The prevalence of Dirofilaria immitis and D. repens in the Old World.

Dirofilaria immitis and D. repens are endemic throughout Europe and southern eastern regions of Asia and reported with increasing frequency in Africa. Nevertheless, the increased awareness of veterinary practitioners, even in countries where the prevalence is low, has led to a decrease D. immitis prevalence in dogs, especially in previously endemic/hyper-endemic areas. Prevalence has significantly increased, however, in areas where heartworm has apparently spread more recently, such as Central and North Eastern Europe. Furthermore, autochthonous cases have been observed in Siberia. Low seroprevalence has been reported in Croatia, while in Romania it has reached 14%. In Greece, the prevalence ranges between 0.7% and 25% whilst in Turkey is 0-18%. Data for canine dirofilariosis in Africa is scarce, and most are case reports. Overall, the dominant species is Achanthocheilonema dracunculoides, although both D. immitis and D. repens have been reported from some countries. In the Far East, the prevalence ranges from 2% to 15% in northeastern of China. In Hong Kong a novel species has been found in dogs and humans (Candidatus Dirofilaria hongkongensis). In India, the prevalence ranges from 4.7%-29.5% in Northeastern states. The main factors that have influenced the spreading of Dirofilaria infections are the climate changes and the introduction of new, invasive, competent mosquito species such as Aedes albopictus and Ae. koreicus. Other factors include relocation and insufficient prevention in dogs, manly in the new areas of colonization. Feline heartworm infection has been diagnosed in every European country when diagnosed either by the Knott test or by serology for circulating antibodies and antigens of the parasite. However, prevalence is much lower than in dogs. In spite of the continuing spreading of heartworm infection, D. repens is the main concern in Europe, mostly for physicians, while the infection is nearly always asymptomatic in dogs. The infection is spreading from Portugal to the Southeastern regions of Finland and Siberia, and in some areas its prevalence overlaps that of D. immitis. Many reasons make more difficult the control of D. repens than D. immitis: the frequent lack of clinical symptoms of suspicion, the specific diagnosis being possible only by blood examination and the inefficacy of some macrocyclic lactones.

Recent advances on Dirofilaria repens in dogs and humans in Europe.

Dirofilaria repens is a nematode affecting domestic and wild canids, transmitted by several species of mosquitoes. It usually causes a non-pathogenic subcutaneous infection in dogs and is the principal agent of human dirofilariosis in the Old World. In the last decades, D. repens has increased in prevalence in areas where it has already been reported and its distribution range has expanded into new areas of Europe, representing a paradigmatic example of an emergent pathogen. Despite its emergence and zoonotic impact, D. repens has received less attention by scientists compared to Dirofilaria immitis. In this review we report the recent advances of D. repens infection in dogs and humans, and transmission by vectors, and discuss possible factors that influence the spread and increase of this zoonotic parasite in Europe. There is evidence that D. repens has spread faster than D. immitis from the endemic areas of southern Europe to northern Europe. Climate change affecting mosquito vectors and the facilitation of pet travel seem to have contributed to this expansion; however, in the authors' opinion, the major factor is likely the rate of undiagnosed dogs continuing to perpetuate the life-cycle of D. repens. Many infected dogs remain undetected due to the subclinical nature of the disease, the lack of rapid and reliable diagnostic tools and the poor knowledge and still low awareness of D. repens in non-endemic areas. Improved diagnostic tools are warranted to bring D. repens diagnosis to the state of D. immitis diagnosis, as well as improved screening of imported dogs and promotion of preventative measures among veterinarians and dog owners. For vector-borne diseases involving pets, veterinarians play a significant role in prevention and should be more aware of their responsibility in reducing the impact of the zoonotic agents. In addition, they should enhance multisectorial collaboration with medical entomologists and the public health experts, under the concept and the actions of One Health-One Medicine.

Subcutaneous dirofilariosis (Dirofilaria repens): an infection spreading throughout the old world.

