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Climate change is most strongly felt in the polar regions of the world, with significant impacts for the species that live in these extreme environments. The arrival of parasites and pathogens from more temperate areas may become a significant problem for these populations, but current observations of parasite presence often lack a historical reference of prior absence. Observations in the high Arctic of the seabird tick Ixodes uriae suggested that this species recently expanded its range poleward. As this tick can have a direct impact on the breeding success of its seabird hosts and is vector of many potential disease agents, including Lyme disease spirochaetes, its presence and origin are important elements for predicting its impact on polar seabird populations. Here, we use population genetic data and host serology to test the hypothesis that Ixodes uriae has recently expanded into the Svalbard archipelago. Both Black-legged kittiwakes (Rissa tridactyla) and Thick-billed murres (Uria lomvia) were captured in Kongsfjorden, Spitsbergen and sampled for ticks and blood. Collected ticks were genotyped using microsatellite markers and population genetic analyses were carried out using data from 14 additional seabird colonies distributed across the tick’s northern distribution. In contrast to predictions based on a recent expansion, the Spitsbergen population showed high genetic diversity and significant differentiation from the more southern populations, suggesting long-term population isolation. Host serology also demonstrated a high exposure rate to Lyme disease spirochaetes (Bbsl). Targeted PCR on tick DNA extracts and sequencing identified the presence of Borrelia garinii in a Spitsbergen tick, confirming seabird exposure and demonstrating the presence of Lyme disease bacteria in the high Arctic for the first time. Taken together, results contradict the notion that Ixodes uriae has recently expanded into the high Arctic region. Rather, this tick has likely been present for some time, maintaining relatively high population sizes and an endemic transmission cycle of Bbsl spirochaetes. Close future observations of population infestation/infection rates will now be necessary to relate epidemiological changes to ongoing climate modifications.Author summaryThe climate in the Arctic is rapidly changing, and with it, the flora and fauna that live there. These new environmental conditions can favor the establishment of invasive species, including novel parasites and pathogens. Here, we use population genetic data and host serology to examine whether recent observations of ticks infesting breeding seabirds in the high Arctic represent a poleward expansion of the parasite. Contrary to predictions, tick populations showed no evidence of a recent colonization of the region. Ticks have likely be present for a relatively long time, maintaining high local diversity despite harsh environmental conditions and vectoring infectious agents among breeding birds. Indeed, we demonstrate the presence of Lyme disease spirochaetes in the high Arctic for the first time, with bacterial DNA found in one of the sampled ticks and seabird serology demonstrating high exposure to this pathogen. This Lyme disease agent has therefore likely been established in the region and circulating at low frequency between seabirds and ticks for some time.

Lyme Borreliosis is caused by spirochetes grouped together in a complex named Borrelia burgdorferi sensu lato. In veterinary medicine, the dog could represent a major asset in revealing the presence of the spirochete in several geographical areas and be used as a sentinel for humans. Dogs are the most susceptible domestic species to Lyme borreliosis, the disease manifests primarily with arthritis or nephritis. The diagnosis of this disease is difficult. However, it is possible to detect seropositive patients using tests showing anti-C6 antibodies, an antigen corresponding to an invariable zone of a surface protein of the spirochete. We studied results from the IDEXX laboratory database based on the performance of 4Dx Plus and LymeQuantC6 tests carried out by veterinarians working in mainland France. They are qualitatively and quantitatively studying seropositivity to the C6 antigen in dogs. The frequency of positive animals in the qualitative test is 2.7 % (53/1975) and 31.1 % (170/546) in the quantitative test. These results show circulation of Borrelia burgdorferi throughout the year with an increase in cases in hot and humid summer. Seropositive dogs are distributed throughout the metropolitan territory with a predominance in Center-East and East of France. Overall, this temporal and geographic distribution of seropositive dogs is consistent with the results observed in humans. This observation reinforces the dog's position as an adapted sentinel revealing the circulation of Lyme Borreliosis in certain regions of France; La Borréliose de Lyme est due à des spirochètes regroupées sous un complexe nommé Borrelia burgdorferi sensu lato. En médecine vétérinaire, le chien pourrait représenter un atout majeur afin de révéler la présence du spirochète dans certaines zones géographiques et servir de sentinelle pour l'Homme. Le chien est l'espèce domestique la plus sensible à la borréliose de Lyme chez qui la maladie s'exprime principalement sous forme d'arthrite ou de néphrite. Le diagnostic de cette maladie est difficile. Il est cependant possible de détecter les animaux séropositifs grâce à des tests mettant en évidence des anticorps anti-C6, antigène correspondant à une zone invariable d'une protéine de surface du spirochète. Nous avons étudié des résultats issus de la banque de données du laboratoire IDEXX basés sur la réalisation de tests 4Dx Plus et LymeQuantC6 par des vétérinaires installés en France métropolitaine. Ces derniers étudient de manière qualitative et quantitative la séropositivité à l'antigène C6 chez les chiens. La fréquence d'animaux positifs en test qualitatif est de 2,7 % (53/1975) et de 31,1 % (170/546) en test quantitatif. Ces résultats montrent une circulation de Borrelia burgdorferi toute l'année avec une augmentation des cas en période estivale chaude et humide. La répartition géographique des chiens séropositifs s'observe sur l'ensemble du territoire métropolitain avec une prédominance des régions du Centre-Est et de l'Est de la France. Globalement, cette répartition temporelle et géographique des chiens séropositifs concorde avec les résultats observés chez l'Homme. Cette observation vient renforcer la position du chien comme une sentinelle adaptée révélant la circulation de la Borréliose de Lyme dans certaines régions de France.

