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International audience; Mass-participation events in temperate forests are now well-established features of outdoor activities and represent high-risk activities regarding human exposition to tick bites. In this study we used a citizen science approach to quantify the space–time frequency of tick bites and undetected tick bites among orienteers that participated in a 6-day orienteering competition that took place in July 2018 in the forests of Eastern France, and we looked at the use and efficacy of different preventive behaviors. Our study confirms that orienteers are a high-risk population for tick bites, with 62.4% of orienteers bitten at least once during the competition, and 2.4 to 12.1 orienteers per 100 orienteers were bitten by ticks when walking 1 km. In addition, 16.7% of orienteers bitten by ticks had engorged ticks, meaning that they did not detect and remove their ticks immediately after the run. Further, only 8.5% of orienteers systematically used a repellent, and the use of repellent only partially reduced the probability of being bitten by ticks. These results represent the first attempt to quantify the risk of not immediately detecting a tick bite and provide rare quantitative data on the frequency of tick bites for orienteers according to walking distance and time spent in the forest. The results also provide information on the use of repellent, which will be very helpful for modeling risk assessment. The study also shows that prevention should be increased for orienteers in France.

BackgroundIn 2002, a previously healthy 69-year-old man travelled to France from the United States and presented to our hospital with a febrile illness that subsequently was determined to be babesiosis. The blood isolated from this patient served as a source for propagation of the Babesia microti R1 strain with subsequent sequencing and annotation of the parasite genome.MethodsUpon admission, we obtained a medical history, performed a physical examination, and examined his blood for the presence of a blood borne pathogen by microscopy, PCR and indirect immunofluorescence antibody testing. Once the diagnosis of babesiosis was made, we reviewed the literature to assess the distribution of B. microti-associated babesiosis cases in immunocompetent patients from outside the USA.ResultsThe patient recalled a tick bite during the previous month on Cape Cod, Massachusetts. The diagnosis was confirmed by identification of Babesia-infected red blood cells on blood smears, amplification of B. microti DNA in blood by PCR and the presence of B. microti antibody in the serum. This strain was the first isolate of B. microti to be fully sequenced and its annotated genome serves as a reference for molecular and cell biology studies aimed at understanding B. microti pathophysiology and developing diagnostic tests and therapies. A review of babesiosis cases demonstrates a worldwide distribution of B. microti and identifies potential emerging endemic areas where travelers may be at risk of contracting B. microti infection.ConclusionThis case provides clinical information about the patient infected with the R1 isolate and a review of travel risk, diagnosis and treatment of babesiosis in endemic and non-endemic areas.

International audience; Today, we are witnessing changes in the spatial distribution and abundance of many species, including ticks and their associated pathogens. Evidence that these changes are primarily due to climate change, habitat modifications, and the globalisation of human activities are accumulating. Changes in the distribution of ticks and their invasion into new regions can have numerous consequences including modifications in their ecological characteristics and those of endemic species, impacts on the dynamics of local host populations and the emergence of human and livestock disease. Here, we review the principal causes for distributional shifts in tick populations and their consequences in terms of the ecological attributes of the species in question (i.e. phenotypic and genetic responses), pathogen transmission and disease epidemiology. We also describe different methodological approaches currently used to assess and predict such changes and their consequences. We finish with a discussion of new research avenues to develop in order to improve our understanding of these host-vector-pathogen interactions in the context of a changing world.

The indicator value (Ind Val) method which combines measures of fidelity and specificity has been used in a study on wild boar parasites in Corsica during 2001–2003. Because of its resilience to changes in abundance,IndValis a particularly effective tool for ecological bioindication. TheInd Valmethod showed how season can influence the occurrence of parasite species in the wild boar, and also identified parasites as bioindicators relative to host age. The randomization test identified five parasite species having a significant indicator value for the season (the ticks,Hyalomma aegyptiumandRhipicephalus sanguineus, the louse,Haematopinus suisand the nematodesGlobocephalus urosubulatusandAscaris suumand two indicator species of an age class (the nematodesG. urosubulatusandMetastrongylussp.). Data on species composition and infection levels would help improve the monitoring and management of parasitism in Suidae populations.

To the Editor: Granulocytic anaplasmosis is a tickborne zoonosis caused by Anaplasma phagocytophilum bacteria, which are emerging in Europe. Besides infecting humans, A. phagocytophilum infect a wide range of wild and domestic mammals (1). In Europe, the Ixodes ricinus tick is the main vector for the bacteria, but A. phagocytophilum has also been detected in association with Rhipicephalus and Dermacentor spp. ticks (2). The climate and biotopes of the Mediterranean region are particularly favorable for several species of ticks and, therefore, for tickborne diseases. Although I. ricinus ticks are rare or absent in the Mediterranean Basin, serosurveys performed on equine populations in Camargue, southern France, indicated an A. phagocytophilum seroprevalence of ≈10% (3). To investigate the prevalence and diversity of A. phagocytophilum bacteria in ticks in Camargue, we collected questing ticks from horse pastures and feeding ticks from horses. Ticks feeding on horses were collected in randomly selected stables during 2007 (84 stables), 2008 (72 stable), and 2010 (19 stables). The stables were chosen among those where evidence of A. phagocytophilum seroconversion in horses had been previously found (3). In 2008 and 2010, questing ticks were collected by the dragging method in 19 pastures, around bushes, and in areas where horses spent the most time. Surveys were conducted in the spring, which represents the peak activity time of Ixodes ticks. A total of 406 adult ticks were collected, representing 6 species: Rhipicephalus bursa, R. sanguineus, R. turanicus, R. pusillus, Dermacentor marginatus, and Hyalomma marginatum. Tick species were identified by morphologic criteria and molecular analyses based on mitochondrial 12S rDNA sequences (4). Total DNA was extracted from the ticks by using the NucleoSpin Tissue Kit (Macherey-Nagel, Duren, Germany) (5). A. phagocytophilum was detected by nested PCR targeting the 16S rDNA (Technical Appendix 1). Of the 406 ticks, 40 were infected with A. phagocytophilum. The infected group included ticks from all 6 collected species except R. pusillus. Infection rates among the species ranged from 0 to 22% (Technical Appendix 2). The prevalence of A. phagocytophilum infection did not differ significantly between species (logistic regression model, p = 0.76) but was higher among questing ticks than feeding ticks (p

