A survey of ticks (Acari: Ixodidae) on dairy cattle on the island of Menorca in Spain

A survey of ticks affecting dairy cattle under extensive management on Menorca island (off the Spanish Mediterranean coast) was performed through 1999-2000 on seven farms. The species collected were Rhipicephalus bursa, R. turanicus, Hyalomma m. marginatum, H. lusitanicum and Boophilus annulatus. The most abundant species were R. bursa and H. m. marginatum, with peaks of 10.7 (in summer) and 7.5 (in spring) ticks/cow, respectively. R. turanicus was scarcely encountered, while B. annulatus and H. lusitanicum were abundant only in a few localities. The mild climate and adequate vegetation on the island provide satisfactory habitat for extended periods of tick activity, as compared with other regions where these ticks have been collected. The competence of the ticks as vectors for pathogens and the difficulty of using acaricide treatments in the region are discussed.     

Detection of Theileria annulata by the PCR in ticks (Acari: Ixodidae) collected from cattle in Mauritania

We report on the detection of Theileria annulata in infected Hyalomma ticks by the PCR using primers derived from the gene encoding the 30 kDa major merozoite surface antigen (Tams1–1). No inhibition of the PCR was observed and as little as 0.1 pg of parasite DNA, corresponding to 12 sporozoites, could be detected in non-infected tick DNA samples, spiked with T. annulata genomic DNA. Hyalomma dromedarii ticks, fed on a calf experimentally infected with T. annulata, were used to validate the PCR further. The infection rate in the adult ticks, fed as nymphs during the febrile reaction, was high (62%), dropped to zero for 1 day in tick batches that engorged after treatment with ButalexTM and increased to 30% 2 days later and 38% of the ticks acquired the infection after feeding as nymphs during a carrier state piroplasm parasitaemia of less than 0.1%. As an internal control, 16S tick rDNA sequences could be amplified from T. annulata-negative tick samples. Finally, 202 adult ticks from Mauritania, collected from zebu cattle carrying low levels of Theileria piroplasms, were tested by the PCR. Thirty-eight out of 52 (73%) and 17 out of 30 (57%) H. dromedarii from the Gorgol and Trarza regions, respectively and two out of 30 (7%) Hyalomma marginatum rufipes from the Gorgol region were positive. Hyalomma marginatum rufipes, Rhipicephalus evertsi evertsi and Rhipicephalus guilhoni from the Trarza region were negative. These findings confirm that H. dromedarii is the main vector of T. annulata in Mauritania and that the PCR is a useful method of determining the infection rates in ticks collected from cattle carrying low levels of T. annulata piroplasms.     

Distribution and ecology of ticks (Acari: Ixodidae) infesting livestock in Tunisia: an overview of eighth years field collections

Ticks (Ixodidae) play a significant role as vectors of pathogens of domestic animals in Tunisia. The major losses caused by ticks are related to transmission of protozoan parasites. These include agents of tropical theileriosis and babesiosis in ruminants. Since 1991, we conducted research studies on tick population of livestock in Tunisia. This overview reports a synthesis on tick distribution, their biology and their role as vectors of pathogens in domestic animals, particularly cattle. During the whole period of the study about 15,000 tick specimens were collected from different zones of the country. A total of 14 species were identified. Hyalomma detritum detritum was the most abundant and important (vector of Theileria annulata) species infesting cattle. Hyalomma dromedarii and Hyalomma impeltatum were collected on domestic ruminants in the arid and desertic zones. Hyalomma marginatum marginatum and Hyalomma anatolicum excavatum were widespread and found on livestock hosts. Ixodes ricinus, vector of Babesia divergens and Borrelia burgdorferi sl, colonises mainly the humid zone. Boophilus annulatus and Rhipicephalus bursa infesting cattle, sheep and goats were found in the sub-humid and semi-arid zones. Haemaphysalis sulcata and Hae. punctata were collected in humid and sub-humid zones on cattle and sheep. Rhipicephalus turanicus were collected in different regions, on different animal species. Rhipicephalus sanguineus, tick of dogs, were often collected on livestock. Only few specimens of Hyalomma marginatum rufipes and Hyalomma franchinii were collected.     

