Serological survey of Babesia bovis, Babesia bigemina, and Anaplasma marginale antibodies in cattle from the semi-arid region of the state of Bahia, Brazil, by enzyme-linked immunosorbent assays

Babesia bigemina (smith and Kilbourne, 1893) detection in Amblyomma sculptum (Berlese, 1888) ticks in the Mato Grosso do Sul state, Brazil

Ticks parasitize various hosts, including humans, and are known to transmit pathogens that can be harmful not only to animals but also to humans. To evaluate the possible presence of pathogens in ticks, we aimed to collect and identify tick fauna specimens in Lagoa Comprida Municipal Natural Park, an anthropogenic urban area located in Aquidauana, Mato Grosso do Sul, Brazil. A total of 1216 ticks, of which 51.2% were Amblyomma sculptum, 1.2% were Amblyomma dubitatum, and 41% were Amblyomma spp. were collected. These results show that the prevalence of A. sculptum is significantly higher than that of A. dubitatum across all four seasons. Molecular analyses revealed positive samples for the genus Babesia, including the confirmation of Babesia bigemina in an A. sculptum specimen, marking the first record of this relationship. This unexpected finding demands greater attention and deeper analysis in the context of the epidemiology of tick-borne diseases.

Can herd seroprevalence be used as an indicator of enzootic stability for bovine anaplasmosis? Insights from a case-control field study in Brazil

Bovine anaplasmosis presents a significant challenge to livestock production in tropical, subtropical, and temperate regions. For many years, the concept of enzootic stability/instability (initially established for babesiosis) and herd seroprevalence as an indicator of outbreak risks have been applied to anaplasmosis. However, this model has never been definitively validated for Anaplasma marginale. The objective of this study was to examine the relationship between herd immunity (seroprevalence) and the occurrence of anaplasmosis outbreaks in Southern Brazil. A case-control study was conducted, categorizing farms into two groups: cases (farms with a history of clinical anaplasmosis) and controls (those without anaplasmosis). Thirteen farms were identified as "cases", while 23 were identified as "controls". A substantial difference in seroprevalence distribution between the two groups was observed. The majority of "control" farms exhibited over 75% of animals with antibodies to A. marginale in both calves and heifers, whereas the majority of "case" farms had a seropositive cattle percentage below 75%. Additionally, twelve months after cattle serology tests, we conducted a prospective follow-up survey to identify any clinical cases of anaplasmosis. Statistical associations (P < 0.05) were found between both retrospective and prospective anaplasmosis outbreaks and the hypothetical threshold of herd seroprevalence (75%). We hypothesize that herd seroprevalence may be an indicator of the risk of occurrence of clinical anaplasmosis. It appears that the epidemiology of cattle anaplasmosis, at least in our conditions, aligns with the well-known model of enzootic stability/instability originally applied to bovine babesiosis.

Effects of cattle on vector-borne disease risk to humans: A systematic review

Vector-borne pathogens (VBPs) causing vector-borne diseases (VBDs) can circulate among humans, domestic animals, and wildlife, with cattle in particular serving as an important source of exposure risk to humans. The close associations between humans and cattle can facilitate the transmission of numerous VBPs, impacting public health and economic security. Published studies demonstrate that cattle can influence human exposure risk positively, negatively, or have no effect. There is a critical need to synthesize the information in the scientific literature on this subject, in order to illuminate the various ecological mechanisms that can affect VBP exposure risk in humans. Therefore, the aim of this systematic review was to review the scientific literature, provide a synthesis of the possible effects of cattle on VBP risk to humans, and propose future directions for research. This study was performed according to the PRISMA 2020 extension guidelines for systematic review. After screening 470 peer-reviewed articles published between 1999-2019 using the databases Web of Science Core Collection, PubMed Central, CABI Global Health, and Google Scholar, and utilizing forward and backward search techniques, we identified 127 papers that met inclusion criteria. Results of the systematic review indicate that cattle can be beneficial or harmful to human health with respect to VBDs depending on vector and pathogen ecology and livestock management practices. Cattle can increase risk of exposure to infections spread by tsetse flies and ticks, followed by sandflies and mosquitoes, through a variety of mechanisms. However, cattle can have a protective effect when the vector prefers to feed on cattle instead of humans and when chemical control measures (e.g., acaricides/insecticides), semio-chemicals, and other integrated vector control measures are utilized in the community. We highlight that further research is needed to determine ways in which these mechanisms may be exploited to reduce VBD risk in humans.