Unspezifische klinische Ver��nderungen, chronische Krankheitsverl��ufe, verzweifelte Pferdebesitzer und fehlendes Wissen um eine Erkrankung, die sich experimentell bislang nicht reproduzieren lie��, f��hren zu Unsicherheit in der Borreliendiagnostik bei Pferden. Das Fehlen eines einheitlichen Krankheitsbildes oder pathognomonischer klinischer Ver��nderungen wie in der Humanmedizin und auch die mangelnde Standardisierung der Untersuchungsmethoden tragen ihr ��briges zur Verunsicherung bei. Ziele dieser Arbeit waren es, Einblicke in die Seropr��valenzen von Borrelia burgdorferi sensu lato (Bbsl) und Anaplasma phagocytophilum (Ap) Infektionen bei Pferden in Deutschland zu erlangen, Risikofaktoren f��r eine Infektion zu ermitteln und das Krankheitsbild der equinen Lyme-Borreliose (ELB) besser einzugrenzen zu k��nnen. Hierzu sollte eine kranke Fallgruppe mit klinischem ELB-Verdacht mit einer gesunden Kontrolltiergruppe verglichen werden, wobei f��r die Untersuchung jedes Verdachtstieres ein Kontrolltier aus demselben Stall Voraussetzung war. Im Rahmen dieser Studie wurden Blutproben von Pferden aus ganz Deutschland mittels ELISA und Immunoblot auf Bbsl- und mittels eines validierten Snap-Tests (SNAP�� 4Dx Plus�� ELISA) auf Ap-Antik��rper untersucht. Umfangreiche Frageb��gen f��r Pferdebesitzer betroffener Patienten und behandelnde Tier��rzte dienten der Erhebung begleitender Daten zum Signalement, Krankheitsbild, medizinischer Vorgeschichte und der Erhebung von Risikofaktoren f��r die Erregerexposition. Insgesamt wurden 236 Pferde in die Studie eingeschlossen, davon 123 kranke Fall- bzw. Verdachtstiere und 113 gesunde Kontrolltiere. Die Probenerhebung fand von Mai 2017 bis August 2018 statt. Regionale Unterschiede in der Seropr��valenz konnten festgestellt werden: In S��ddeutschland (27,3 %) wurden h��ufiger als in Norddeutschland (17,5 %) Nachweise von Bbsl-Antik��rpern erbracht (p=0,022). Auch die Chance f��r den Nachweis von Antik��rpern, die auf Koinfektion mit Ap hindeuteten, ist in S��ddeutschland h��her (OR=3,1 (1,195-7,848)). F��r die ELB charakteristische klinische Ver��nderungen konnten mit dem gewonnenen Datenmaterial nicht herausgearbeitet werden. Die Tier��rzteschaft zeigte sich gespalten, was ihre Einsch��tzung der klinischen Relevanz der ELB beim Pferd generell betrifft: 51,4 % der Tier��rzte gaben an eine klinisch manifeste Lyme-Borreliose Erkrankung beim Pferd in der Praxis gesehen zu haben, w��hrend der Rest (48,6 %) die Existenz ausschloss oder selbst noch keine F��lle gesehen hatte. Der serologische Nachweis infektionsspezifischer Antik��rper mittels Zweistufentest und erg��nzendem C6-Peptid-Schnelltest liefert einen wichtigen Hinweis auf Bbsl- und Ap-Infektionen, kann und darf jedoch eine eingehende Diagnostik nicht ersetzen. Serologische Befunde m��ssen stets im Kontext mit den beobachteten klinischen Ver��nderungen sowie vorberichtlicher Zeckenexposition interpretiert werden. Die Diagnosestellung sollte zudem nur nach Ausschluss anderer Differentialdiagnosen erfolgen und kann durch die Besserung klinischer Erscheinungen sp��testens innerhalb einer Woche nach eingeleiteter erregerspezifischer Antibiose gest��tzt werden. Ohne konkreten Verdacht muss derzeit von einer unspezifischen Testung auf Antik��rper gegen