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parasites of domestic and wild animals in south africa. l. ixodid ticks infesting horses and donkeys.the aim of the study was to determine the species spectrum of ixodid ticks that infest horses and donkeys in south africa and to identify those species that act as vectors of disease to domestic livestock. ticks were collected opportunistically from 391 horses countrywide by their owners or grooms, or by veterinary students and staff at the faculty of veterinary science, university of pretoria. ticks were also collected from 76 donkeys in limpopo province, 2 in gauteng province and 1 in north we ...201728281774
shifts in the distribution of ixodid ticks parasitizing cattle in zimbabwe.in an attempt to update information on the ecological distribution of ixodid ticks (ixodida: ixodidae) in zimbabwe, a cross-sectional survey was carried out between september 2013 and may 2015 at 322 dip tanks. a total of 15 tick species were collected, namely: amblyomma hebraeum koch (65.2%, n = 210/322), amblyomma variegatum fabricius (14.9%, n = 48/322), hyalomma rufipes koch (62.4%, n = 201/322), hyalomma truncatum koch (37.9%, n = 122/322), rhipicephalus appendiculatus neumann (60.6%, n = 1 ...201727935088
molecular and maldi-tof identification of ticks and tick-associated bacteria in mali.ticks are considered the second vector of human and animal diseases after mosquitoes. therefore, identification of ticks and associated pathogens is an important step in the management of these vectors. in recent years, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (maldi-tof ms) has been reported as a promising method for the identification of arthropods including ticks. the objective of this study was to improve the conditions for the preparation of tick samples ...201728742123
genetic parameters for tick counts across months for different tick species and anatomical locations in south african nguni cattle.the objective of the study was to characterise genetic parameters across months for different tick species and anatomical locations in south african nguni cattle. tick counts were conducted monthly, over a 2-year period, on 586 nguni cattle under natural infestation, from four herds located in different provinces of south africa. the counts were recorded for six species of ticks (amblyomma hebraeum, rhipicephalus evertsi evertsi, rhipicephalus decoleratus and microplus (boofilids), rhipicephalus ...201728687941
seroepidemiological studies of crimean-congo hemorrhagic fever virus in domestic and wild animals.crimean-congo hemorrhagic fever (cchf) is a widely distributed, tick-borne viral disease. humans are the only species known to develop illness after cchf virus (cchfv) infection, characterized by a nonspecific febrile illness that can progress to severe, often fatal, hemorrhagic disease. a variety of animals may serve as asymptomatic reservoirs of cchfv in an endemic cycle of transmission. seroepidemiological studies have been instrumental in elucidating cchfv reservoirs and in determining endem ...201626741652
multiple pathogens including potential new species in tick vectors in côte d'ivoire.our study aimed to assess the presence of different pathogens in ticks collected in two regions in côte d'ivoire.201626771308
infestation and identification of ixodid tick in cattle: the case of arbegona district, southern ethiopia.the study was conducted from october 2014 to june 2015 to estimate tick prevalence and identify major tick genera infesting cattle and the associated risk factors in arbegona district, southern ethiopia. a total of 2024 adult ticks were collected from main body parts of animals and eight species of ticks which belong to three genera were identified. questionnaire survey was employed concerning the general case on the tick infestation problems on the cattle. from 384 cattle examined, 291 (75.7%) ...201628105466
matrix-assisted laser desorption/ionization time of flight mass spectrometry for comprehensive indexing of east african ixodid tick species.the tick population of africa includes several important genera belonging to the family ixodidae. many of these ticks are vectors of protozoan and rickettsial pathogens including theileria parva that causes east coast fever, a debilitating cattle disease endemic to eastern, central and southern africa. effective surveillance of tick-borne pathogens depends on accurate identification and mapping of their tick vectors. a simple and reproducible technique for rapid and reliable differentiation of l ...201626979606
arachnids of medical importance in brazil: main active compounds present in scorpion and spider venoms and tick saliva.arachnida is the largest class among the arthropods, constituting over 60,000 described species (spiders, mites, ticks, scorpions, palpigrades, pseudoscorpions, solpugids and harvestmen). many accidents are caused by arachnids, especially spiders and scorpions, while some diseases can be transmitted by mites and ticks. these animals are widely dispersed in urban centers due to the large availability of shelter and food, increasing the incidence of accidents. several protein and non-protein compo ...201526273285
ethnoecological knowledge of ticks and treatment of tick-borne diseases among maasai people in northern tanzania.the aim of this study was to understand traditional knowledge of tick ecology and remedies for tick-borne diseases (tbds) among the maasai people in northern tanzania.201527065643
molecular detection of zoonotic tick-borne pathogens from ticks collected from ruminants in four south african provinces.ticks carry and transmit a remarkable array of pathogens including bacteria, protozoa and viruses, which may be of veterinary and/or of medical significance. with little to no information regarding the presence of tick-borne zoonotic pathogens or their known vectors in southern africa, the aim of our study was to screen for anaplasma phagocytophilum, borrelia burgdorferi, coxiella burnetii, rickettsia species and ehrlichia ruminantium in ticks collected and identified from ruminants in the easte ...201526227797
an update on the ecological distribution of the ixodidae ticks in zimbabwe.in total 7657 ticks were collected from 121 dip tanks in 12 districts representative of zimbabwe's five ecological regions between september 2013 and may 2014. based on morphological traits four genera and 13 species of ticks were identified. amblyomma hebraeum (60.3 %), rhipicephalus microplus (58.7 %), rhipicephalus decoloratus (47.1 %), rhipicephalus appendiculatus (56.2 %), rhipicephalus evertsi evertsi (67.8 %), rhipicephalus (near) punctatus (13.2 %), hyalomma truncatum (38 %) and hyalomma ...201525721256
identification of rickettsial pathogens in ixodid ticks in northern senegal.the spotted fevers, caused by the rickettsia bacteria, are a group of emerging diseases that are responsible for significant human morbidity. in africa, the distribution of different species of rickettsia in their tick vectors is poorly studied. we have collected 1169 hard ticks from 5 different species in the northern senegal, close to the saharan border. in a far northern collection site, corresponding to the rickettsia africae distribution area, we collected three amblyomma variegatum ticks i ...201424908548
