Marginatus Ticks Research Articles

Sindbis viruses and other alphaviruses as cause of human arthritic disease

Amongst the arthritis-causing arboviruses, i.e. those spread by insects, the alphavirus group is of special interest. These viruses occasionally cause vast outbreaks, such as O'nyong-nyong in Africa in 1959. In Fennoscandia, Sindbis-related Ockelbo, Pogosta, or Karelian fever viruses have been found to cause significant morbidity. The major symptoms in addition to joint inflammation are fever, fatigue, headache and rash. The joint symptoms may persist for weeks, even months. The diagnosis is based on the clinical picture and serology. The causative viruses are closely related but not identical. It appears that at least in Finland the Pogosta disease is more common than thought, and the symptoms may often be overlooked. Several factors related to the viruses, their hosts, and global environmental changes may affect the spread of these viruses. All over the world arbovirus-caused diseases have increased, because of global changes.

Human otoacariasis: a retrospective study from an area of Sri Lanka

Intra-aural ticks were present in 870 (15.2%) of 5714 patients who reported with ear-related complaints to the ear, nose and throat ward at Ratnapura Hospital, Sabaragamuwa Province, Sri Lanka, from January 2000 to December 2001. A retrospective study of 383 of these otoacariasis cases showed that the majority (70.8%) of surgically-removed ticks were nymphal Amblyomma integrum, together with nymphal and adult Rhipicephalus haemaphysaloides, R. sanguineus, Hyalomma brevipunctata, H. marginatum, and unidentified (damaged) ticks (collectively, 29.2%). Tick infestations peaked during the period November–February. More female than male patients reported with otoacariasis, and more children (aged 0–10 years) and adults (aged ≥21 years) than adolescents. There was no evidence of age-dependent differences in infestation among male and female patients. The tick-infested cases were widespread, spanning 75 km on a north–south axis and 55 km on an east–west axis within Sabaragamuwa Province. The present report represents the largest episode of human otoacariasis recorded in the literature, and may be indicative of a wider, but little-reported, human tick problem in Sri Lanka.

Prevalence of Rickettsia spp. in Dermacentor marginatus ticks removed from game pigs (Sus scrofa) in southern France.

During the months of October and November 2000 a total of 70 Dermacentor marginatus ticks were removed from different game pigs Sus scrofa in southern France and investigated by PCR using primers derived from the citrate synthase (gltA) and the outer membrane protein (OmpB) genes of rickettsiae. Based on sequence analysis of 1,150 bp fragment of gltA, Rickettsia slovaca was identified in 11 ticks (15.7%). These results confirm that Rickettsia slovaca, an emerging pathogen is highly prevalent in Dermacentor marginatus ticks in France. Moreover, a new Rickettsia genotype was detected in one specimen (1.4%). The pathogenic role of this new rickettsia has yet to be demonstrated.

Genetic variability of Crimean-Congo haemorrhagic fever virus in Russia and Central Asia.

Hyalomma marginatum ticks (449 pools, 4787 ticks in total) collected in European Russia and Dermacentor niveus ticks (100 pools, 1100 ticks in total) collected in Kazakhstan were screened by ELISA for the presence of Crimean-Congo haemorrhagic fever virus (CCHFV). Virus antigen was found in 10.2 and 3.0 % of the pools, respectively. RT-PCR was used to recover partial sequences of the CCHFV small (S) genome segment from seven pools of antigen-positive H. marginatum ticks, one pool of D. niveus ticks, four CCFH cases and four laboratory virus strains. Additionally, the entire S genome segments of the CCHFV strains STV/HU29223 (isolated from a patient in European Russia) and TI10145 (isolated from H. asiaticum in Uzbekistan) were amplified, cloned and sequenced. Phylogenetic analysis placed all CCHFV sequences from Russia in a single, well-supported clade (nucleotide sequence diversity up to 3.2 %). Virus sequences from H. marginatum were closely related or identical to those recovered from patients in the same regions of southern Russia. Newly described CCHFV strains from Central Asian countries fell into two genetic lineages. The first lineage was novel and included closely related virus sequences from Kazakhstan and Tajikistan (nucleotide sequence diversity up to 3.2 %). In contrast, a newly described CCHFV strain from Uzbekistan, strain TI10145, clustered on the phylogenetic trees with strains from China.

