Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
216 result(s) for "Theileriasis - epidemiology"
Sort by:
A Review on Equine Piroplasmosis: Epidemiology, Vector Ecology, Risk Factors, Host Immunity, Diagnosis and Control
Equine Piroplasmosis (EP) is a tick-borne disease caused by apicomplexan protozoan parasites, Babesia caballi and Theileria equi. The disease is responsible for serious economic losses to the equine industry. It principally affects donkeys, horses, mules, and zebra but DNA of the parasites has also been detected in dogs and camels raising doubt about their host specificity. The disease is endemic in tropical and temperate regions of the world where the competent tick vectors are prevalent. Infected equids remain carrier for life with T. equi infection, whilst, infection with B. caballi is cleared within a few years. This review focuses on all aspects of the disease from the historical overview, biology of the parasite, epidemiology of the disease (specifically highlighting other non-equine hosts, such as dogs and camels), vector, clinical manifestations, risk factors, immunology, genetic diversity, diagnosis, treatment, and prevention.
Theileria luwenshuni and Novel Babesia spp. Infections in Humans, Yunnan Province, China
Piroplasmid parasites such as Theileria luwenshuni protozoa pose a global threat to both animal and human health. However, human theileriosis remains underexplored compared to infections caused by Plasmodium and Babesia species parasites. We investigated potential hemoparasite infections among 1,721 persons with fever, anemia, or both in Yunnan Province, China. Molecular detection identified 13 cases positive for T. luwenshuni protozoa, of which 5 patients were further confirmed by Western blot antibody analysis. We also identified 6 babesiosis cases, 3 infections with B. microti and 3 with novel Babesia spp. Subsequent vector and host investigations in the vicinity of the index cases revealed T. luwenshuni protozoa in 1 tick and 53 livestock animals. Of note, 3.3% combined vector-host samples tested positive for genetically diverse Babesia species. Our findings highlight the endemic circulation of T. luwenshuni and Babesia spp. parasites in southwest China, underscoring their importance as emerging public health concerns.
Molecular prevalence, associated risk factors and phylogenetic evaluation of Theileria lestoquardi in the blood samples of small ruminants
Raising small ruminants is the main source of income for farmers in Pakistan especially in rural areas of Dera Ghazi Khan in Punjab. Despite having large sheep population, the prevalence of intra-erythrocytic protozoa, Theileria ( T .) lestoquardi , has never been reported from this area. This study was conducted to fill this knowledge gap and 333 blood samples of apparently healthy small ruminants (168 sheep and 165 goats) along with their epidemiological data were collected from Dera Ghazi Khan district during August till November 2022. The polymerase chain reaction (PCR) analysis amplified a 785 base pair amplicon specific for the Merozoite surface antigen ( ms 1–2 ) gene of T . lestoquardi in 2 out of the 168 (3.3%) sheep blood samples, while no goat blood sample out of 165 was found to be infected with T . lestoquardi . DNA sequencing confirmed the presence of Theileria lestoquardi in both samples and phylogenetic analysis revealed that these amplicon resembled the partial ms 1–2 gene sequences detected in small ruminants from Pakistan, India Iran and Egypt. All the studied epidemiological factors (age, sex, breed, size of herd, dogs with herd, composition of herd, size of herd and Tick burden on sheep) were not found associated with the prevalence of T . lestoquardi . In conclusion, this study reports a low prevalence of T . lestoquardi infection in the Dera Ghazi Khan District of Punjab, Pakistan. The data generated from this work will help pave the way for the prophylactic detection and control of ovine and caprine theileriosis in the region.