protozoan and bacterial pathogens in tick salivary glands in wild and domestic animal environments in south africa.a total of 7364 ticks belonging to 13 species was collected from 64 game animals (belonging to 11 species) and from 64 livestock animals (cattle and sheep) living in close vicinity at 6 localities in 3 south african provinces (free state, mpumalanga, and limpopo). the geographic distribution of all tick species was congruent with the literature except for haemaphysalis silacea. from each infested host, a maximum of 10 males and 10 females of each tick species were dissected to isolate the saliva ...201424378080
molecular detection of piroplasms in ixodid ticks infesting cattle and sheep in western oromia, ethiopia.in ethiopia, ticks and tick-borne diseases are widely distributed and contribute to important economic losses. several studies investigated the prevalence and species composition of ticks infesting ruminants; however, data on tick-borne pathogens are still scarce. during the study period from october 2010 to april 2011, a total of 1,246 adult ticks and 264 nymphs were collected from 267 cattle and 45 sheep in bako district, western oromia, ethiopia. the study showed infestation of 228/267 (85.4  ...201423846769
history and development of research on wildlife parasites in southern africa, with emphasis on terrestrial mammals, especially ungulates.the history of wildlife parasitology in south africa, and to some extent southern africa, is reviewed, giving a brief overview of the early years and following its development from the founding of the onderstepoort veterinary institute in 1908 until the turn of the century. an emphasis is placed on game species. the main findings on protozoan parasites, including those of carnivores, are presented, starting in the 1890s and leading up to the first decade of the 21st century. important developmen ...201425830101
detection of borrelia theileri in rhipicephalus geigyi from mali.disease burden within cattle is a concern around the world. bovine borreliosis, one such disease, is caused by the spirochete borrelia theileri transmitted by the bite of an infected rhipicephalus (boophilus) species tick. a number of species within the genus are capable of transmitting the agent and are found on multiple continents. cattle in the west african nation of mali are infested with four species of rhipicephalus ticks of the subgenus boophilus: rhipicephalus annulatus, rhipicephalus mi ...201424709337
first molecular detection of rickettsia africae in ticks from the union of the comoros.rickettsia africae is the agent of african tick bite fever, a disease transmitted by ticks in sub-saharan africa. in union of the comoros, a recent study reported the presence of a rickettsia africae vector but no information has been provided on the circulation of the pathogenic agent in this country.201425245895
are ticks venomous animals?as an ecological adaptation venoms have evolved independently in several species of metazoa. as haematophagous arthropods ticks are mainly considered as ectoparasites due to directly feeding on the skin of animal hosts. ticks are of major importance since they serve as vectors for several diseases affecting humans and livestock animals. ticks are rarely considered as venomous animals despite that tick saliva contains several protein families present in venomous taxa and that many ixodida genera ...201425006341
new data regarding distribution of cattle ticks in the south-western indian ocean islands.recent studies have produced new insight into the origin and distribution of some cattle ticks in the south-western indian ocean islands. rhipicephalus appendiculatus, introduced from tanzania in 2002, is now well established on grande comore but has not yet reached the other islands of the archipelago (mohéli, anjouan and mayotte). only one of the two clades identified in africa has settled so far. amblyomma variegatum, which was not supposed to be able to persist in the antananarivo region (13 ...201324016261
relationship between the prevalence of ectoparasites and associated risk factors in free-range pigs in kenya.a cross-sectional study was undertaken to determine the prevalence of ectoparasites and possible risk factors in free-range pigs from 135 farms of busia district, kenya. three hundred and six pigs were examined for presence of external parasites using standard parasitological methods. data on management practices including housing and history of acaricide spraying were also collected. the ectoparasites found in the pigs were haematopinus suis (96.1%), sarcoptes scabiei (63.7%), and ticks (29.7%) ...201323984085
host specialization in ticks and transmission of tick-borne diseases: a review.determining patterns of host use, and the frequency at which these patterns change, are of key importance if we are to understand tick population dynamics, the evolution of tick biodiversity, and the circulation and evolution of associated pathogens. the question of whether ticks are typically host specialists or host generalists has been subject to much debate over the last half-century. indeed, early research proposed that morphological diversity in ticks was linked to host specific adaptation ...201324109592
a comparison between tick species collected in a controlled and control free area on a game ranch in south africa.despite the large number of collection records, there are no recent collections of ixodid ticks of this magnitude in the waterberg area, limpopo province, south africa. free-living ticks on a commercial game farm were obtained by a total of 432 drag-samples in eight sample sites from september 2003 to august 2008. the ticks were collected to establish the difference between tick species and densities associated with acaricide-controlled (semi-intensive) and control-free areas on a game farm in t ...201323718159
tick infestation patterns in free ranging african buffalo (syncercus caffer): effects of host innate immunity and niche segregation among tick species.ticks are of vast importance to livestock health, and contribute to conflicts between wildlife conservation and agricultural interests; but factors driving tick infestation patterns on wild hosts are not well understood. we studied tick infestation patterns on free-ranging african buffalo (syncercus caffer), asking (i) is there evidence for niche segregation among tick species?; and (ii) how do host characteristics affect variation in tick abundance among hosts? we identified ticks and estimated ...201224533310
ticks (acari: ixodidae) infesting cattle and african buffaloes in the tsavo conservation area, kenya.several ixodid tick species are shared between domestic cattle and african buffaloes (syncerus caffer). so too, are a number of tick-borne diseases. the aim of the study was to compare the species composition of ticks that infest cattle and buffaloes utilising the same habitat within the tsavo conservation area, kenya. to this end, 25 cattle and 62 buffaloes were each opportunistically sampled for ticks on a single occasion in february 2010. eight species, namely amblyomma gemma, amblyomma lepid ...201223327329
