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treatment of cattle with dna-encoded flt3l and gm-csf prior to immunization with theileria parva candidate vaccine antigens induces cd4 and cd8 t cell ifn-? responses but not ctl responses.theileria parva antigens recognized by cytotoxic t lymphocytes (ctls) are prime vaccine candidates against east coast fever in cattle. a strategy for enhancing induction of parasite-specific t cell responses by increasing recruitment and activation of dendritic cells (dcs) at the immunization site by administration of bovine flt3l and gm-csf prior to inoculation with dna vaccine constructs and mva boost was evaluated. analysis of immune responses showed induction of significant t. parva-specific ...201121288576
construction of a genetic map for theileria parva: identification of hotspots of recombination.the tick-borne protozoan parasite theileria parva is the causal agent of east coast fever (ecf), a severe lymphoproliferative disease of cattle in eastern, central and southern africa. the life cycle of t. parva is predominantly haploid, with a brief diploid stage occurring in the tick vector that involves meiotic recombination. resolved genetic studies of t. parva are currently constrained by the lack of a genome-wide high-definition genetic map of the parasite. we undertook a genetic cross of ...201121310160
response of nkedi zebu and ankole cattle to tick infestation and natural tick-borne, helminth and trypanosome infections in uganda.a cross-sectional study was conducted in soroti district of uganda to establish important traits of nkedi zebu and ankole cattle regarding their production performance responses to natural infections of trypanosomes, gastrointestinal nematodes, theileria parva, babesia bigemina, anaplasma marginale and tick infestations. over four visits between october 2006 to august 2007, tick counts were performed and blood, faecal samples and sera were collected from the nkedi zebu (295) and ankole (165) cat ...201121350849
molecular characterization of live theileria parva sporozoite vaccine stabilates reveals extensive genotypic diversity.the current infection and treatment method of vaccination against east coast fever comprises an inoculation of live theileria parva sporozoites and simultaneous administration of oxytetracycline. immunization with a combination of parasite types has been shown to provide broader protection than inoculation of individual strains. in this study, we used a high-throughput capillary electrophoresis system to determine the genotypic composition of the muguga cocktail, a widely used vaccine stabilate ...201121367527
spatial variation of tick abundance and seroconversion rates of indigenous cattle to anaplasma marginale, babesia bigemina and theileria parva infections in uganda.tick abundance and seroconversion rates of 640 indigenous cattle in a mixed crop-livestock system in uganda were investigated in a 14 months longitudinal study. up to 100% of the cattle in buyimini, kubo, nanjeho, ojilai and sitengo villages (high tick challenge zone) were consistently infested with rhipicephalus appendiculatus, whereas on average 50% of the cattle in bunghaji, hitunga and magoje villages (low tick challenge zone) were inconsistently infested. likewise, up to 50% of the cattle i ...201121499913
mixed theileria infections in free-ranging buffalo herds: implications for diagnosing theileria parva infections in cape buffalo ( syncerus caffer).summarybuffalo-adapted theileria parva causes corridor disease in cattle. strict control measures therefore apply to the movement of buffalo in south africa and include mandatory testing of buffalo for the presence of t. parva. the official test is a real-time hybridization pcr assay that amplifies the v4 hypervariable region of the 18s rrna gene of t. parva, t. sp. (buffalo) and t. sp. (bougasvlei). the effect that mixed t. parva and t. sp. (buffalo)-like infections have on accurate t. parva di ...201121524322
two theileria parva cd8 t cell antigen genes are more variable in buffalo than cattle parasites, but differ in pattern of sequence diversity.theileria parva causes an acute fatal disease in cattle, but infections are asymptomatic in the african buffalo (syncerus caffer). cattle can be immunized against the parasite by infection and treatment, but immunity is partially strain specific. available data indicate that cd8(+) t lymphocyte responses mediate protection and, recently, several parasite antigens recognised by cd8(+) t cells have been identified. this study set out to determine the nature and extent of polymorphism in two of the ...201121559495
analyses of genes encoding theileria parva p104 and polymorphic immunodominant molecule (pim) reveal evidence of the presence of cattle-type alleles in the south african t. parva population.restriction fragment length polymorphism analysis of pcr products (pcr-rflp) and sequencing of the variable region of the p104 and pim genes was performed on samples obtained from south african t. parva parasites originating from cattle on farms with suspected theileriosis and from buffalo. p104 and pim pcr-rflp profiles similar to those of the t. parva muguga stock, an isolate that causes ecf in kenya, were obtained from three of seven cattle samples collected on a farm near ladysmith in kwazul ...201121621920
identification of theileria parva and theileria sp. (buffalo) 18s rrna gene sequence variants in the african buffalo (syncerus caffer) in southern africa.theileria parva is the causative agent of corridor disease in cattle in south africa. the african buffalo (syncerus caffer) is the reservoir host, and, as these animals are important for eco-tourism in south africa, it is compulsory to test and certify them disease free prior to translocation. a t. parva-specific real-time polymerase chain reaction (pcr) test based on the small subunit ribosomal rna (18s rrna) gene is one of the tests used for the diagnosis of the parasite in buffalo and cattle ...201121700394
trends of selected cattle diseases in eastern zambia between 1988 and 2008.livestock diseases have long been a challenge to livestock production and public health in sub-saharan africa and zambia in particular. the eastern province of zambia is one area in zambia that is not spared by this challenge. among various livestock diseases affecting cattle in this region, the most prominent are east coast fever (ecf) and african animal trypanasomiasis (aat). since little has been published on the epidemiological trends of these diseases in eastern zambia, a retrospective epid ...201121723631
Theileria parvaisolate of low virulence infects a subpopulation of lymphocytes.Theileria parva is a tick-transmitted protozoan parasite that infects and transforms bovine lymphocytes. We have previously shown that Theileria parvaChitongo (TpC) is an isolate of lower virulence than T.parvaMuguga (TpM). Lower virulence appeared correlated with a delayed onset of thelogarithmic growth phase of TpC-tranformedperipheral blood mononuclear cells after in vitro infection. In the current study, infection experiments of WC1(+)-?d-T cellsrevealed thatonly TpMcould infect these cells ...201122202119
escape from cd8+ t cell response by natural variants of an immunodominant epitope from theileria parva is predominantly due to loss of tcr recognition.polymorphism of immunodominant cd8(+) t cell epitopes can facilitate escape from immune recognition of pathogens, leading to strain-specific immunity. in this study, we examined the tcr β-chain (trb) diversity of the cd8(+) t cell responses of cattle against two immunodominant epitopes from theileria parva (tp1(214-224) and tp2(49-59)) and investigated the role of tcr recognition and mhc binding in determining differential recognition of a series of natural variants of the highly polymorphic tp2 ...201122058411