BACKGROUND: Two main Dirofilaria species infect dogs: D. immitis and D. repens. While D. immitis has a worldwide distribution, D. repens is currently found only in Europe, Asia, and Africa. Adult D. repens are located in subcutaneous tissues of natural hosts where they survive for long periods of time. First-stage larvae, microfilariae, circulate in the peripheral bloodstream, where they are taken up by the mosquito intermediate hosts. Infected mosquitoes then transmit infective third-stage (L3) larvae to new hosts through the blood meal. In dogs, most infections are asymptomatic, although cutaneous disorders such as pruritus, dermal swelling, subcutaneous nodules, and ocular conjunctivitis can be observed. Currently, two factors have increased the concerns about this parasitic infection 1) its spread throughout the European countries and to other continents and its prevalence in dog populations, where in some cases it has overcome D. immitis; and 2) its zoonotic potential, which is much greater than that of D. immitis. RESULTS: Different hypotheses can be put forward to explain these concerns. First, climate change has allowed more favorable conditions for survival of culicid vectors. Second, accidental hosts such as humans may have a less efficient immune reaction against a parasite that is located in subcutaneous tissues, and thus less exposed to the host's immune response than, for instance, D. immitis. Furthermore, the absence of clinical signs in the majority of canine infections and the difficulty in diagnosing the infection, due to the lack of serologic tests and thus the reliance on the identification of microfilariae and differentiation from D. immitis to confirm the presence of the parasite, favor the further spread of this species. Finally, among the macrocyclic lactones currently used to prevent heartworm infection, only moxidectin has been found to be fully effective against the infective larvae transmitted by mosquitoes and partially effective (efficacy 96%) against adult D. repens in experimental studies. CONCLUSIONS: Dirofilaria repens infection is much more difficult than D. immitis to diagnose and control in the reservoir population (microfilaremic dogs). In addition, lack of familiarity with D. repens infection could lead to lack of vigilance underestimation for this parasite. The number of human cases in Europe and Asia is currently a serious public health concern. Medical doctors and veterinarians must collaborate closely for better control and surveillance of D. repens infection.

Pharmacokinetics and efficacy of an ivermectin implant for long-term prevention of Dirofilaria immitis infection in dogs.

An exploratory study was carried out to assess the in vivo efficacy of different prototypes of subcutaneous implants containing ivermectin (IVM) for the prevention of canine Dirofilaria immitis infection. The implants consisted of an ethylcellulose matrix containing IVM (3.0, 4.5, and 6.0 mg/implant; from 0.29 to 0.63 mg/kg bw) as active ingredient designed to release approximately 0.1 ng of IVM/mL in the plasma for at least 12 months. Six dogs were implanted on day -365. On day -12, three heartworm-free dogs were included in the study as a control group. All nine dogs were examined on day -7 and day 0 for circulating D. immitis microfilariae and by an antigen ELISA kit to confirm that the dogs were heartworm-free. The dogs were artificially infected with 75 D. immitis infective larvae (L3) each on day 0. Dogs in the control group were humanely euthanized on day 153 to verify the infectivity of the larvae, while implanted dogs were further examined for circulating D. immitis microfilariae and antigen on days 153, 195, and 246. The treated dogs were not necropsied. The pharmacokinetic profile of the IVM implant was assessed in plasma samples taken on day -364, then at different times until the infection day, and again on days, 15, 30, 60, 90, 120, and 153. Throughout the study, body weights were measured during clinical examination on days 0, 30, 60, 90, 120, and 153. At necropsy, all control dogs were found infected, each with 10-11 adult heartworms. Implanted dogs were negative at both microfilaria and D. immitis antigen examinations until day 246 (8 months from the infection). IVM plasma levels ranged 0.06-0.16 ng/mL on day 0 and remained stable until day 60, afterward they gradually decreased under the limit of quantification of the method. Throughout the study, no side effect was observed. On the basis of these results, it was possible to conclude that the different prototypes of implants were able to protect the dogs from D. immitis artificial infection for at least 12 months.

The prevalence, abundance and distribution of cyathostomins (small stongyles) in horses from Western Romania.