Bbsl oder Ap abgeraten werden. Vorhandene Prophylaxema��nahmen sollten nach Risikoabw��gung sinnvoll eingesetzt werden., Unspecific clinical changes with often chronic courses of the disease, desperate horse owners and lack of knowledge about a disease that could not be reproduced experimentally so far, lead to uncertainty in in the diagnosis of Lyme Disease (LD) in horses. The lack of a uniform clinical picture or pathognomonic clinical changes as in human medicine, and the lack of standardization of examination methods contribute to the uncertainty. The objectives of this study were to gain insight into the seroprevalence of Borrelia burgdorferi sensu lato (Bbsl) and Anaplasma phagocytophilum (Ap) infections in horses in Germany, and to identify risk factors for infection, to better delineate the clinical picture of equine LD, and to better assess the clinical relevance of both equine LD and equine granulocytic anaplasmosis. For this purpose, a sick case group with clinical suspicion of LD was to be compared with a healthy control animal group, whereby a control animal from the same stable was a prerequisite for the examination of each suspect animal. In this study, blood samples from horses all over Germany were tested for Bbsl-antibodies by ELISA and immunoblot and for Ap-antibodies by a validated snap test (SNAP�� 4Dx Plus�� ELISA). Extensive questionnaires for the owners(own) of the affected equine patients and the treating veterinarians(vet) were used to collect accompanying data on signaling, clinical picture, medical history, and risk factors for pathogen exposure. A total of 236 horses were included in the study, of which 123 were sick case animals and 113 healthy control animals. Sample collection took place from May 2017 to August 2018. Regional differences in seroprevalence could be detected: Southern Germany (27.3 %) had more frequent detections of Bbsl-antibodies than Northern Germany (17.5 %) (p=0.022). The chance for detection of antibodies suggestive of coinfection with Ap was also higher in Southern Germany (OR=3.1 (1.195-7.848)). Clinical changes characteristic for equine LD have not been found with the data material obtained. The veterinary community was divided in their assessment of the clinical relevance of LD in horses in general: 51.4 % of veterinarians reported having seen clinically manifest LD in horses in practice, while the remainder (48.6 %) ruled out its existence or had not seen any cases themselves. Serologic detection of infection-specific antibodies using a two-step test and supplemental rapid C6 peptide test provides an important clue to Bbsl- and Ap-infections but cannot and should not replace a thorough diagnostic workup. Serological findings must always be interpreted in the context of the observed clinical changes as well as pre-reported tick exposure. Furthermore, the diagnosis should only be made after exclusion of other differential diagnoses and can be supported by the improvement of clinical manifestations within one week at the latest after the initiation of pathogen-specific antibiosis. Without concrete suspicion, non-specific testing for antibodies against Bbsl or Ap must currently be discouraged. Existing prophylactic measures should be used judiciously after risk assessment.