ectoparasites of sheep in three agro-ecological zones in central oromia, ethiopia.a cross-sectional study was conducted to determine the prevalence and risk factors for ectoparasites infestation in sheep in three agro-ecological zones in central oromia, ethiopia, from october 2009 to april 2010. the study revealed that 637 (48.1%) of the 1325 sheep examined were infested with one or more ectoparasites. the ectoparasites identified were bovicola ovis (27.2%), melophagus ovinus (16.4%), ctenocephalides sp. (2.3%), linognathus africanus (1.2%), linognathus ovillus (0.3%), sarcop ...201223327319
theileriosis (cytauxzoonosis) in roan antelope (hippotragus equinus): field exposure to infection and identification of potential vectors.four hand-reared, naïve roan antelope, 4 months of age, were exposed to naturally infected pasture on a game farm in mpumalanga province, south africa, where roan are known to die from theileriosis. various clinical parameters were recorded during this period. the predominant ticks parasitising these animals at the time (january to february), were rhipicephalus appendiculatus and rhipicephalus evertsi evertsi adults. after a period of 5 weeks the animals developed signs of clinical theileriosis ...201223327309
tick paralysis in australia caused by ixodes holocyclus neumann.ticks are obligate haematophagous ectoparasites of various animals, including humans, and are abundant in temperate and tropical zones around the world. they are the most important vectors for the pathogens causing disease in livestock and second only to mosquitoes as vectors of pathogens causing human disease. ticks are formidable arachnids, capable of not only transmitting the pathogens involved in some infectious diseases but also of inducing allergies and causing toxicoses and paralysis, wit ...201121396246
colonization of grande comore island by a lineage of rhipicephalus appendiculatus ticks.union of the comoros suffered a severe east coast fever epidemic in 2004. rhipicephalus appendiculatus was probably involved in pathogen transmission as this competent tick species, although previously absent from comoros, was sampled on 4 animals on one geographical site during the epidemic. we carried out an entomological survey on all three islands of union of the comoros to establish cattle tick species distribution with a special emphasis on r. appendiculatus. we investigated r. appendicula ...201121414194
prevalence and species composition of ixodid ticks infesting horses in three agroecologies in central oromia, ethiopia.a cross-sectional study was conducted to determine the species composition and prevalence of ixodid ticks infesting horses in three agroecological zones in central ethiopia. for this purpose, a total of 1,168 horses were examined for tick infestation. an overall prevalence of 39.04% of tick infestation on horses was recorded. a total of 917 adult ticks were collected from infested horses. amblyomma, boophilus, rhipicephalus, and hyalomma genera with the respective prevalence of 3.2%, 1.8%, 29.2% ...201121656133
control of tick populations by spraying metarhizium anisopliae conidia on cattle under field conditions.conidia of the entomopathogenic fungus, metarhizium anisopliae, in oil/water formulation (1-á+ù-á10(8) conidia/ml) were sprayed at 3-áweekly intervals on rhipicephalus evertsi evertsi and rhipicephalus (boophilus) decoloratus ticks while feeding on afrikana bulls grazing in paddocks for a period of 1-áyear. the fungus reduced the on-host tick populations by 83% 3-ámonth after commencement of the experiment. the formulation by itself had only minimal effect on the tick population. tick population ...201121725837
an elisa to detect serum antibodies to the salivary gland toxin of ixodes holocyclus neumann in dogs and rodents.the ixodes holocyclus tick causes paralysis in up to 10,000 companion and domestic animals each year in australia. treatment requires the removal of the parasite and the administration of a commercial tick antiserum that is prepared from hyperimmune dogs. each batch of this serum is initially tested for toxin-neutralising potency in a mouse bioassay that is expensive, time consuming, and subjective. with the aim of developing a rapid in vitro assay to replace the bioassay, we used a partially pu ...201121687655
relationships between tick counts and coat characteristics in nguni and bonsmara cattle reared on semiarid rangelands in south africa.indigenous nguni cattle are adapted to the semiarid rangeland and appear to be resistant to ticks; however, the mechanism for tick resistance is yet to be established. to understand tick resistance in cattle, relationships among skin thickness, hair length, coat score, and tick counts were estimated in nguni (n=12) and bonsmara (n=12) heifers on semiarid rangelands of south africa. the tick species observed to infest the heifers were rhipicephalus (boophilus) decoloratus (frequency: 76%), rhipic ...201121890073
ticks on pastures and on two breeds of cattle in the eastern cape province, south africa.many studies on the population dynamics of questing ticks on pastures and of parasitic ticks on cattle have been conducted. few, however, have attempted to link the two in a single study. this study aimed to assess the population dynamics of questing ixodid ticks on pastures and of adult ticks on two breeds of cattle with different levels of susceptibility to tick infestation on the same pastures. between january 2005 and december 2009 questing ixodid ticks were collected monthly from natural pa ...201123327215
the dynamics of questing ticks collected for 164 consecutive months off the vegetation of two landscape zones in the kruger national park (1988-2002). part iii. the less commonly collected species.despite many studies regarding tick ecology, limited information on long-term changes in tick populations exist. this study assessed the long-term population dynamics of the less frequently collected questing ixodid ticks in the kruger national park (knp). from 1988 to 2002, monthly dragging of the vegetation was performed in three habitats (grassland, woodland and gully) at two sites in the knp (nhlowa road, landscape zone 17, and skukuza, landscape zone 4). amblyomma marmoreum and rhipicephalu ...201123327206
tick-borne rickettsioses, neglected emerging diseases in rural senegal.rickettsioses are one of the most important causes of systemic febrile illness among travelers from developed countries, but little is known about their incidence in indigenous populations, especially in west africa.201020856858
tick loads in cattle raised on sweet and sour rangelands in the low-input farming areas of south africa.the objective of this study was to compare tick loads and prevalence in nguni and non-descript cattle in the sweet (palatable throughout the year) and sour (palatable only in the rainy season) communal rangelands of the eastern cape province, south africa. engorged adult female ixodid ticks were collected and identified seasonally from 144 cattle raised on sweet and sour rangelands from august 2007 to april 2008. three tick species were identified in the sweet and sour rangelands namely rhipicep ...201020967568
coxiella burnetii in humans and ticks in rural senegal.q fever is a worldwide zoonotic disease caused by coxiella burnetii. epidemiologically, animals are considered reservoirs and humans incidental hosts.201020386603