Forty seven working horses from Romania were post-mortem examined for small strongyles (Cyathostominae) infections. All horses were found infected. The overall cyathostomins intensity ranged from 390 to 13,010 and horses were infected by 8-24 species. The intensity was higher in ventral colon (1531) and dorsal colon (824), the lowest in the caecum (524). Twenty four species were identified. Cyathostomum catinatum, Cylicocyclus insigne, and C. Nassatus had 100% of prevalence. Over 50% of horses were infected by Coronocyclus coronatus, Cylicostephanus calicatus, C. goldi, and C. longibursatus. Other prevalent species (34%-45%) were Cyathostomum tetracanthum, Cylicostephanus minutus and Gyalocephalus capitatus. Coronocyclus labiatus, Parapoteriostomum mettami, Poteriostomum imparidentatum and P. ratzii had the lowest prevalence. Most species showed high organ preference with a niche breadth value between 1 and 1.96 while only 7 species (Coronocyclus labiatus, Cyathostomum tetracanthum, C. brevicapsulatus, Cylicocyclus elongatus, C. insigne, C. leptostomum and C. radiatus) showed a more generalist selection. The niche breadth of 10 species was significantly (p<0.05) influenced by itself intensity (Coronocyclus labratus, Cyathostomum pateratum, C. tetracanthum, Cylicocyclus elongatus, C. radiatus, C. ultrajectinus, C. leptostomum, Cylicodontophorus euproctus, Poteriostomum imparidentatum, P. ratzii). The niche breadth of Cylicocyclus nassatus was positively (p<0.05) influenced by the summed intensity of the other species while that of Cylicocyclus elongatus was negatively (p<0.05) influenced by the intensity of the other species. The cluster analysis of the Cyathostominae community composition showed a major cluster composed by the three dominant species, followed by a cluster composed by Coronocyclus coronatus, while all the other species presented a tree like structure.

Evaluation of the Adulticidal Efficacy of Imidacloprid 10 %/Moxidectin 2.5 % (w/v) Spot-on (Advocate®, Advantage® Multi) against Dirofilaria repens in Experimentally Infected Dogs.

This study aimed to evaluate the efficacy of imidacloprid 10 %/moxidectin 2.5 % (w/v) spot-on (Advocate®/Advantage® Multi, Bayer) against adult Dirofilaria repens in a blinded, placebo-controlled randomised laboratory study. Twenty-four Beagle dogs were experimentally infected with approximately 75 infective D. repens larvae each on study day (SD) 0. Treatment was initiated on SD 228 after patency had been confirmed in 21 dogs, using a modified Knott Test. Eleven dogs received monthly treatments with imidacloprid/moxidectin at the minimum therapeutic dose (10 mg/kg imidacloprid and 2.5 mg/kg moxidectin) for six consecutive months and 12 control dogs were treated with a placebo formulation. Approximately one month after the last treatment, all dogs were euthanised and necropsied for the detection of D. repens worms. Eleven control dogs harboured live adult D. repens (range 2-11, geometric mean 5.44). Eight of 11 imidacloprid/moxidectin-treated dogs were free of live worms. The live worm count was reduced by 96.2 % (range 0-1, geometric mean 0.21). The majority of dead worms were encapsulated and degenerated. After the first treatment, Knott Tests were negative in all imidacloprid/moxidectin-treated dogs and this status was maintained in 10 dogs until study end. One dog showed a low microfilariae count (1 and 4/mL) on four occasions but was also negative before necropsy. The treatment was well tolerated by all study animals. It is concluded that six consecutive monthly treatments with imidacloprid/moxidectin spot-on are effective and safe against adult D. repens and provide an option for preventing the further spread of this zoonotic parasite.

The role of wild canids and felids in spreading parasites to dogs and cats in Europe. Part II: Helminths and arthropods.

Over the last few decades, ecological factors, combined with everchanging landscapes mainly linked to human activities (e.g. encroachment and tourism) have contributed to modifications in the transmission of parasitic diseases from domestic to wildlife carnivores and vice versa. In the first of this two-part review article, we have provided an account of diseases caused by protozoan parasites characterised by a two-way transmission route between domestic and wild carnivore species. In this second and final part, we focus our attention on parasitic diseases caused by helminth and arthropod parasites shared between domestic and wild canids and felids in Europe. While a complete understanding of the biology, ecology and epidemiology of these parasites is particularly challenging to achieve, especially given the complexity of the environments in which these diseases perpetuate, advancements in current knowledge of transmission routes is crucial to provide policy-makers with clear indications on strategies to reduce the impact of these diseases on changing ecosystems.