Active surveillance for Theileria orientalis and the invasive Asian longhorned tick (Haemaphysalis longicornis) in three Missouri beef herds
Theileria orientalis is a protozoan hemoparasite of cattle vectored by the rapidly emerging invasive Asian longhorned tick ( Haemaphysalis longicornis ). Theileria -associated bovine anemia (TABA) is easily mistaken for bovine anaplasmosis, which can lead to delayed diagnosis in areas where bovine anaplasmosis is endemic and TABA is newly emerging. Our objective was to surveil for infestation of cattle by H. longicornis and infection with T. orientalis on three Missouri cow-calf operations in counties where H. longicornis is known to be established. A total of 147 apparently healthy adult cows from 3 herds were inspected for ticks. Whole blood was collected for T. orientalis and Anaplasma marginale quantitative PCR and was also used for immediate preparation of blood smears and measurement of packed cell volumes. A total of 527 ticks were collected from the cows and taxonomically identified to the species level. Eighteen H. longicornis , including 9 adult females and 9 nymphs, were collected from 16 cows (Farm A, 2 cows; Farm B, 4 cows; Farm C, 10 cows). Intraerythrocytic T. orientalis organisms were presumptively identified on blood smears from 10 cows. Quantitative PCR screening of blood samples with primers designed to amplify all T. orientalis genotypes detected 11 positive samples (Farm A, 7 cows; Farm B, 3 cows; Farm C, 1 cow). Positive samples were re-tested with probes specific for the Ikeda, Chitose, and Buffeli genotypes, which detected the Chitose genotype in 10 samples and the Ikeda genotype in 1 sample. Detection of T. orientalis with concurrent infestation of cows by H. longicornis within these 3 herds, along with collection of H. longicornis from vegetation on the premises, supports local tick-borne transmission of this emerging pathogen.
Comparative diagnostic performance of recombinant Tams1 protein based dot-ELISA in detecting tropical theileriosis in naturally infected cattle
This study is the first to conduct a sero-surveillance of Bovine Tropical Theileriosis (BTT) caused by the protozoan parasite Theileria annulata (T. annulata) using a recombinant Tams1 protein-based dot-ELISA in cattle, and to compare its efficacy with plate-ELISA, single PCR, nested PCR, and blood microscopy. The goal was to identify the most effective method for the early and accurate detection of theileriosis, which significantly impacts livestock through reduced milk yield and increased mortality. A total of 101 field blood samples were examined using blood smear analysis, single PCR, nested PCR, and dot-ELISA. The recombinant Tams1 protein was successfully cloned and expressed using a pET-30b (+) expression vector in a prokaryotic system. The protein was purified with Ni-NTA chromatography, confirmed for immunoreactivity with T. annulata positive serum via Western blot analysis, and used to optimize both dot-ELISA and plate-ELISA. Both dot-ELISA and plate-ELISA using recombinant Tams1 protein exhibited comparable diagnostic performance, with a kappa value of 0.826 and similar analytical productivity ( P  = 0.6165). Dot-ELISA revealed a BTT seroprevalence of 58.4% in the cattle population, demonstrating good sensitivity (93.33%) and specificity (90%). The diagnostic performance of dot-ELISA was found to be superior to other molecular techniques, including microscopy, single PCR, and nested PCR. Dot-ELISA is also a sustainable solution in comparison to other laboratory diagnostic techniques with benefits of early diagnosis, reduced waste generation, resource efficiency, cost-effective point of care disease surveillance. With its minimal antigen requirement, Tams1 molecule based dot-ELISA is recommended as an effective tool for epidemiological studies and field surveys of BTT.
Identification of genetic variations linked to buparvaquone resistance in Theileria annulata infecting dairy cattle in India
Buparvaquone (BPQ) is used for the treatment of bovine theileriosis, a tickborne disease caused by parasites of the Theileria genus. Studies on T. annulata have linked the mechanism of BPQ resistance predominantly to genetic variations in the parasite cytochrome b ( cytb ) gene. In addition, cryptic mechanisms of resistance involving the parasite peptidyl-prolyl isomerase ( pin1 ) and dihydroorotate dehydrogenase ( dhodh ) genes require assessment. In India, where bovine theileriosis is endemic, and BPQ is widely used for treatment, it is necessary to establish the prevalence of genetic variations linked to BPQ resistance. In this study, multiplexed PCR amplification and nanopore sequencing method was used for genotyping the complete gene loci of the three target genes. Analysis of 454 T. annulata field samples collected from seven different states of India revealed the presence of previously reported BPQ resistance associated variations S129G, A146T and P253S in cytb gene and A53P in pin1 gene. The A146T and I203V variations in cytb were found to be prevalent and mostly co-occurring, and their role in BPQ resistance needs further evaluation. This study has revealed the presence of previously reported BPQ resistance-linked mutations in cytb and pin1 genes in T. annulata infecting dairy cattle in India and establishes an Oxford nanopore sequencing method suitable for large-scale surveillance of genetic variation in Theileria parasites from field samples.