History and critical review of Theileria parva (Boleni), the vaccine stock against Zimbabwean cattle theileriosis.The paper reviews the infectivity, cross-immunization experiments, and cattle vaccination of Zimbabwean cattle-derived Theileria parva (Boleni) sporozoite stabilates produced at the Central Veterinary Laboratory (CVL) in Harare between 1980 and 2003. The Boleni stock was first isolated in July 1978 during a theileriosis outbreak and was shown to be virulent in susceptible cattle. Thereafter, the reactions observed in susceptible cattle produced by different tick stabilates derived from the origi ...201121890071
The Hybrid II assay: a sensitive and specific real-time hybridization assay for the diagnosis of Theileria parva infection in Cape buffalo (Syncerus caffer) and cattle.SUMMARYCorridor disease is an acute, fatal disease of cattle caused by buffalo-adapted Theileria parva. This is a nationally controlled disease in South Africa and strict control measures apply for the movement of buffalo, which includes mandatory testing for the presence of T. parva and other controlled diseases. Accurate diagnosis of the T. parva carrier state in buffalo using the official real-time hybridization PCR assay (Sibeko et al. 2008), has been shown to be affected by concurrent infec ...201121902875
identification of papain-like cysteine proteases from the bovine piroplasm babesia bigemina and evolutionary relationship of piroplasms c1 family of cysteine proteases.papain-like cysteine proteases have been shown to have essential roles in parasitic protozoa and are under study as promising drug targets. five genes were identified by sequence similarity search to be homologous to the cysteine protease family in the ongoing babesia bigemina genome sequencing project database and were compared with the annotated genes from the complete bovine piroplasm genomes of babesia bovis, theileria annulata, and theileria parva. multiple genome alignments and sequence an ...201120655912
theileria parva genetic diversity and haemoparasite prevalence in cattle and wildlife in and around lake mburo national park in uganda.wildlife, especially cape buffalo (syncerus caffer), are thought to act as a reservoir for many of the important tick-borne pathogens of cattle. in this study, we have determined the prevalence of the most significant tick-borne haemoparasites in wildlife (buffalo, impala, eland and bushbuck) as well as in cattle grazing inside and neighbouring lake mburo national park (lmnp) in uganda. a high percentage of buffalo were carriers of theileria parva, theileria mutans, theileria velifera, theileria ...201120827491
environment and farm factors associated with exposure to theileria parva infection in cattle under traditional mixed farming system in mbeere district, kenya.the objective of this study was to investigate the relationship between seroprevalence to theileria parva infection in cattle and potential environmental and farm-level effects in 80 farms under traditional crop-livestock system in mbeere district, kenya. a standardized questionnaire was used to collect the effects characteristics as related to t. parva infection epidemiology. serum samples were collected from 440 cattle of all ages for detection of t. parva antibodies by the enzyme-linked immun ...201120835912
mhc class i bound to an immunodominant theileria parva epitope demonstrates unconventional presentation to t cell receptors.t cell receptor (tcr) recognition of peptide-mhc class i (pmhc) complexes is a crucial event in the adaptive immune response to pathogens. peptide epitopes often display a strong dominance hierarchy, resulting in focusing of the response on a limited number of the most dominant epitopes. such t cell responses may be additionally restricted by particular mhc alleles in preference to others. we have studied this poorly understood phenomenon using theileria parva, a protozoan parasite that causes a ...201020976198
haemoparasite prevalence and theileria parva strain diversity in cape buffalo (syncerus caffer) in uganda.cape buffalo (syncerus caffer) are considered to be an important reservoir for various tick-borne haemoparasites of veterinary importance. in this study we have compared the haemoparasite carrier prevalence in buffalo from four geographically isolated national parks in uganda [lake mburo national park (lmnp), queen elizabeth national park (qenp), murchison falls national park (mfnp) and kidepo valley national park (kvnp)]. differences were seen in haemoparasite prevalence in buffalo from the fou ...201021074945
evaluation of a taqman real-time pcr for the detection of theileria parva in buffalo and cattle.a real-time pcr assay based on taqman probe chemistry was developed for the detection of theileria parva dna in blood samples. it uses a theileria genus-specific pcr primer set and a t. parva-specific probe to amplify and hybridize with a species-specific part of the 18s rrna gene of the parasite. the test was evaluated using positive and negative reference blood samples and shown to be specific for t. parva. analytical sensitivity was determined by testing a dilution series of t. parva positive ...201021075533
epidemiological analysis of tick-borne diseases in zambia.tick-borne diseases are a constraint to livestock production in many developing countries as they cause high morbidity and mortality, which results in decreased production of meat, milk and other livestock by-products. the most important tick-borne diseases of livestock in sub-saharan africa are east coast fever (caused by theileria parva), babesiosis (caused by babesia bigemina and b. bovis), anaplasmosis (caused by anaplasma marginale) and heartwater (caused by ehrlichia ruminantium). despite ...201021106294
loop-mediated isothermal amplification (lamp) assays for detection of theileria parva infections targeting the pim and p150 genes.we have developed two loop-mediated isothermal amplification (lamp) assays for the detection of theileria parva, the causative agent of east coast fever (ecf), an economically important cattle disease in eastern, central and southern africa. these assays target the polymorphic immunodominant molecule (pim) and p150 lamp genes. the primer set for each gene target consists of six primers, and each set recognises eight distinct regions on the target gene to give highly specific detection of t. parv ...201019654009
development of a tandem repeat-based multilocus typing system distinguishing babesia bovis geographic isolates.mini- and microsatellite sequences have proven to be excellent tools for the differentiation of strains and populations in several protozoan parasites due to their high variability. in the present work we have searched the genome of the tick-transmitted bovine hemoprotozoon babesia bovis for tandem repeats (trs) that could be useful for a multilocus typing system. hundred and nineteen sequences were shortlisted and tested in five common b. bovis reference isolates originating from distinct geogr ...201019833439
four p67 alleles identified in south african theileria parva field samples.previous studies characterizing the theileria parva p67 gene in east africa revealed two alleles. cattle-derived isolates associated with east coast fever (ecf) have a 129bp deletion in the central region of the p67 gene (allele 1), compared to buffalo-derived isolates with no deletion (allele 2). in south africa, corridor disease outbreaks occur if there is contact between infected buffalo and susceptible cattle in the presence of vector ticks. although ecf was introduced into south africa in t ...201019836893