survey of ixodid ticks in domestic ruminants in bedelle district, southwestern ethiopia.a survey aimed at determining the status of ticks in cattle, sheep and goats in bedelle district (southwestern ethiopia) was carried out from november 2007 to april 2008. out of the total 330 animals examined, 314 (95.2%) were found to be infested (harbouring of at least a single tick). high rates of infestations were recorded across all three host species. factors like month of collection, age and sex of host species did not show significant association with infestation rates. a total of 5,507 ...201020563884
bm86 homologues and novel ataq proteins with multiple epidermal growth factor (egf)-like domains from hard and soft ticks.tick control on livestock relies principally on the use of acaricides but the development of acaricide resistance and concerns for environmental pollution underscore the need for alternative control methods, for instance through the use of anti-tick vaccines. two commercial vaccines based on the recombinant bm86 protein from rhipicephalus (boophilus) microplus ticks were developed. partial protection of the bm86 vaccine against other rhipicephalus (boophilus) and hyalomma tick species suggests t ...201020647015
the comparative prevalence of five ixodid tick species infesting cattle and goats in maputo province, mozambique.this study compares the prevalence of ixodid tick species on cattle and goats in maputo province. adult ticks as well as the nymphs of three species, and only the adults of two species were collected from sets of five cattle at 21 localities throughout the province and compared with those collected from similar sets of goats at the same places. amblyomma hebraeum adults and/or nymphs were present on cattle and on goats at all 21 localities, and 90 cattle and 22 goats were infested with adult tic ...200920698440
tick infestation, and udder and teat damage in selected cattle herds of matabeleland south, zimbabwe.a cross-sectional survey was conducted to determine tick infestation, and udder and teat damage in 286 lactating cows and heifers at six properties in the smallholder and commercial sectors in gwanda district of matabeleland south province, zimbabwe. eight tick species were identified: amblyomma hebraeum, hyalomma truncatum, hyalomma marginatum rufipes, rhipicephalus evertsi evertsi, rhipicephalus (boophilus) decoloratus, rhipicephalus appendiculatus, rhipicephalus zambeziensis and rhipicephalus ...200920698443
species composition and geographic distribution of ticks infesting cattle, goats and dogs in a temperate and in a subtropical region of south-east africa.the species and distribution of ticks infesting cattle, goats and dogs in the eastern region of the eastern cape province, south africa and maputo province, mozambique were determined from collections made from these animals at 72 localities in the former region and 30 in the latter. eleven ixodid and one argasid species were recovered in the eastern cape province and 15 ixodid species in maputo province. the most common ticks infesting cattle and goats in both provinces were amblyomma hebraeum, ...200921105593
identification of a novel babesia sp. from a sable antelope (hippotragus niger harris, 1838).babesiosis in a sable antelope (hippotragus niger harris, 1838) was first reported in 1930; the parasite was named babesia irvinesmithi. recently, specimens from an adult sable that presented with a sudden onset of disease and that subsequently died during immobilization were submitted for molecular characterization. microscopic examination of thin blood smears revealed the presence of small piroplasms. dna was extracted from blood samples; the v4 variable region of the 18s rrna gene was amplifi ...200818508943
reliminary survey of ticks (acari: ixodidae) on cattle in central equatoria state, southern sudan.in a preliminary survey conducted in 2005, the species composition and seasonality of ticks infesting cattle in central equatoria state, southern sudan was determined. three locations were selected (gumbo, khor rumla and nyaing) and surveyed every 3 months. two cattle herds in each of the three locations were visited four times during the study period. total body collections of ticks were made from each of five cattle (nilotic zebu breed) kept in six different herds. four tick genera and ten spe ...200818575063
protection of metarhizium anisopliae conidia from ultra-violet radiation and their pathogenicity to rhipicephalus evertsi evertsi ticks.metarhizium anisopliae conidia were formulated in water or in olive oil containing 3% commercial sunscreens (everysun or e45 sun block 50) and exposed to an artificial uv source for up to 5 hours. survival of conidia after 5 h of exposure to uv in oil formulation was 29% when protected with everysun, 40% when protected with e45, and 4% in control. in comparison, survival of conidia formulated in water was 13% when protected with everysun, 24% when protected with e45, and 0% in control. furthermo ...200818712608
the prevalence of serum antibodies to ehrlichia ruminantium infection in ranch cattle in tanzania: a cross-sectional study.serum samples collected in a cross-sectional survey of grazing cattle on manyara ranch, monduli district, tanzania, were tested by indirect major antigenic protein 1 fragment b (map 1-b) elisa to determine the seroprevalence of ehrlichia ruminantium and to assess ranch-level risk factors for heartwater. heartwater-exposed cattle were widespread on the ranch and overall seroprevalence was 50.3% (95% ci, 44.9-55.6), enough to indicate an endemically unstable situation. multivariate logistic regres ...200818846851
host surveys, ixodid tick biology and transmission scenarios as related to the tick-borne pathogen, ehrlichia canis.the ehrlichioses have been subject to increasing interest from veterinary and public health perspectives, but experimental studies of these diseases and their etiologic agents can be challenging. ehrlichia canis, the primary etiologic agent of canine monocytic ehrlichiosis, is relatively well characterized and offers unique advantages and opportunities to study interactions between a monocytotropic pathogen and both its vertebrate and invertebrate hosts. historically, advances in tick-borne dise ...200818963493
ixodid ticks infesting domestic goats in communal land areas of zimbabwe.the purpose of this study was to determine the species spectrum of ticks infesting goats owned by resource-limited farmers in the state-owned communal land areas of zimbabwe. ticks were collected from goats at a single locality within each of 5 communal land areas, and a total of 14 ixodid tick species was recovered. the most numerous tick was rhipicephalus evertsi evertsi, which was present in all areas at each sampling, and a rhipicephalus sp. (near r. punctatus), which was most abundant on go ...200819244819
the extent of acaricide resistance in 1-, 2- and 3-host ticks on communally grazed cattle in the eastern region of the eastern cape province, south africa.in order to determine the extent of acaricide resistance in the eastern region of the eastern cape province 1-, 2- and 3-host ticks were collected from cattle at 59 dip-tanks over a period of 2 years. these ticks were tested for resistance against 3 compounds, namely amitraz, cypermethrin and chlorfenvinphos. the shaw larval immersion test detected emerging resistance to amitraz in rhipicephalus (boophilus) microplus at 2 dip-tanks and resistance at a 3rd. it also revealed resistance in this tic ...200819244821