Epidemiological aspects of cattle tick fever in Brazil

The present work reviews the epidemiologic situation of Anaplasma marginale and Babesia spp. infections and the occurrence of cattle tick fever outbreaks in Brazil. In areas of tick fever enzootic instability, environmental conditions interfere with the development of Rhipicephalus (Boophilus) microplus: chilly winter in the southern region, floods in the Pantanal, and low humidity in the Caatinga. In contrast, the climatic conditions of stable zones (Cerrado, Amazon and Atlantic Forest biomes) favor tick development. In enzootic areas, tick fever is uncommon because the animals are in frequent contact with the parasite, acquiring immunity naturally during the period of innate resistance; however, outbreaks may occur when calves become infested by considerable numbers of infected ticks during this period or in adults raised in tick-free environments that become infested for the first time when transporting to stable areas. It is necessary to better understand the disease's risk factors under stable conditions and the implications of the mechanical and other vector transmission of A. marginale. To prevent tick fever outbreaks in Brazil, it is important to develop and use anaplasmosis and babesiosis vaccines in cattle from enzootic unstable regions, especially when animals are moved to stable areas.

Bovine anaplasmosis as a risk factor for retained placenta, mastitis, and abomasal displacement in dairy cattle

This study aimed to evaluate the frequency of IgG antibodies against A. marginale, the occurrence of this bacterium by qPCR, and the effect of bovine anaplasmosis as a risk factor for clinical cases of retained placenta, mastitis, and abomasal displacement in dairy cattle. For that 179 Holstein cows out of three dairy herds, in the municipality of Sertão, Rio Grande do Sul, Brazil. These cows were on farms that were vulnerable to risk factors that are crucial to susceptibility among these animals to this intracellular hemoparasite. The mean seropositivity for A. marginale from the periods evaluated was 54% on farm A, 69.4% on farm B, and 27.3% on farm C. Molecular diagnosis was performed with qPCR and the mean positivity for A. marginale among the cows on farms A, B, and C in December 2017 was 34.6% (67/179). Infected animals showed clinical cases of retained placenta (6.1%), mastitis (6.1%), and abomasal displacement (0.5%). The association between positivity for anaplasmosis and these clinical cases was assessed through the odds ratio. Our results show that females with a positive qPCR assay for A. marginale had 52.48 times increased probability (OR) to develop clinical cases of retained placenta and mastitis (P < 0.001). These clinical cases negatively impact the productivity of positive females. Thus, implementing preventive and prophylactic control measures to ensure the sanitary quality of the herds is needed to avoid losses due to morbidity and mortality and diminish the economic losses suffered by farmers.

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.

Assessing the Immunochromatographic Test Strip for Serological Detection of Bovine Babesiosis in Uganda

In Uganda, bovine babesiosis continues to cause losses to the livestock industry because of shortages of cheap, quick, and reliable diagnostic tools to guide prescription measures. In this study, the presence of antibodies to Babesia bigemina and Babesia bovis in 401 bovine blood samples obtained from eastern and central areas of Uganda were detected using enzyme-linked immunosorbent assays (ELISAs) and immunochromatographic test strips (ICTs). The ELISA and ICT test used targeted the B. bigemina C-terminal rhoptry-associated protein (RAP-1/CT17) and B. bovis spherical body protein-4 (SPB-4). Using ELISA, single-ICT and dual-ICT, positive samples for B. bovis were detected in 25 (6.2%), 17 (4.3%), and 14 (3.7%) samples respectively, and positive samples for B. bigemina were detected in 34 (8.4%), 27 (6.7%), and 25 (6.2%), respectively. Additionally, a total of 13 animals (3.2%) had a mixed infection. The correlation between ELISA and single-ICT strips results revealed slight agreement with kappa values ranging from 0.088 to 0.191 between both methods, while the comparison between dual-ICT and single-ICT results showed very good agreement with kappa values >0.80. This study documented the seroprevalence of bovine babesiosis in central and eastern Uganda, and showed that ICT could, after further optimization, be a useful rapid diagnostic test for the diagnosis of bovine babesiosis in field settings.