demonstration of differences in virulence between two theileria parva isolates.in areas with a low incidence of infection due to unimodal presence of ticks, theileria parva has been observed to induce a disease with relatively low pathology. this is followed by a carrier state, rather than death and therefore provides a better chance of transmission of the parasite back to the tick vector since in unimodal conditions, the different tick stages occur at different times. one isolate from such an area in zambia, t. parva chitongo, was compared for virulence with t. parva mugu ...201020044208
evolution and diversity of secretome genes in the apicomplexan parasite theileria annulata.little is known about how apicomplexan parasites have evolved to infect different host species and cell types. theileria annulata and theileria parva invade and transform bovine leukocytes but each species favours a different host cell lineage. parasite-encoded proteins secreted from the intracellular macroschizont stage within the leukocyte represent a critical interface between host and pathogen systems. genome sequencing has revealed that several theileria-specific gene families encoding secr ...201020082698
estimating seroprevalence and variation to four tick-borne infections and determination of associated risk factors in cattle under traditional mixed farming system in mbeere district, kenya.a cross-sectional study of serum antibody responses of cattle to tick-borne disease (tbd) parasites (theileria parva, theileria mutans, anaplasma marginale and babesia bigemina) was conducted on traditional smallholder mixed farms in mbeere district in kenya. the objective was to estimate the infections' seroprevalence and variation and identify associated risk factors. a total of 440 cattle in 80 farms, selected by stratified random sampling from the four divisions in the district, were surveye ...201020434227
comparison between reverse line blot and enzyme-linked immunosorbent assay in diagnosis of major tick-borne diseases of cattle in southern sudan.the performance of reverse line blot (rlb) in detecting dna of theileria parva, theileria mutans and babesia bigemina was assessed in comparison with specific antibody detection using indirect enzyme-linked immunosorbent assays (elisa) for the same parasites. among 90 field samples from central equatoria state, southern sudan, elisa reported more positive samples than rlb did. the concordance of rlb showed 66.7%, 81.1% and 48.9% relative to the results of elisa for t. parva, t. mutans and b. big ...201020537106
a schizont-derived protein, tpscop, is involved in the activation of nf-kappab in theileria parva-infected lymphocytes.theileria parva is a tick-transmitted intracellular protozoan parasite that causes east coast fever, a fatal bovine lymphoproliferative disease. the molecular mechanisms that underlie host cell transformation by t. parva schizonts have been studied extensively, and it is known that the nuclear factor-kappa b (nf-kappab) is activated in schizont-infected cells, making t. parva-transformed cells resistant to apoptosis. however, the mechanism by which the parasite triggers the activation of nf-kapp ...201020540970
occurrence of theileria parva and other haemoprotozoa in cattle at the edge of hluhluwe-imfolozi park, kwazulu-natal, south africa.theileria parva, the most important bovine theilerial species in sub-saharan africa, causes widespread mortality and morbidity in endemic areas. a survey was conducted using buffy-coat specimens from 60 apparently healthy adult communally herded nguni-type cattle at the northeastern edge of the hluhluwe-imfolozi park to determine, by means of pcr and reverse line blot (rlb) hybridisation, the occurrence of theileria and babesia species. the presence of trypanosoma species was determined using pc ...201020649154
genotypic diversity, a survival strategy for the apicomplexan parasite theileria parva.the tick-borne protozoan parasite theileria parva causes east coast fever (ecf), a severe lymphoproliferative disease of cattle that is a major constraint to the improvement of livestock in eastern, central and southern africa. studies in cattle experimentally infected with t. parva have shown that the protective cytotoxic t lymphocyte (ctl) response is tightly focused, with individual animals recognizing only one or two dominant antigens, the identity of which varies with mhc class i phenotype. ...201019837514
a nested pcr assay exhibits enhanced sensitivity for detection of theileria parva infections in bovine blood samples from carrier animals.theileria parva causes east coast fever, an economically important disease of cattle in sub-saharan africa. we describe a nested polymerase chain reaction (npcr) assay for the detection of t. parva dna in cattle blood spotted onto filter paper using primers derived from the t. parva-specific 104-kda antigen (p104) gene. the sensitivity of this assay was compared to a previously described p104-based pcr and also the reverse line blot (rlb) technique, using serial dilutions of blood from a calf wi ...201019902251
development of a new score to estimate clinical east coast fever in experimentally infected cattle.east coast fever is a tick-transmitted disease in cattle caused by theileria parva protozoan parasites. quantification of the clinical disease can be done by determining a number of variables, derived from parasitological, haematological and rectal temperature measurements as described by rowlands et al. (2000). from a total of 13 parameters a single ecf-score is calculated that allows categorization of infected cattle in five different classes that correlate with the severity of clinical signs. ...201019819632
development and laboratory evaluation of a lateral flow device (lfd) for the serodiagnosis of theileria annulata infection.several dna-based and serological tests have been established for the detection of theileria annulata infection, including polymerase chain reaction, reverse line blot and loop-mediated isothermal amplification, indirect enzyme-linked immunosorbent assay (elisa), and competitive elisa. in this study, we have applied knowledge from the development and application of a recombinant protein-based indirect elisa and competitive elisa to establish a rapid test for point-of-care diagnosis of t. annulat ...201020680339
bovipain-2, the falcipain-2 ortholog, is expressed in intraerythrocytic stages of the tick-transmitted hemoparasite babesia bovis.abstract:201021092313
pcr-based detection of blood parasites in cattle and adult rhipicephalus appendiculatus ticks.to ascertain the infection rate for tick-borne pathogens in zambia, an epidemiological survey of theileria parva, babesia bigemina and anaplasma marginale in traditionally managed sanga cattle was conducted using pcr. of the 71 native zambian cattle, 28 (39.4%) were positive for t. parva, 16 (22.5%) for b. bigemina and 34 (47.9%) for a. marginale. the mixed infection rate in cattle was 8.5% (6/71), 16.9% (12/71), 7.0% (5/71) and 2.8% (2/71) for t. parva/b. bigemina, t. parva/a. marginale, b. big ...200918700182
live immunization against east coast fever--current status.the infection-and-treatment method (itm) for immunization of cattle against east coast fever has historically been used only on a limited scale because of logistical and policy constraints. recent large-scale deployment among pastoralists in tanzania has stimulated demand. concurrently, a suite of molecular tools, developed from the theileria parva genome, has enabled improved quality control of the immunizing stabilate and post-immunization monitoring of the efficacy and biological impact of it ...200919135416
expression analysis of the theileria parva subtelomere-encoded variable secreted protein gene family.the intracellular protozoan parasite theileria parva transforms bovine lymphocytes inducing uncontrolled proliferation. proteins released from the parasite are assumed to contribute to phenotypic changes of the host cell and parasite persistence. with 85 members, genes encoding subtelomeric variable secreted proteins (svsps) form the largest gene family in t. parva. the majority of svsps contain predicted signal peptides, suggesting secretion into the host cell cytoplasm.200919325907