General review of tick species present in Portugal

At present, 24 species are known to occur in Portugal: Argas vespertilionis, Ornithodoros maritimus and Ornithodoros erraticus in Argasidae; Ixodes acuminatus, Ixodes bivari, Ixodes canisuga, Ixodes frontalis, Ixodes hexagonus, Ixodes ricinus, Ixodes simplex simplex, Ixodes ventalloi, Ixodes vespertilionis, Dermacentor marginatus, Dermacentor pictus', Haemaphysalis hispanica, Haemaphysalis inermis, Haemaphysalis punctata, Rhipicephalus bursa, Rhipicephalus pusillus, Rhipicephalus sanguineus, Rhipicephalus turanicus, Hyalomma lusitanicum, Hyalomma marginatum marginatum and Boophilus annulatus in Ixodidae. The more relevant diseases transmitted to cattle by ticks, particulary in Ribatejo and Alentejo regions, are the babesiosis due to Babesia bigemina and Babesia bovis, the theileriosis by Theileria annulata and the anaplasmosis due to Anaplasma marginale; the theileriosis by Theileria mutans2 may not be considered significant. The sheep and goats parasitoses transmitted by ticks are of less importance than the cattle diseases. However the babesiosis due to Babesia motasi and Babesia ovis and also theileriosis by Theileria hirci3 are present in some districts of the country.     

The hard-tick fauna of mainland Portugal (Acari: Ixodidae): an update on geographical distribution and known associations with hosts and pathogens

This work is an updated revision of the available information on Portuguese ixodid tick species. It includes data on tick biology, ecology, taxonomy and host/pathogen-associations. The current list of Portuguese ixodid ticks comprises twenty species: Dermacentor marginatus (Sulzer, 1776), Dermacentor reticulatus (Fabricius, 1794), Haemaphysalis hispanica Gil Collado, 1938, Haemaphysalis inermis Birula, 1895, Haemaphysalis punctata Canestrini & Fanzago, 1878, Hyalomma lusitanicum Koch, 1844, Hyalomma marginatum Koch, 1844, Ixodes acuminatus Neumann, 1901, Ixodes bivari Dias, 1990, Ixodes canisuga Johnston, 1849, Ixodes frontalis (Panzer, 1798), Ixodes hexagonus Leach, 1815, Ixodes ricinus (Linnaeus, 1758), Ixodes simplex Neumann, 1906, Ixodes ventalloi Gil Collado, 1936, Ixodes vespertilionis Koch, 1844, Rhipicephalus (Boophilus) annulatus (Say, 1821), Rhipicephalus bursa Canestrini & Fanzago, 1878, Rhipicephalus pusillus Gil Collado, 1938, and Rhipicephalus sanguineus (Latreille, 1806).     

Prevalence of ixodid ticks on cattle in Mazandaran province, Iran

A survey was carried out to investigate the prevalence of hard tick species (Acari: Ixodidae) on cattle in Mazandaran province, Iran. A total of 953 ticks were collected from 86 infested cattle during activating seasons of ticks during 2004-2005. Nine species were identified: Boophilus annulatus (51.3%), Rhipicephalus bursa (16.8%), Haemaphysalis punctata (6.3%), Ixodes ricinus (6.8%), Hyalomma marginatum (12.5%), Hyalomma anatolicum excavatum (5.2%), Hyalomma asiaticum (0.6%), Hyalomma detritum (0.2 %), and Dermacentor spp. (0.1%). The results show that Boophilus annulatus, Rhipicephalus bursa, and Hyalomma species are dominant tick species in the surveyed area.     

Transstadial transmission of Theileria annulata through common ixodid ticks infesting Indian cattle.

Transstadial transmission of Theileria annulata with Hyalomma anatolicum anatolicum, H. dromedarii and H. marginatum isaaci, and Haemaphysalis bispinosa, Rhipicephalus haemaphysaloides haemaphysaloides and Boophilus microplus was determined. It was found that the infection was successfully transmitted by H. a. anatolicum from larva to nymph and nymph to adult in all attempts. When larvae were fed on an infected calf the succeeding adults transmitted the infection when the intervening nymphs fed on a rabbit (non-susceptible host) but not when fed on a calf (susceptible host). Infective adult ticks transmitted the parasite during the first 24 h of feeding on a calf. When the feeding was interrupted after 24 h, and the tick transferred to another calf, the infection was transmitted to the latter as well. H. dromedarii successfully transmitted the infection from larva to nymph and from nymph to adult. Larvae of H. marginatum isaaci did not feed on calves but the infection was successfully transmitted from nymph to adult. Haemaphysalis bispinosa, Rhipicephalus h. haemaphysaloides and Boophilus microplus did not transmit Th. annulata from larva to nymph to adult.     

