Many factors are involved in determining the latitudinal and altitudinal spread of the important tick vector Ixodes ricinus (Acari: Ixodidae) in Europe, as well as in changes in the distribution within its prior endemic zones. This paper builds on published literature and unpublished expert opinion from the VBORNET network with the aim of reviewing the evidence for these changes in Europe and discusses the many climatic, ecological, landscape and anthropogenic drivers. These can be divided into those directly related to climatic change, contributing to an expansion in the tick’s geographic range at extremes of altitude in central Europe, and at extremes of latitude in Scandinavia; those related to changes in the distribution of tick hosts, particularly roe deer and other cervids; other ecological changes such as habitat connectivity and changes in land management; and finally, anthropogenically induced changes. These factors are strongly interlinked and often not well quantified. Although a change in climate plays an important role in certain geographic regions, for much of Europe it is non-climatic factors that are becoming increasingly important. How we manage habitats on a landscape scale, and the changes in the distribution and abundance of tick hosts are important considerations during our assessment and management of the public health risks associated with ticks and tick-borne disease issues in 21st century Europe. Better understanding and mapping of the spread of I. ricinus (and changes in its abundance) is, however, essential to assess the risk of the spread of infections transmitted by this vector species. Enhanced tick surveillance with harmonized approaches for comparison of data enabling the follow-up of trends at EU level will improve the messages on risk related to tick-borne diseases to policy makers, other stake holders and to the general public.

Background: Anaplasma phagocytophilum, the causative agent of canine granulocytic anaplasmosis (CGA), is a Gram-negative intracellular organism transmitted by ixodid ticks. Thus far, only a few clinical studies evaluating dogs with CGA have been published.Objectives: Evaluation of dogs naturally infected with A. phagocytophilum in which known co-infections were excluded. Animals: Eighteen dogs with CGA. Methods: Prospective study. The diagnosis of CGA was based on a positive PCR test result; dogs with co-infections were excluded. History, clinical findings, CBC, clinical biochemistry, infectious disease screening, diagnostic imaging, and the course of disease were evaluated.Results: CGA was diagnosed based on a positive PCR test for A. phagocytophilum; 10 dogs also had morulae in neutrophils. Six of 18 dogs were seronegative to A. phagocytophilum, the others were seropositive. All dogs were acutely ill. The most common clinical findings were lethargy, inappetence, fever, and splenomegaly. Abnormal laboratory results included thrombocytopenia, anemia, lymphopenia, hypoalbuminemia, and abnormally high plasma alkaline phosphatase activity. In 6 of 10 dogs tested, the platelet-bound antibody test was positive; Coombs' test was negative in 9 dogs. All dogs were treated with doxycycline and recovered. PCR testing as well as blood smear analysis for morulae were negative in 14 tested dogs 2-8 weeks after beginning treatment.Conclusions and Clinical Importance: Clinical findings in dogs with CGA were nonspecific. Positive platelet-bound antibody test results suggest immune-mediated platelet destruction as an important pathogenic mechanism. With correct diagnosis and treatment, prognosis is good.

No abstract

BackgroundThe aims of this study were to evaluate the host-tick-pathogen interface of Babesia spp. and Anaplasma phagocytophilum in restored areas in both questing and host-attached Ixodes ricinus and Dermacentor reticulatus and their small mammalian hosts.MethodsQuesting ticks were collected from 5 sites within the city of Leipzig, Germany, in 2009. Small mammals were trapped at 3 of the 5 sites during 2010 and 2011. DNA extracts of questing and host-attached I. ricinus and D. reticulatus and of several tissue types of small mammals (the majority bank voles and yellow-necked mice), were investigated by PCR followed by sequencing for the occurrence of DNA of Babesia spp. and by real-time PCR for A. phagocytophilum. A selected number of samples positive for A. phagocytophilum were further investigated for variants of the partial 16S rRNA gene. Co-infection with Rickettsia spp. in the questing ticks was additionally investigated.Results4.1% of questing I. ricinus ticks, but no D. reticulatus, were positive for Babesia sp. and 8.7% of I. ricinus for A. phagocytophilum. Sequencing revealed B. microti, B. capreoli and Babesia spp. EU1 in Leipzig and sequence analysis of the partial 16S RNA gene of A. phagocytophilum revealed variants either rarely reported in human cases or associated with cervid hosts. The statistical analysis revealed significantly less ticks infected with A. phagocytophilum in a city park in Leipzig as compared to the other sampling sites. A. phagocytophilum-DNA was detected in 2 bank voles, DNA of B. microti in 1 striped field-mouse and of Babesia sp. EU1 in the skin tissue of a mole. Co-infections were detected.ConclusionOur results show the involvement of small mammals in the natural endemic cycles of tick-borne pathogens. A more thorough understanding of the interactions of ticks, pathogens and hosts is the essential basis for effective preventive control measures.

No abstract

The occurrence of genetic variants of Anaplasma phagocytophilum was studied in wild ungulates from the northern and central eastern Alps in Tyrol, Austria. For this purpose, spleen samples collected from 53 game animals during the hunting season 2008/2009 (16 roe deer [Capreolus capreolus], 10 red deer [Cervus elaphus], 16 Alpine chamois [Rupicapra r. rupicapra], 7 Alpine ibex [Capra i. ibex], and 4 European mouflons [Ovis orientalis musimon]) were analyzed. Thirty-five animals originated from the Karwendel mountains, 12 from the Kaunertal area (Ötztal Alps), and the remaining from other mountainous areas in Tyrol. DNA extracts were screened with a real-time polymerase chain reaction targeting the msp2 gene of A. phagocytophilum. A total of 23 (43.4%) samples, from all ungulate species studied, were A. phagocytophilum positive. As of the date of this article, A. phagocytophilum has not been reported in the Alpine ibex. The positive samples were investigated further with polymerase chain reactions for amplification of the partial 16S rRNA, groEL, and msp4 genes. Sequence analysis using forward and reverse primers revealed seven different 16S rRNA gene variants. No variant could be attributed to any particular ungulate species. The groEL gene revealed 11 different variants, which grouped in the phylogenetic analysis into two distinct clusters: one cluster contained the sequences from roe deer, whereas the sequences of the other species formed the second cluster. The msp4 gene showed a high degree of variability in the amplified part with a total of 10 different sequence types. The results show that the wild mountain ungulates were infected to a considerable extent with various variants of A. phagocytophilum. The pathogenicity of the variants and the reservoir competence of the species investigated in this study deserve further attention in future studies.

No abstract

No abstract