highly syntenic and yet divergent: a tale of two theilerias.the published genomic sequences of the two major host-transforming theileria species of cattle represent a rich resource of information that has allowed novel bioinformatic and experimental studies into these important apicomplexan parasites. since their publication in 2005, the genomes of t. annulata and t. parva have been utilised for a diverse range of applications, ranging from candidate antigen discovery to the identification of genetic markers for population analysis. this has led to advan ...200919460310
quantification of theileria parva in rhipicephalus appendiculatus (acari: ixodidae) confirms differences in infection between selected tick strains.theileria parva is the etiologic agent of east coast fever, an economically important disease of cattle in sub-saharan africa. this protozoan parasite is biologically transmitted by rhipicephalus appendiculatus (neumann) (acari: ixodidae). an understanding of the vector-parasite interaction may aid the development of improved methods for controlling transmission. we developed quantitative polymerase chain reaction (qpcr) and nested pcr (npcr) assays targeting the t. parva-specific p104 gene to s ...200919645294
quantitative analysis of cytokine mrna expression and protozoan dna load in theileria parva-infected cattle.theileria parva (t. parva) causes a highly serious bovine disease called east coast fever (ecf), which is characterized by pyrexia, dyspnea and cachexia and is of great economic importance in african countries. we hypothesize that the clinical symptoms of ecf could be explained by a cytokine dysregulation. in this study, we investigated the relationship between t. parva dna load and expression levels of cytokine mrnas in leukocytes from experimentally infected calves by quantitative pcr. the p10 ...200919194076
fusion of a cell penetrating peptide from hiv-1 tat to the theileria parva antigen tp2 enhances the stimulation of bovine cd8+ t cell responses.immunity to the bovine apicomplexan parasite theileria parva is associated with mhc-i restricted cd8+ t cell responses directed against the intralymphocytic schizont stage of the parasite. a number of schizont-stage antigens that are targets of cd8+ t cell responses from immune animals have been identified but an effective delivery strategy that consistently induces protective cd8+ t cell responses remains to be developed. this study aimed to determine whether fusing tat, a cell penetrating pept ...200919249107
bovine immunity - a driver for diversity in theileria parasites?theileria parva and theileria annulata are tick-borne parasites of cattle that infect and transform leukocytes, causing severe and often fatal parasitic leukoses. both species provoke strong immunity against subsequent infection. however, considerable diversity is observed in field populations of each parasite and protection is only assured against homologous challenge. the life cycles of these parasites are complex and involve prolonged exposure to host and vector defence mechanisms. although t ...200919423397
cd8+ t-cell responses to theileria parva are preferentially directed to a single dominant antigen: implications for parasite strain-specific immunity.although immunodominance of cd8(+) t-cell responses is a well-recognised feature of viral infections, its role in responses to more antigenically complex pathogens is less clear. in previous studies we have observed that cd8(+) t-cell responses to theileria parva exhibit different patterns of parasite strain specificity in cattle of different mhc genotypes. in the current study, we demonstrated that animals homozygous for the a10 and a18 mhc haplotypes have detectable responses to only one of 5 ...200919670382
progress towards understanding the immunobiology of theileria parasites.the pathogenic theileria species theileria parva and t. annulata infect bovine leukocytes and erythrocytes causing acute, often fatal lymphoproliferative diseases in cattle. the parasites are of interest not only because of their economic importance as pathogens, but also because of their unique ability to transform the leukocytes they infect. the latter property allows parasitized leukocytes to be cultured as continuously growing cell lines in vitro, thus providing an amenable in vitro system t ...200919691866
a rapid and sensitive intracellular flow cytometric assay to identify theileria parva infection within target cells.theileria parva is an intracellular protozoan parasite transmitted by ticks that causes a fatal lymphoproliferative disease of cattle known as east coast fever. vaccination against the disease currently relies on inoculation of the infective sporozoite stage of the parasite and simultaneous treatment with long-acting formulations of oxytetracycline. sporozoites are maintained as frozen stabilates of triturated infected ticks and the method requires accurate titration of stabilates to determine a ...200817892619
characterization of the fine specificity of bovine cd8 t-cell responses to defined antigens from the protozoan parasite theileria parva.immunity against the bovine intracellular protozoan parasite theileria parva has been shown to be mediated by cd8 t cells. six antigens targeted by cd8 t cells from t. parva-immune cattle of different major histocompatibility complex (mhc) genotypes have been identified, raising the prospect of developing a subunit vaccine. to facilitate further dissection of the specificity of protective cd8 t-cell responses and to assist in the assessment of responses to vaccination, we set out to identify the ...200818070892
titrating theileria parva: single stocks against combination of stocks.theileria parva is the causative agent of east coast fever (ecf), an important cattle disease in east and central africa. one of the methods for control of ecf is 'infection and treatment', a procedure in which an animal is infected with the live parasite and at the same time treated with a long-acting oxytetracycline formulation, restraining the infection and allowing a protective cellular immune response to develop. optimal immunizing doses were estimated using models of trichotomous response: ...200818155195
the sensitivity of pcr and serology in different theileria parva epidemiological situations in rwanda.theileria parva is the causative agent of a lethal tick-borne disease of cattle occurring in eastern, central and southern africa. variations in the sensitivity of the serological and molecular tests with seasonal vector occurrence and discrepancies between low pcr prevalence and high t. parva vector density are a setback to estimate true prevalences. therefore, the objectives of the present studies were to evaluate (1) the sensitivity of three serological tests (ifat, elisa and selisa) and one ...200818384961
dissection of the clonal composition of bovine alphabeta t cell responses using t cell receptor vbeta subfamily-specific pcr and heteroduplex analysis.although techniques that permit analysis of the clonal composition of t cell populations have been used extensively to provide a better understanding of the mechanisms that influence efficacy of t cell responses in humans and mice, such methods are lacking for other animal species. in this paper we report the establishment and validation of a panel of vbeta subfamily-specific semi-nested pcr assays, and a cdr3beta heteroduplex technique for analysing the clonal diversity of bovine alphabeta t ce ...200818436232