The role of wild canids and felids in spreading parasites to dogs and cats in Europe. Part I: Protozoa and tick-borne agents.

Over the last few decades, the world has witnessed radical changes in climate, landscape, and ecosystems. These events, together with other factors such as increasing illegal wildlife trade and changing human behaviour towards wildlife, are resulting into thinning boundaries between wild canids and felids and their domestic counterparts. As a consequence, the epidemiology of diseases caused by a number of infectious agents is undergoing profound readjustements, as pathogens adapt to new hosts and environments. Therefore, there is a risk for diseases of wildlife to spread to domestic carnivores and vice versa, and for zoonotic agents to emerge or re-emerge in human populations. Hence, the identification of the hazards arising from the co-habitation of these species is critical in order to plan and develop adequate control strategies against these pathogens. In the first of this two-part article, we review the role that wild canids and felids may play in the transmission of protozoa and arthropod-borne agents to dogs and cats in Europe, and provide an account of how current and future progress in our understanding of the ecology and epidemiology of parasites, as well as of host-parasite interactions, can assist efforts aimed at controlling parasite transmission.

Canine and human Dirofilaria infections in the Balkan Peninsula.

Dirofilaria immitis and Dirofilaria repens infections are mosquito-borne diseases, mainly of dogs. Both parasites are zoonotic, and they sometimes cause serious infections in humans. The aim of this short review was to examine the situation in the Balkan Peninsula, from where it is not always easy to obtain suitable data, often reported in journals and other publications difficult to be retrieved and with poor or no visibility. The review included data from international and regional literature, doctoral theses, and conference proceedings.

Occurrence and genetic characterization of Echinococcus granulosus in naturally infected adult sheep and cattle in Romania.

An epidemiological and molecular study was conducted to investigate the occurrence and genetic diversity of Echinococcus granulosus isolates from adult sheep and cattle in Romania. Overall, 642 sheep (aged over 3 years) and 1878 cattle (aged over 5 years) from 16 counties were examined for hydatid cysts. Of them, 421 (65.6%) sheep and 754 (40.1%) cattle were found infected by cystic echinococcosis (CE). Germinal layers were collected from 98 individual cysts (one cyst per animal; 31 from sheep and 67 from cattle), DNA was extracted and two different mitochondrial DNA genes, namely cytochrome c oxidase subunits 1 (CO1) and 12S ribosomal DNA (12S rDNA) were used as genetic markers. The assessment of the genetic diversity of the Echinococcus strains showed the presence of the E. granulosus sensu stricto complex and disclosed an apparent dominance of the G1 genotype within the G1­G3 complex. Furthermore, several mitochondrial variants were identified for the G1 and G2 genotypes of E. granulosus s.s. complex. Overall, the findings were of epidemiological relevance and highlighted a high potential risk of zoonotic infection.

ABC transporters are involved in defense against permethrin insecticide in the malaria vector Anopheles stephensi.

BACKGROUND: Proteins from the ABC family (ATP-binding cassette) represent the largest known group of efflux pumps, responsible for transporting specific molecules across lipid membranes in both prokaryotic and eukaryotic organisms. In arthropods they have been shown to play a role in insecticide defense/resistance. The presence of ABC transporters and their possible association with insecticide transport have not yet been investigated in the mosquito Anopheles stephensi, the major vector of human malaria in the Middle East and South Asian regions. Here we investigated the presence and role of ABCs in transport of permethrin insecticide in a susceptible strain of this mosquito species. METHODS: To identify ABC transporter genes we obtained a transcriptome from untreated larvae of An. stephensi and then compared it with the annotated transcriptome of Anopheles gambiae. To analyse the association between ABC transporters and permethrin we conducted bioassays with permethrin alone and in combination with an ABC inhibitor, and then we investigated expression profiles of the identified genes in larvae exposed to permethrin. RESULTS: Bioassays showed an increased mortality of mosquitoes when permethrin was used in combination with the ABC-transporter inhibitor. Genes for ABC transporters were detected in the transcriptome, and five were selected (AnstABCB2, AnstABCB3, AnstABCB4, AnstABCmember6 and AnstABCG4). An increased expression in one of them (AnstABCG4) was observed in larvae exposed to the LD50 dose of permethrin. Contrary to what was found in other insect species, no up-regulation was observed in the AnstABCB genes. CONCLUSIONS: Our results show for the first time the involvement of ABC transporters in larval defense against permethrin in An. stephensi and, more in general, confirm the role of ABC transporters in insecticide defense. The differences observed with previous studies highlight the need of further research as, despite the growing number of studies on ABC transporters in insects, the heterogeneity of the results available at present does not allow us to infer general trends in ABC transporter-insecticide interactions.