Molecular epidemiology and risk factors of Anaplasma spp., Babesia spp. and Theileria spp. infection in cattle in Chongqing, China
Tick-borne pathogens (TBPs) seriously affect cattle production and can be economically damaging. The epidemiology of these organisms in the Chongqing municipality of China is not well described. This study aimed to investigate the prevalence and risk factors of TBPs including Anaplasma spp., Babesia spp. and Theileria spp. in cattle in Chongqing municipality. The results showed that 43.48% (150/345) of cattle were infected with at least one TBP, of which single infections were detected in 104 (30.14%), double infections in 34 cattle (9.86%) and triple infections in 12 (3.48%) of the cattle. The overall prevalence of Anaplasma spp., Theileria spp. and B. bigemina were 22.32%, 23.19% and 7.24%, respectively. Among these, the prevalence of A. bovis, A. central, A. phagocytophilum, A. platys, A. marginale, T. sinensisi and T. orientalis were 8.41%, 7.83%, 4.93%, 4.35%, 2.61%, 22.32% and 2.60%, respectively. We could not detect B. bovis, T. annulata, T. luwenshuni or T. uilenbergi in cattle. Cattle ≥1-year-old were more likely to be infected with Theileria spp. [adjusted odd ratio (AOR) = 2.70, 95% CI = 1.12-6.56)] compared with younger cattle, while cattle ≥1-year-old had reduced susceptibility to B. bigemina (AOR = 0.14, 95% CI = 0.03-0.60). Cattle living at higher altitude (≥500 m) were more susceptible to B. bigemina (AOR = 6.97, 95% CI = 2.08-23.35) and Theileria spp. infection (AOR = 1.87, 95% CI = 1.06-3.32). The prevalence of Theileria spp. on farms with cats was significantly higher than that without cats (AOR = 2.56, 95% CI = 1.12-5.88). Infection with A. bovis and A. central were significantly associated with A. phagocytophilum infection. Furthermore, there were significant associations between A. bovis and A. central infection, T. sinensisi and A. marginale infection, and B. bigemina and T. orientalis infection. This study provides new data on the prevalence of Anaplasma spp., Babesia spp. and Theileria spp. in cattle in Chongqing, and for the first time we reveal a possible relationship between the afore-mentioned pathogens, which will help in formulating appropriate control strategies for these pathogens in this area.
Molecular epidemiology and genetic diversity of Anaplasma and Theileria spp. in Pakistani sheep
Pakistan has a huge sheep population (37.2 million in 2024) that is largely unexplored for the presence of vector transmitted parasites. Present study was aimed to document the prevalence of Anaplasma sp. , Anaplasma ovis , Theileria ovis and Theileria lestoquardi in sheep blood samples (N = 329) that were collected from six districts (Muzaffargarh, Rajanpur, Dera Ghazi Khan, Layyah, Taunsa and Khanewal) during August till December 2024 and to report the genetic diversity of screened pathogens. Molecular analyses revealed that the prevalence of Anaplasma sp. , Anaplasma ovis and Theileria ovis in screened sheep was 11%, 20% and 21% respectively. None of the screened sheep was Theileria lestoquardi infected. Co-infection of the screened pathogens was also observed. Presence of the detected pathogens was confirmed by DNA sequencing and subsequent BLAST analysis. Phylogenetic analysis revealed that these pathogens displayed genetic similarities with the sequences that were deposited from various countries across the globe. Prevalence of all screened pathogens varied significantly between the sampling districts. Similarly, the Anaplasma sp., Anaplasma ovis and Theileria ovis prevalence varied significantly among the sheep breeds. Anaplasma ovis infection was more common in large herds and in un-infested sheep. Theileria ovis infection was more frequent in small herds. In conclusion, we are reporting the presence of Anaplasma sp., Anaplasma ovis and Theileria ovis in Pakistani sheep that were enrolled from all six districts. Large-scale studies are recommended in various geo-climatic regions of Pakistan to confirm the genetic diversity, epidemiology and host-pathogen interactions that will contribute towards effective control of these infections among the local sheep population.