orientation of bovine ctl responses towards pim, an antibody-inducing surface molecule of theileria parva, by dna subunit immunization.east coast fever, an acute lymphoproliferative disease of cattle, is caused by the apicomplexan parasite theileria parva. protective immunity is mediated by cd8(+) cytotoxic t lymphocytes directed against schizont-infected cells. the polymorphic immunodominant molecule, although an antibody-inducing surface molecule of the schizont, has been hypothesized to play a role in protective immunity. in order to evaluate the immunogenicity of pim for inducing ctl, cattle were immunized with pim in isola ...200818466981
development and evaluation of a real-time polymerase chain reaction test for the detection of theileria parva infections in cape buffalo (syncerus caffer) and cattle.corridor disease, caused by the tick-borne protozoan parasite theileria parva, is a controlled disease in south africa. the cape buffalo is the reservoir host and uninfected buffalo have become sought-after by the game industry in south africa, particularly for introduction into corridor disease-free areas. a real-time polymerase chain reaction (pcr) test for detection of t. parva dna in buffalo and cattle was developed to improve the sensitivity and specificity of the official diagnostic test p ...200818514421
clinical features associated with seroconversion to anaplasma marginale, babesia bigemina and theileria parva infections in african cattle under natural tick challenge.a longitudinal study was conducted in southeast uganda for 14 months on 640 zebu cattle kept under natural tick challenge, with a view to identifying clinical features for prediction of seroconversion to anaplasma marginale, babesia bigemina and theileria parva infections. physical examination, condition scoring and tick counts were undertaken on all cattle every 4 weeks. in addition, 5300 sera were collected and analysed for antibodies against a. marginale, b. bigemina and t. parva infections u ...200818579313
infection of cattle with theileria parva induces an early cd8 t cell response lacking appropriate effector function.theileria parva causes an acute lympho-proliferative disease in cattle, which can result in death of susceptible animals within 2-3 weeks of infection. analyses of the cellular response in the lymph node draining the site of infection demonstrated an early t cell response, with the appearance of large numbers of uninfected lymphoblasts between 6 and 9 days p.i., coinciding with initial detection of parasitised cells. there was a marked increase in the representation of cd8(+) t cells and the eme ...200818590735
use of a pan-vbeta primer permits the amplification and sequencing of tcrbeta chains expressed by bovine t-cell clones following a single semi-nested pcr reaction.we report in this study the design and validation of a pan-vbeta primer that in combination with cbeta-specific primers enables the amplification, in a single semi-nested pcr, of tcrbeta chains expressed by bovine t-cell clones irrespective of the expressed vbeta sequence. using the pan-vbeta primer we examined the tcrbeta chains expressed by 16 theileria parva-specific clones that had not been previously analysed. tcrbeta chain sequence was obtained from 15 of the clones following direct sequen ...200818635266
development and evaluation of a loop-mediated isothermal amplification method for diagnosis of tropical theileriosis.a loop-mediated isothermal amplification (lamp) assay was developed and evaluated for diagnosis of tropical theileriosis. a set of six primers was designed based on the unique gene of theileria annulata (theileria annulata strain ankara hypothetical protein (genedb ta04795). the protocol for the reaction was setup and the specificity and sensitivity of the assay were established. the specificity experiment showed that lamp primers amplified t. annulata dna successfully, while no amplification wa ...200818666968
distribution and application of elisa for the seroprevalence of tick-borne diseases in central equatoria state, sudan.this study was carried out to estimate the prevalence of theileria parva, theileria mutans, babesia bigemina and anaplasma marginale antibodies among naturally infected cattle in central equatoria state, southern sudan using indirect enzyme-linked immunosorbent assay (elisa). three locations (khor rumla, nyaing and gumbo) were selected and surveyed every 3 months during the period from january to december 2005. six cattle herds in the three locations were visited four times during the study peri ...200818666971
occurrence of theileria parva infection in cattle on a farm in the ladysmith district, kwazulu-natal, south africa.theileria parva causes widespread morbidity and mortality in cattle in endemic regions. an outbreak of theileriosis occurred on a farm near ladysmith in kwazulu-natal, south africa, which is not a declared corridor disease-infected area. a survey of red brangus cattle from all age groups and areas of the farm was performed. transmission of the parasite from infected animals on the farm to susceptible animals by tick transmission and tick-stabilate injection, was attempted. the survey indicated h ...200818678189
effects of anti-tick cocktail vaccine against rhipicephalus appendiculatus.rhipicephalus appendiculatus serpin-3 (ras-3), r. appendiculatus serpin-4 (ras-4) and a 36-kda immuno-dominant protein of r. appendiculatus (rim36) were reported as candidate antigens for the anti-tick vaccine to control ixodid ticks. in the present study, we generated recombinant proteins of ras-3 (rras-3), ras-4 (rras-4) and rim36 (rrim36), and assessed their potency as an anti-tick cocktail vaccine in cattle model. rt-pcr analysis showed that ras-3, ras-4 and rim36 transcripts were detected i ...200818828446
properties of non-coding dna and identification of putative cis-regulatory elements in theileria parva.parasites in the genus theileria cause lymphoproliferative diseases in cattle, resulting in enormous socio-economic losses. the availability of the genome sequences and annotation for t. parva and t. annulata has facilitated the study of parasite biology and their relationship with host cell transformation and tropism. however, the mechanism of transcriptional regulation in this genus, which may be key to understanding fundamental aspects of its parasitology, remains poorly understood. in this s ...200819055776
evaluation of the recognition of theileria parva vaccine candidate antigens by cytotoxic t lymphocytes from zebu cattle.east coast fever (ecf) is a highly fatal lymphoproliferative disease of cattle caused by theileria parva, a tick-borne intracellular apicomplexan parasite. parasite antigens that are targets of protective cytotoxic t lymphocyte (ctl) responses are required to formulate a sub-unit vaccine against ecf. a number of ctl target antigens have recently been identified and initial evaluation has shown their vaccine potential. this study aimed to evaluate whether these antigens were recognised by ctl obt ...200817983665
attenuated vaccines for tropical theileriosis, babesiosis and heartwater: the continuing necessity.overwhelming evidence has accumulated of the effectiveness of immunization with live attenuated vaccines to control tick-borne diseases of livestock. despite several disadvantages, vaccination with live attenuated organisms against tropical theileriosis, babesiosis and possibly heartwater constitutes one of the most cost-effective intervention strategies. although great advances have been made through genomics and proteomics research, this has not yet translated into effective non-living vaccine ...200717656155
epidemiological studies on tick-borne diseases of cattle in central equatoria state, southern sudan.a herd-based study was carried out in central equatoria state, southern sudan, to study epidemiological aspects of tick-borne diseases. six herds of cattle situated in three different locations were selected and investigated every 3 months during the year 2005. blood smears for giemsa staining and blood spots on filter paper for deoxyribonucleic acid extraction were collected from 600 apparently healthy indigenous cattle. a total of 69 (11.5%) samples showed the presence of piroplasms in giemsa- ...200717530477