Detection and identification of spotted fever group rickettsiae in ticks collected in southern Croatia.

A total of 197 ticks belonging to four species (Haemaphysalis punctata, Hyalomma marginatum, Rhipicephalus bursa and Dermacentor marginatus) collected in October 2000 from domestic animals in southern Croatia were examined for the presence of rickettsiae by molecular techniques. Specific sequences of the rickettsiae were detected in 25 (12.7%) of ticks tested. The prevalence of infection in D. marginatus and H. marginatum ticks was 36.8 and 64.7%, respectively. None of the ticks belonging to the species H. punctata or Rh. bursa were infected. Sequence analysis of amplified products revealed that D. marginatus ticks are infected with Rickettsia slovaca, whereas H. marginatum are infected with R. aeschlimannii. The results of this study extend the knowledge of the geographic distribution of SFG rickettsiae and indicate that at least two of them, with yet uncertain pathogenicity to humans, are present in ticks in southern Croatia.

Evidence for the reproductive isolation of Dermacentor marginatus and Dermacentor reticulatus (Acari: Ixodidae) ticks based on cross-breeding, morphology and molecular studies

The species status of Dermacentor marginatus and Dermacentor reticulatus was evaluated by scanning electron microscope (SEM) examination of adult ticks, cross-breeding experiments and molecular biological analysis of eggs derived from transspecific pairings. The SEM investigations including the morphometric quantification of phenotypic features resulted in an unequivocal differentiation of adult D. marginatus and D. reticulatus ticks. The cross-breeding experiments demonstrated that irrespective of whether female ticks of both species were applied with con- or transspecific male ticks or without males to sheep, they engorged and laid eggs. The larvae, however, developed only in eggs which originated from conspecific matings. A nested polymerase chain reaction (PCR) of the second internal transcribed spacer (ITS2) using the DNA of eggs from transspecific pairings and sequencing of the PCR products revealed two different genotypes. The genotypes of eggs originating from D. marginatus and D. reticulatus females of these pairings differed. However, the eggs deposited by D. marginatus always possessed the same two genotypes as did the eggs produced by D. reticulatus. These results argue for a strict reproductive isolation of D. marginatus and D. reticulatus and, therefore, for a separate species status.

Ticks of domestic animals in the Macedonia region of Greece

A study was carried out on ticks of domestic animals in the Macedonia region of Greece. During 1983–1986, 11 620 tick specimens, belonging to 18 species and subspieces, were collected from cattle, sheep, goats and dogs, in 64 localities throughout Macedonia. Rhipicephalus bursa, the most common tick, and Hyalomma marginatum marginatum occurred in all bioclimatic zones, as well as the two one-host ticks, Boophilus annulatus and H. detritum scupense, which were present in fewer localities. R. turanicus, R. sanguineus, Ixodes gibbosus and H. anatolicum excavatum occurred essentially in the mesomediterranean bioclimatic zone. I. ricinus, Dermacentor marginatus and Haemaphysalis ticks ( Hm. inermis, Hm. punctata, Hm. sulcata, Hm. parva) were found frequently in the biotopes of the attenuated mesomediterranean and submediterranean bioclimates. Rhipicephalus adults and the two-host Hyalomma ticks were active in the spring-summer period. Ixodes spp., Haemaphysalis spp., D. margiantus, as well as H. detritum scupense and the immature stages of R. bursa appeared during autumn and winter. Hyalomma and Boophilus ticks fed mainly on cattle. R. sanguineus almost exclusively parasitized dogs, which were also the only hosts from which I. hexagonus has been collected. The infestations were generally weak or moderate. Few heavy infestations were observed on cattle, especially in autumn. Most of the tick species showed a strong preference for some particular sites on the vertebrate body. This predilection could vary according to the host species. The rare specimens of H. marginatum rufipes, H. marginatum turanicum and Amblyomma variegatum were probably introduced by migratory birds.