Canine heartworm disease (Dirofilaria immitis) in Western Europe: survey of veterinary awareness and perceptions.

BACKGROUND: This survey examines the experience and opinion of veterinarians with canine heartworm (HW; Dirofilaria immitis) infection in non-endemic and endemic areas of Europe. METHODS: A questionnaire was distributed by e-mail to veterinary practitioners within non-endemic countries including UK, Germany, and Netherlands,non-endemic regions of France, Spain, Italy and endemic regions of France, Spain and Italy. The main questions were about the HW cases seen in the last 12 months, if the number of cases had changed over the last 5 years and practitioner awareness of the ESCAAP Guidelines on HW. Additional questions examined practitioner perception regarding the risk of HW for pets travelling in endemic areas and the use of preventatives including veterinary perception of pet owner compliance. RESULTS: Overall 584 responses, 389 from non-endemic countries and regions and 195 from endemic regions were obtained. Most of the cases were seen in endemic regions, although in Germany 20% of veterinarians reported cases of HW infection. Overall, 10% of practitioners in non-endemic areasand 12% in endemic areas, respectively, reported an increasing number of cases. The practitioner awareness of ESCCAP guidelines is low. Veterinarians responded that preventative drugs were prescribed to most client dogs in endemic areas and most practitioners rated owner compliance as good or excellent in following the veterinarian's guidance for HW prevention. Overall 63% of veterinarians responded that owners are more or less aware of the HW risk traveling with their dogs in endemic areas. Forty four percent of responders in non-endemic regions considered it somewhat likely to very likely that HW infection will become endemic in their regions. CONCLUSIONS: In both non-endemic and endemic countries at least 1 responding practitioner admitted seeing a case of canine HW infection and has shown awareness regarding infection. Ten percent of practitioners stated that the number of cases is increasing. Although the number of owners traveling with their dogs was low, the perception of surveyed veterinarians was that owners were quite aware of the HW risk for their dogs. Several veterinary practitioners believe that HW infection could become endemic in their non-endemic area within the next 10 years.

Where are we with Wolbachia and doxycycline: an in-depth review of the current state of our knowledge.

Dirofilaria immitis, the cause of canine and feline heartworm disease, was the first filarial nematode described to harbour the bacterial endosymbiont Wolbachia. This ground-breaking discovery has led to intense research aimed at unravelling the nature of the endosymbiotic relationship; genomic studies have revealed how the bacteria may interact with the parasite and help explain why each is so dependent on the other. Analysis of the immune response to these bacteria may elucidate the mechanisms through which filarial parasites are able to survive for long periods of time in otherwise immune-competent hosts. Finally, studies aimed at the removal of the bacteria using specific antibiotic treatment in infected hosts is leading to the development of novel approaches for interrupting the transmission cycle and for the treatment and control of heartworm disease.

Rapid differentiation of Dirofilaria immitis and Dirofilaria repens in canine peripheral blood by real-time PCR coupled to high resolution melting analysis.

Dirofilaria immitis and D. repens are the principal causative agents of canine filariosis and, although the number of dogs subjected to specific prevention is increasing, the prevalence of these parasites remains high in many areas of the world. The discrimination between the two Dirofilaria species using the classical diagnostic methods can be difficult and may lead to misdiagnosis especially on samples from areas where both Dirofilaria are present. Over the last years, several molecular methods with higher sensitivity and specificity compared to classical microscopy and ELISA assays were designed. Nevertheless, a need for simple, rapid, and cost-effective molecular protocols to accurately discriminate between D. immitis and D. repens still remains. High resolution melting analysis coupled to real-time PCR (real-time PCR-HRMA) is a widely used technique to target sequence polymorphisms of the same gene in different species without the need to perform DNA sequencing or to use species-specific probes. In this work, a fast and cost-effective real-time PCR-HRMA protocol to detect and differentiate simultaneously and unequivocally D. immitis and D. repens microfilarial DNA extracted from peripheral dog blood samples is described. The present method is simpler to use than most other DNA-based methods and provides comparable discrimination between the two sibling species.