an outbreak of east coast fever on the comoros: a consequence of the import of immunised cattle from tanzania?in 2003 and 2004, a severe epidemic decimated the cattle population on grand comore, the largest island of the union of comoros. fatalities started soon after the import of cattle from tanzania. theileria parva and its vector, rhipicephalus appendiculatus, could be identified as the main culprits of the epidemic. characterisation by multilocus genotyping revealed that the t. parva parasites isolated on the comoros were identical to the components of the muguga cocktail vaccine used in tanzania t ...200716996692
a comparison of seroprevalence and risk factors for theileria parva and t. mutans in smallholder dairy cattle in the tanga and iringa regions of tanzania.a cross sectional serological survey was carried out in two geographical small-scale dairying areas of tanzania to determine the distribution and prevalence and to quantify risk factors for theileria parva and t. mutans during the period january to april 1999. the prevalence of serum antibodies to these two theileria parasites was determined using an indirect enzyme-linked immunosorbent assay (elisa) technique. the results suggest that the parasites are widely distributed through out the two stu ...200717015024
epidemiological studies on theileriosis and the dynamics of theileria parva infections in rwanda.an epidemiological analysis based on three country wide surveys was carried out to determine the prevalence of infections with theileria spp. in rwanda. in the 1998 dry season, a total of 264 blood samples were submitted to theileria spp. characterisation using the 18s species-specific pcr-rflp assay. the same samples together with 634 samples (317 samples/season) collected during the 2002 dry season and the 2003 wet season were further analysed using the p104 theileria parva specific pcr. the r ...200717055650
theileria parva live vaccination: parasite transmission, persistence and heterologous challenge in the field.the 'muguga cocktail' live vaccine, delivered by an infection and treatment protocol, has been widely deployed in eastern, central and southern africa to protect cattle against east coast fever, caused by theileria parva. the vaccine contains 3 component stocks (muguga, serengeti-transformed and kiambu 5). in a previous study, parasites from vaccinated and unvaccinated animals were genotyped with a panel of micro- and minisatellite markers (oura et al. 2004a) and it was shown that only the kiamb ...200717352850
genome sequence of babesia bovis and comparative analysis of apicomplexan hemoprotozoa.babesia bovis is an apicomplexan tick-transmitted pathogen of cattle imposing a global risk and severe constraints to livestock health and economic development. the complete genome sequence was undertaken to facilitate vaccine antigen discovery, and to allow for comparative analysis with the related apicomplexan hemoprotozoa theileria parva and plasmodium falciparum. at 8.2 mbp, the b. bovis genome is similar in size to that of theileria spp. structural features of the b. bovis and t. parva geno ...200717953480
live immunisation against theileria parva: containing or spreading the disease?although a live vaccine against theileria parva has been available for over 30 years, concerns that vaccine strains can become established in resident tick populations have impeded its uptake in endemic areas. recently, oura et al. have examined the persistence of vaccine strains in immunised cattle using polymorphic genomic markers. they confirm that elements of the vaccine establish a carrier state in vaccinated animals and present evidence that alleles associated with vaccine strains emerge i ...200717964219
determination of potential risk factors associated with theileria annulata and theileria parva infections of cattle in the sudan.a multi-variate logistic regression analysis was performed on two sets of data on the prevalence of theileria annulata in northern sudan and theileria parva in southern sudan, to determine the potential risk factors that might affect the distribution of the infections in those regions. the logistic regression model was fit with the tested risk factors for each disease, separately. the results indicated that locations, management systems and age could be held as risk factors for t. annulata infec ...200717594114
influence of host immunity on parasite diversity in theileria parva.we examined the influence of host immunity on the genotypic diversity of the intracellular transforming cattle parasite theileria parva. by tracking the emergence of discrete parasite genotypes in an animal challenged with a bulk stabilate following immunization with its major component clone, we observed a profound modulation of genotypic frequencies in the breakthrough schizont population. in particular, no incidences of the immunizing clone were observed and a progressive decline was apparent ...200717635866
comparison of the survival on ice of thawed theileria parva sporozoites of different stocks cryoprotected by glycerol or sucrose.stabilates of theileria parva sporozoites are mostly delivered in liquid nitrogen tanks to the east coast fever immunization points. using an in vitro titration model, we assessed the loss of infectivity of several stabilates when they are stored in ice baths for up to 24 h. comparisons, with respect to rates of loss of infectivity, were made between t. parva stocks (chitongo and katete), cryoprotectants (sucrose and glycerol) and method of assessment (in vivo and in vitro techniques). chitongo ...200717708148
red blood cell volume as a predictor of fatal reactions in cattle infected with theileria parva katete.a comparison of mean corpuscular volume (mcv) and packed cell volume (pcv) was made between cattle undergoing lethal and non-lethal reactions following experimental infections with the apicomplexan protozoa, theileria parva katete. this work confirmed that anaemia occurs in infected animals. however, the fall in pcv was steeper in lethal reactions compared to non-lethal reactions. our results show that animals with initially lower mcv values are more prone to fatal reaction, despite having norma ...200717708152
immunostimulatory cpg oligodeoxynucleotides enhance the induction of bovine cd4+ cytotoxic t-lymphocyte responses against the polymorphic immunodominant molecule of the protozoan parasite theileria parva.enhancement of the induction of cytotoxic t-cell responses by immunostimulatory cpg oligodeoxynucleotides has been described in humans and mouse models. the present study attempted to address whether cpg has a similar effect in cattle. immunisation of cattle with a recombinant form of the polymorphic immunodominant molecule from theileria parva emulsified with immunostimulatory cpg oligodeoxynucleotides in adjuvant had no effect on the induction of antibody responses including the isotype profil ...200717197038
a novel strategy for the identification of antigens that are recognised by bovine mhc class i restricted cytotoxic t cells in a protozoan infection using reverse vaccinology.immunity against the bovine protozoan parasite theileria parva has previously been shown to be mediated through lysis of parasite-infected cells by mhc class i restricted cd8+ cytotoxic t lymphocytes. it is hypothesized that identification of ctl target schizont antigens will aid the development of a sub-unit vaccine. we exploited the availability of the complete genome sequence data and bioinformatics tools to identify genes encoding secreted or membrane anchored proteins that may be processed ...200717291333
