Babesia bovis and Babesia bigemina infection levels estimated by qPCR in Angus cattle from an endemic area of São Paulo state, Brazil

Detection and quantification of Babesia bovis and Babesia bigemina using different target genes

Molecular assays have been widely used for the detection and quantification of bovine babesiosis due to their high sensitivity and specificity. However, variations in the sensitivity of pathogen detection may occur depending on the selected target gene. Thus, this study aimed to compare the detection sensitivity (DS) of Babesia bovis and B. bigemina infection levels in artificially and naturally infected cattle using quantitative PCR (qPCR) and six target genes. For B. bovis, the merozoite surface antigen genes 2b and 2c (msa-2b and msa-2c), and the mitochondrial cytochrome b gene (cybmt) were used. For B. bigemina, the genes encoding the proteins associated with rhoptry 1c (rap-1c), rap-1a, and cybmt were used. Six bovines, free of babesiosis, were artificially infected with 1 × 10-8 red blood cells infected (iRBC) with B. bovis (n = 3) or 1 × 10-6B. bigemina iRBC (n = 3). The animals were evaluated daily until parasitemia was confirmed (≥ 2.0%). The quantity of iRBC present in each animal was determined by examining blood smears. Blood samples were then subjected to DNA extraction, serial dilution, and qPCR analysis to determine the DS of each target gene. In addition, 30 calves naturally infected by Babesia spp. were also evaluated using the same six target genes. Regarding the artificial infection, B. bovis cybmt showed 25-fold higher sensitivity than the msa-2b and msa-2c genes, while the B. bigemina cybmt exhibited 5-fold and 25-fold higher sensitivity than the rap-1a and rap-1c genes, respectively. The rap-1a gene was found to be 5 times more sensitive than the rap-1c gene, while the B. bovis msa-2b and msa-2c genes exhibited similar DS. The positive frequencies of naturally infected calves for the target cybmt, msa-2b, and msa-2c genes (B. bovis) were: 100%, 33.3% and 50%, while cybmt, rap-1a, and rap-1c genes (B. bigemina) were 90%, 83.3%, and 63.3%, respectively. This study may contribute to the selection of suitable genes for molecular monitoring of bovine babesiosis. Mitochondrial genes could be considered as an alternative to improve the sensitivity of B. bovis and B. bigemina detection using qPCR.

Latitude and seasons influence the prevalence of Theileria orientalis and affect the hematology of non-grazed dairy cows in Korea

This pilot study aimed to investigate the effects of regional and seasonal variations on the prevalence of Theileria orientalis and the hematological profile of non-grazed dairy cows in Korea. A total of 365 clinically healthy lactating Holstein Friesian cows from 26 dairy farms in 7 provinces that were categorized into northern, central, and southern regions were sampled during the warm period from July to August and the cold period from October to December. The detection of T. orientalis major piroplasm surface protein gene and the hematology non-grazed dairy cows were analyzed using peripheral blood samples. The T. orientalis prevalence was 20.0% (73/365). The prevalence in the southern region was 35.9%, which was significantly higher than that in the central (21.6%) and northern (12.9%) regions (P < 0.05). The prevalence during warm period was higher (43.0%) than that during the cold season (13.5%). The infected cows showed significantly lower erythrocyte counts in the southern region (5.8 ± 0.6 M/µl) and during the warm period (5.8 ± 0.7 M/µl) compared with those in the central and northern regions and during the cold season, which affected the extended RBC parameters, including hematocrit and hemoglobin concentrations. Our findings revealed the prevalence of T. orientalis in Korea, highlighting its high occurrence during warm periods and in certain geographical regions. Climatic factors could contribute to the health and productivity of cattle, as evidenced by the prevalence of T. orientalis and its negative impact on animals.

Control of Rhipicephalus microplus tick larvae in the field based on distancing from the host - Lone tick system

The aim of this study was to evaluate a host-tick distancing control system using Rhipicephalus microplus in cattle. Its impact on the profiles of the pathogens Anaplasma marginale and Babesia bigemina was also assessed using enzyme-linked immunosorbent and real-time polymerase chain reaction. Experiments were conducted in Mato Grosso do Sul, Brazil. A total of 37 Senepol animals with natural tick infestation were used in this study. The ticks on the animals were counted, and pasture rotation was performed at 28-day intervals. This approach was repeated until the end of the experiment to maintain a low number of ticks, resulting in a final average of 6.3 ticks/host. Cattle maintained an immune response to the cattle tick fever (CTF) agents. DNA copies of A. marginale (X̄ 1.1) and B. bigemina (X̄ 0.05) did not vary significantly with the decrease in tick count throughout the study period. Based on these results, we conclude that a distancing period of 84 days between ticks and cattle in conditions of the Cerrado biome can control ticks in animals and maintain enzootic stability. Thus, it is possible to create productive breeds with lower tick control costs.