Molecular screening of cattle ticks, tick-borne pathogens and amitraz resistance in ticks of Santo Domingo de los Tsáchilas province in Ecuador

The province of Santo Domingo de los Tsáchilas in Ecuador is a strategic place for cattle production and trade. The lack of knowledge about tick species, tick control and tick-borne diseases in Ecuador prompted this study with the goal of identifying the cattle-tick species and tick-borne agents present in the area and molecularly determining the potential acaricide resistance to amitraz of the major cattle tick species. Eighty-four cattle farms were visited and in 88 % of them, cattle were infested with ticks. Additionally, 24 historical samples from other surrounding Ecuadorian provinces, were screened as well. Besides morphological keys, PCR-RFLP MspI was used to confirm the presence of the Rhipicephalus ticks. The tick samples were also screened for tick-borne agents using PCR-RFLP BseDI and Hhal tests to identify circulating Babesia sp. and Anaplasma spp. Furthermore, the PCR-RFLP EciI technique was used to identify the amitraz resistance gene in populations of Rhipicephalus microplus in the province. Pooled testing was used to determine prevalence at individual-tick level. The presence of R. microplus and Amblyomma cajennense sensu lato (s.l.) ticks was found in 83 % and 21 % of the cattle farms respectively, showing R. microplus is widespread in the province of Santo Domingo de los Tsáchilas. Regarding tick-borne agents, only Anaplasma marginale was observed in 50 % of the visited farms of the province, while about 27 % of the ticks tested positive according to estimations from the data of the tick pools. The presence of Babesia bigemina was only confirmed in samples collected outside the province. The amitraz resistance allele in R. microplus was found in 62 % of the farms, but the percentage of farms with cattle ticks completely resistant to this acaricide was low (2%). The findings of this study should prompt cattle producers and animal health authorities to monitor control strategies, which address the management of resistant tick populations and the epidemiologically-unstable areas of tick-borne diseases.

Serological occurrence for tick-borne agents in beef cattle in the Brazilian Pantanal

This study investigated the seropositivity for five different tick-borne agents, namely Anaplasma marginale, Babesia bovis, Babesia bigemina, Coxiella burnetii, Anaplasma phagocytophilum, and Trypanosoma vivax in beef cattle in the Brazilian Pantanal. The serum samples collected from animals (200 cows; 200 calves) were used in indirect enzyme-linked immunosorbent assays (iELISA) to detect IgG antibodies against A. marginale, B. bovis, B. bigemina, and T. vivax, and Indirect Fluorescent Antibody Test (IFAT) for detecting IgG antibodies against C. burnetii and A. phagocytophilum. No correlation was observed between seropositivity for C. burnetii and A. phagocytophilum with other agents whereas moderate correlation was observed for A. marginalexB. bigemina x B. bovis. Cows were more seropositive for T. vivax whereas calves were more seropositive for B. bovis and B. bigemina. The highest number of seropositive animals by a single agent was observed for T. vivax (15.2%). Co-seropositivity for T. vivax + A. marginale was higher in cows (25.5%) and for T. vivax + B. bovis + B. bigemina + A. marginale was higher in calves (57.5%). The high seropositivity correlation for A. marginale x B. bovis x B. bigemina is probably due to the presence of the tick biological vector, Rhipicephalus microplus, in the studied farms. Common transmission pathways, mediated by hematophagous dipterans and fomites, may explain the high co-seropositivity of cows for A. marginale and T. vivax. Low seropositivity to C. burnetii is probably due to the type of breeding system employed (extensive). Seropositivity for A. phagocytophilum in only one animal suggests the occurrence of a cross-serological reaction with another agent of the genus Anaplasma.