Ticks infesting domestic animals in northern Greece

The tick species infesting grazing animals in the countryside of 11 prefectures in Northern Greece were investigated during April-July and September-December of consecutive years 2003-2006. A total of 3,249 (1,952 males, 1,297 females) adult ticks were collected from goats, sheep, cattle and dogs. Ticks were identified as Ixodes ricinus (44.57%), Ixodes gibbosus (4.09%), Rhipicephalus bursa (19.14%), Rhipicephalus sanguineus, Rhipicephalus turanicus (5.79%), Hyalomma marginatum marginatum (12.40%), Dermacentor marginatus (0.31%) and Boophilus annulatus (4.43%). Rhipicephalus spp. and Hyalomma spp. were abundant in all prefectures, Ixodes spp. were present in 9/11 prefectures, Boophilus spp. in 4/11, while Dermacentor spp. were found only in one. Results of this study give an insight into the ecology of ticks and their potential of tick-borne diseases in the country.     

Monthly dynamics of ticks (Acari: Ixodida) infesting N'Dama cattle in the Republic of Guinea

The occurrence of ixodid ticks on N'Dama cattle was studied in the Republic of Guinea between June 1994 and May 1995. Monthly tick collections were performed on 80 animals from 14 villages located in Dabola, Kouroussa and Dinguiraye prefectures. A total of 19,804 ticks was collected and classified using standard taxonomic keys. The following tick species were identified: Amblyomma variegatum, Hyalomma marginatum rufipes, Hyalomma trunctum, Hyalomma nitidum, Rhipicephalus lunulatus, Rhipicephalus muhsamae, Rhipicephalus senegalensis, Rhipicephalus sulcatus, Rhipicephalus turanicus, Boophilus annulatus, Boophilus geigyi. Boophilus spp. were the most numerous adult ticks (57.1%), Am. variegatum adults constituted 27.4%, while 12.4% were Rhipicephalus spp. and 2.5% Hyalomma spp. Rhipicephalus turanicus and Hyalomma nitidum were recorded for the first time in the country. Am. variegatum and Boophilus spp. were present throughout the year, whereas Am. variegatum adults showed a peak during the rainy season between April and September. Immature stages collected belonged exclusively to the genera Amblyomma and Boophilus. Am. variegatum larvae and nymphs showed a peak during the dry season (October-March); no significant variation between seasons was observed for Boophilus immatures. A significantly higher infestation of cattle by Rhipicephalus spp. was found in Dabola and Kouroussa prefectures, located in the southern part of the study area, with similar climatic, vegetation and rainfall characteristics. Possible options for the control of ticks in the study area are briefly discussed.     

Studies on theileriosis in Southern Spain

Mediterranean theileriosis is widely distributed throughout Southern Spain, where it causes economic losses of considerable importance. In recent studies on 221 fighting bulls from 29 locations of different provinces, mainly in Southern Spain, the seroprevalence was 75.1% by IFAT. On the other hand, we are carrying out studies on beef and dairy breeds from eight provinces in the southern half of Spain where the positivity by IFAT ranges from 50 to more than 90% of the sampled cattle. Studies on the isolation of T. annulata strains, the demonstration of the vectorial role of some tick species, and cattle immunisation, have been carried out as well. In order to isolate the causative agent of the disease, infected blood or biopsies of lymph nodes from infected animals were used to establish in vitro cultures of T. annulata-infected lymphoblastoid cells, in six different cell lines. Attenuation of the parasites was achieved by growth in successive passages of a cell line by in vitro culture. Nowadays, a tissue culture vaccine has been developed from a local strain which is tried in experimental calves and under field condition with successful results. Besides, some studies on the transmission of T. annulata to cattle by the tick Hyalomma lusitanicum have been done.     

