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Wilhelmsson, Peter
Publications (10 of 17) Show all publications
Wilhelmsson, P., Fryland, L., Lindblom, P., Sjöwall, J., Ahlm, C., Berglund, J., . . . Lindgren, P.-E. (2016). A prospective study on the incidence of Borrelia infection after a tick bite in Sweden and on the Åland Islands, Finland (2008-2009). Ticks and Tick-borne Diseases, 7(1), 71-79
Open this publication in new window or tab >>A prospective study on the incidence of Borrelia infection after a tick bite in Sweden and on the Åland Islands, Finland (2008-2009)
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2016 (English)In: Ticks and Tick-borne Diseases, ISSN 1877-959X, E-ISSN 1877-9603, Vol. 7, no 1, p. 71-79Article in journal (Refereed) Published
Abstract [en]

Lyme borreliosis (LB) is a common and increasing tick-borne disease in Europe. The risk of acquiring a Borrelia infection after a tick bite is not fully known. Therefore, we investigated the incidence of Borrelia infection after a tick bite and if the Borrelia load and/or the duration of tick-feeding influenced the risk of infection. During 2008-2009, ticks and blood samples were collected from 1546 tick-bitten persons from Sweden and the Åland Islands, Finland. Follow-up blood samples were taken three months after the tick bite. The duration of tick feeding was microscopically estimated and Borrelia was detected and quantified in ticks by real-time PCR. Anti-Borrelia antibodies were detected in sera using ELISA assays and immunoblot.

Even though 28 % of the participants were bitten by a Borrelia-positive tick, only 7.5% (32/428) of them developed a Borrelia infection, half of them LB. All who seroconverted removed “their” ticks significantly later than those who did not. The Borrelia load in the ticks did not explain the risk of seroconversion. Regional as well as gender differences in the Borrelia seroprevalence were found. The risk of developing a Borrelia infection after a bite by a Borrelia-infected tick is small but increases with the duration of tick feeding.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
Borrelia burgdorferi sensu lato; tick bite; incidence of infection; Lyme borreliosis; asymptomatic infection; bacterial load; tick-feeding.
National Category
Infectious Medicine
Identifiers
urn:nbn:se:liu:diva-105475 (URN)10.1016/j.ttbdis.2015.08.009 (DOI)000366953400012 ()
Note

Funding agencies: Swedish Research Council Branch of Medicine [K2008-58X-14631-06-3]; Medical Research Council of South-East Sweden [FORSS-8967, FORSS-12573, FORSS-29021, FORSS-86911]; EU Interreg IV A project ScandTick [167226]; County Council of Ostergotland [LIO-56191];

Available from: 2014-03-25 Created: 2014-03-25 Last updated: 2017-05-03Bibliographically approved
Wilhelmsson, P. & Lindgren, P. E. (2016). Detection of a novel Lyme borreliosis pathogen.. Lancet. Infectious diseases (Print), 16(5), 511-512
Open this publication in new window or tab >>Detection of a novel Lyme borreliosis pathogen.
2016 (English)In: Lancet. Infectious diseases (Print), ISSN 1473-3099, E-ISSN 1474-4457, Vol. 16, no 5, p. 511-512Article in journal, Editorial material (Other academic) Published
Place, publisher, year, edition, pages
Elsevier, 2016
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-126677 (URN)10.1016/S1473-3099(15)00483-1 (DOI)000374272900006 ()26856776 (PubMedID)
Available from: 2016-04-01 Created: 2016-04-01 Last updated: 2017-11-30
Aase, A., Hajdusek, O., Oines, O., Quarsten, H., Wilhelmsson, P., Herstad, T. K., . . . Aaberge, I. S. (2016). Validate or falsify: Lessons learned from a microscopy method claimed to be useful for detecting Borrelia and Babesia organisms in human blood. INFECTIOUS DISEASES, 48(6), 411-419
Open this publication in new window or tab >>Validate or falsify: Lessons learned from a microscopy method claimed to be useful for detecting Borrelia and Babesia organisms in human blood
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2016 (English)In: INFECTIOUS DISEASES, ISSN 2374-4235, Vol. 48, no 6, p. 411-419Article in journal (Refereed) Published
Abstract [en]