ehrlichia ruminantium variants which do not cause heartwater found in south africa.in 1994 a batch of apparently healthy goats was selected for intended export to the usa from a heartwater-free and vector tick-free region of south africa. the animals were tested serologically for heartwater, using either or both an ifa and an elisa test, and 52% were found to be serologically positive. a pcr assay based on ehrlichia ruminantium 16s gene sequences gave positive results for 54% of the animals, suggesting that apparently non-pathogenic e. ruminantium variants existed in this hear ...200717123750
detection of rickettsia africae in rhipicephalus (boophilus) decoloratus ticks from the republic of botswana, south africa.a total of 53 engorged adult ticks belonging to the species rhipicephalus (boophilus) decoloratus (n = 9), rhipicephalus evertsi evertsi (n = 27), rhipicephalus appendiculatus (n = 9), amblyomma hebraeum (n = 5), and hyalomma marginatum turanicum (n = 3), were removed from oryx in botswana (south africa). they were tested for the presence of spotted fever group (sfg) rickettsia and anaplasma phagocytophilum using polymerase chain reaction (pcr). seventy-seven percent of r. decoloratus as well as ...200717690416
goats as alternative hosts of cattle ticks.the objective of this study was to compare the presence on goats and cattle of adult ticks that usually infest cattle. to this end ticks collected from sets of five goats were compared with those collected from sets of five cattle at 72 communal dip-tanks in the eastern region of the eastern cape province. amblyomma hebraeum was present on goats at 25 and on cattle at 39 dip-tanks, and a total of 61 goats and 138 cattle were infested. adult rhipicephalus (boophilus) microplus was present on goat ...200717708147
ticks associated with the three largest wild ruminant species in southern africa.the objective of this study was to assess the host status of the three largest southern african wild ruminants, namely giraffes, giraffa camelopardalis, african buffaloes, syncerus caffer, and eland, taurotragus oryx for ixodid ticks. to this end recently acquired unpublished data are added here to already published findings on the tick burdens of these animals, and the total numbers and species of ticks recorded on 12 giraffes, 18 buffaloes and 36 eland are summarized and discussed. twenty-eigh ...200717933365
distribution and population dynamics of ticks (acari: ixodidae) infesting sheep in sennar state, sudan.a cross-sectional survey of ticks infesting sheep was conducted in sennar state, sudan. a total body collection of ticks was carried out at five localities sennar town, singa, dinder, abu naama and um banein on two types of desert sheep (watish and ashgar) on two farms at each locality at two monthly intervals for one year starting july 2002 to may 2003. four tick genera and eight species were identified. they were amblyomma lepidum, hyalomma anatolicum anatolicum, hyalomma truncatum, rhipicepha ...200718453239
the use of a pour-on and spray dip containing amitraz to control ticks (acari: ixodidae) on cattle.knockdown and persistence efficacies of a pour-on containing amitraz 1% and cypermethrin 1% and a spray dip containing 12.5% amitraz were compared. knock-down and persistence efficacies of the amitraz spray dip against rhipicephalus (boophilus) decoloratus and amblyomma hebraeum were significantly higher for the duration of the trial than those of the pour-on. in the case of rhipicephalus appediculatus and rhipicephalus evertsi evertsi, efficacy was significantly higher on days 2 and 5. resistan ...200617120621
transstadial and intrastadial experimental transmission of ehrlichia canis by male rhipicephalus sanguineus.the acquisition and transmission of rickettsial pathogens by different tick developmental stages has important epidemiological implications. the purpose of this study was to determine if male rhipicephalus sanguineus can experimentally acquire and transmit ehrlichia canis in the absence of female ticks. two trials were performed where nymphal and male r. sanguineus were simultaneously acquisition fed on the same infected donor hosts, and transstadially or intrastadially exposed male ticks were f ...200515941624
detection of babesia canis rossi, b. canis vogeli, and hepatozoon canis in dogs in a village of eastern sudan by using a screening pcr and sequencing methodologies.babesia and hepatozoon infections of dogs in a village of eastern sudan were analyzed by using a single pcr and sequencing. among 78 dogs, 5 were infected with babesia canis rossi and 2 others were infected with b. canis vogeli. thirty-three dogs were positive for hepatozoon. hepatozoon canis was detected by sequence analysis.200516275954
some observations on ticks (acari: ixodidae) infesting sheep in river nile province of northern sudan.five species of ixodid ticks were found in a cross-sectional survey in which 200 sheep were examined for ticks in river nile province, sudan. hyalomma anatolicum anatolicum was the predominant species (73.6%), whereas ticks belonging to the rhipicephalus sanguineus group (14.7%), rhipicephalus evertsi evertsi (9.1%), rhipicephalus simus (2%) and hyalomma dromedarii (0.5%) were also found. the mean tick load was 11.2 per animal. in a subsequent longitudinal survey ticks were collected on a monthl ...200516300192
acaricide efficiency of amitraz/cypermethrin and abamectin pour-on preparations in game.the efficacy of an amitraz/cypermethrin pour-on preparation (1% w/v each) was tested against natural tick infestations of buffaloes, eland and blesbok in three separate trials. the eland were also treated with a 0.02% abamectin (w/v) acaricidal pour-on preparation. the amitraz/cypermethrin pour-on was effective against amblyomma hebraeum, rhipicephalus evertsi evertsi, rhipicephalus appendiculatus and hyalomma marginatum rufipes on the buffaloes. both acaricides were effective against r. appendi ...200516562734
ticks on crested francolins, francolinus sephaena, and on the vegetation on a farm in limpopo province, south africa.ticks were collected at approximately bi-monthly intervals between june 1996 and june 1997 from crested francolins, francolinus sephaena, and from the vegetation on a mixed cattle and wildlife farm in limpopo province, south africa. the birds were infested with the immature stages of 13 tick species, of which amblyomma hebraeum, amblyomma marmoreum and hyalomma marginatum rufipes were the most numerous and prevalent. ten ixodid tick species were collected from the vegetation, of which the immatu ...200516562738
a sero-epidemiological survey of blood parasites in cattle in the north-eastern free state, south africa.a survey to determine the incidence of parasites in cattle (n = 386) was conducted in the north eastern free state between august 1999 and july 2000. giemsa-stained blood smears were negative for blood parasites. a total of 94% of the cattle were sero-positive for babesia bigemina by indirect fluorescent antibody test while 87% were sero-positive for anaplasma by enzyme-linked immunosorbent assay. the observation of negative blood smears but high incidence of positive serological results for ana ...200415185577