Detection of Dirofilaria immitis in mid-western arid Argentina.

Dirofilariosis, caused by Dirofilaria immitis and D. repens, is (re-) emerging worldwide. Dogs are the main reservoirs, while human infection has recently become an important focus of interest and attention. In Argentina, canine D. immitis infection has been described in eastern and northern subtropical and temperate humid regions, but never reported in mid-western arid regions so far. In this research note we report for the first time the occurrence of autochthonous human and canine D. immitis infection in the region.

Effects of global changes on the climatic niche of the tick Ixodes ricinus inferred by species distribution modelling.

BACKGROUND: Global climate change can seriously impact on the epidemiological dynamics of vector-borne diseases. In this study we investigated how future climatic changes could affect the climatic niche of Ixodes ricinus (Acari, Ixodida), among the most important vectors of pathogens of medical and veterinary concern in Europe. METHODS: Species Distribution Modelling (SDM) was used to reconstruct the climatic niche of I. ricinus, and to project it into the future conditions for 2050 and 2080, under two scenarios: a continuous human demographic growth and a severe increase of gas emissions (scenario A2), and a scenario that proposes lower human demographic growth than A2, and a more sustainable gas emissions (scenario B2). Models were reconstructed using the algorithm of "maximum entropy", as implemented in the software Maxent 3.3.3e; 4,544 occurrence points and 15 bioclimatic variables were used. RESULTS: In both scenarios an increase of climatic niche of about two times greater than the current area was predicted as well as a higher climatic suitability under the scenario B2 than A2. Such an increase occurred both in a latitudinal and longitudinal way, including northern Eurasian regions (e.g. Sweden and Russia), that were previously unsuitable for the species. CONCLUSIONS: Our models are congruent with the predictions of range expansion already observed in I. ricinus at a regional scale and provide a qualitative and quantitative assessment of the future climatically suitable areas for I. ricinus at a continental scale. Although the use of SDM at a higher resolution should be integrated by a more refined analysis of further abiotic and biotic data, the results presented here suggest that under future climatic scenarios most of the current distribution area of I. ricinus could remain suitable and significantly increase at a continental geographic scale. Therefore disease outbreaks of pathogens transmitted by this tick species could emerge in previous non-endemic geographic areas. Further studies will implement and refine present data toward a better understanding of the risk represented by I. ricinus to human health.

Molecular and serological evidence for the circulation of the tick symbiont Midichloria (Rickettsiales: Midichloriaceae) in different mammalian species.

BACKGROUND: The Midichloriaceae is a novel family of the order Rickettsiales, that encompasses intracellular bacteria associated with hard ticks (Ixodidae) and other arthropods. The most intensively investigated member of this family is Midichloria mitochondrii, a symbiotic bacterium of the sheep tick Ixodes ricinus, characterized by the capacity of multiplying inside the mitochondria. A recent study suggested that these bacteria might be inoculated into the human host during the tick bite. The purpose of this study was to determine the potential infectivity of Midichloria bacteria for non-human animals exposed to the risk of tick bite. METHODS: Blood from horses, cattle, sheep and dogs exposed to the risk of tick bite was included in this study. DNAs were extracted, and amplified using 16S ribosomal RNA primers conserved in the Midichloria genus. Furthermore, sera from dogs exposed to the risk of tick bite were analyzed in order to evaluate the presence of antibodies against the recombinant flagellar protein (rFliD) from M. mitochondrii using an ELISA test. RESULTS: Here we present two lines of evidence that support the possibility that bacteria from the genus Midichloria are inoculated into vertebrate hosts during a tick bite: (i) a direct evidence, i.e. the detection of circulating DNA from bacteria related with M. mitochondrii, in the blood of vertebrates exposed to tick parasitism; (ii) a further indirect evidence, i.e. the presence of antibodies against an antigen from M. mitochondrii in dogs exposed to the risk of tick bite. It is interesting to note that variability was detected in the Midichloria gene sequences recovered from positive animals, and that some of these sequences were identical to those generated from tick-associated Midichloria. CONCLUSIONS: Based on the results, and on the overall information so far published on the genus Midichloria, we suggest that these bacteria are likely to represent a novel group of vector-borne agents, with the potential of infecting mammalian hosts. Whether inoculation of Midichloria bacteria could cause a true infection and pathological alteration in mammalian hosts is still to be determined. Surely, results emphasize the relevance of Midichloria bacteria in investigations on tick immunology and tick-bite markers.

