Hard ticks (Ixodidae) in Romania: surveillance, host associations, and possible risks for tick-borne diseases

Hard Tick Species Parasitism Levels in Domestic Ruminants with Their Distribution and Role as Vectors: A Detailed Global Meta-analysis and Systematic Review

PURPOSE

This comprehensive global meta-analysis reviews the parasitism levels of tick genera and species, life stages, seasonality, attachment sites, the global mean ranks of tick species parasitism rates and records, and their distribution and role as vectors.

METHODS

From the 418 papers identified, 390 papers were selected to become part of the study.

RESULTS

The genera recorded as infesting domestic ruminants were Rhipicephalus (42 species), Haemaphysalis (32 species), Hyalomma (19 species), Amblyomma (18 species), Ixodes (10 species), Dermacentor (8 species), Margaropus and Nosomma (1 species). Globally, domestic ruminants are more infested by adult females and males than by the nymphal and larval stages of the tick species. The global tick species parasitism levels at the attachment sites of domestic ruminants were, in order, tail and anal region, neck and dewlap, scrotum or udder, ear region, thigh and abdomen, and dorsal surface.

CONCLUSIONS

Among 131 species of eight genera of hard ticks recorded infesting domestic ruminants, 42 species had mean ranks of tick species parasitism rates up to 10%, and 37 species had mean ranks of tick species parasitism up to 10 records. Briefly, the higher the indexes of tick species parasitism rates and records, the more important their role as vectors. In addition, the majority of them are found among tick species-infested humans with nearly high ranks of tick species parasitism rates and records that double their medical, veterinary, and zoonotic importance to be the most common vectors and reservoirs of bacterial, protozoan, and viral pathogenic microorganisms, causing severe infectious diseases, and as a result, can be more dangerous to humans and domestic ruminants.

Effects of Season, Habitat, and Host Characteristics on Ectoparasites of Wild Rodents in a Mosaic Rural Landscape

Despite the large number of studies on rodent ectoparasites-most of them vectors of epidemiologically important pathogens-infestation patterns remain poorly understood in various ecological contexts, such as the highly patchy agricultural landscapes. We aimed to relate the infestation of rodents to temporal, habitat, and host variables. We assessed the difference in parasite prevalence and mean abundance depending on host sex, age, and body weight, season, and land use intensity. Furthermore, we analysed the effect of host species abundance and the differential responses of parasites in main and minor host species. The field survey was conducted in a rural landscape in southern Transylvania (Romania) between June and September 2010-2011. We live-trapped small mammals, collected the ticks and fleas, and recorded the presence of lice and mites. Overall, we found the same infestation patterns largely reported in the literature: higher prevalence and mean abundance in heavier adult males, significant seasonality and differences among host species, and evidence of the dilution effect. The uniqueness of our study system was the negative effect of the land use intensity on the prevalence and mean abundance of parasites, explained by the highly patchy mosaic landscape.

Monitoring of hard tick parasitism in domestic ruminants: A scale evidence for policymakers

Domestic ruminants such as camels, cattle, goats, and sheep represent a substantial part of the global world economy. Hard ticks are well-known as obligatory bloodsucking ectoparasites of domestic ruminants. Policymakers need to get results that show the global distribution of tick genera and species, their parasitic levels, and their roles as disease vectors in camels, cattle, goats, and sheep. Iran is endemic to a broad range of hard tick-borne diseases. A study that reviews the tick genera and species, life stage, seasonal and attachment site parasitism levels, the global mean ranks of tick species parasitism rates and records, and their distribution in target animals would be of particular importance. Accordingly, this review aims to summarize the above objectives. After evaluating the identified articles, 147 were selected to be part of the survey based on the study objectives. Globally, tick parasitism levels were 28.7, 29.9, 36.0 and 47.6% for goats, cattle, sheep, and camels, respectively. The tick parasitism trends have exhibited an increasing trend for camels and sheep over the years while remaining constant for cattle and goats, indicating that current tick control measures are not being properly followed. Ticks tend to parasitize females more than males because males are more resistant to certain pests than females. The distribution of tick genera and species, their parasitism levels, and their roles as disease vectors provided. This information addresses the needs of decision-makers to make decisions.

First Morphological and Molecular Identification of Demodex injai in Golden Jackal (Canis aureus Linnaeus, 1758) in Romania

Demodicosis is one of the most important external parasitic diseases found in carnivores. Three species of the Demodex mite inhabit the skin of dogs and related species, D. canis being the most prevalent. This paper describes the first case of infestation with D. injai in a golden jackal in Romania. An emaciated golden jackal female body found in Timiș County, western Romania, was examined at Parasitology Department of Faculty of Veterinary Medicine, Timișoara. The gross lesions were present on different regions of the body: feet, tail, axillary and inguinal areas, and skin folds as well, consisting of erythema, extensive severe alopecia with lichenification, seborrhea, and scaling. In order to establish diagnosis, microscopic examination of skin scrapes, trichogram (hair plucking), acetate tape test (impression), fungal culture, and PCR were performed. Both microscopic measurements and PCR analysis have confirmed the presence of D. injai.

