tick-Borne Disease Risk. Annu Rev Entomol. 2021 Jan 7;66:373-388. doi: 10.1146/annurev-ento-052720-094533.
PubMed 33417823
Study at a glance
From the registry record, last updated by the sponsor on 27 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- FINtick - a Prospective Multicenter Study on Tick-borne Infections in Finland
- ClinicalTrials.gov ID
- NCT07897825
- Acronym / sponsor ID
- FINtick / VARHA/10387/13.02.02/2024
- Conditions
- Tick Borne Encephalitis (TBE), Lyme Borreliosis, Neoehrlichiosis, Tick-Borne Diseases, Anaplasmosis, Babesiosis, Human
- Keywords
- tick-borne diseases, Lyme borreliosis, tick-borne encephalitis, neoehrlichiosis, anaplasmosis, babesiosis
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 850 participants (estimated)
- Lead sponsor
- Turku University HospitalOther government
- Collaborators
- Helsinki University Central Hospital, Ålands hälso- och sjukvård ÅHS
- Study start
- 23 Apr 2025 (actual)
- Primary completion
- 31 Dec 2034 (estimated)
- Study completion
- 31 Dec 2034 (estimated)
- First posted
- 27 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Ticks in Finland can carry several microbes that may infect humans. The best known tick-borne diseases are Lyme borreliosis and tick-borne encephalitis (TBE). In recent years, scientists have also found other microbes in Finnish ticks, such as Anaplasma, Rickettsia, Neoehrlichia, Borrelia miyamotoi, and Babesia. Infections caused by these microbes are called emerging tick-borne diseases. Climate change may also increase the number of ticks and expand their range further north. This could lead to more tick-borne diseases in the future.
The public health impact of these emerging infections is still unclear. Some of them may cause severe illness, especially in people with weakened immune systems or without a spleen. However, we still know little about how common these infections are, how they develop in the body, and what symptoms they cause. Some people may have no symptoms, while others may become seriously ill. Good diagnostic tests are also lacking.
More knowledge is also needed about Lyme borreliosis and TBE. Some forms of Lyme disease, such as arthritis, heart inflammation, or eye problems, may be underdiagnosed. In addition, TBE cases have increased in Finland in recent years. This study will examine the symptoms, recovery, and quality of life of patients with these infections.
Another goal is to improve laboratory diagnostics. Current tests for Lyme disease and TBE mainly detect antibodies. These tests cannot always tell when the infection occurred or distinguish a past Lyme borreliosis infection from a current one. This also makes it difficult to detect reinfections in Lyme borreliosis or TBE-infections in vaccinated individuals. By collecting samples from patients, we aim to develop better diagnostic methods.
The main goal of the study is to improve knowledge about tick-borne diseases in Finland. We will study how common emerging infections are, what symptoms they cause, and whether people can have more than one tick-borne infection at the same time. We will also examine how the immune system responds to these infections and how this relates to disease severity and recovery.
This study includes both children and adults who are being examined for a suspected tick-borne disease. Participants will be followed for six months using questionnaires at initiation, one, three, and six months. Blood samples and other samples, depending on the patient's symptoms, will be collected together with routine clinical samples. The samples will be analyzed to detect tick-borne pathogens and antibodies against them. Molecular tests (PCR) will look for the genetic material of the microbes. Researchers will also search for new biological markers of these diseases and study the immune response using advanced laboratory methods.
The study will be conducted in collaboration with the SWETICK study.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| TBD | – | –Patients with confirmed tick-borne disease |
| Possible TBD | – | –Patients with possible but not confirmed tick-borne disease |
| Non-TBD | – | –Patients investigated for suspected tick-borne disease but diagnosed with another condition (tick-borne disease excluded) |
Who may qualify
- Ages
- 1 year and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Medical history: tick exposure, tick bite, splenectomy, immunosuppressive treatment (e.g. anti-CD20 or other biological/immunomodulatory drugs, cortisone corresponding to >10 mg prednisolone/day, chemotherapy, hematologic malignancy, other malignancy, rheumatologic disease) Symptoms/clinical signs: fever after tick bite, fever of unknown origin, skin rashes (single/multiple erythema migrans, lymphocytoma, acrodermatitis chronica atrophicans or other), venous thrombosis, repeated thrombophlebitis, vasculitis, meningitis, encephalitis, myelitis, cranial nerve palsy, radiculitis, peripheral nerve involvement, mono-/oligoarthritis, carditis, ocular or otogenic disturbances of uncertain origin where medical history includes recent tick bite. Laboratory findings in combination with suspicion of tick-borne disease: leukopenia, thrombocytopenia, anemia, elevated liver enzymes, slightly elevated erythrocyte sedimentation rate and/or C-reactive protein, pleocytosis in CSF or synovial fluid.
Key inclusion criteria (1 listed)
- Clinical suspicion of tick-borne disease.
Key exclusion criteria (4 listed)
- Prisoners
- Adults who are unable to decide, unless next of kin gives consent.