Identification of Spotted Fever Group Rickettsiae Isolated from Dermacentor Marginatus and Ixodes Ricinus Ticks Collected in Switzerland

When 155 ticks collected in different regions of Switzerland were tested by the hemolymph test, 10.3% were found to contain spotted fever group rickettsiae. Six rickettsial isolates were made from Dermacentor marginatus ticks and three were made from Ixodes ricinus ticks. The polymerase chain reaction followed by restriction fragment length polymorphism analysis showed that the Dermacentor ticks were infected with Rickettsia length polymorphism analysis showed that the Dermacentor ticks were infected with Rickettsia slovaca and the Ixodes ticks were infected with a spotted fever group rickettsia. Microimmunofluorescence serologic type, sodium dodecyl sulfate-polyacrylamide gel electrophoresis of proteins, and Western blot assay with polyclonal mouse antisera confirmed the results and determined that the Ixodes were infected with R. helvetica, the only previously described Swiss rickettsia. However, an additional new strain that could not be isolated was detected in one I. ricinus by hemolymph test and provisionally characterized by enzymatic restriction of its amplified DNA.

Detection of the protozoan parasite Theileria annulata in Hyalomma ticks by the polymerase chain reaction

Adult Hyalomma ticks were examined for the presence of Theileria annulata infection using the Polymerase Chain Reaction (PCR). A 372 bp DNA fragment derived from the small ribosomal RNA gene of T. annulata was amplified from 45 out of 50 (90%) H. dromedarii ticks and from 36 out of 50 (72%) H. marginatum marginatum ticks. No product was amplified from non-infected control ticks. Restriction enzyme digestion with Sac II confirmed that the product was derived from the targeted T. annulata gene. As a further confirmation it was shown that both species of Hyalomma ticks were able to transmit T. annulata to experimental calves. PCR detection of Theileria parasites in ticks was compared with conventional staining of dissected salivary glands using methyl green pyronin and its comparative advantages are discussed.

Epidemiology and significance of Q fever in Czechoslovakia

Over the last 35 years most parts of Czechoslovakia have experienced Q fever. Of particular note were outbreaks in factories processing imported cotton, wool and hides that had been contaminated in their countries of origin. Some areas of the southern part of Central Slovakia became a natural focus of Q fever with the Dermacentor marginatus tick being the main vector of coxiellae. Currently, Coxiella (C.) burnetii infection appears to be dormant in the country since only sporadic cases are encountered. Cattle vaccination practiced since 1980 may have contributed to the decreasing incidence of human Q fever.

Bahig virus (Tete group) in naturally- and transovarially-infected Hyalomma marginatum ticks from Egypt and Italy.

Arboviruses of the Tete group (Tete, Bahig, Matruh, Tsuruse) were previously recorded only from avian blood and organs from South Africa, Egypt, Italy, and Japan. We report Bahig virus, identified by complement-fixation and neutralization teats, from 2 subspecies ofHyalomma marginatum (family Ixodidae) ticks. One isolate was from larvae of the African subspecies,H. marginatum rufipes Koch, parasitizing a northward-migrating common wheatear,Oenanthe oenanthe subsp., in Egypt. Other isolates were from transovarially-infected F1 larvae and nymphs reared from an engorged female of the Eurasian subspecies,H. m. marginatum Koch, taken from a race horse near Naples, Italy. Transovarial transmission is relatively rarely documented among arboviruses. BothH. marginatum subspecies have already been implicated as vectors of pathogens causing serious human diseases in Eurasia and Africa. The present findings indicate the need for field and laboratory investigations of Tete group epidemiology and factors possibly involving human infections.