crimean-congo hemorrhagic fever, mauritania.from february to august 2003, 38 persons were infected with crimean-congo hemorrhagic fever (cchf) virus in mauritania; 35 of these persons were residents of nouakchott. the first patient was a young woman who became ill shortly after butchering a goat. she transmitted the infection to 15 persons in the hospital where she was admitted and four members of her family. in nouakchott, two disease clusters and 11 isolated cases were identified. the case-fatality ratio was 28.6%. of the patients not i ...200415663851
preliminary survey of ticks (acari: ixodidae) on cattle in northern sudan.in a cross sectional survey conducted during the period june 2001 to july 2002, the geographical distribution of ticks on cattle in the sudan was determined. seventeen locations were surveyed from northern, central, eastern, western, blue nile and white nile provinces. total body collections of ticks were made from 20 cattle at each location. four tick genera and 11 species were identified. the tick species collected included amblyomma lepidum, amblyomma variegatum, boophilus decoloratus, hyalom ...200415732459
seasonal fluctuation of parasitic infestation in donkeys (equus asinus) in oodi village, kgatleng district, botswana.during the period march to september 2000, a study was conducted in oodi village, kgatleng district, botswana, to investigate the seasonal fluctuation of internal, external and blood parasites of donkeys. twelve adult donkeys were randomly selected from a farmer with a herd of 15 donkeys. monthly visits were made to the farmer when the donkeys were examined for parasites. the only ectoparasites recovered from the donkeys were instars of various tick species. the most prevalent tick was rhipiceph ...200312836744
ticks and tick-borne diseases of livestock belonging to resource-poor farmers in the eastern free state of south africa.the paper provides a summary of three studies conducted in the eastern free state of south africa between 1998 and 2000. in a questionnaire-based study approximately 21% of interviewed resource-poor farmers (n = 150) indicated that they experienced problems with ticks and tick-borne diseases. about 56% of farmers indicated that tick-related problems were most severe in summer, while 32% indicated that the most problems were encountered in winter. about 12% indicated that the tick problems were e ...200214570134
ixodid ticks on indigenous goats owned by small-scale farmers in four communal grazing areas in south africa.indigenous goats belonging to small-scale farmers in 4 communal grazing areas in south africa were sampled for ixodid ticks during the period september 1991 to may 1993. three of these areas were in the north west province (rietgat, madinyane and bethany), and one in mpumalanga province (geluk). no tick control was practised unless requested by the owners. seven ixodid tick species, of which the majority were immature ticks, were collected from the goats in north west province. amblyomma hebraeu ...200212088070
seasonal abundance of adult ixodid ticks infesting cattle belonging to resource-limited farmers in the north-eastern free state province of south africa.a study was undertaken to determine the seasonal abundance of the ticks infesting cattle owned by resource-limited farmers in the north-eastern free state province of south africa. infestations of boophilus decoloratus koch, 1844, rhipicephalus evertsi evertsi neumann, 1897, rhipicephalus follis donitz, 1910, rhipicephalus gertrudae feldman-muhsam, 1960 and rhipicephalus warburtoni walker & horak, 2000, were monitored on cattle of mixed breeds at monthly intervals from may 1998 to april 1999. hi ...200212092776
ixodid ticks on cattle belonging to small-scale farmers at 4 communal grazing areas in south africa.ixodid ticks were collected during the period september 1991 to august 1993 from cattle belonging to small-scale farmers utilising 4 communal grazing areas. three of these were in north west province and 1 in mpumalanga province, south africa. ten tick species were collected in north west province and 7 in mpumalanga. the adults of amblyomma hebraeum, rhipicephalus appendiculatus and rhipicephalus evertsi evertsi were most numerous in north west province, while in mpumalanga boophilus decoloratu ...200212515294
tick infestation of borana cattle in the borana province of ethiopia.a study was conducted to identify and determine burdens of ticks infesting borana cattle in the borana province of ethiopia. rhipicephalus pulchellus, rhipicephalus pravus, rhipicephalus muhsamae, rhipicephalus praetextatus, rhipicephalus evertsi evertsi, amblyomma gemma, amblyomma variegatum, amblyomma cohaerens, amblyomma lepidum, hyalomma truncatum, hyalomma marginatum rufipes and boophilus decoloratus were identified on the cattle. their burdens ranged from 658-1,554 with a mean of 1,205 tic ...200111403429
influence of sheep breed and application site on the efficacy of a flumethrin pour-on formulation against ticks.the objectives of this study were to determine the influence of application site and sheep breed on the efficacy of a flumethrin (1% m/v) solution for the control of 'bont'-legged (hyalomma spp.) and red-legged ticks (rhipicephalus evertsi evertsi). this study was conducted from november 1996 to february 1997 on 3 farms in the southwestern free state province. two trials were conducted on dorper sheep and 2 on merino sheep. for each specific application 30 sheep were selected and allocated to 3 ...200111811701
the distribution of ixodid ticks (acari: ixodidae) in central ethiopia.ixodid ticks were collected from domestic animals, mainly cattle, in 11 administrative zones covering 84 districts in central ethiopia over a period of 2 years (july 1996 to june 1998). nineteen tick species were identified. four of these belonged to the genus amblyomma, one to boophilus, two to haemaphysalis, three to hyalomma and nine to rhipicephalus. amblyomma variegatum and rhipicephalus evertsi evertsi were present in all 11 administrative zones and, with the exception of afar, boophilus d ...200112026058
detection and micro-scale isolation of a low molecular mass paralysis toxin from the tick, argas (persicargas) walkerae.this study describes the isolation of a 11 kda paralysis toxin from crude larval extracts of argas (persicargas) walkerae by exploiting the cross-reactivity of a monoclonal antibody (4b12), directed against the paralysis toxin of rhipicephalus evertsi evertsi. this low molecular mass is in contrast to previous findings of a 60-70 kda toxin for a. (p.) walkerae, but is similar to neurotoxins isolated from venomous forms of the class arachnida, which comprise the orders araneae (spiders). scorpion ...200011201354
population dynamics of ticks on indigenous cattle in a pastoral dry to semi-arid rangeland zone of uganda.studies on seasonality and population dynamics of ticks on indigenous cattle and their crosses (calves) were carried out in buruli ranching scheme, nabiswera, luwero district of uganda on three treatment groups of animals: group 1 (twice a week dipping), group 2 (once a month dipping) and group 3 (no tick control). during this study, four major species of ticks of economic importance were recorded in decreasing order of abundance: rhipicephalus appendiculatus, rhipicephalus evertsi evertsi, ambl ...199910353189
