Călin Mircea Gherman

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.

Helminth parasites of reptiles (Reptilia) in Romania.

Necropsy of 82 specimens of reptiles (snakes, lizards, and turtles) was performed between 2002 and 2006 to determine the helminth fauna. We examined 7 species of reptiles: Natrix natrix (n=25), Natrix tessellata (n=20), Vipera berus (n=5), Coluber caspius (n=12), Anguis fragilis (n=2), Lacerta agilis (n=10), and Emys orbicularis (n=8). Overall prevalence of helminthic infections in Romanian reptiles was 81.71%. In snakes, the most prevalent group of helminths was trematodes. The helminth species, their prevalence, intensity, and abundance are shown in Table 1. In two reptile species, all individuals were infected with helminths (N. natrix and E. orbicularis). The lowest prevalence of helminthic infection was in C. caspius. Three digenean trematodes, namely, Leptophallus nigrovenosus, Metaleptophallus gracillimus, and Spirhapalum polesianum, and three nematodes, Entomelas entomelas, Strongyloides mirzai, and Hexametra quadricornis, are new records for Romania. N. natrix has a new host record for infection with nematode genus Eustrongylides.

Ixodid ticks in red foxes (Vulpes vulpes) from Romania

Among wildlife, the red foxes (Vulpes vulpes) are one of the most adapted wild species to anthropic ecosystems. They are well recognized as important reservoirs for a large number of zoonotic agents in Europe, including ticks and tick-borne pathogens. Currently, there are few available data on the importance of red foxes in the ecoepidemiology of vector-borne diseases. Therefore, the aim of this study was to screen the dynamics of tick infestation in 357 red foxes from 12 Romanian counties. Tick identification was performed using the morphological keys. The overall prevalence of tick infestation was 43.7%. The 5753 collected ticks belonged to five species: Ixodes hexagonus (on 113 out of 156 foxes; prevalence 72.44%), I. ricinus (28.84%), I. crenulatus (7.7%), Dermacentor marginatus (7.05%) and Haemaphysalis punctata (0.64%). Coinfestation occurred in 24 foxes (22 with 2 tick species; 2 with 3 tick species) with the following associations: I. ricinus + I. hexagonus (n = 10), I. hexagonus + D. marginatus (n = 5), I. ricinus + I. crenulatus (n = 4), I. ricinus + D. marginatus (n = 2), I. hexagonus + I. crenulatus (n = 1), D. marginatus + I. hexagonus + I. ricinus (n = 1), and H. punctata + I. hexagonus + I. ricinus (n = 1). This study indicates that foxes are hosts to a relevant number of tick species with recognized vectorial role. The provided information can facilitate the understanding of the ecology of ticks and can be the basis for studies on the epidemiology of tick-borne diseases. The high prevalence of tick infestation in red foxes, coupled with the increasing presence of this species in synanthropic environments and a more nature-oriented lifestyle of people, can pose a significant threat to human health, through the emergence of tick-borne diseases. Moreover, foxes represent a good model of sentinel species. This research was performed as part of project IDEI PCE 236/2011.

Coendangered hard-ticks: threatened or threatening?

The overwhelming majority of animal conservation projects are focused on vertebrates, despite most of the species on Earth being invertebrates. Estimates state that about half of all named species of invertebrates are parasitic in at least one stage of their development. The dilemma of viewing parasites as biodiversity or pest has been discussed by several authors. However, ticks were omitted. The latest taxonomic synopses of non-fossil Ixodidae consider valid 700 species. Though, how many of them are still extant is almost impossible to tell, as many of them are known only from type specimens in museums and were never collected since their original description. Moreover, many hosts are endangered and as part of conservation efforts of threatened vertebrates, a common practice is the removal of, and treatment for external parasites, with devastating impact on tick populations. There are several known cases when the host became extinct with subsequent coextinction of their ectoparasites. For our synoptic approach we have used the IUCN status of the host in order to evaluate the status of specifically associated hard-ticks. As a result, we propose a number of 63 coendangered and one extinct hard-tick species. On the other side of the coin, the most important issue regarding tick-host associations is vectorial transmission of microbial pathogens (i.e. viruses, bacteria, protozoans). Tick-borne diseases of threatened vertebrates are sometimes fatal to their hosts. Mortality associated with pathogens acquired from ticks has been documented in several cases, mostly after translocations. Are ticks a real threat to their coendangered host and should they be eliminated? Up to date, there are no reliable proofs that ticks listed by us as coendangered are competent vectors for pathogens of endangered animals.