A One Health approach to study the circulation of tick-borne pathogens: A preliminary study

Tick-borne pathogens (TBPs) have complex life cycles involving tick vectors and vertebrate hosts. However, there is limited empirical evidence on the zoonotic circulation of TBPs. In this study, we used a One Health approach to study the possible circulation of TBPs in ticks, animals and humans within a rural household in the foothills of the Fruška Gora mountain, northern Serbia. The presence of TBP DNA was assessed using microfluidic PCR (25 bacterial species, 7 parasite species, 5 bacterial genera, 3 parasite genera) in animal, human and tick samples and the presence of tick-borne encephalitis virus (TBEV) RNA was screened for using RT-qPCR on tick samples. In addition, Lyme borreliosis serology was assessed in patients sera. Rhipicephalus sanguineus and Ixodes ricinus ticks were identified on dogs and Haemaphysalis punctata was identified on house walls. Rickettsia helvetica was the most common pathogen detected in pooled R. sanguineus and I. ricinus tick samples, followed by Hepatozoon canis. None of the H. punctata tick samples tested positive for the presence of TBPs. Anaplasma phagocytophilum and Rickettsia monacensis were the most frequent pathogens detected in dogs, followed by Rickettsia felis, whereas Anaplasma bovis was the only pathogen found in one of the goats tested. None of the human blood samples collected from family members tested positive for the presence of TBPs. Although microfluidic PCR did not detect Borrelia sp. in any of the tested tick or blood samples, a family member with a history of Lyme disease was seropositive for Borrelia burgdorferi sensu lato (s.l.). We conclude that, despite the presence of TBPs in tick and vertebrate reservoirs, there is no evidence of infection with TBPs across various components of the epidemiological chain in a rural Fruška Gora household.

First report of the dog louse fly Hippobosca longipennis in Romania

Hippobosca longipennis (Diptera: Hippoboscidae), the dog fly or dog louse fly, is an obligate blood-feeding ectoparasite of wild and domestic carnivores in Africa and the Middle East. Outside its typically known geographic range, H. longipennis has been reported occasionally on mainly domestic dogs in Asia and southern Europe, and infrequently in other areas (central Europe and the U.S.A.). This paper presents the first report of H. longipennis in Romania and the second record of Lipoptena fortisetosa (Diptera: Hippoboscidae), a potentially invasive species. Hippobosca longipennis was found on domestic dogs in two regions of the country (northern Romania in Maramures and southwestern Romania in Dobrogea) and on two road-killed wildcats in Maramures. Lipoptena fortisetosa was found on domestic dogs in Maramures. In both species identification was based on morphology and confirmed by barcoding of the cytochrome c oxidase subunit 1 gene. It is not clear for how long H. longipennis has been present in central Europe, nor if it was introduced (via the movement of domestic dogs or import of exotic carnivores) or present historically (Holocene remnants). This paper discusses the possible origins of H. longipennis in central Europe as its current distribution in the area is sparse and patchy.

Diversity of Babesia spp. in cervid ungulates based on the 18S rDNA and cytochrome c oxidase subunit I phylogenies

Free ranging ungulates, represented in Europe mostly by several deer species, are important hosts for ticks and reservoirs of tick-borne infections. A number of studies have focused on the prevalence of tick borne pathogens in deer chiefly with the aim to determine their potential role as reservoir hosts for important human and livestock pathogens. However, genetic similarity of Babesia spp. forming a group commonly termed as a clade VI that accommodates the deer piroplasms, complicates this task and has led to the description of a bewildering array of poorly characterised strains. This study aims to resolve this issue by using two independent genetic loci, nuclear 18S rRNA and mitochondrial cytochrome c oxidase subunit I genes, used in parallel to identify Babesia isolates in free-ranging red, sika, and roe deer in two areas of their co-occurrence in the Czech Republic. The COX1 loci, in contrast to 18S rRNA gene, shows a clear difference between interspecific and intraspecific variation at the nucleotide level. The findings confirm B. divergens, Babesia sp. EU1 and B. capreoli in studied deer species as well as common presence of another unnamed species that matches a taxon previously referred to as Babesia sp. or Babesia cf. odocoilei or Babesia CH1 group in several other sites throughout Europe. The invasive sika deers enter the life cycle of at least three piroplasmid species detected in native deer fauna. The presence of B. divergens in both sika and red deer in an area where bovine babesiosis is apparently absent raises important questions regarding the epidemiology, host specificity and taxonomic status of the parasite.