[experimental transmission of crimean-congo hemorrhagic fever virus by rhipicephalus evertsi evertsi (acarina:ixodidae)].we have conducted experiments to assess the ability of rhipicephalus evertsi evertsi tick to transmit the crimean-congo haemorrhagic fever (cchf) and determine their reproductive cycle. the rh. e. evertsi was infected by intracoelomic (transparietal and intra-anal) inoculation during the imaginal stases and by oral feeding on an infected viremic goat during imaginal and nymphal stases. the infection rate, transovarial and trans-stasial cchf virus transmission were monitored for virus reisolation ...199910472436
spatial and temporal distributions of parasites: can wild and domestic ungulates avoid african tick larvae?infestation of a new host is a crucial stage in the life-cycle of parasites, and the possibility that hosts avoid infesting contact depends, in part, on the predictability of infestation risk. immature free stages of ticks (acari, ixodidae) have limited mobility and survival in the vegetation and strongly depend on host behaviours for their infestation. we studied spatial and temporal distributions of the larvae of 2 major groups of african risk species in a ranch in zimbabwe. no difference in t ...199910599078
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 confin ...19989737594
isolation and characterization of a babesia species from rhipicephalus evertsi evertsi ticks picked off a sable antelope (hippotragus niger) which died of acute babesiosis.transmission of a babesia species to susceptible cattle by rhipicephalus evertsi evertsi ticks picked off a sable which died of acute babesiosis is described. the parasite was initially isolated by feeding r. e. evertsi ticks on a susceptible, splenectomised bovine which developed parasitaemia. blood stabilate from the parasitaemic bovine produced a fatal babesiosis in a spleen--intact bovine. clinical signs shown by the affected animals corresponded with those of acute babesiosis. parasitologic ...19989741050
ixodid tick infestations of wild birds and mammals on a game ranch in central province, zambia.ticks were collected at irregular intervals from december 1995 to november 1996 from wildlife on mtendere game ranch in the chisamba district of central province, zambia. total collections were made from two species of ground-nesting birds and 20 species of small and large mammals. thirteen species/subspecies of ixodid ticks were recovered. rhipicephalus appendiculatus was the most abundant, followed by boophilus decoloratus and rhipicephalus evertsi evertsi. small numbers of immature ticks of o ...19989741055
tick diversity, abundance and seasonal dynamics in a resource-poor urban environment in the free state province.the objectives of this study were to determine the diversity, seasonal dynamics and abundance of ticks infesting cattle in urban, small-scale farming communities in and around botshabelo and thaba nchu in the eastern free state province, south africa. a total of ten cattle, ear-tagged for individual identification, were investigated monthly at each of five localities. adult ticks were removed from the right hand side of each animal and placed in containers filled with 70% ethanol. they were subs ...199810192844
evidence to show that an agent that cross-reacts serologically with cowdria ruminantium in zimbabwe is transmitted by ticks.the serological diagnosis of heartwater based on reactions to the immunodominant cowdria ruminantium major antigen protein-1 (map-1) is impaired by the detection of false-positive reactions. in this study, the prevalence of false-positive reactions on seven heartwater-free farms in zimbabwe was determined to be 8-94% by immunoblotting against c. ruminantium antigens. the highest prevalence of false-positives on spring valley farm correlated with the presence of rhipicephalus evertsi evertsi tick ...19989493330
predation of livestock ticks by chickens as a tick-control method in a resource-poor urban environment.the possible use of chickens as predators of livestock ticks was studied. chickens were allowed to scavenge for 3 h among tick-infested cattle in a typical township backyard during the milking period. boophilus decoloratus, hyalomma marginatum rufipes, rhipicephalus evertsi evertsi and otobius megnini were recovered from the crops and gizzards at necropsy. the numbers of ticks ingested ranged from 0-128, with an average of 28.81 (+/- 8.42) per chicken. this study has confirmed that chickens are ...19979551478
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 (tamsi-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 ...19979203350
a sero-epidemiological survey of equine piroplasmosis in the northern and eastern cape provinces of south africa.serum samples from yearling thoroughbred horses (n = 176) in the magisterial districts of colesberg, venterstad, and wodehouse in the northern and eastern cape provinces were collected between september and november 1995 to determine the prevalence of antibodies to babesia equi and babesia caballi in these regions. samples were examined for specific antibodies using the indirect fluorescent antibody test. the 95% confidence intervals for the prevalence of serum antibodies in the 3 districts comb ...19969284032
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-bread, 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. ...19968665816
efficacy of pheromone-acaricide-impregnated tail-tag decoys for controlling the bont tick, amblyomma hebraeum (acari: ixodidae), on cattle in zimbabwe.a large-scale field test using pheromone-acaricide-impregnated plastic tail-tag decoys demonstrated excellent efficacy of these devices for control of the bont tick, amblyomma hebraeum, on cattle in zimbabwe. the tail tags were impregnated with a mixture containing o-nitrophenol, methyl salicylate, 2,6-dichlorophenol and phenylacetaldehyde and one of three different acaricides (cyfluthrin, flumethrin or alphacypermethrin). o-nitrophenol and methyl salicylate are components of the a. hebraeum att ...19968746132
an assessment of host resistance to ticks on cross-bred cattle in burundi.groups of cattle of four different cross-breeds (ankole x friesian, ankole x brown-swiss, ankole x guernsey, ankole x sahiwal) plus a group of pure ankole cattle were immunized against tick-borne diseases: east coast fever, using a theileria parva trivalent vaccine, and anaplasmosis, babesiosis and, subsequently, heartwater. with the exception of two small subgroups of ankole and ankole x sahiwal which were treated by weekly spraying using delnav, all the groups were exposed to natural field cha ...19968834737
adult ixodid ticks on two cattle breeds in the south-western free state, and their seasonal dynamics.a study was conducted to compare the species of adult ixodid ticks on friesian and bonsmara cattle and their seasonal dynamics. between five and ten animals of each breed were kept on natural false upper karoo vegetation, typical of the south-western free state. between may 1990 and october 1991, the animals were examined once or twice a month for the presence of adult ticks which were removed, counted and identified. six species of ixodid ticks were recorded. the species composition on the two ...19968848299