Tick parasites of rodents in Romania: host preferences, community structure and geographical distribution

BackgroundTicks are among the most important vectors of zoonotic diseases in temperate regions of Europe, with widespread distribution and high densities, posing an important medical risk. Most ticks feed on a variety of progressively larger hosts, with a large number of small mammal species typically harbouring primarily the immature stages. However, there are certain Ixodidae that characteristically attack micromammals also during their adult stage. Rodents are widespread hosts of ticks, important vectors and competent reservoirs of tick-borne pathogens. Micromammal-tick associations have been poorly studied in Romania, and our manuscript shows the results of a large scale study on tick infestation epidemiology in rodents from Romania.MethodsRodents were caught using snap-traps in a variety of habitats in Romania, between May 2010 and November 2011. Ticks were individually collected from these rodents and identified to species and development stage. Frequency, mean intensity, prevalence and its 95% confidence intervals were calculated using the EpiInfo 2000 software. A p value of <0.05 was considered statistically significant.ResultsWe examined 423 rodents (12 species) collected from six counties in Romania for the presence of ticks. Each collected tick was identified to species level and the following epidemiological parameters were calculated: prevalence, mean intensity and mean abundance. The total number of ticks collected from rodents was 483, with eight species identified: Ixodes ricinus, I. redikorzevi, I. apronophorus, I. trianguliceps, I. laguri, Dermacentor marginatus, Rhipicephalus sanguineus and Haemaphysalis sulcata. The overall prevalence of tick infestation was 29.55%, with a mean intensity of 3.86 and a mean abundance of 1.14. Only two polyspecific infestations were found: I. ricinus + I. redikorzevi and I. ricinus + D. marginatus.ConclusionsOur study showed a relatively high diversity of ticks parasitizing rodents in Romania. The most common tick in rodents was I. ricinus, followed by I. redikorzevi. Certain rodents seem to host a significantly higher number of tick species than others, the most important within this view being Apodemus flavicollis and Microtus arvalis. The same applies for the overall prevalence of tick parasitism, with some species more commonly infected (M. arvalis, A. uralensis, A. flavicollis and M. glareolus) than others. Two rodent species (Mus musculus, Rattus norvegicus) did not harbour ticks at all. Based on our results we may assert that rodents generally can act as good indicators for assessing the distribution of certain tick species.

Genetic variability of Eucoleus aerophilus from domestic and wild hosts

Eucoleus aerophilus (syn. Capillaria aerophila) is a trichuroid nematode affecting domestic and wild carnivores and, sometimes, humans. This parasite has a worldwide distribution and may cause significant clinical disease in pet animals. The present paper investigates the sequence variation in partial mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of E. aerophilus isolates from pets and wild animals from different countries. Forty-four egg pools of E. aerophilus were collected from dogs, cats and foxes from Italy, while seventeen adult stages of E. aerophilus were obtained from red foxes and beech martens from Portugal, Romania, Serbia and UK. Fifteen different haplotypes were characterized and five were shared between pets in Italy and wildlife from Europe. The remaining haplotypes were either confined only in hosts or countries, or in a given host from a country. The phylogenetic analysis showed that all haplotypes clustered as a monophyletic group with a strong nodal support, indicating that all sequence types represented E. aerophilus. The results here presented have implications for a better understanding of the epidemiology, phylo-geography and clinical impact of E. aerophilus. In particular, the geographic distribution of E. aerophilus haplotypes in different host species and geographic regions, and their variation in terms of pathogenic impact and zoonotic role, warrant further investigations.

Prevalence and intensity of blood apicomplexan infections in reptiles from Romania.

In order to evaluate prevalence and intensity of apicomplexan hemoparasites in free-ranging reptiles from Romania, blood smears were collected from European pond turtles (Emys orbicularis), sand lizards (Lacerta agilis), and spur-thighed tortoises (Testudo graeca). All three host species were positive for blood parasites, with prevalence of infected individuals between 60.71% and 100% and variable intensity. Similarities and differences with other epidemiological data are discussed.

Zoonotic pathogens associated with Hyalomma aegyptium in endangered tortoises: evidence for host-switching behaviour in ticks?