Association between chronic Anaplasma marginale and Babesia spp. infection and hematological parameters of taurine heifers

The aim of this study was to investigate the association between chronic Anaplasma marginale and Babesia spp. infection and hematological parameters of pregnant and non-pregnant taurine heifers. Blood samples from 94 females were collected on the first day (D-10) of timed artificial insemination (TAI) protocol and on pregnancy diagnosis (D+34). Hematological parameters were determined and compared between pregnant (PG) and non-pregnant (NPG) heifers, and within group at different sampling days. Real-time PCR (qPCR) was used to determine A. marginale and Babesia bovis infection, and for absolute quantification of Babesia spp. between PG and NPG groups. Correlation analysis was performed between the number of gDNA copies (CN) of Babesia spp. and hematological parameters. On D-10, mean hemoglobin concentration was higher for NPG, and hematocrit and total plasma protein were higher on D+34 for both groups. There was no difference in Babesia spp. CN between groups. In the first qPCR, all heifers were positive for A. marginale and B. bovis. Significant correlations were found between hemoglobin and erythrocyte and between hemoglobin and hematocrit (r = 0.8082 and r = 0.3009, respectively). Low levels of A. marginale and Babesia spp. did not affect hematological parameters of chronically infected pregnant and non-pregnant taurine heifers.

Natural levels of Rhipicephalus microplus infestation and Anaplasma marginale infection in Angus and Ultrablack calves

Infections by Anaplasma marginale and infestations by Rhipicephalus microplus occur endemically in Brazil, representing an obstacle to expanding the use of taurine breeds, which are more susceptible. In this study, the levels of infection by A. marginale and infestation by R. microplus were monitored in 31 calves that were either purebred or had a high degree of taurine blood: 17 Angus (100% taurine) and 14 Ultrablack (ca. 82% taurine and 18% Zebu). The animals were evaluated on 13 occasions at 12-day intervals. The levels of A. marginale infection were determined by quantification of DNA copy number (CN) by qPCR, and ticks were monitored by two methods: counting adult females (≥ 4.5 mm) and scoring the level of tick infestation considering all visible instars in the animals' bodies. No significant effects were observed between the means of CN of A. marginale, tick counts and scores among Angus and Ultrablack animals. The repeatability estimates for CN of A. marginale, tick counts and tick scores were 0.53, 0.12 and 0.16, respectively. The correlations between CN and tick counts and scores were close to zero, whereas the correlations between tick assessment methods were 0.57. The absence of differences between the two genetic groups indicates, under the conditions of the present study, that the low degree of Zebu blood did not influence the levels of infection by A. marginale or infestation by R. microplus. The results also suggest that the evaluation of the levels of infestation by ticks using scores can provide information closer to the real infestation rate considering that it uses all the visible instars of the parasites.

Repeatability of Health and Welfare Traits and Correlation with Performance Traits in Dairy Goats Reared under Low-Input Farming Systems

The objectives of the study were to estimate the repeatability of health and welfare traits and investigate their association with performance in three breeds of dairy goats reared under low-input farming systems in Greece. A total of 1210 goats of Eghoria (n = 418), Skopelos (n = 429), and Damascus (n = 363) breeds were assessed. Udder health, parasitic resistance, welfare, milk yield and quality, and body condition score were recorded monthly for two milking periods. Udder health records included somatic cell count (SCC) and total viable count (TVC). Based on combinations of SCC and TVC and thresholds set at >106 cells/mL and >2 × 104 cfu/mL, respectively, additional udder health phenotypes were defined. Parasitism included myiasis, tick infestation, gastrointestinal nematode (GIN) and cestode faecal egg count (FEC), and lungworm faecal larval count (FLC). Infection with each of the endoparasites was defined based on FEC/FLC. Welfare assessment parameters included the presence of ear and horn injuries, ocular and nasal discharge, body and udder abscesses, injury and lesions on the skin of different regions, diarrhoea, hernias, overgrown hooves, arthritis, lameness, and udder asymmetry. Trait repeatability and animal correlations were estimated. Significant (p < 0.05) repeatability was reported for all udder health and most welfare traits in all breeds, GIN and cestode FEC, and GIN and lungworm infection in Eghoria, and myiasis in Skopelos. Correlations of health and most of welfare traits with performance were non-significant or favourable. Overall, results demonstrate potential to improve health and welfare of the studied breeds without compromising performance.