Zu den häufigsten Symptomen der Neuroborreliose zählen Meningopolyradikulitis, lymphozytäre Meningitis und eine Beteiligung von Hirnnerven. Die Diagnosestellung erfolgt anhand klinischer Symptomatik, Liquoranalyse und Antikörperuntersuchungen von Liquor und Serum. Besonders in der Frühphase der Infektion gestaltet sich die Diagnosesicherung aufgrund der noch fehlenden Antikörperreaktion jedoch oftmals sehr schwierig. Die Ergebnisse mehrerer Studien legen nahe, dass CXCL-13 einen wertvollen Beitrag leisten könnte, um diese diagnostische Lücke zu schließen. Ziel der Studie war es, die Wertigkeit des Liquorbiomarkers CXCL-13 in der Diagnostik der Neuroborreliose und anderer neuroinflammatorischer Erkrankungen anhand eines großen unselektierten Kollektivs zu ermitteln, einen cut-off Wert für die Verwendung im klinischen Alltag zu definieren und die Ergebnisse mit der bestehenden Literatur zu vergleichen. Dafür wurden am Klinikum Wels-Grieskirchen über einen Zeitraum von 3 Jahren alle Patienten analysiert, bei denen im Rahmen einer Liquorpunktion die CXCL-13 Konzentration bestimmt wurde. Die Patienten wurden anhand der Hauptdiagnose bei Entlassung in 12 Diagnosegruppen aufgeteilt, für die Einteilung der Neuroborreliose Patienten wurden die Diagnoseleitlinien der DGN herangezogen. Alle Liquorproben wurden routinemäßig auf Zellzahl, Gesamteiweiß und Laktat untersucht, die CXCL-13 Konzentration wurde anhand eines enzyme-linked immunsorbent assay (CXCL-13 ELISA, Euroimmun) bestimmt. Unter den 1410 augewerteten Patienten fanden sich 29 Fälle mit gesicherter Neuroborreliose sowie 9 Fälle mit wahrscheinlicher/möglicher Neuroborreliose. Beide Neuroborreliosegruppen zeigten eine deutlich erhöhte mediane CXCL-13 Konzentration (554pg/ml bzw. 649pg/ml), in der Gruppe der bakteriellen und Pilzinfektionen (n=6) fand sich ebenfalls ein deutlich erhöhter Median von 410pg/ml. Alle anderen Gruppen wiesen signifikant niedrigere CXCL-13 Konzentrationen auf (p, Introduction: The B-cell chemoattractant CXCL13 has been suggested as a cerebrospinal fluid (CSF) biomarker for Lyme neuroborreliosis (LNB). Our aim was to substantiate the value of CXCL13 in a large unselected cohort and determine a practical cut-off value to diagnose LNB. Methods: We retrospectively studied clinical and CSF data of consecutive patients who underwent CSF CXCL13 testing over a period of three years (February 2015 to January 2018) at our academic teaching hospital. Patients were classified into 12 groups according to their final diagnosis. To diagnose LNB (definite or probable/possible), definitions of the respective guideline of the German Neurological Society were applied. Results: Of 1410 patients, 29 were diagnosed with definite LNB and 9 with probable/possible LNB. Median CXCL13 levels were highly elevated in both LNB groups (exceeding the test limit of 500 pg/mL) and the group with bacterial/fungal CNS infections (410 pg/mL; n= 6), while the other nine disease groups had markedly lower median CXCL13 levels (p < 0.001). For definite LNB, the best CXCL13 test cut-off was 55.5 pg/mL with a sensitivity of 96.6% (95% confidence interval, CI, 80.4%-99.8%) and a specificity of 94.9% (95% CI 93.5%- 95.9%). All patients diagnosed with LNB showed improvement of clinical symptoms after antibiotic treatment. Conclusion: In this large monocentric cohort, CSF CXCL13 was found to be a highly sensitive and useful marker for LNB. A review of the literature on the sensitivity and specificity of CSF CXCL13 in the differential of LNB is provided.