east coast fever and multiple el niño southern oscillation ranks.east coast fever (ecf), a tick-borne disease of cattle, is a major constraint to livestock development in africa in general and southern zambia in particular. understanding the transmission patterns of this disease complex is very difficult as shown by previous studies in southern and eastern zambia due to the interplay of risk factors. in this long-term study, we investigated whether global weather changes had any influence on disease transmission in traditionally kept cattle in southern zambia ...200616213095
current status of vaccine development against theileria parasites.the tick-borne protozoan parasites theileria parva and theileria annulata cause economically important diseases of cattle in tropical and sub-tropical regions. because of shortcomings in disease control measures based on therapy and tick control, there is a demand for effective vaccines against these diseases. vaccines using live parasites have been available for over two decades, but despite their undoubted efficacy they have not been used on a large scale. lack of infrastructure for vaccine pr ...200617274845
infectivity of theileria parva sporozoites following cryopreservation in four suspension media and multiple refreezing: evaluation by in vitro titration.theileria parva sporozoite stabilates are used for immunizing cattle against east coast fever and in in vitro sporozoite neutralization assays. in this study, we attempted to identify a cheaper freezing medium and quantified the infectivity loss of sporozoites due to refreezing of stabilates, using an in vitro technique. pools of stabilates prepared using minimum essential medium (mem), roswell park memorial institute (rpmi 1640), foetal calf serum (fcs) and phosphate-buffered saline (pbs) were ...200617058443
cloned theileria parva produces lesser infections in ticks compared to uncloned t. parva despite similar infections in cattle.experimental transmissions of cloned theileria parva in cattle with rhipicephalus appendiculatus ticks were compared to transmissions with uncloned t. parva during studies on the potential for genetic recombination during syngamy of theileria to produce antigenic diversity for evasion of bovine immunity. prevalence and abundance of t. parva infection in adult ticks, which resulted from the feeding of nymphs on the calves, were significantly higher in the uncloned compared to the cloned t. parva. ...200616958269
theileria parva infection in calves causes massive lymphocyte death in the thymus, spleen and lymph nodes without initial proliferation.in a study of trends and magnitudes of lymphocytes proliferation, destruction or apoptosis eleven 3-month-old healthy calves were experimentally infected with the protozoan parasite theileria parva, which is reported to cause lymphocyte proliferation. four control calves were not infected. infected and non-infected calves were sacrificed on days 9, 12, 16, 19, 23, 24 and 25 to examine lymphoid tissue changes and lymphocyte proliferation, apoptosis or necrosis in the thymus, spleen and lymph node ...200616962242
extensive genotypic diversity in a recombining population of the apicomplexan parasite theileria parva.we evaluated sexual recombination in the apicomplexan parasite theileria parva using genome-wide marker analysis of haploid sporozoite populations obtained from infected rhipicephalus appendiculatus ticks. analysis of 231 parasite clones derived by in vitro infection of bovine lymphocytes revealed 48 distinct combinations of 64 polymorphic marker loci. one genotype accounted for more than 75% of the clones, and the population was highly inbred with respect to this. the occurrence of frequent rec ...200616988220
alteration of host cell phenotype by theileria annulata and theileria parva: mining for manipulators in the parasite genomes.the apicomplexan parasites theileria annulata and theileria parva cause severe lymphoproliferative disorders in cattle. disease pathogenesis is linked to the ability of the parasite to transform the infected host cell (leukocyte) and induce uncontrolled proliferation. it is known that transformation involves parasite dependent perturbation of leukocyte signal transduction pathways that regulate apoptosis, division and gene expression, and there is evidence for the translocation of theileria dna ...200616221473
clinical efficacy and plasma concentrations of two formulations of buparvaquone in cattle infected with east coast fever (theileria parva infection).east coast fever, caused by the protozoan parasite theileria parva, kills about 600,000 cattle annually in africa. the hydroxynaphthoquinone compound buparvaquone (bpq) is curative. sixteen calves were infected with t. parva. on manifestation of disease symptoms, eight were injected with the original (pioneer) bpq product and eight with a test product containing bpq. all 16 calves were cured by one injection of 2.5 mg bpq/kg bodyweight. the concentration of bpq in blood plasma was monitored by h ...200616289157
theileria parva candidate vaccine antigens recognized by immune bovine cytotoxic t lymphocytes.east coast fever, caused by the tick-borne intracellular apicomplexan parasite theileria parva, is a highly fatal lymphoproliferative disease of cattle. the pathogenic schizont-induced lymphocyte transformation is a unique cancer-like condition that is reversible with parasite removal. schizont-infected cell-directed cd8(+) cytotoxic t lymphocytes (ctl) constitute the dominant protective bovine immune response after a single exposure to infection. however, the schizont antigens targeted by t. pa ...200616492763
notch is constitutively active in theileria-transformed b cells and can be further stimulated by the filarial nematode-secreted product, es-62.theileria parva-infected b cells express jagged-1 and activate notch signalling in a parasite-dependent manner. es-62, a filarial nematode-secreted phosphorylcholine-containing glycoprotein, is able to further stimulate notch-mediated signalling in parasitized cells. notch is also activated to a similar extent by addition of exogenous il-10, and this occurs prior to any increase in proliferation in t. parva-infected b cells.200616524753
evaluation of buparvaquone (buta-kel kela, belgium) as a treatment of east coast fever in cattle, in the peri-urban of dar es salaam city, tanzania.evaluation trials of the efficacy of buparvaquone (buta-kel kela laboratoria, n.v. belgium), as a treatment of field cases of theileria parva infection (east coast fever - ecf) were carried out on 63 cattle in the peri-urban of dar es salaam city, tanzania, during the period november 2004 to august 2005. thirty-two cattle (56%) received single-dose treatment (2.5 mg buparvaquone per kg body weight), while two and three-dose treatment with interval(s) of 48 h was given to 33% and 11% of total tre ...200616567050
linkage disequilibrium between alleles at highly polymorphic mini- and micro-satellite loci of theileria parva isolated from cattle in three regions of kenya.theileria parva schizont-infected lymphocyte culture isolates from western, central and coastal kenya were analysed for size polymorphism at 30 t. parva-specific variable number tandem repeat (vntr) loci using a panel of mini- and micro-satellite markers. the mean number of alleles ranged from 3 to 11 at individual loci and 183 distinct alleles were observed in total, indicating high genetic diversity within the t. parva gene pool in kenyan cattle. the frequency distribution of the length variat ...200616600240