BackgroundHyalomma aegyptium is a hard-tick with a typical three-host life cycle. The main hosts are Palearctic tortoises of genus Testudo. However, other hosts can be used by immature ticks for feeding in natural conditions. Given this complex ecology and multiple host use, the circulation of pathogens by H. aegyptium between various hosts can be important from epidemiological point of view. The aim of this study was to evaluate the role of H. aegyptium as natural carrier of four important zoonotic pathogens.MethodsFrom 2008 to 2011, 448 H. aegyptium ticks were collected from 45 Spur-thighed tortoises, Testudo graeca in Romania. DNA was extracted individually from each tick using a commercial kit. DNA was examined for the presence of specific sequences of Borrelia burgdorferi s.l., Anaplasma phagocytophilum, Ehrlichia canis and Coxiella burnetii by PCR, according to previously described protocols.ResultsPCR analysis of H. aegyptium revealed the presence of A. phagocytophilum (18.8%), E. canis (14.1%) and C. burnetii (10%). 32.4% of the ticks were infected with at least one pathogen and 9.8% had co-infections. The stages most frequently infected were nymphs (50%) followed by males (33.9%) and females (27%). The number of tortoises which harboured infected ticks was 27/45 examined (60%). From all tested T. graeca, 40% harboured ticks infected with A. phagocytophilum, 46.7% had ticks infected with E. canis and 33.3% had ticks with C. burnetii. This study reports for the first time the presence of A. phagocytophilum and E. canis in H. aegyptium.ConclusionsThe presence and relatively high prevalence of three important zoonotic pathogens in H. aegyptium raises the question of their epidemiologic importance in disease ecology. As tortoises are unlikely to be reservoir hosts for A. phagocytophilum and E. canis and both these pathogens are common in H. aegyptium, this is an important indication for (1) a possible increased host-switching behaviour of these ticks to competent reservoir hosts (i.e. hedgehogs) and (2) transstadial transmission. Furthermore, if we consider also the presence of C. burnetii, we conclude that T. graeca and its ticks should be evaluated more seriously when assessing the eco-epidemiology of zoonotic diseases.

Geographical distribution and prevalence of Borrelia burgdorferi genospecies in questing Ixodes ricinus from Romania: a countrywide study.

The paper reports the prevalence and geographical distribution of Borrelia burgdorferi sensu lato (s.l.) and its genospecies in 12,221 questing Ixodes ricinus ticks collected at 183 locations from all the 41 counties of Romania. The unfed ticks were examined for the presence of B. burgdorferi s.l. by PCR targeting the intergenic spacer 5S-23S. Reverse line blot hybridization (RLB) and restriction fragment length polymorphism (RFLP) analysis were performed for identification of B. burgdorferi genospecies. The overall prevalence of infection was 1.4%, with an average local prevalence between 0.75% and 18.8%. B. burgdorferi s.l. was found in ticks of 55 of the 183 localities. The overall prevalence B. burgdorferi s.l. in ticks in the infected localities was 3.8%. The total infection prevalence was higher in female ticks than in other developmental stages. Three Borrelia genospecies were detected. The most widely distributed genospecies was B. afzelii, followed by B. garinii and B. burgdorferi sensu stricto (s.s.). The study is the first countrywide study and the first report of B. burgdorferi s.s. in Romania. The distribution maps show that higher prevalences were recorded in hilly areas, but Lyme borreliosis spirochetes were also present in forested lowlands, albeit with a lower prevalence.

Do the Ticks of Birds at an Important Migratory Hotspot Reflect the Seasonal Dynamics of Ixodes ricinus at the Migration Initiation Site? A Case Study in the Danube Delta

Migratory birds play important roles as distributors of ticks within and between continents. In the Old World, the most important migratory route of birds links Asia, Europe and Africa. During their migration, birds use various stopover sites, where they feed and rest and where ticks may attach or detach, creating new natural foci for vector-borne diseases. Danube Delta is one of the most important migration hotspots and so far no studies were focused on ticks of migratory birds herein. The aim of the present study was to assess the species diversity and seasonal dynamics of ticks parasitizing migratory birds in Danube Delta Biosphere Reserve. Migratory birds were trapped on Grindul Lupilor (44°41′N; 28°56′E) using mist nets during 4 migratory seasons (2 spring and 2 autumn) in 2011 and 2012. From each bird, all the ticks were collected and identified based on morphological features. Epidemiological parameters (prevalence, mean abundance, mean intensity) were calculated and all data were analysed statistically based on the season (spring and autumn), regional status of birds (migrants and breeding) and foraging behaviour (ground feeders, reed-bed feeders, foliage feeders). A total of 1434 birds (46 species) were captured. Ticks were found on 94 birds (10 species). Significantly more migratory birds hosted ticks, compared to resident birds. The 400 collected ticks belonged to four species: Ixodes ricinus (92.25%), I. arboricola (6.25%), I. redikorzevi (1.00%) and Haemaphysalis punctata (0.50%). A higher prevalence was found for I. ricinus in spring, with higher prevalence of nymphs in this season, while larvae occurred with the same prevalence in both seasons. Larval intensity was higher during spring and nymphs were more abundant during autumn. The seasonal differences in our study may be related not to the local seasonal dynamics of ticks, but on the seasonal dynamics at the site of migration initiation.