La maladie de Lyme ou borréliose de Lyme est sujet à controverse depuis 2016. C’est à cette période que les associations de patients atteints de Lyme se sont tournées vers les médecins pour défendre leur combat pour une meilleure prise en charge diagnostic et thérapeutique de la maladie. Cette année-là, 100 médecins signaient un manifeste « L’appel des 100 » publié par l’Obs, dans lequel ils réclamaient notamment, des financements publics pour améliorer les tests de diagnostic, la demande de reconnaissance de la forme chronique de la maladie et la prise en compte des récentes données scientifiques pour établir un nouveau consensus thérapeutique adapté. La Société de Pathologies Infectieuses de la Langue Française répond alors que la révision du consensus thérapeutique n’est pas justifiée au regard des données de la littérature scientifique de l’époque, que les traitements antibiotiques administrés de manière prolongée et répétée ne sont pas utiles, et qu’il n’existe pas de preuves d’une maladie de Lyme chronique. En 2014, le Haut Conseil de la Santé Publique (HCSP) parle dans son rapport de SPPT (Sémiologie Persistante après Piqûre de Tique) pour définir les symptômes polymorphes chronique tels que l’asthénie persistante, les douleurs diffusent de type myalgie, arthralgie migratrice, neuropathique, une diminution des capacités cognitives (troubles mnésiques, difficultés de concentration) qui durent plus de 6 mois après un premier traitement contre la maladie ou une possible piqûre de tique. Aux États-Unis, cette symptomatologie est appelée PTLDS (Post-Treatment Lyme Disease Syndrome). Il s’agit d’un diagnostic d’exclusion, les autres pathologies envisageables doivent donc être écartées avant de conclure à un SPPT. Malgré une définition englobant ces symptômes peu spécifiques, aucun test diagnostic objectif ne permet pour le moment d’établir un véritable diagnostic. Je me suis donc intéressée dans mes recherches pour cette thèse, à ce qui fait la complexité de Borrelia Burgdorferi, cette bactérie responsable de la maladie de Lyme qui suscite de telles divergences de point de vue, et à l’hypothèse émise par de nombreux chercheurs que les formes atypiques de la bactérie telles que les biofilms ou les bactéries persistantes puissent participer à l’étiologie d’une potentielle chronicité de la maladie et donc du SPPT ou PTLDS. Nous verrons quel rôle joue la tique, vecteur de la maladie de Lyme, lors de la transmission de Borrelia burgdorferi à l’homme puis nous aborderons les nombreuses manifestations cliniques possibles de la maladie, dont la maladie de Lyme post-traitement (PTLDS), les diagnostics biologiques couramment utilisés et leurs limites. Je vous parlerai aussi des recommandations officielles du traitement de la maladie, rédigées par les sociétés savantes, et de l’incertitude à laquelle conduisent ces recommandations officielles concernant la prise en charge thérapeutique de la maladie de Lyme Post-traitement. Nous verrons alors certaines des perspectives thérapeutiques allopathiques et phytothérapiques, ainsi que les huiles essentielles prometteuses étudiées ces dernières années afin de traiter le PTLDS. Enfin, nous terminerons avec la prévention contre les piqûres de tiques, le seul moyen actuel encore trop peu connu par la population de prévenir la maladie de Lyme et ses co-infections.

Zusammenfassung Zecken sind Überträger einer Vielzahl humanpathogener Krankheitserreger mit einer großen Bandbreite klinischer Symptome. Das Verbreitungsgebiet der einzelnen Erreger ist vom Vorkommen der Vektoren und Wirte abhängig. Aufgrund verschiedener Faktoren ist es in den letzten Jahren zum Teil zu einer Ausdehnung der Endemiegebiete gekommen. Am weitesten verbreitet sind Zecken-übertragene Rickettsiosen, welche v.a. in der Reisemedizin eine Rolle spielen. Die häufigsten Zecken-übertragbaren Erkrankungen in Deutschland und Europa sind Lyme-Borreliose und Frühsommer-Meningoenzephalitis (FSME). Meist verlaufen die Infektionen mild oder sind — im Falle bakterieller Infektionen — gut behandelbar. Die wichtigsten präventiven Maßnahmen bei Aufenthalten in einem Risikogebiet sind der Schutz vor Zeckenstichen und im Falle der FSME die sehr gut wirksame Impfung.

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Lyme disease (LD) and relapsing fevers (RF) are vector-borne diseases caused by bacteria of the Borrelia genus. Here, we report on the widespread infection by a non-described Borrelia species in passerine-associated ticks in tropical rainforests of French Guiana, South America. This novel Borrelia species is common in two tick species, Amblyomma longirostre and A. geayi, which feed on a broad variety of neotropical mammal and bird species, including migratory species moving to North America. The novel Borrelia species is divergent from the LD and RF species, and is more closely related to the reptile- and echidna-associated Borrelia group that was recently described. Genome sequencing showed that this novel Borrelia sp. has a relatively small genome consisting of a 0.9-Mb-large chromosome and an additional 0.3 Mb dispersed on plasmids. It harbors an RF-like genomic organization but with a unique mixture of LD- and RF-specific genes, including genes used by RF Borrelia for the multiphasic antigen-switching system and a number of immune-reactive protein genes used for the diagnosis of LD. Overall, our data indicate that this novel Borrelia is an intermediate taxon between the LD and RF species that may impact a large host spectrum, including American mammals. The designation “Candidatus Borrelia mahuryensis” is proposed for this species.