Ixodid ticks (Acari: Ixodidae) infesting humans in Tokat Province of Turkey: species diversity and seasonal activity

Ixodid ticks (Acari: Ixodidae) are the major vectors of pathogens threatening animal and human health. Tokat Province, Turkey, is a suitable habitat for extended tick activity with its moderate climate and vegetation. In the present study, we surveyed humans visiting health centers to determine the species diversity, geographical distribution, and seasonal activity of ixodid ticks infesting them. Out of 5,999 adult ticks collected from humans from April to September, 2008, 800 ticks were identified to species, while the remaining were identified to genus according to their distinct morphological characteristics. Hyalomma marginatum, Hyalomma detritum, Rhipicephalus bursa, Rhipicephalus (Boophilus) annulatus, Haemaphysalis punctata, Dermacentor marginatus, and Ixodes laguri were the most prevalent tick species among 24 ixodid tick species infesting humans in the region. One of these tick species, Hyalomma isacii was identified as a new record for the ixodid tick fauna of Turkey. Hyalomma species were the most abundant in summer, while Dermacentor and Ixodes species displayed the lowest frequency. Hyalomma aegyptium infestation was very common on humans in the province. Results indicated that a variety of ixodid tick species infest humans depending on the season in the target area. It is possible that a variety of ixodid tick species may contribute to the spread of tick‐borne diseases such as Crimean‐Congo haemorrhagic fever virus (CCHFV), which is endemic in the region.     

A survey of the ixodid ticks parasitising cattle in the Eastern Province of Zambia

The results of tick surveys carried out in the Eastern province of Zambia between December 1982 and February 1996 were principally in agreement with the findings of earlier surveys conducted during the period 1965–72. Boophilus decoloratus has almost been replaced by Boophilus microplus . Hyalomma truncatum was found in small numbers throughout the province and Hyalomma marginatum rufipes was only rarely encountered in collections made from cattle. Rhipicephalus evertsi evertsi was largely confined to the southern part of the plateau and the valleys of the Zambezi tributaries. The main difference between the present survey and the previous one concerns the status of Rhipicephalus appendiculatus . This species is currently expanding its range in a westward direction, whereas it was virtually absent from the southern part of the province during the period 1965–72. The majority of specimens collected are morphologically intermediate between R. appendiculatus and the closely allied Rhipicephalus zambeziensis . The available evidence indicates that R. zambeziensis ( sensu stricto ) is absent from the province. The phenology of R. appendiculatus is aberrant in the province: at lower altitudes a second generation of adult ticks is recorded on the hosts at the start of the dry season.     

Experimental transmission of Crimean-Congo hemorrhagic fever virus: role of 3 vector species in the maintenance and transmission cycles in Senegal

In this article, we published the role of three species of ticks Amblyomma variegatum (Fabricius, 1974), Hyalomma marginatum rufipes (Koch, 1844) and Hyalomma truncatum (Koch, 1844) in the maintenance and transmission of the CCHF virus. The imagos of these species were infected by intracoelomic route. Vertical transmission (transtasial and transovarial) and horizontal transmission for different stases were studied by isolation on newborn mice, polymerase chain reaction, indirect immunofluorescence and ELISA. Our results proved that 15 days after inoculation, infection rates of 100% were noted with Hyalomma marginatum rufipes and Hyalomma truncatum. This rate is about 60% for Amblyomma variegatum. The imagos of the three species infected have transmitted the virus to their host during blood feeding (100%). A high transovarial transmission for Hyalomma marginatum rufipes and Hyalomma truncatum were observed (respectively 53 and 50%). This rate is about 12% for Amblyomma variegatum. The tick infection does not persist up to the first generation for the three species studied. Ticks are temporary reservoirs vectors but not permanent reservoirs of CCHF virus.     