the effect of host resistance on the metabolic rate of engorged females of rhipicephalus evertsi evertsi.this study investigated the effect of acquired resistance in guinea-pigs on the metabolic rate of adult females of the tick rhipicephalus evertsi evertsi. guinea-pigs were subjected to three successive infestations of ticks and the rate of co2 production (vco2) measured in first and third infestation engorged females. ticks which fed on resistant hosts showed a 52% decrease in mass compared to ticks that fed on naive animals. reduction in mass was accompanied by a decrease in vco2 (mlh-1) per ti ...19957548947
prevalence of rickettsia-like organisms and spotted fever group rickettsiae in ticks (acari: ixodidae) from zimbabwe.the prevalence of rickettsia-like organisms in ticks from zimbabwe was determined using the hemolymph test. amblyomma hebraeum had the highest prevalence of rickettsia-like organisms. other species with rickettsia-like organisms included amblyomma sparsum, amblyomma variegatum, hyalomma marginatum rufipes, ripicephalus simus, haemaphysalis leachi, amblyomma rhinocerotis, and hyalomma truncatum. ticks with no demonstrable rickettsia-like organisms infection were boophilus decoloratus, haemaphysal ...19958551500
the effects of tick numbers and intervals between infestations on the resistance acquired by guinea-pigs to adults of rhipicephalus evertsi evertsi (acari: ixodidae).guinea-pigs were infested three times at short (1 week) intervals or long (10 week) intervals between successive infestations with low (1), medium (8) and high (15) numbers of adult rhipicephalus evertsi evertsi. to compare the resistance developed by the hosts at short and long intervals between infestations, a challenge (fourth) infestation was performed with the high number of ticks. resistance was assessed by comparing the mean weight of engorged female ticks that dropped from the hosts. con ...19947555412
a shared epitope found in the major paralysis inducing tick species of africa.cross-reactivity between all the paralysis inducing tick species of veterinary relevance in africa was demonstrated, by using a monoclonal antibody directed against the paralysis inducing toxin of rhipicephalus evertsi evertsi. western blot results, together with amino acid composition studies indicated that this monoclonal antibody recognizes protein bands of similar molecular mass and amino acid composition in r. evertsi evertsi and ixodes rubicundus. this suggests that the karoo paralysis tox ...19947543039
[descriptive epidemiology of bovine theileriosis caused by theileria annulata in mauritania, subsaharian west africa].tropical bovine theileriosis due to theileria annulata has been discovered recently in mauritania. an epidemiological study performed in the dry season allowed to better determine the serological prevalence of t. annulata infection and its associated factors. the sex does not seem to have any influence, the role of the breed could not be clearly established, whereas, the age, the geographical origin and the management of the herd have a significant influence on the serological prevalence. these ...19947863061
[ticks and hemoparasitoses of livestock in senegal. vi. the soudano-sahelian zone].the authors report the results of a study on ticks and hemoparasitoses among cattle, sheep and goats in the sudano-sahelian zone. during a period of 15 months, ticks were systematically removed from 40 cattle, 40 sheep and 40 goats in order to assess the population dynamics and determine more accurately the preferential sites of settlement of the different species. the following species were collected in ruminants: hyalomma truncatum, h. marginatum rufipes, rhipicephalus evertsi evertsi, rh. gui ...19947991897
[crimean-congo hemorrhagic fever in senegal. latest data on the ecology of the cchf virus].the authors finalize the knowledge on the ecology of the cchf virus in senegal, west africa. they specify two new major data for the understanding of the viral ecology in west africa. the recognition of a bird species, common and widely distributed in senegal (tockus erythrorhynchus, coraciiformes, bucerotidae), that replicates the virus and infects the immature stages of its current parasite hyalomma marginatum rufipes in more than 90% of the cases, explains why the minimum infection rate of th ...19948003897
control of tsetse flies in uganda by dipping cattle in deltamethrin.the effect of treating cattle with deltamethrin to control tsetse flies and ticks was investigated on 2 ranches 8 km apart in central uganda where there is a high risk of trypanosomosis. this area had a moderate challenge of glossina pallidipes. the cattle had very low challenge of rhipicephalus appendiculatus, amblyomma variegatum, boophilus decolaratus and rhipicephalus evertsi evertsi, due to regular treatment with dioxathion. on one ranch a dip was charged with deltamethrin to treat cattle r ...19948009646
observations on cattle ticks in huila province (angola).in huila province of angola, 3864 ticks were collected during a parasitological survey carried out in the rainy season from october 1990 to april 1991. the samples were collected from cattle gathered for the annual vaccination campaign against contagious bovine pleuropneumonia, anthrax and blackleg in 18 veterinary stations of six municipalities. after tick classification, the following proportions of ticks were obtained: rhipicephalus evertsi mimeticus (27.1%), amblyomma pomposum (26.4%), booph ...19948171837
parasites of domestic and wild animals in south africa. xxxii. ixodid ticks on scrub hares in the transvaal.a total of 264 scrub hares (lepus saxatilis) were examined for ixodid ticks at various localities in the kruger national park, eastern transvaal lowveld. thirteen tick species were recovered from these hares. the seasonal abundances of the immature stages of amblyomma hebraeum, amblyomma marmoreum, hyalomma truncatum, rhipicephalus appendiculatus, rhipicephalus evertsi evertsi, rhipicephalus simus and rhipicephalus zambeziensis and all stages of a rhipicephalus sp. (near r. pravus) were determin ...19937970571
the localization of a paralysis toxin in granules and nuclei of prefed female rhipicephalus evertsi evertsi tick salivary gland cells.a monoclonal antibody directed against a paralysis toxin of rhipicephalus evertsi evertsi ticks was used to localize the toxin in cytoplasmic granules and, surprisingly, chromatin of the nuclei of cells which resemble the "b" cell type in the salivary glands of rhipicephalus appendiculatus, boophilus microplus and ixodes holocyclus. the association of toxin with chromatin indicates that the toxin may have a regulatory function. evidence is provided to support the view that the toxin is made up o ...19937628232
investigations into lymphocyte transformation and histamine release by basophils in sheep repeatedly infested with rhipicephalus evertsi evertsi ticks.the immune response of a natural host of rhipicephalus evertsi evertsi to feeding by this tick species was investigated with respect to the effects of tick salivary gland extracts on the transformation of peripheral blood lymphocytes and the release of histamine by basophils obtained from repeatedly infested sheep. the results indicated that there was no stimulation of lymphocyte transformation but that histamine release was elevated 10 fold after four infestations. although this suggests a hype ...19937628233
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