Evaluation of the efficacy of imidacloprid 10 % / moxidectin 2.5 % (Advocate®, Advantage® Multi, Bayer) for the prevention of Dirofilaria repens infection in dogs.

The efficacy of imidacloprid 10 %/moxidectin 2.5 % (Advocate®, Advantage® Multi, Bayer) against experimental Dirofilaria (D.) repens infection in dogs was evaluated in a blinded, negative controlled randomised laboratory efficacy study. On SD (study day) 0, eight dogs received a spot-on treatment at a dose of 10 mg imidacloprid and 2.5 mg moxidectin per kg body weight. Another 8 dogs were left untreated. On SD 28 each dog was infected with approximately 75 infective D. repens larvae. Blood samples were collected every 4 weeks after treatment. A modified Knott test was conducted to detect mf (microfilaria). PCR analysis was performed with mf-positive blood samples. On SDs 245 and 246, all dogs were euthanised for detection of D. repens worms. Blood samples of all treated dogs were negative for mf at all sampling days. Blood samples of control dogs were positive for mf in 5 out of 8 control dogs. Individual mf counts ranged from 7 to 2800 mf/ml. In mf-positive blood samples, only D. repens was identified by PCR analysis. During necropsy D. repens worms could be detected in eight untreated control dogs (range: 3­21 worms per dog), whereas no worm could be detected in any of the treated dogs. These results indicate a 100 % preventive efficiency of a single spot-on treatment of imidacloprid 10 %/moxidectin 2.5 % in dogs against experimental infection with D. repens (L3 larvae). The product was well tolerated in all study animals, no treatment related adverse reactions were observed throughout the study.

Vector-borne helminths of dogs and humans in Europe.

Presently, 45% of the total human population of Europe, as well as their domestic and companion animals, are exposed to the risk of vector-borne helminths (VBH) causing diseases. A plethora of intrinsic biological and extrinsic factors affect the relationship among helminths, vectors and animal hosts, in a constantly changing environment. Although canine dirofilarioses by Dirofilaria immitis and Dirofilaria repens are key examples of the success of VBH spreading into non-endemic areas, another example is represented by Thelazia callipaeda eyeworm, an emergent pathogen of dogs, cats and humans in several regions of Europe. The recent finding of Onchocerca lupi causing canine and human infestation in Europe and overseas renders the picture of VBH even more complicated. Similarly, tick-transmitted filarioids of the genus Cercopithifilaria infesting the skin of dogs were recently shown to be widespread in Europe. Although for most of the VBH above there is an increasing accumulation of research data on their distribution at national level, the overall impact of the diseases they cause in dogs and humans is not fully recognised in many aspects. This review investigates the reasons underlying the increasing trend in distribution of VBH in Europe and discusses the diagnostic and control strategies currently available. In addition, this article provides the authors' opinion on some topics related to VBH that would deserve further scientific investigation.

A One-Health integrated approach to control fascioliasis in the Cajamarca valley of Peru.

Fasciola hepatica infection is reported from many Latin American countries, with very high prevalence rates in both humans and livestock in the Andean countries. Due to its environmental characteristics, particularly suitable for liver fluke infection, the Cajamarca valley of Peru has often been chosen as a model to study the epidemiology of liver fluke infection in the Andes. In this paper we describe the profile of a project aimed at a multidisciplinary and integrated approach for the control of fascioliasis in animals and humans in this valley. The One-Health integrated approach applied here is based on accurate and sensitive diagnostics, namely the FLOTAC, and the use of geospatial tools for epidemiological scrutiny.