A doença de Lyme é uma zoonose pouco relatada no Brasil e o cão comporta-se como reservatório no ambiente domiciliar, o que favorece a transmissão do patógeno para o homem e outros animais. Assim, o objetivo deste trabalho foi relatar a presença de anticorpos anti-Borrelia burgdorferi em um cão atendido em uma clínica de São Luís – MA. A doença de Lyme ou borreliose de Lyme é uma enfermidade infecciosa de distribuição mundial, determinada por espiroquetas do gênero Borrelia, que acomete diferentes espécies de animais domésticos, silvestres e também o homem. Foi atendido em uma clínica particular, um cão da raça Rottweiler, macho, 01 ano de idade com a queixa de apatia, secreção ocular bilateral e presença de ectoparasitas. Ao exame físico foi observado que o animal estava magro, mucosas conjuntival e oral hipocoradas, linfonodos submandibular, pré-escapular e poplíteos normais à palpação e sem alterações à auscultação pulmonar e cardíaca. O presente caso permitiu concluir que as alterações clínicas e hematológicas podem ser inespecíficas, no entanto em regiões onde a incidência de carrapatos é de grande relevância e por ser uma zoonose, torna-se importante a investigação de borreliose em animais que apresentem histórico de carrapato. O diagnóstico preciso de borreliose canina deve ser feito a fim de instituir a terapêutica adequada para o caso. É de suma importância o controle dos vetores, pois são eles os responsáveis pela transmissão da borreliose. Sendo assim, é necessário que haja orientação do Médico Veterinário para os proprietários de animais infectados minimizando os riscos à saúde humana e animal.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2022-05-05T20:39:35Z No. of bitstreams: 1 2019 - Marcio Barizon Cepeda.pdf: 2233401 bytes, checksum: c2854a07666a5fc6776dba78f820c2e3 (MD5) Made available in DSpace on 2022-05-05T20:39:35Z (GMT). No. of bitstreams: 1 2019 - Marcio Barizon Cepeda.pdf: 2233401 bytes, checksum: c2854a07666a5fc6776dba78f820c2e3 (MD5) Previous issue date: 2019-08-21 CAPES - Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior Avian borreliosis is an acute and septicemic disease that can affect a variety of avian species and is caused by the bacterium Borrelia anserina. It is an extremely mobile spirochete and can be detected in the blood plasma of sick fowls during the acute phase of the disease. The vector responsible for the transmission is the Argas (Persicargas) miniatus tick. The experimental study aimed to study the evolution of B. anserina infection in domestic chickens, clinically characterizing the disease through the use of molecular and pathological techniques. A total of 38 fowls were infested with B.anserina infected third stage (N3) nymphs and for study control, two fowls were infested with B.anserina free third stage nymphs. The course of infection was evaluated for 44 days after exposure of ticks to fowls and the experimental procedures were divided into over-acute phase corresponding to day 1 to day 4 post-infection (DPI), acute (5 to 10 DPI) and subacute (14 to 44? DPI), considering the progression of the disease. In the three phases, serum samples were collected daily from 10 fowls and organ fragments during autopsy. The collected material was used in molecular, histopathological and immunohistochemical exams. In all stages, negative samples from healthy birds submitted to the same experimental conditions were analyzed. In PCR, the fowls presented positive organs for B. anserina from the 4th to the 8th DPI, especially the liver, spleen and heart, which presented larger amounts of amplified DNA for the flaB gene. As for serum samples, B. anserina DNA amplification was obtained from the 5th to the 10th DPI. Histopathological analysis revealed significant mild to severe changes and lesions in all organs studied, especially at the liver and splenic level. From the 5th DPI it was possible to detect spirochetes in the liver, kidneys, spleen and heart of infected fowls when impregnated with silver. They could be visualized in these and other tissues up to the 8th DPI, when the massive presence of spirochetes in the bone marrow and ovaries were marked and evidenced, more precisely within the ovarian follicles. Immunohistochemistry was standardized to aid the diagnosis and after performing the technique it was possible