Background A modified microscopy protocol (the LM-method) was used to demonstrate what was interpreted as Borrelia spirochetes and later also Babesia sp., in peripheral blood from patients. The method gained much publicity, but was not validated prior to publication, which became the purpose of this study using appropriate scientific methodology, including a control group. Methods Blood from 21 patients previously interpreted as positive for Borrelia and/or Babesia infection by the LM-method and 41 healthy controls without known history of tick bite were collected, blinded and analysed for these pathogens by microscopy in two laboratories by the LM-method and conventional method, respectively, by PCR methods in five laboratories and by serology in one laboratory. Results Microscopy by the LM-method identified structures claimed to be Borrelia- and/or Babesia in 66% of the blood samples of the patient group and in 85% in the healthy control group. Microscopy by the conventional method for Babesia only did not identify Babesia in any samples. PCR analysis detected Borrelia DNA in one sample of the patient group and in eight samples of the control group; whereas Babesia DNA was not detected in any of the blood samples using molecular methods. Conclusions The structures interpreted as Borrelia and Babesia by the LM-method could not be verified by PCR. The method was, thus, falsified. This study underlines the importance of doing proper test validation before new or modified assays are introduced.

Place, publisher, year, edition, pages
TAYLOR & FRANCIS LTD, 2016
Keywords
Lyme disease; Borrelia burgdorferi sensu lato; babesiosis; Babesia spp.; Lyme borreliosis; PCR; microscopy
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-127739 (URN)10.3109/23744235.2016.1144931 (DOI)000373810800001 ()27030913 (PubMedID)
Note

Funding Agencies|Grant Agency of the Czech Republic [13-27630P, 13-12816P]; EU FP7 project MODBIOLIN [316304]; Interreg IV A project ScandTick

Available from: 2016-05-12 Created: 2016-05-12 Last updated: 2016-05-12
Labbe Sandelin, L., Tolf, C., Larsson, S., Wilhelmsson, P., Salaneck, E., Jaenson, T. G. T., . . . Waldenstrom, J. (2015). Candidatus Neoehrlichia mikurensis in Ticks from Migrating Birds in Sweden. PLoS ONE, 10(7), e0133250
Open this publication in new window or tab >>Candidatus Neoehrlichia mikurensis in Ticks from Migrating Birds in Sweden
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2015 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, no 7, p. e0133250-Article in journal (Refereed) Published
Abstract [en]

Candidatus Neoehrlichia mikurensis (CNM; family Anaplasmataceae) was recently recognized as a potential tick-borne human pathogen. The presence of CNM in mammals, in host-seeking Ixodes ticks and in ticks attached to mammals and birds has been reported recently. We investigated the presence of CNM in ornithophagous ticks from migrating birds. A total of 1,150 ticks (582 nymphs, 548 larvae, 18 undetermined ticks and two adult females) collected from 5,365 birds captured in south-eastern Sweden was screened for CNM by molecular methods. The birds represented 65 different species, of which 35 species were infested with one or more ticks. Based on a combination of morphological and molecular species identification, the majority of the ticks were identified as Ixodes ricinus. Samples were initially screened by real-time PCR targeting the CNM 16S rRNA gene, and confirmed by a second real-time PCR targeting the groEL gene. For positive samples, a 1260 base pair fragment of the 16S rRNA gene was sequenced. Based upon bacterial gene sequence identification, 2.1% (24/1150) of the analysed samples were CNM-positive. Twenty-two out of 24 CNM-positive ticks were molecularly identified as I. ricinus nymphs, and the remaining two were identified as I. ricinus based on morphology. The overall CNM prevalence in I. ricinus nymphs was 4.2%. None of the 548 tested larvae was positive. CNM-positive ticks were collected from 10 different bird species. The highest CNM-prevalences were recorded in nymphs collected from common redpoll (Carduelis flammea, 3/7), thrush nightingale (Luscinia luscinia, 2/29) and dunnock (Prunella modularis, 1/17). The 16S rRNA sequences obtained in this study were all identical to each other and to three previously reported European strains, two of which were obtained from humans. It is concluded that ornithophagous ticks may be infected with CNM and that birds most likely can disperse CNM-infected ticks over large geographical areas.

Place, publisher, year, edition, pages
Public Library of Science, 2015
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-120741 (URN)10.1371/journal.pone.0133250 (DOI)000358622000071 ()26207834 (PubMedID)
Note

Funding Agencies|Medical Research Council of Southeast Sweden [FORSS-307591, FORSS-387231]; Carl Tryggers Foundation for Scientific Research; Langmanska kulturfonden; Magnus Bergvalls Foundation for Scientific Research; Helge Ax:son Johnsons Foundation; EU Interreg IVA project ScandTick