Molecular Survey of Babesia and Anaplasma Infection in Cattle in Bolivia

Latin American countries produce more than a quarter of the world's beef and are a major global supplier of livestock protein. Tick-borne diseases (TBDs) are a major constraint to the livestock industry worldwide, including in Latin America. The aim of this study was to detect and characterise tick-borne pathogens in cattle from Santa Cruz, Bolivia, where no detailed epidemiological data are available. Blood samples were collected from 104 cattle. Apicomplexan parasites were detected by nested PCR amplification of the 18S ribosomal RNA gene (rDNA), and Anaplasmataceae was screened by the PCR amplification of 16S rDNA, followed by characterisation based on the heat shock protein and citrate synthase gene sequences. Babesia infection was observed in nine cattle (one Babesia bovis and eight Babesia bigemina), while Anaplasmataceae infection was detected in thirty-two cattle. A sequencing analysis confirmed the presence of Anaplasma marginale and Anaplasma platys-like. These results provide the first molecular evidence for the four above-mentioned tick-borne pathogens in cattle in Bolivia. This information improves our understanding of the epidemiology of TBDs and will help in formulating appropriate and improved pathogen control strategies.

Semi-quantitative evaluation of Babesia bovis and B. bigemina infection levels estimated by HRM analysis

Bovine babesiosis is economically the most important arthropod-borne disease of cattle worldwide. The most significant damage caused by bovine babesiosis is attributed to Babesia bovis due to its higher pathogenicity. This study aimed to develop a real-time PCR method followed by HRM (high-resolution melting) analysis for the simultaneous detection of B. bovis and B. bigemina, enabling a semi-quantitative analysis of Babesia levels using a single-tube reaction. The HRM was compared with real-time PCR using species-specific hydrolysis probes. The HRM analysis allowed to differentiate both Babesia species and was sensitive in the detection and differentiation of 10% for each Babesia species in the sample. Our results suggest the use of this method to estimate the prevalence of infections by B. bovis or B. bigemina as an alternative to the methods of absolute quantification by real-time PCR since it neither requires precise estimates of the number of DNA loads nor the construction of calibration curves. The simultaneous detection of the two Babesia species can be used to characterise the infection levels in cattle populations from different geographical regions, allowing a better control of these diseases.

Challenges in Tick-Borne Pathogen Detection: The Case for Babesia spp. Identification in the Tick Vector

The causative agents of Babesiosis are intraerythrocytic protozoa of the genus Babesia. Babesia parasites are present around the world, affecting several mammals including humans, pets and livestock, hence its medical and veterinary relevance. Babesia spp. detection in its invertebrate host is a main point in understanding the biology of the parasite to acquire more knowledge on the host–Babesia–vector interactions, as increasing knowledge of the Babesia lifecycle and babesiosis epidemiology can help prevent babesiosis outbreaks in susceptible mammals. The aim of the present review is to highlight the newest findings in this field, based on a bibliographic compilation of research studies recently carried out for the detection of the main Babesia species found in tick vectors affecting mammalian hosts, including the different tick stages such as adult ticks, larvae, nymphs and eggs, as well as the detection method implemented: microscopic tools for parasite identification and molecular tools for parasite DNA detection by conventional PCR, nested-PCR, PCR-RFLP, PCR-RLB hybridization, real time-PCR, LAMP and RAP assays. Although molecular identification of Babesia parasites has been achieved in several tick species and tissue samples, it is still necessary to carry out transmission experiments through biological models to confirm the vectorial capacity of various tick species.