Comparison of resistance in three breeds of cattle against African ixodid ticks

Tick resistance in three breeds of cattle, two indigenous breeds (Arssi and Boran) and one Boran x Friesian cross-breed, were compared following natural tick infestations at Abernossa ranch in Ethiopia. The local Arssi breed was found to have the highest tick resistance, followed by the Boran breed, whereas the Boran x Friesian was the least resistant. Over a period of 12 months, from October 1991 to September 1992, a total of 32 897 ticks composed of four genera were collected from the animals. The four most abundant tick species were Amblyomma variegatum (61.7%), Boophilus decoloratus (16%); Rhipicephalus evertsi evertsi (16.3%) and Hyalomma marginatum rufipes (3.7%). Furthermore, 63.5% of all ticks were collected from cross-breed cattle, and 26.2% from the Boran, whereas the local Arssi breed carried only 10.3%. The results indicated that cattle resistant to one species of tick were also resistant to other tick species.     

Host-parasite relationships of the genus Hyalomma Koch, 1844 (Acari, Ixodidae) and their connection with microevolutionary process

Host-parasite relationships of Hyalomma species of the world fauna are analyzed. The majority of species infests predominately various mammals. Birds and reptiles are used as preferred hosts by several Hyalomma species, and only on certain stage: adults of H. aegyptium parasitize tortoises; immature stages of H. marginatum parasitize birds. It is hypothesized that relationships of H. aegyptium adults (subgenus Hyalomma s. str.) with reptiles are secondarily in origin. Immature stages of H. aegyptium retain the primary wide diapason of hosts, which are various small mammals, birds and reptiles. The life cycle of this species is the three-host type that is considered as a primary type in ixodid ticks. A typical scheme of relationships with their hosts in all well-examined Hyalommina species has following features: the adult stage parasitize large and medium sized mammals, immature stages parasitize small mammals, three-host life cycle. A variety of preferred hosts and types of life cycle is observed in the subgenus Euhyalomma. All species of this subgenus can be arranged into two groups. In the first group, the immature stages infest only small mammals and birds, and the adults parasitize large mammals; this type of host preferences is probably primary host-parasite relationships of Hyalomma. This group includes: H. albiparmatum, H. asiaticum, H. excavatum, H. franchinii, H. impeltatum, H. impressum, H. lusitanicum, H. marginatum, H. nitidum, H. schulzei, and H. truncatum. Hyalomma marginatum and H. schulzei are two-host species; H. excavatum is two- or three-host tick. All the remaining species (except H. albiparmatum, which life cycle is unknown) are three-host ticks. In the second group, the immature stages as well as the adult stage parasitize large mammals. This group includes: H. dromedarii, H. anatolicum, and H. scupense. These species are two- or one-host ticks.     

Ticks infesting domestic animals in Italy: current acarological studies carried out in Sardinia and Basilicata regions

The note reviews published and unpublished data on acaralogical studies carried out by different parasitologists' groups in Sardinia and Basilicata regions. In Sardinia 72 collecting sites were investigated and a total of 4,086 ticks were collected from hosts (cattle, sheep, goats and pigs) and from soil. So far 2,413 ticks belonging to six genera have been identified: Rhipicephalus (67.2%), Haemaphysalis (24.1%), Hyalomma (2.7%), Boophilus (0.7%), Dermacentor (4.9%), Ixodes (0.3%). Host-associated ticks were collected from 50 out of 200 selected farms in Basilicata. About 4,000 tick specimens were collected and 1,794 ticks have been identified (of which 1,215 were adults, 6 larvae and 573 nymphs). The following genera were identified: Ixodes (20%), Rhipicephalus (27%), Hyalomma (31%), Haemaphysalis (18%), Dermacentor (6%). The seasonal distribution of the species identified in the two regions studies is discussed from a geographical and climatic point of view.     

Modelling the transmission dynamics of Theileria annulata: model structure and validation for the Turkish context

A mathematical model that describes the transmission dynamics of Theileria annulata is proposed that consists of 2 host components: the Hyalomma tick population and a compartmental model of T. annulata infection in the cattle population. The model was parameterized using data describing tick infestation and the infection status of cattle in Turkey from 2006 to 2008. The tick attachment rates are highly seasonal and because of the temporal separation of infectious and susceptible ticks virtually all ticks are infected by carrier cattle, so that annual peaks of disease in cattle do not impact on infection in the Hyalomma tick population. The impact of intervention measures that target the tick population both on the host and in the environment and their impact on the transmission of T. annulata were investigated. Interventions that have a limited 'one-off' impact and interventions that have a more permanent impact were both considered. The results from the model show the importance of targeting ticks during the period when they have left their first host as nymphs but have yet to feed on their second host.     