A synoptic overview of golden jackal parasites reveals high diversity of species

The golden jackal (Canis aureus) is a species under significant and fast geographic expansion. Various parasites are known from golden jackals across their geographic range, and certain groups can be spread during their expansion, increasing the risk of cross-infection with other carnivores or even humans. The current list of the golden jackal parasites includes 194 species and was compiled on the basis of an extensive literature search published from historical times until April 2017, and is shown herein in synoptic tables followed by critical comments of the various findings. This large variety of parasites is related to the extensive geographic range, territorial mobility and a very unselective diet. The vast majority of these parasites are shared with domestic dogs or cats. The zoonotic potential is the most important aspect of species reported in the golden jackal, some of them, such as Echinococcus spp., hookworms, Toxocara spp., or Trichinella spp., having a great public health impact. Our review brings overwhelming evidence on the importance of Canis aureus as a wild reservoir of human and animal parasites.

Ixodid ticks parasitizing wild carnivores in Romania

In Romania, data regarding hard-tick diversity and tick-host associations in wild carnivores are scarce. We aimed to identify tick species in wild carnivores and to establish reliable data on tick-host associations. The study was conducted in various Romanian localities from all five ecoregions found in the country. Fourteen species of wild carnivores were examined. Immature and adult ticks were collected and identified using the morphological keys. The frequency and mean intensity of tick infestation, overall and differentiated by species, developmental stage and host were calculated. Of 202 wild carnivores, 68 were parasitized by seven tick species (predominantly Ixodes ricinus, I. hexagonus and Dermacentor reticulatus). The mean intensity of tick infestation was similar in males (6.97, BCa 95% CI 5.15-9.88) and females (5.76, BCa 95% CI 4.15-9.17). The highest prevalence of infested animals was recorded in the pannonian and steppic ecoregions, 66.7 and 52.7%, respectively. In the continental ecoregion the prevalence was 26.7%, whereas in the pontic ecoregion it was 28%. The lowest value, 16.7% was recorded in the alpine ecoregion. In total 430 ticks were collected, and 24.8% (n = 50) of the animals were infested with more than one tick species. Fourteen new tick-host associations were recorded. Our results suggest that anthropogenic changes of the environment lead to the diminishing of the boundaries, between wild and domestic animals, increasing the exposure for both animals and humans, to infective agents, including tick-borne pathogens.

Seasonal dynamics of Rhipicephalus rossicus attacking domestic dogs from the steppic region of southeastern Romania

Background

Danube Delta Biosphere Reserve is one of the most interesting regions in Europe from an epidemiological point of view due to its great biodiversity, local climatic conditions and various types of habitats. Moreover, there is no data regarding the ectoparasite communities of dogs from this area. In this frame, the aims of our study were to establish the tick communities parasitizing dogs and to provide new data regarding seasonal dynamics of a neglected tick species, Rhipicephalus rossicus.

Methods

A survey was carried out in order to gather information regarding tick species attaching to domestic dogs from a steppic region of southeastern Romania and to establish their seasonal dynamics. The research was conducted from 1 December 2012 to 30 November 2013, on 8 dogs from Iazurile, a locality from the west-central part of the Danube Delta Biosphere Reserve. In total, 384 examinations were made, each dog being checked for tick infestation 4 times per month, for one year.

Results

The 893 ticks found belonged to six species: R. rossicus (95.6%), Dermacentor reticulatus (3.2%), Ixodes ricinus (0.5%), Hyalomma marginatum (0.3%), Rhipicephalus sanguineus sensu lato (s.l.) (0.2%) and Ixodes crenulatus (0.1%). From the 91 positive examinations, R. rossicus was found in 80 (87.9%). Single species infestation occurred in 84 examinations. In 7 out of 91 positive examinations mixed infestation were found. No ticks were found in December, January and September.

Conclusions

For R. rossicus, high frequency and intensity were observed in May, June and July. The activity peaks for D. reticulatus were in spring and autumn. Our results highlight that within the range of R. sanguineus s.l., the most common dog tick worldwide, selected dog populations may be predominantly infested by closely related species, like in our case, R. rossicus.

Synopsis of the hard ticks (Acari: Ixodidae) of Romania with update on host associations and geographical distribution

The current paper is a synoptic review of the distribution and host associations of the 25 species of hard tick fauna (family Ixodidae) in Romania. In addition to a full literature survey, original data is presented, based on eight years of occasional or targeted sample collection. The literature data on geographical distribution was transposed digitally to the decimal degree coordinate system. For each species, an updated distribution map is given together with all historical data and new host associations. Overall, our paper records 58 new tick-host associations for Romania: 20 for Ixodes ricinus, 1 for I. apronophorus, 6 for I. arboricola, 2 for I. hexagonus, 9 for I. redikorzevi, 1 for I. trianguliceps, 2 for I. vespertilionis, 2 for Haemaphysalis punctata, 1 for H. sulcata, 2 for H. concinna, 1 for D. marginatus, 4 for Rhipicephalus sanguineus sensu lato, 1 for R. bursa and 6 for Hyalomma marginatum.