Genomic Study of Babesia bovis Infection Level and Its Association With Tick Count in Hereford and Braford Cattle

Bovine babesiosis is a tick-borne disease caused by intraerythrocytic protozoa and leads to substantial economic losses for the livestock industry throughout the world. Babesia bovis is considered the most pathogenic species, which causes bovine babesiosis in Brazil. Genomic data could be used to evaluate the viability of improving resistance against B. bovis infection level (IB) through genomic selection, and, for that, knowledge of genetic parameters is needed. Furthermore, genome-wide association studies (GWAS) could be conducted to provide a better understanding of the genetic basis of the host response to B. bovis infection. No previous work in quantitative genetics of B. bovis infection was found. Thus, the objective of this study was to estimate the genetic correlation between IB and tick count (TC), evaluate predictive ability and applicability of genomic selection, and perform GWAS in Hereford and Braford cattle. The single-step genomic best linear unbiased prediction method was used, which allows the estimation of both breeding values and marker effects. Standard phenotyping was conducted for both traits. IB quantifications from the blood of 1,858 animals were carried using quantitative PCR assays. For TC, one to three subsequent tick counts were performed by manually counting adult female ticks on one side of each animal's body that was naturally exposed to ticks. Animals were genotyped using the Illumina BovineSNP50 panel. The posterior mean of IB heritability, estimated by the Bayesian animal model in a bivariate analysis, was low (0.10), and the estimations of genetic correlation between IB and TC were also low (0.15). The cross-validation genomic prediction accuracy for IB ranged from 0.18 to 0.35 and from 0.29 to 0.32 using k-means and random clustering, respectively, suggesting that genomic predictions could be used as a tool to improve genetics for IB, especially if a larger training population is developed. The top 10 single nucleotide polymorphisms from the GWAS explained 5.04% of total genetic variance for IB, which were located on chromosomes 1, 2, 5, 6, 12, 17, 18, 16, 24, and 26. Some candidate genes participate in immunity system pathways indicating that those genes are involved in resistance to B. bovis in cattle. Although the genetic correlation between IB and TC was weak, some candidate genes for IB were also reported in tick infestation studies, and they were also involved in biological resistance processes. This study contributes to improving genetic knowledge regarding infection by B. bovis in cattle.

Correlation between Rhipicephalus microplus ticks and Anaplasma marginale infection in various cattle breeds in Brazil

The tick Rhipicephalus microplus is responsible for the transmission of Anaplasma marginale, which causes hemolytic anemia, abortion, decreased production, and mortality in cattle in Brazil. However, A. marginale can also persist in cattle herds without any clinical signs. This study investigated the relationship between the number of ticks present on each cattle and the circulating number of A. marginale msp1β gene copies in the blood of Brangus and Nellore cattle reared in the Brazilian Cerrado through a year period. Twenty-three animals (11 Brangus and 12 Nellore) were raised for 12 months with ticks counted every 18 days, and blood collected every 36 days. Blood sera was used for total antigen iELISA, genomic DNA was extracted from whole blood by the phenol/chloroform method and then analyzed by PCR to confirm A. marginale presence with the msp5 gene. Positive samples were quantified by qPCR using msp1β gene. Brangus cattle presented 4.5 fold more ticks than Nellore group. Although Brangus cattle carried a higher overall A. marginale msp1β gene presence than Nellore cattle, no relationship of tick count and copy number could be achieved due to high variability in copy number. Moreover, both breeds showed similar weight gain and a similar serological pattern throughout the year. None of the animals showed any clinical signs of anaplasmosis during the experimental period, indicating that a low level of tick infestation may be sufficient to maintain a stable enzootic situation.

Correlations and repeatability between Babesia spp. infection levels using two dairy cattle breeding systems

Babesia bovis and Babesia bigemina are tick-transmitted piroplasms that cause severe damage to the livestock industry in tropical regions of the world. Recent studies demonstrated differences in infection levels of these haemoparasites among bovine breeds and variation between individual cows regarding resistance to these diseases. This study aimed to estimate the repeatability and correlations between B. bovis and B. bigemina using two cattle breeding systems, an individual system (IS) and a collective paddock system (CPS). All animals were Holstein breed, and the levels of B. bovis and B. bigemina in blood samples were estimated by quantitative polymerase chain reaction (qPCR). The estimated correlations for the B. bigemina and B. bovis DNA copy number for IS and CPS were moderate and high, respectively, whereas repeatability estimates for both systems and both Babesia species were moderate. Although we cannot infer that the type of rearing system directly influenced the correlation and repeatability coefficients, it appears that the bovine parasitemia burden may be dependent on (or determine) the parasitemia burden on ticks because the bovines remained in the same place for a longer time in both systems. Thus, the babesiosis infection levels of the ticks may have been uniform, a phenomenon that also ensures greater uniformity in cattle infection. This factor may have favored the occurrence of infected ticks leading to higher repeatability estimates and correlations. Our study confirms high variability in resistance/susceptibility between breeds, and the high correlations found may be linked to this characteristic and the most intensive breeding type of dairy cattle. Besides, under the present study conditions, the estimated correlations suggest that measuring an infection level of one Babesia species can predict the level of infection of the other.