Occurrence of Babesia bigemina and Anaplasma marginale in clinically affected cattle in western Santa Catarina, Brazil

ABSTRACT The objective of this study was to obtain data on the occurrence of Babesia bigemina e Anaplasma marginale in cattle with characteristic clinical signs of the disease, in different properties in western Santa Catarina. For this, 149 blood sample were collected and slides smears were done and the staining with the Romanowsky kind dye subsequently. Of the 149 samples surveyed, 78 (52.35%) were positive for A. marginale, 04 (2.68%) for B. bigemina, and 03 (2.01%) samples showed co-infection. All described cases occurred in adult animals, from two years old, with Holstein females the highest occurrence represented 119/149 (79.86%). Regarding the presence of ectoparasites, hematophagous flies were observed in all properties and ticks in 58/149 (38.92%) animals. The results showed a higher occurrence of A. marginale, evidencing the need to seek strategies of control and prevention by the veterinary professionals, especially in moments of greater occurrence of the vectors. The confirmation as from laboratory support by stained blood smears beyond being cheaper practical is a method that helping professionals identify the suspected cases etiology. Moreover, based on this information, we can promote the elaboration of prevention and treatment strategies based on simple and fast diagnostic techniques, focused on especific disease agents.

Prevalence of Anaplasma marginale, Babesia bovis, and Babesia bigemina in cattle in the Campos de Lages region, Santa Catarina state, Brazil, estimated by multiplex-PCR

This study aimed to determine the prevalence of three common hemoparasites (Anaplasma marginale, Babesia bovis and Babesia bigemina) in cattle from 16 counties in the Campos de Lages region, Santa Catarina state, Brazil, and the factors affecting disease occurrence. The study population consisted of 257 clinically healthy animals from 21 rural farms. Bovine blood samples were collected by jugular venipuncture. DNA was extracted from whole blood by the phenol/ chloroform method. Genomic DNA extracted from blood samples was subjected to Multiplex PCR for screening of B. bovis, B. bigemina, and A. marginale using specific primers. Prevalences of A. marginale, B. bigemina, and B. bovis were 27%, 16%, and 29%, respectively. Mixed infection was observed in 17.5% of samples. The most frequent was Babesia bovis and Babesia bigemina in 6.62% of samples. A. marginale infection rates were statistically correlated with age groups of cattle. The infections detected in the study population were considered to be subclinical, based on the presence pathogen DNA and absence of clinical symptoms. Seasonality of the pathogens resulted in various degrees of infection, related to the age of the animals and the season. The Campos de Lages region is characterized by enzootic instability for these pathogens because of its climatic and geographic features.

Prevalence of Anaplasma species in India and the World in dairy animals: A systematic review and meta-analysis

In the present study, the prevalence of Anaplasma species in diary animals from India and World was estimated using meta-analysis. Based on systematic review of studies on Anaplasma species from India [35] and World [66] from 1988 to 2017 and 1978-2017, respectively, using online databases and offline literatures, meta-analysis using meta package in R-Software was done. Prevalence of Anaplasma species in India and World were 11% [95% level, Confidence Interval[CI] 7-16%, Prediction Interval[PI] 1-69%] and 39% [95% level, CI 30-49%, PI 2-95%], and these were obtained using 31,117 and 46,365 samples, respectively. Period-wise analysis revealed high Anaplasma species prevalence before 2011 for India and the World than from 2011 through 2017. Zone-wise prevalence indicated high prevalence in Central zone [61%] and low in West and South zones [6%] in India, and continent-wise, it was high in South America [82%]. The studies used methods including blood smear examination, serology and nucleic acid-based techniques and revealed high prevalence in serology for India [34%] and World [46%], low prevalence by blood smear for India [7%] and World [21%], but higher sensitivity using nucleic acid-based techniques. Species-wise indicated higher prevalence in cattle [12%] than buffaloes [2%] in India. Prevalence was lower in India compared to the World and higher in South America. Overall, anaplasmosis causes low productivity in dairy animals and economic loss to dairy farmers. Hence, there is a need to control Anaplasma infections in high risk areas by adopting effective therapeutic and preventive measures so as to improve the economic benefits in dairy farming.