Available from: 2015-08-24 Created: 2015-08-24 Last updated: 2017-12-04
Grankvist, A., Labbe Sandelin, L., Andersson, J., Fryland, L., Wilhelmsson, P., Lindgren, P.-E., . . . Wenneras, C. (2015). Infections with Candidatus Neoehrlichia mikurensis and Cytokine Responses in 2 Persons Bitten by Ticks, Sweden. Emerging Infectious Diseases, 21(8), 1462-1465
Open this publication in new window or tab >>Infections with Candidatus Neoehrlichia mikurensis and Cytokine Responses in 2 Persons Bitten by Ticks, Sweden
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2015 (English)In: Emerging Infectious Diseases, ISSN 1080-6040, E-ISSN 1080-6059, Vol. 21, no 8, p. 1462-1465Article in journal (Refereed) Published
Abstract [en]

The prevalence of Candidatus Neoehrlichia mikurensis infection was determined in 102 persons bitten by ticks in Sweden. Two infected women had erythematous rashes; 1 was co-infected with a Borrelia sp., and the other showed seroconversion for Anaplasma phagocytophilum. Both patients had increased levels of Neoehrlichia DNA and serum cytokines for several months.

Place, publisher, year, edition, pages
Centers for Disease Control and Prevention, 2015
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-120731 (URN)10.3201/eid2108.150060 (DOI)000358458300031 ()26197035 (PubMedID)
Note

Funding Agencies|ALF-Goteborg [71580]; Cancer and Allergy Foundation [149781]; Vastra Gotaland Region Research and Development [94510]; Laboratory Medicine at Sahlgrenska University Hospital [6333]; Medical Research Council of South-East Sweden [FORSS-297311, FORSS-307591, FORSS-87231]; Swedish Research Council/Medicine [2011-345]; ALF-Ostergotland

Available from: 2015-08-24 Created: 2015-08-24 Last updated: 2017-12-04
Henningsson, A. J., Wilhelmsson, P., Gyllemark, P., Kozak Ljunggren, M., Matussek, A., Nyman, D., . . . Forsberg, P. (2015). Low risk of seroconversion or clinical disease in humans after a bite by an Anaplasma phagocytophilum-infected tick. Ticks and Tick-borne Diseases, 6(6), 787-792
Open this publication in new window or tab >>Low risk of seroconversion or clinical disease in humans after a bite by an Anaplasma phagocytophilum-infected tick
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2015 (English)In: Ticks and Tick-borne Diseases, ISSN 1877-959X, E-ISSN 1877-9603, Vol. 6, no 6, p. 787-792Article in journal (Refereed) Published
Abstract [en]

The risk of contracting human granulocytic anaplasmosis (HGA) after a tick bite is mainly unknown. In this study we investigated the clinical and serological response in 30 humans bitten by ticks positive for Anaplasma phagocytophilum (Group A), 30 humans bitten by Borrelia burgdorferi sensu lato (s.l.)-positive ticks (Group B), and 30 humans bitten by ticks negative for both A. phagocytophilum and B. burgdorferi s.l. (Group C). Ticks, blood samples and questionnaires were collected from tick-bitten humans at 34 primary healthcare centres in Sweden and in the Åland Islands, Finland, at the time of the tick bite and after three months. A total of 2553 ticks detached from humans in 2007-2009 were analyzed by polymerase chain reaction, and 31 (1.2%) were positive for A. phagocytophilum, 556 (21.8%) were positive for B. burgdorferi s.l., and eight (0.3%) were co-infected by A. phagocytophilum and B. burgdorferi s.l. The overall prevalence of Anaplasma IgG antibodies in the included participants (n=90) was 17%, and there was no significant difference between the groups A-C. Only one of the participants (in Group C) showed a four-fold increase of IgG antibodies against A. phagocytophilum at the three-month follow-up, but reported no symptoms. The frequency of reported symptoms did not differ between groups A-C, and was unrelated to the findings of A. phagocytophilum and B. burgdorferi s.l. in the detached ticks. We conclude that the risk for HGA or asymptomatic seroconversion after a tick bite in Sweden or in the Åland Islands is low, even if the tick is infected by A. phagocytophilum.