- Patients, who cannot attend the first follow-up visit or phone call.
- Patients, who are not willing to give a blood sample at the initiation.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
The number of diagnosed neoehrlichiosis cases
Time frame: From enrollment to the end of the follow-up at 6 months.
The number of patients in whose plasma (EDTA blood sample) Neoehrlichia mikurensis nucleic acid can be detected by a nucleic acid amplification test (NAAT).
The number of diagnosed cases with Borrelia miyamotoi -infection
Time frame: From enrollment to the end of follow-up at 6 months
The number of patients in whose blood or cerebrospinal fluid sample Borrelia miyamotoi nucleic acid can be detected by a nucleic acid amplification test (NAAT).
The number of diagnosed babesiosis cases
Time frame: From enrollment to the end of follow-up at 6 months
The number of patients with laboratory evidence of Babesia infection in a blood sample, detected by blood smear microscopy or nucleic acid amplification test.
The number of diagnosed anaplasmosis cases
Time frame: From enrollment to the end of follow-up at 6 months
The number of patients with laboratory-confirmed Anaplasma phagocytophilum infection, demonstrated either by seroconversion in paired serum samples together with symptoms or by detection of nucleic acid in a blood sample using a nucleic acid amplification test (NAAT).
The number of diagnosed rickettsiosis cases
Time frame: From enrollment to the end of follow-up at 6 months
The number of patients with laboratory-confirmed Rickettsia spp. infection, demonstrated either by seroconversion in paired serum samples together with symptoms or by detection of nucleic acid in a blood sample using a nucleic acid amplification test (NAAT).
The number of diagnosed Lyme borreliosis cases
Time frame: From enrollment to the end of follow-up at 6 months
The number of patients diagnosed with Lyme borreliosis according to the European clinical case definitions (Stanek G, Fingerle V, Hunfeld K-P, et al. Lyme borreliosis: clinical case definitions for diagnosis and management in Europe. Clin Microbiol Infect. 2011;17(1):69-79).
The number of diagnosed tick-borne encephalitis cases
Time frame: From enrollment to the end of follow-up at 6 months
The number of patients diagnosed with tick-borne encephalitis (TBE), confirmed either by serology or by a nucleic acid amplification test (NAAT).
2 secondary outcomes
EuroQoL-5 Dimension Questionnaire (EQ-5D)
Time frame: 6 months
Visual Analogue Scale for Health (VAS) from 0 to 100 (100 best)
Time frame: 6 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Oct 2026.
- Background: PubMed 30355331Laaksonen M, Klemola T, Feuth E, Sormunen JJ, Puisto A, Makela S, Penttinen R, Ruohomaki K, Hanninen J, Saaksjarvi IE, Vuorinen I, Sprong H, Hytonen J, Vesterinen EJ. Tick-borne pathogens in Finland: comparison of Ixodes ricinus and I. persulcatus in sympatric and parapatric areas. Parasit Vectors. 2018 Oct 24;11(1):556. doi: 10.1186/s13071-018-3131-y.
- Background: PubMed 31896541Madison-Antenucci S, Kramer LD, Gebhardt LL, Kauffman E. Emerging Tick-Borne Diseases. Clin Microbiol Rev. 2020 Jan 2;33(2):e00083-18. doi: 10.1128/CMR.00083-18. Print 2020 Mar 18.
- Background: PubMed 27004834Sormunen JJ, Penttinen R, Klemola T, Hanninen J, Vuorinen I, Laaksonen M, Saaksjarvi IE, Ruohomaki K, Vesterinen EJ. Tick-borne bacterial pathogens in southwestern Finland. Parasit Vectors. 2016 Mar 22;9:168. doi: 10.1186/s13071-016-1449-x.
- Background: PubMed 37116420Quarsten H, Henningsson A, Krogfelt KA, Strube C, Wenneras C, Mavin S. Tick-borne diseases under the radar in the North Sea Region. Ticks Tick Borne Dis. 2023 Jul;14(4):102185. doi: 10.1016/j.ttbdis.2023.102185. Epub 2023 Apr 26.
- Background: PubMed 33417823Gilbert L. The Impacts of Climate Change on Ticks and Tick-Borne Disease Risk. Annu Rev Entomol. 2021 Jan 7;66:373-388. doi: 10.1146/annurev-ento-052720-094533.
- Individual participant dataSharing planned: No. Finnish legislation is very strict regarding the sharing of patient data, and reliable anonymisation of the data requires expertise. Although the patient data are collected without personal identifiers, patients may still be identifiable due to the rarity of their condition. For this reason, we do not share patient-level data.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Tick Borne Encephalitis (TBE) and Lyme Borreliosis, run by Turku University Hospital at 3 sites in Finland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 27 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in Finland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Jukka Hytönen, professor (+358294504544, jukka.hytonen@utu.fi), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
The number of diagnosed neoehrlichiosis cases (time frame: From enrollment to the end of the follow-up at 6 months.). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07897825, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Oct 2026.