Longitudinal evaluation of humoral immune response and merozoite surface antigen diversity in calves naturally infected with Babesia bovis, in São Paulo, Brazil

Babesiosis is an economically important infectious disease affecting cattle worldwide. In order to longitudinally evaluate the humoral immune response against Babesia bovis and the merozoite surface antigen diversity of B. bovis among naturally infected calves in Taiaçu, Brazil, serum and DNA samples from 15 calves were obtained quarterly, from their birth to 12 months of age. Anti-B. bovis IgG antibodies were detected by means of the indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA). The polymerase chain reaction (PCR) was used to investigate the genetic diversity of B. bovis, based on the genes that encode merozoite surface antigens (MSA-1, MSA-2b and MSA-2c). The serological results demonstrated that up to six months of age, all the calves developed active immunity against B. bovis. Among the 75 DNA samples evaluated, 2, 4 and 5 sequences of the genes msa-1, msa-2b and msa-2c were obtained. The present study demonstrated that the msa-1 and msa-2b genes sequences amplified from blood DNA of calves positive to B. bovis from Taiaçu were genetically distinct, and that msa-2c was conserved. All animals were serologically positive to ELISA and IFAT, which used full repertoire of parasite antigens in despite of the genetic diversity of MSAs.

Dynamics of natural infection by Babesia bovis and Babesia bigemina in dairy cattle from an enzootic instability area in Northeastern Brazil

This study aimed to determine the dynamics of natural infection in the transmission of Babesia spp. to cattle in an enzootic instability area in Northeastern Brazil. Blood samples were collected from 30 calves located on two dairy farms to determine the packed cell volume (PCV) and the timing of the primo-infection using polymerase chain reaction (PCR) and their association with climatic factors and management practices. On Farm A, the determination of primo-infection was observed on average at 249.4 (±24.42) days of age for B. bigemina and at 252.6 (±17.07) days of age for B. bovis; there was no significant difference between the times of infection (P> 0.05). The infection coincided with a period of high rainfall in the region. On Farm B, primo-infection infection was not observed. There was no infection by Babesia spp. on Farm B due to the intensive use of acaricides that led to an absence of ticks. There was no significant difference between the average PCV of animals from Farms A and B (P> 0.05). The management practices on the properties, in addition to the weather conditions influenced the exposure of the animals to disease vectors and may have contributed to the maintenance of this enzootic area in Northeastern Brazil.

Bovine anaplasmosis and tick-borne pathogens in cattle of the Galapagos Islands

A cross-sectional study was conducted to determine the species of Anaplasma spp. and estimate its prevalence in cattle of the three main cattle-producing Galapagos Islands (Santa Cruz, San Cristóbal and Isabela) using indirect PCR assays, genetic sequencing and ELISA. Ticks were also collected from cattle and scanned for 47 tick-borne pathogens in a 48 × 48 real-time PCR chip. A mixed effects logistic regression was performed to identify potential risk factors explaining Anaplasma infection in cattle. A. phagocytophilum was not detected in any of the tested animals. Genetic sequencing allowed detection of A. platys-like strains in 11 (36.7%) of the 30 Anaplasma spp.-positive samples analysed. A. marginale was widespread in the three islands with a global between-herd prevalence of 100% [89; 100]_{95% CI} and a median within-herd prevalence of 93%. A significant association was found between A. marginale infection and age with higher odds of being positive for adults (OR = 3.3 [1.2; 9.9]_{95% Bootstrap CI} ). All collected ticks were identified as Rhipicephalus microplus. A. marginale, Babesia bigemina, Borrelia theileri and Francisella-like endosymbiont were detected in tick pools. These results show that the Galapagos Islands are endemic for A. marginale.