Species composition, distribution, and ecological preferences of the ticks of grazing sheep in north-central Spain

The distribution and ecological preferences of tick (Acari: Ixodidae) parasites of grazing sheep in the region of Aragón (north-central Spain) were surveyed on flocks four times a year and mapped into a 5 x 5 km grid. Nine tick species were found. These were species of the Rhipicephalus sanguineus group (about 95% of them Rhipicephalus turanicus Pomerantsev, in 91% of cells of the grid), Rhipicephalus bursa Canestrini & Fanzago (79% of cells), Dermacentor marginatus (Sulzer) (58% of cells), Haemaphysalis punctata Canestrini & Fanzago (74% of cells) and Ixodes ricinus (Linnaeus) 14% of cells. Other species weakly represented in the surveys were Dermacentor reticulatus (Fabricius), Haemaphysalis sulcata Canestrini & Fanzago and Hyalomma m. marginatum Koch. Data on temperature, Normalized Difference Vegetation index (NDVI), topography, vegetation categories and plant productivity were used to build models of distribution and abundance of D. marginatus, H. punctata, R. bursa and R. turanicus. The occurrence models largely incorporated climatic variables and had good discrimination ability (P < 0.0001 for every modelled species, correct classification rate or sensitivity within 0.89 and 0.99), whereas the abundance models had a lower explanatory power. These models are relevant in the understanding of the variables composing the main distribution patterns, but they are unable adequately to predict the density. Abundance models produce good predictions in cells with low tick density, whereas poor correlation is observed in sites with high tick abundance. Several causes may be responsible for this low predictive power of the abundance models. Model output might be sensible to host density, to local farming practices, or to the size of the grid used to refer the results of the survey. In the latter case, small patches may support locally important populations of ticks, influencing largely the results of the survey. These patches of particular abiotic conditions, or supporting large host densities, may have been undetected at the resolution of the survey, thus obscuring the impact of the predictive variables.     

Ticks Parasitizing Wild Birds in Portugal: Detection of Rickettsia aeschlimannii, R. helvetica and R. massiliae

From January 2002 to December 2004, 152 ticks were collected from 40 wild birds recovered in Santo André Natural Reserve and Monsanto Forestal Park, Portugal mainland. Five ticks species were identified from 22 species of birds, and new host record were provided for some species. In addition, 32 (21%) ticks were screened by PCR to detect infections with agents belonging to order Rickettsiales: Anaplasma phagocytophilum, Ehrlichia chaffeensis, and Rickettsia spp. PCR amplicons were obtained in 5 (15.6%) tick samples. Rickettsia DNA exhibiting gltA sequences similar to those of Rickettsia aeschilimannii, R. helvetica and R. massiliae were identified in Hyalomma marginatum, Ixodes ventalloi and in Rhipicephalus turanicus, respectively. This is the first report of rickettsiae infections in ticks collected from wild birds in Portugal. Giving the results presented above wild birds play an important role in the maintenance and dissemination of several tick species and associated rickettsiae.     

Acarological studies in two protected areas of Central Italy

In the present note are reported the results of preliminary studies on tick distribution in two wildlife areas of Abruzzo (National Park of Abruzzo, a mountainous area, approximately 40,000 ha, in Central Apennines, interesting Abruzzo, Latium and Molise regions) and Latium (Capocotta-Castel Porziano Presidential reserve, on the Tyrrhenian coast, 30 km from Rome). Sampling of ticks from domestic and wild mammals as well as from vegetation, was performed in three different areas of the National Park in 1995. Tick species identified include Rhipicephalus bursa, R. sanguineus, Hyalomma marginatum, Haemaphysalis punctata, Dermacentor marginatus, Ixodes ricinus, I. hexagonus. The presence of I. ricinus was discontinuous and sporadic. In Capocotta estate, samplings were performed bimonthly from March to November 1997 in an restricted area (1 ha) with typical Mediterranean flora and fauna. The following species were collected: I. ricinus, Haemaphysalis concinna, D. marginatus, R. bursa, Hy. marginatum. There was a high dominance of I. ricinus and H. concinna.