Place, publisher, year, edition, pages
Elsevier, 2015
National Category
Microbiology in the medical area
Identifiers
urn:nbn:se:liu:diva-122245 (URN)10.1016/j.ttbdis.2015.07.005 (DOI)000362143800015 ()26187418 (PubMedID)
Note

Funding text: Swedish Research Council; Medical Research Council of Southeast Sweden (FORSS); Futurum Academy of Healthcare; Jonkoping County Council; Interreg IV A Programme ScandTick; Division of Medical Services, Ryhov County Hospital, Jonkoping

Available from: 2015-10-26 Created: 2015-10-26 Last updated: 2018-01-10
Dessau, R. B., Fryland, L., Wilhelmsson, P., Ekerfelt, C., Nyman, D., Forsberg, P. & Lindgren, P.-E. (2015). Study of a Cohort of 1,886 Persons To Determine Changes in Antibody Reactivity to Borrelia burgdorferi 3 Months after a Tick Bite. Clinical and Vaccine Immunology, 22(7), 823-827
Open this publication in new window or tab >>Study of a Cohort of 1,886 Persons To Determine Changes in Antibody Reactivity to Borrelia burgdorferi 3 Months after a Tick Bite
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2015 (English)In: Clinical and Vaccine Immunology, ISSN 1556-6811, E-ISSN 1556-679X, Vol. 22, no 7, p. 823-827Article in journal (Refereed) Published
Abstract [en]

Lyme borreliosis is a tick-borne disease caused by the bacterium Borrelia burgdorferi. The most frequent clinical manifestation is a rash called erythema migrans. Changes in antibody reactivity to B. burgdorferi 3 months after a tick bite are measured using enzyme-linked immunosorbent assays (ELISAs). One assay is based on native purified flagellum antigen (IgG), and the other assay is based on a recombinant antigen called C6 (IgG or IgM). Paired samples were taken at the time of a tick bite and 3 months later from 1,886 persons in Sweden and the Åland Islands, Finland. The seroconversion or relative change is defined by dividing the measurement units from the second sample by those from the first sample. The threshold for the minimum level of significant change was defined at the 2.5% level to represent the random error level. The thresholds were a 2.7-fold rise for the flagellar IgG assay and a 1.8-fold rise for the C6 assay. Of 1,886 persons, 102/101 (5.4%) had a significant rise in antibody reactivity in the flagellar assay or the C6 assay. Among 40 cases with a diagnosis of Lyme borreliosis, the sensitivities corresponding to a rise in antibodies were 33% and 50% for the flagellar antigen and the C6 antigen, respectively. Graphical methods to display the antibody response and to choose thresholds for a rise in relative antibody reactivity are shown and discussed. In conclusion, 5.4% of people with tick bites showed a rise in Borrelia-specific antibodies above the 2.5% threshold in either ELISA but only 40 (2.1%) developed clinical Lyme borreliosis.

National Category
Infectious Medicine
Identifiers
urn:nbn:se:liu:diva-120003 (URN)10.1128/CVI.00026-15 (DOI)000356863200016 ()25994550 (PubMedID)
Available from: 2015-07-02 Created: 2015-07-02 Last updated: 2017-10-31
Wilhelmsson, P. (2014). A STING from a Tick: Epidemiology, Ecology and Clinical Aspects of Lyme Borreliosis. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>A STING from a Tick: Epidemiology, Ecology and Clinical Aspects of Lyme Borreliosis
2014 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Lyme borreliosis (LB) is the most common tick-borne disease in the Northern Hemisphere and the number of LB cases is increasing. The infection is caused by spirochetes belonging to the Borrelia burgdorferi sensu lato complex, and is, in Europe, transmitted to humans by Ixodes ricinus ticks.

To gain a deeper knowledge of the interactions between ticks, humans and Borrelia bacteria, we investigated temporal differences in exposure to tick bites in different parts of Sweden and the Åland Islands, Finland during the years 2008 and 2009. We also investigated the site of tick attachment on the human body and the time it takes for a person to detected and remove such ticks. Furthermore, the distribution of Borrelia species and the number of Borrelia cells in the ticks were investigated. Sera taken from the tick-bitten persons at study inclusion were analyzed for the presence of Borrelia antibodies. Three months later, the clinical outcome and the serological response of the tick-bitten persons were investigated. A total of 2154 I. ricinus ticks and 1546 participants were included in the studies.

Participants were exposed to tick bites between April and November, but temporal and spatial differences in exposure to ticks was found. The majority of the tick bites were caused by nymphs (70%) and most tick bites took place on the legs (50%). The site of tick attachment on the body as well as the age and gender of the participant influenced how soon a tick was detected. The majority of participants removed “their” ticks later than 24 hours of attachment. Of all ticks, 26% was Borrelia-infected, but the prevalence varied between the life stages of the tick and between the studied areas. Six species of the B. burgdorferi sensu lato complex and one Borrelia species that may cause tick-borne relapsing fever were detected. Adult ticks that had fed more than 36 hours contained a lower number of Borrelia cells than adult ticks that had fed less than 36 hours. The seroprevalence among the participants varied between genders as well as between the studied areas. Of all participants, 2% was diagnosed with LB and 2.5% seroconverted without an LB diagnose. A correlation between seroconversion and duration time of tick attachment was found, but the number of Borrelia cells in the tick, did not explain the risk of infection for the bitten person.