International audience; Seventy-four cattle, from three farms endemic for tropical theileriosis in the north of Tunisia, were studied for tick populations from June 1991 to June 1992. Ticks were removed from cattle twice a month in the summer and every month the rest of the year. They were identified and assessed for Theileria infection. A total of 5083 Hyalomma adult ticks were collected and the major species found was H. detritum (84.3%). The activity of this species is limited between June and August with a peak in numbers observed at the end of June and the beginning of July. Amongst the 2356 Hyalomma ticks dissected, no evidence of salivary gland infection was found in either H. m. marginatum or H. a. excavatum. However, 12.4% (277/2230) of H. d. detritum dissected ticks were infected with Theileria species and amongst these, 62% had one to two sporoblasts in their salivary glands (range 1-91). The prevalence, but not the intensity, of infection was greater in females than in male ticks, and the cases of tropical theileriosis followed the peak of infected females. This suggests that female ticks have a more important role in theileriosis transmission than male ticks. A significantly lower number of adult H. detritum were collected from calves, at their first tick season, than from adult cattle. Finally, this study showed that the infestation level of cattle by H. d. detritum and the prevalence of Theileria-infection in these cattle varied between the three farms studied.

International audience; The genetic diversity and prevalence of Babesia and Theileria species in the equine population of Tunisia were studied using reverse line blot (RLB) hybridization on blood samples and unfed adult ticks collected from apparently healthy horses from three bioclimatic zones in Tunisia. Piroplasms were identified in 13 of 104 of the horse blood samples analyzed (12.5%) and five genotype groups were identified: Theileria equi group A (nine animals, 8.7%), group C (one animal, 1.0%) and group D (three animals, 2.9%), and Babesia caballi groups A and B (one animal each). All horses from the semi-arid zone were negative and prevalence in the humid and sub-humid zones were 12.9% and 20.0%, respectively. Three Ixodid tick species (Hyalomma marginatum, Hyalomma excavatum and Rhipicephalus bursa) were collected from examined horses and equine piroplasms were detected in 10.8% of them. T. equi groups A and D (9.2%), and B. caballi group B (1.6%) were identified in ticks. This work represents the first epidemiological report of equine piroplasmosis in Tunisia. Results showed a high level of diversity within the 18S rRNA gene of equine piroplasm species, and confirmed the presence in Tunisia of two T. equi genetic groups, C and D, only reported before in South Africa and Sudan.

International audience

International audience; Between October and November 2006, a total of 278 bovine blood samples were examined, and 104 (37.4%) were positive for piroplasms by microscopy. A reverse line blot hybridisation with polymerase chain reaction detected Theileria annulata, T. buffeli, Babesia bovis and B. bigemina in cattle accounting for 48.6% of positive samples. The most frequently found species was T. buffeli, which was present in 39.2% of the samples. T. annulata was found in 48 samples (17.3%). Babesia infections were less frequently detected: B. bovis was found in 6.8% of the samples and B. bigemina in 4.3%. Mixed infections were detected in 45 samples, accounting for seven different combinations of species. Seven Ixodid tick species (Boophilus annulatus, Ixodes ricinus, Hyalomma marginatum, Hyalomma excavatum, Hyalomma detritum, Haemaphysalis punctata and Haemaphysalis sulcata) were collected from examined cattle in the 23 visited farms. I. ricinus was the dominant species (36%), mainly collected in the humid zone, while it seemed to be very rare in the semi-arid zone (where only 15 specimens were collected), whereas B. annulatus was the most commonly collected species in the sub-humid area (68.5% of ticks collected in this zone).

Ticks are obligate haematophagous acarines that parasitise every class of vertebrate (including man) and have a worldwide distribution. An increasing awareness of tick-borne diseases among clinicians and scientific researchers has led to the recent description of a number of emerging tick-borne bacterial diseases. Since the identification of Borrelia burgdorferi as the agent of Lyme disease in 1982, 11 tick-borne human bacterial pathogens have been described in Europe. Aetiological diagnosis of tick-transmitted diseases is often difficult and relies on specialised laboratories using very specific tools. Interpretation of laboratory data is very important in order to establish the diagnosis. These guidelines aim to help clinicians and microbiologists in diagnosing infection transmitted by tick bites and to provide the scientific and medical community with a better understanding of these infectious diseases.

International audience; Four Theileria annulata cell lines were characterised at low passage levels using two polymorphic markers and then used to infect calves. Their virulence seemed to be related to the number of genotypes present within the cell line. In all, 3 of the 4 cell lines were cultured up to passage 100 or 200 and inoculated into calves. Their characterisation using the same markers indicated that the attenuation was related to a reduction in the parasite polymorphism down to a single genotype. The immunogenicity of the three attenuated cell lines was assessed in calves using two types of challenge. Optimal protection was observed against homologous challenges. The level of immunity to heterologous challenges appeared to decrease with attenuation and seemed to depend on the cell line used.