Nationwide investigation of eukaryotic pathogens in ticks from cattle and sheep in Kyrgyzstan using metabarcoding
Ticks are significant vectors of bacterial, viral, and protozoan pathogens, impacting both public health and agriculture. In Kyrgyzstan, tick-borne diseases are a growing concern for livestock and human health. While bacterial and viral pathogens are widely studied, and limited previous investigations have focused on specific Babesia and Theileria species in certain host animals, comprehensive data on tick eukaryotic microbiota and potential pathogens across diverse hosts nationwide is scarce. To address this gap, our study provides the comprehensive nationwide assessment of the potential protozoan pathogens in ticks from cattle and sheep, analyzing data of Babesia and Theileria at the genus level. We collected 472 tick samples from cattle and sheep across seven regions of Kyrgyzstan (March-July 2022). Tick species were identified via microscope and Sanger sequencing (mitochondrial COI gene). Eukaryotic microbiota was analyzed using 18S rRNA V9 NGS. Sanger sequencing identified five genera and 11 tick species. NGS analysis revealed Babesia (13.3%) and Theileria (12.7%) as among the most prevalent protozoa detected at the genus level. Babesia was significantly more prevalent in nymph-stage ticks and those collected from sheep, whereas Theileria was detected across a broader range of tick species and host animals, showing less variation across life stages. No significant differences in prevalence were observed based on tick sex or the number of hosts in the tick life cycle. Regionally, Babesia detection was highest in the Osh region, particularly in ticks collected from both cattle and sheep. This is the first comprehensive nationwide analysis of tick eukaryotic metabarcoding study in Kyrgyzstan focusing on pathogenic protozoa detected at the genus level. Findings provide crucial baseline data on Babesia and Theileria geographic and host-specific prevalence. Understanding these information is essential for advancing future research and supporting the development of effective surveillance and control strategies against babesiosis and theileriosis in regional livestock.
Prevalence and seasonal variation of tick-borne haemoparasites in cattle from north-eastern Uganda
Theileriosis, babesiosis, anaplasmosis, and ehrlichiosis are the most important constraints to livestock production in Karamoja region, North-eastern Uganda. However, there are no large-scale studies on the prevalence and seasonal variation of tick-borne haemoparasites that are needed to design and implement tick-borne disease control programs. We collected 7080 blood samples from cattle across four districts of north-eastern Uganda during the dry (November 2022 to February 2023) and wet (July to August 2023) seasons. These samples were screened for the most important tick-borne haemoparasites (TBH) by conventional PCR, followed by capillary sequencing of representative PCR amplicons. There was no statistically significant difference [ p  > 0.05] in the overall prevalence of infection with at least one of the screened TBHs during the wet [39.0%; CI 7.3–40.6] and dry seasons [39.2%: CI 37.6–40.9]. Prevalence of the individual TBHs during the dry season were:— Babesia bigemina 11.8% (CI 10.8–12.9), Babesia bovis 11.8% (CI 10.8–12.9), Anaplasma marginale 9.2% (CI 8.2–10.2), Ehrlichia ruminantium 5.1% (CI 4.4–5.8) and Theileria parva 1.3% (CI 1.0–1.8). Prevalence of individual TBHs during the dry season were:— T. parva 22.6% (CI 21.3–24), A. marginale 13.6% (CI 12.5–14.8), B. bigemina 12.7% (CI 11.6–13.8), E. ruminantium 1.4% (CI 1.1–1.9) and B. bovis 0.3% (CI 0.1–0.5). Geospatial location, increasing age, sex, overnight stay in cattle kraals, and cattle breeds were significant predictors of infection with different TBHs during either season. Co-infection with the individual TBHs ranged between 0.14–2.74% and 0–1.64% during the dry and wet seasons respectively. In both seasons, the co-infection rate with all five TBHs was 0.03% (CI 0.0–0.16). Phylogenetic analyses of the representative TBH sequences revealed high level of conservation within the targeted genes of the samples in this study and those within the East Africa region that were retrieved from the GenBank. This study demonstrate high level of infection/co-infection with different TBHs in both dry and wet seasons indicating that ticks and tick-borne diseases are a major impediment to livestock production in Karamoja region. This shows the need of having a ticks and tick-borne disease control program. Moreover, B. bovis was detected for the first time in this region.