to visualize the presence of spirochetes inside vessels and macrophages in the affected renal tissue, as well as confirm the antigen-antibody reaction. Infection by B.anserina caused mild and severe macro and microscopic changes in the organs studied, especially in the liver, kidneys and spleen, and the presence of spirochetes in all tissues evaluated in the acute phase of the disease. This information confirms its septicemic character. The interaction of techniques such as clinical semiology, molecular biology and histopathology in the study of infection, more faithfully portrayed the health status of fowls and contributes to a more appropriate treatment of the disease. A Borreliose avi?ria ? uma doen?a de car?ter agudo e septic?mica, podendo afetar uma variedade de esp?cies avi?rias e causada pela bact?ria Borrelia anserina. ? uma espiroqueta extremamente m?vel, podendo ser detectada no plasma sangu?neo das aves enfermas durante a fase aguda da doen?a. O vetor respons?vel pela transmiss?o ? o carrapato argas?deo Argas (Persicargas) miniatus. O estudo experimental teve por objetivo estudar a evolu??o da infec??o por B. anserina em galinhas dom?sticas, caracterizando clinicamente a enfermidade atrav?s da utiliza??o de t?cnicas moleculares e patol?gicas. Um total de 38 aves foram infestadas com ninfas de terceiro est?gio (N3) infectadas com B.anserina e para controle do estudo, duas aves foram infestadas com ninfas de terceiro est?gio livres de B.anserina. O curso da infec??o foi avaliado durante 44 dias ap?s a exposi??o dos carrapatos ?s aves e os procedimentos experimentais foram divididos em fase superaguda correspondendo do 1? ao 4? dia p?s-infec??o (DPI), aguda (5? ao 10? DPI) e subaguda (14? ao 44?DPI), considerando a progress?o da doen?a. Nas tr?s fases, foram coletadas diariamente amostras de soro de 10 aves e fragmentos de ?rg?os durante a necropsia. O material coletado foi utilizado nos exames moleculares, histopatol?gicos e imuno-histoqu?micos. Em todas as etapas, foram analisadas amostras negativas, oriundas de aves saud?veis submetidas ?s mesmas condi??es experimentais. Na PCR, as aves apresentaram ?rg?os positivos para B. anserina do 4? ao 8? DPI, com destaque para o f?gado, ba?o e cora??o, que apresentaram maiores quantidades de DNA amplificado para o gene flaB. Quanto ?s amostras de soro, obteve-se amplifica??o do DNA de B. anserina, do 5? ao 10? DPI. A an?lise histopatol?gica revelou altera??es e les?es significativas, leves a severas, em todos os ?rg?os estudados, principalmente ao n?vel hep?tico e espl?nico. A partir do 5? DPI j? foi poss?vel detectar as espiroquetas no f?gado, rins, ba?o e cora??o das aves infectadas, quando impregnadas pela prata. Elas puderam ser visualizadas nestes e em outros tecidos at? o 8?DPI, quando foram marcadas e evidenciadas a presen?a maci?a de espiroquetas na medula ?ssea e nos ov?rios, mais precisamente no interior dos fol?culos ovarianos. A imuno-histoqu?mica foi padronizada para o aux?lio no diagn?stico e ap?s a realiza??o da t?cnica foi poss?vel visualizar a presen?a das espiroquetas no interior de vasos e macr?fagos no tecido renal acometido, assim como confirmar a rea??o ant?geno- anticorpo. A infec??o por B.anserina provocou altera??es macro e microsc?picas de leves a severas nos ?rg?os estudados, principalmente no f?gado, rins e ba?o, al?m da presen?a das espiroquetas em todos os tecidos avaliados na fase aguda da doen?a. Essas informa??es confirmam o seu car?ter septic?mico. A intera??o de t?cnicas como a semiologia cl?nica, biologia molecular e histopatologia no estudo da infec??o, retratou mais fielmente o estado de sa?de das aves e contribui para um tratamento mais adequado da enfermidade.

International audience; Cet article fait le point sur la controverse médico-sociale concernant la "maladie de Lyme", jusqu'en juin 2018. Il montre comment, en dépit des avancées scientifiques qui permettent de mieux comprendre le fonctionnement de sa forme chronique, certaines institutions médicales françaises bloquent toute évolution dans sa prise en charge, laissant les patients dans la souffrance alors que des solutions, au moins partielles, sont connues. Il cherche à comprendre les raisons de cette attitude apparemment absurde et montre le rôle des patients et de certains médecins dans l'évolution de la situation.