Characterization of cattle tick fever in calves from the northwestern region of Minas Gerais, Brazil

The present study aimed to characterize the importance of the Anaplasma marginale, Babesia bovis and Babesia bigemina in the genesis of cattle tick fever (CTF) among dairy calves in the northwest of Minas Gerais, Brazil. Blood samples from 300 calves were collected, followed by DNA extraction and nested PCR using oligonucleotide primers to amplify fragments of the semi-nested for the msp5 gene (A. marginale), sbp-4 (B. bovis) and rap-1a (B. bigemina) Among the examined calves, the prevalence of A. marginale was 55.6% (n=167/300), B. bovis was 4.0% (n=12/300) and B. bigemina was 15.3% (n=46/300), by PCR techniques. Parasitic forms of A. marginale and B. bigemina were found in 36,3% and 2,6% of the blood smears while B. bovis was not detected. There was a statistical difference between the positivity of infected animals in the age groups 1 (10-70 days) and (>70-300 days) for A. marginale and B. bigemina. A total of 15 calves with the classic symptoms of disease were examined, and the samples obtained were confirmed as a simple infection by A. marginale through semi-nested PCR. These results confirm bovine anaplasmosis as the primary cause of CTF among the calves of dairy cattle within the studied area.

Molecular epidemiological survey of Babesia bovis, Babesia bigemina, and Babesia sp. Mymensingh infections in Mongolian cattle

Bovine babesiosis caused by Babesia species is an economically significant disease of cattle. Severe clinical babesiosis in cattle is caused by Babesia bovis, B. bigemina, and the recently discovered Babesia sp. Mymensingh. Mongolia is an agricultural country with a large cattle inventory. Although previous studies have detected active infections of B. bovis and B. bigemina in Mongolian cattle, only a few provinces were surveyed. Additionally, the endemicity of Babesia sp. Mymensingh in Mongolia remains unknown. We screened blood DNA samples from 725 cattle reared in 16 of the 21 Mongolian provinces using B. bovis-, B. bigemina-, and Babesia. sp. Mymensingh-specific PCR assays. The overall positive rates of B. bovis, B. bigemina, and Babesia sp. Mymensingh were 27.9% (n = 202), 23.6% (n = 171), and 5.4% (n = 39), respectively. B. bovis and B. bigemina were detected in cattle in all surveyed provinces; whereas Babesia sp. Mymensingh was detected in 11 of the 16 surveyed provinces. On a per province basis, the B. bovis- B. bigemina-, and Babesia sp. Mymensingh-positive rates were 5.9-52.0%, 9.1-76.3%, and 0-35.7%, respectively. In conclusion, this is the first report of Babesia sp. Mymensingh in Mongolia. In addition, we found that species of Babesia that are capable of causing bovine clinical babesiosis, including B. bovis, B. bigemina, and Babesia sp. Mymensingh, are widespread throughout the country.

Immunisation of cattle against Babesia bovis combining a multi-epitope modified vaccinia Ankara virus and a recombinant protein induce strong Th1 cell responses but fails to trigger neutralising antibodies required for protection