A deeper knowledge and a better understanding of the interactions between ticks, humans and Borrelia bacteria may contribute reducing the risk for tick bites and the risk of developing LB after a tick bite.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2014. p. 130
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1385
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-105476 (URN)10.3384/diss.diva-105476 (DOI)978-91-7519-460-8 (ISBN)
Public defence
2014-04-24, Berzeliussalen, Campus US, Linköpings universitet, Linköping, 09:00 (English)
Opponent
Supervisors
Available from: 2014-03-25 Created: 2014-03-25 Last updated: 2014-04-04Bibliographically approved
Lindblom, P., Wilhelmsson, P., Fryland, L., Matussek, A., Haglund, M., Sjöwall, J., . . . Lindgren, P.-E. (2014). Determining factors for successful vaccination against tick-borne encephalitis virus in older individuals.
Open this publication in new window or tab >>Determining factors for successful vaccination against tick-borne encephalitis virus in older individuals
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2014 (English)Manuscript (preprint) (Other academic)
Abstract [en]

We performed a cross-sectional study including 533 persons (median age 61) from the highly TBE endemic Åland Islands in the archipelago between Sweden and Finland. Blood samples, questionnaires and vaccination records were obtained from all study participants. The aim was to investigate if there was any association between TBEV antibody titer and 14 healthrelated factors: [age, gender, number of vaccine doses (0-5), time since last vaccine dose, previous TBE disease, vaccination against other flaviviruses, ≥2 tick-bites during the previous 3 months, pet-ownership, asthma, smoking, allergy, diabetes, medication, and previous tumor]. Measurement of TBEV IgG antibodies was performed using two commercial ELISA assays (Enzygnost and Immunozym), and a third in-house rapid fluorescent focus inhibition test was used to measure TBEV neutralizing antibodies. The age of the person and the number of vaccine doses were the two most important factors determining successful vaccination. The response to each vaccine dose declined linearly with increased age. A 35 year age difference corresponds to a vaccine dose increment from 3 to 4 to achieve the same response. Participants receiving medication and participants previously vaccinated against other flaviviruses had lower TBEV antibody titers on average, while those with self-reported asthma had higher titers. By comparing the 3 serological assays we show that the Enzygnost and Immunozym assay differ due to choice of cutoffs, but not in overall accuracy.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-105919 (URN)
Available from: 2014-04-14 Created: 2014-04-14 Last updated: 2014-04-14Bibliographically approved
Lindblom, P., Wilhelmsson, P., Fryland, L., Matussek, A., Haglund, M., Sjöwall, J., . . . Lindgren, P.-E. (2014). Factors Determining Immunological Response to Vaccination against Tick-Borne Encephalitis Virus in Older Individuals. PLoS ONE, 9(6), e0100860
Open this publication in new window or tab >>Factors Determining Immunological Response to Vaccination against Tick-Borne Encephalitis Virus in Older Individuals
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2014 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 6, p. e0100860-Article in journal (Refereed) Published
Abstract [en]

We performed a cross-sectional study including 533 individuals (median age 61) from the highly TBE endemic A land Islands in the archipelago between Sweden and Finland. Blood samples, questionnaires and vaccination records were obtained from all study participants. The aim was to investigate if there was any association between TBEV antibody titer and 12 health-related factors. Measurement of TBEV IgG antibodies was performed using two commercial ELISA assays (Enzygnost and Immunozym), and a third in-house rapid fluorescent focus inhibition test was used to measure TBEV neutralizing antibodies. The age of the individual and the number of vaccine doses were the two most important factors determining the immunological response to vaccination. The response to each vaccine dose declined linearly with increased age. A 35 year age difference corresponds to a vaccine dose increment from 3 to 4 to achieve the same immunological response. Participants previously vaccinated against other flaviviruses had lower odds of being seropositive for neutralizing TBEV antibodies on average, while participants with self-reported asthma had higher odds of being seropositive. By comparing the 3 serological assays we show that the Enzygnost and Immunozym assay differ due to choice of cutoffs, but not in overall accuracy.

Place, publisher, year, edition, pages
Public Library of Science, 2014
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-109260 (URN)10.1371/journal.pone.0100860 (DOI)000338280800075 ()24967619 (PubMedID)
Available from: 2014-08-12 Created: 2014-08-11 Last updated: 2017-12-05Bibliographically approved
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