c-jun nh2-terminal kinase/c-jun signaling promotes survival and metastasis of b lymphocytes transformed by theileria.theileria parasites infect and transform bovine lymphocytes resulting in tumors with metastatic/invasive potential. importantly, cellular transformation is reversed upon drug-induced parasite death, and the infected lymphocyte dies of apoptosis within 48 hours. theileria-dependent transformation leads to the constitutive activation of c-jun nh2-terminal kinase (both jnk1 and jnk2) and permanent induction of activator protein-1. inactivation of jnk (following transfection of dominant-negative mut ...200616778183
effect of agro-ecological zone and grazing system on incidence of east coast fever in calves in mbale and sironko districts of eastern uganda.between may 2002 and february 2003 a longitudinal survey was carried out in mbale and sironko districts of eastern uganda to determine the influence of agro-ecological zones (aez) and grazing systems on tick infestation patterns and incidence of east coast fever (ecf) in bovine calves. the study area was stratified into aez (lowland, midland and upland) and grazing systems {zero grazing (zg), restricted-outdoor grazing (rog) and communal grazing (cg)}, whose strata had previously been shown to i ...200616797092
theileria parva and the bovine ctl response: down but not out?theileria parva is a tick-borne intracellular protozoan of cattle, with obligate sequential differentiation stages in lymphocytes and erythrocytes. immunity is mediated by cytotoxic t lymphocytes (ctl) that target and clear parasitized lymphocytes but allow persistence of infected erythrocytes, which are required for transmission to the tick. the life cycle of t. parva is haploid with the exception of a brief diploid stage in the tick vector during which sexual recombination occurs. there is evi ...200616842270
acquisition and transmission of theileria parva by vector tick, rhipicephalus appendiculatus.in order to investigate the transmission dynamics of theileria parva (t. parva) by the brown ear tick, rhipicephalus appendiculatus (r. appendiculatus), under experimental conditions, detection of t. parva in ticks and cattle was performed by a quantitative real-time pcr assay. a calf inoculated with a t. parva mixture became pcr-positive for t. parva infection on day 8 post-inoculation, and subsequently, nymphal ticks were introduced and maintained to feed on the infected calf for 6 days. engor ...200616899209
factors influencing the distribution of questing ticks and the prevalence estimation of t. parva infection in brown ear ticks in the tanga region, tanzania.questing ticks from various districts and agro-ecological zones (aez) in the tanga region of tanzania were studied for a two-year period between september 1999 and july 2001. collections of both nymphal and adult ticks occurred at 29 sites using a blanket or white cloth dragging technique. the species recorded in the order of decreasing abundance were rhipicephalus appendiculatus, boophilus spp., and ambylomma variegatum. rhipicephalus appendiculatus field infestation levels varied across admini ...200617249338
disease constraints for utilization of the african buffalo (syncerus caffer) on game ranches in zambia.eco-tourism depending on wildlife is becoming increasingly profitable and landowners are beginning to favor game farming and ecotourism. in these areas, large-scale translocation of wildlife involves a diversity of species and large populations. the african buffalo (syncerus caffer) is one of the major tourist attractions in zambia. it accounts for 8.7% and 12.4% of the total animal species hunted in the game management areas and the total hunting revenue earned in zambia, respectively. it is ec ...200616786973
perception of cattle farmers of the efficacy of east coast fever immunization in southern zambia.a study using a structured questionnaire was conducted to assess the perception of cattle farmers of the efficacy of east coast fever (ecf) immunization in southern zambia. one hundred and seventy-nine farmers from five districts in southern zambia were interviewed. the majority of farmers (85%) perceived ecf immunization as being very effective and about half of them (51.4%) preferred immunization to other ecf control strategies. the study showed that the number of calves immunized was strongly ...200617405623
the kinetics of theileria parva infection and lymphocyte transformation in vitro.theileriaparva is an intracellular protozoan parasite that causes a fatal lymphoproliferative disease of cattle known as east coast fever. the parasite infects host lymphocytes causing their transformation and uncontrolled proliferation. infiltration of major organs with parasitized lymphoblasts results in most cases in death within 3 weeks. although both t and b lymphocytes are susceptible to infection, the majority of cell lines arising from infection of peripheral blood mononuclear cells in v ...200616696979
genome sequence of theileria parva, a bovine pathogen that transforms lymphocytes.we report the genome sequence of theileria parva, an apicomplexan pathogen causing economic losses to smallholder farmers in africa. the parasite chromosomes exhibit limited conservation of gene synteny with plasmodium falciparum, and its plastid-like genome represents the first example where all apicoplast genes are encoded on one dna strand. we tentatively identify proteins that facilitate parasite segregation during host cell cytokinesis and contribute to persistent infection of transformed h ...200515994558
spatial and management factors associated with exposure of smallholder dairy cattle in tanzania to tick-borne pathogens.a cross-sectional study of serum antibody responses of cattle to tick-borne pathogens (theileria parva, theileria mutans,anaplasma marginale, babesia bigemina and babesia bovis) was conducted on smallholder dairy farms in tanga and iringa regions of tanzania. seroprevalence was highest for t. parva (48% in iringa and 23% in tanga) and b. bigemina (43% in iringa and 27% in tanga) and lowest for b. bovis (12% in iringa and 6% in tanga). we use spatial and non-spatial models, fitted using classical ...200516023121
comparison of manual and homogenizer methods for preparation of tick-derived stabilates of theileria parva: equivalence testing using an in vitro titration model.theileria parva sporozoite stabilates are used in the infection and treatment method of immunization, a widely accepted control option for east coast fever in cattle. t. parva sporozoites are extracted from infected adult rhipicephalus appendiculatus ticks either manually, using a pestle and a mortar, or by use of an electric homogenizer. a comparison of the two methods as a function of stabilate infectivity has never been documented. this study was designed to provide a quantitative comparison ...200516038395
population genetic analysis and sub-structuring of theileria parva in uganda.in recent years the population structures of many apicomplexan parasites including plasmodium spp., toxoplasma gondii and cryptospordium parvum have been elucidated. these species show a considerable diversity of population structure suggesting different strategies for transmission and survival in mammalian hosts. we have undertaken a population genetic analysis of another apicomplexan species (theileria parva) to investigate the levels of diversity of this parasite and the role of genetic excha ...200515760662
theileria parva seroprevalence in traditionally kept cattle in southern zambia and el nino.sero-epidemiological surveys involving 27,526 cattle over a period of 8 years show that theileria parva, the parasite causing east coast fever (ecf) is found throughout southern zambia. higher values of t. parva sero-prevalence were observed in the plateau districts of monze, choma and mazabuka than in the valley districts of siavonga and sinazongwe. our results reveal a strong association between high t. parva sero-prevalence and the presence of the periodic climatic phenomenon known as the el ...200515777915
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