Protection against the intraerythrocytic protozoan parasite Babesia bovis depends on both strong innate and adaptive immune response, this latter involving the presentation of parasite antigens to CD4⁺ T-lymphocytes by professional antigen-presenting cells. Secretion of Th1 cytokines by CD4⁺ T cell is also very important for isotype switching to IgG₂, the best opsonising antibody isotype in cattle, to target extracellular parasites and parasite antigens displayed at the erythrocyte surface. In the field of vaccinology, heterologous prime-boost schemes combining protein-adjuvant formulations with a modified vaccinia Ankara vector expressing the same antigen have demonstrated the induction of both humoral and cellular immune responses. It has been previously demonstrated that MVA-infected dendritic cells can present antigens in the context of MHC II and activate CD4⁺ T cell. These results support the use of the MVA viral vector for a pathogen like Babesia bovis, which only resides within erythrocytes. In this study, 13-15-months-old Holstein-Friesian steers were immunised with a subunit vaccine as a prime and a modified vaccinia Ankara vector as a boost, both expressing a chimeric multi-antigen (rMABbo - rMVA). This antigen includes the immunodominant B and T cell epitopes of three B. bovis proteins: merozoite surface antigen - 2c (MSA - 2c), rhoptry associated protein 1 (RAP - 1) and heat shock protein 20 (HSP20). Responses were compared with the Babesia bovis live attenuated vaccine used in Argentina (R1A). Eleven weeks after the first immunisation, all bovines were challenged by the inoculation of a virulent B. bovis strain. All groups were monitored daily for hyperthermia and reduction of packed cell volume. Both the rMABbo - rMVA and R1A vaccinated animals developed high titters of total IgG antibodies and an antigen-specific Th1 cellular response before and after challenge. However, all rMABbo - rMVA steers showed clinical signs of disease upon challenge. Only the R1A live vaccine group developed an immune response associated with in vitro neutralising antibodies at a level that significantly inhibited the parasite invasion. The lack of protection observed with this recombinant formulation indicates the need to perform further basic and clinical studies in the bovine model in order to achieve the desired effectiveness. This is the first report in which a novel vaccine candidate against Babesia bovis was constructed based on a recombinant and rationally designed viral vector and evaluated in the biological model of the disease.

Resistance to the tick Rhipicephalus microplus and Babesia bovis infection levels in beef heifers raised in an endemic area of Sao Paulo state, Brazil

Repeatability coefficients (r) for tick resistance and Babesia bovis infection levels and the correlation (ρ) between these traits were estimated in beef heifers, using artificial infestations and short intervals between measurements. Forty heifers, including 20 Bos taurus taurus (Caracu) and 20 Bos taurus indicus (Nelore) animals, were submitted to three artificial infestations with Rhipicephalus microplus larvae at intervals of 14 days. The number of standard female was counted from the 19th through the 23rd day after each infestation, considering only the left side of each animal. Blood samples were collected on Days 0, 6, 20, 34 and 48 after the first infestation. The number of copies of B. bovis DNA (CN) was estimated from blood samples through the quantitative PCR technique to evaluate the level of infection in the animals. Total tick count (TTC), the percentage of return (PRij) and CN were analysed using the MIXED procedure of the SAS program. The r of the variables were estimated by intraclass correlation between measures of the same animal, with the variance component of the animal being divided by the phenotypic variance (residual + animal), using models with a CS structure matrix. Additionally, ρ among variables were estimated using the CORR procedure. The following results were obtained for Caracu and Nelore animals, respectively: 1.83 ± 0.37 and 0.63 ± 0.40 for TTC, 1.10 ± 0.23 and 0.47 ± 0.23 for PRij, and 2.29 ± 0.64 and 2.32 ± 0.58 for CN. The r was moderate for TTC (0.62) and PRij (0.53) and low for CN (0.10). The ρ between TTC and CN obtained in the same measurement day was not significant in either breed (P &gt; 0.05; –0.07 for Caracu and 0.19 for Nelore). Results showed both breeds were able to develop resistance against B. bovis; however, Nelore exhibited higher tick resistance. The r obtained for CN and the weak association with tick resistance indicate that it is not possible to recommend the use of CN as a trait to predict tick resistance in these two breeds.

qPCR estimates of Babesia bovis and Babesia bigemina infection levels in beef cattle and Rhipicephalus microplus larvae

Babesia spp. are tick-transmitted intraerythrocytic apicomplexan parasites that infect wild and domestic animals. Babesia bovis and B. bigemina are endemic and responsible for enormous economic losses to the livestock industry in most of the Brazilian territory, wherein the tick Rhipicephalus microplus is the unique vector. Better understanding of epidemiology and parasite-host interactions may improve the tools for disease control and genetic management for selection of resistant animals. This study aimed to detect, quantify and measure the correlation between B. bigemina and B. bovis infection levels in bovine blood and into tick, by absolute quantification of hemoparasite DNA using qPCR. Blood bovine samples and larvae pools from 10 engorged R. microplus females were collected from each Canchim heifers (5/8 Charolais + 3/8 zebu, n = 36). All evaluated samples were positive for both Babesia species tested. Correlations of B. bovis and B. bigemina levels between cattle and tick host were 0.58 and 0.66, respectively. These high positive correlation coefficients indicate that parasitemia load in the bovine may be dependent on or may determine the parasitemia load in the ticks.