Tristeza Parasitária em bovinos do semiárido pernambucano

RESUMO: Este estudo objetivou determinar a soroprevalência da Babesiose e Anaplasmose em bovinos dos municípios de Ouricuri e Petrolina, estado de Pernambuco, Brasil; e definir os possíveis fatores de risco para a ocorrência dessas doenças. Amostras de sangue foram coletadas para realização de teste sorológico por Imunofluorescência Indireta (RIFI). Questionários epidemiológicos sanitários foram aplicados aos produtores com o objetivo de identificar possíveis fatores de risco. Carrapatos foram coletados, identificados e testados por Reação em Cadeia da Polimerase (PCR) para o diagnóstico da infecção por Anaplasma marginale, Babesia bigemina e Babaesia bovis. O estudo foi conduzido com 861 bovinos, sendo 468 de Petrolina e 393 de Ouricuri. A soroprevalência de A. marginale, B. bigemina e B. bovis em Petrolina foi de 35,0% (164/468), 35,9% (168/468) e 32,3% (151/468), respectivamente; e em Ouricuri foi de 45,5% (179/393), 38,6% (152/393) e 54,9% (216/393), respectivamente. A co-infecção por Anaplasma spp. e Babesia spp. foi observada em 31,6% e 32,1% de amostras de Petrolina e Ouricuri, respectivamente. A detecção de DNA de Babesia spp. por PCR foi possível em 5,8% (8/137) carrapatos, dos quais em 62,5 % (5/8) foi detectada posteriormente infecção por B. bovis, e em 23,3% (32/137) por A. marginale. A presença de carrapatos, o uso de acaricidas, idade, raça, e o município de residência dos animais foram identificados como fatores de risco para TPB pela análise univariável e multivariável. Este estudo permitiu caracterizar os municípios estudados como de instabilidade enzoótica para esses hemoparasitos, e consequentemente, alertar para adoção de medidas adequadas de controle e realização de novos estudos.

Enzootic instability for bovine anaplasmosis on family farms located in southwestern Paraná, Brazil

The objective of this study was to assess the occurence of animals seropositive for Anaplasma marginale in the municipality of Realeza, Paraná State, Brazil. Blood samples were collected from 344 cows on 18 small farms in the municipality of Realeza-PR. The animals'serum samples were forwarded to the Federal University of Fronteira do Sul, in order to investigate the occurrence of anti-A. marginale IgG antibodies by an enzyme-linked immunosorbent assay commercial kit. IgG antibodies to A. marginale were detected in cattle from 77.7% of the farms. To the best author's knowledge, this is the first report of occurrence of A. marginale in cattle in southwestern Paraná. The serological assay showed that 24.4% of the animals were seropositive, thus characterizing the location investigated as an area of enzootic instability for the disease. The family farms located in the municipality of Realeza-PR showed enzootic instability for bovine anaplasmosis. It is necessary to conduct disease monitoring programs in association with preventive measures in order to ensure the sanitary quality of the herds and to reduce economic losses for the farmers. In addition, it is essential to implement educational extension actions that allow farmers to acquire knowledge, attitudes and perceptions regarding the risk factors that contribute towards herd A. marginale-infection.

Novel Babesia and Hepatozoon agents infecting non-volant small mammals in the Brazilian Pantanal, with the first record of the tick Ornithodoros guaporensis in Brazil

Taking into account the diversity of small terrestrial mammals of the Pantanal, the present study aimed to verify the occurrence of infection by Ehrlichia spp., Anaplasma spp., Rickettsia spp., Hepatozoon spp., Babesia spp. and parasitism by ticks in non-volant small mammals collected in the Brazilian Pantanal. Samples of blood, liver and spleen were collected from 64 captured animals, 22 marsupials and 42 rodents. Pathogen detection was performed by the use of genus-specific Polymerase Chain Reaction (PCR) assays. Ticks collected from the animals consisted of Amblyomma sculptum and Amblyomma triste nymphs, and Ornithodoros guaporensis larvae. None of the vertebrate samples (blood, liver, or spleen) yielded detectable DNA of Rickettsia spp. or Ehrlichia spp. The blood of the rodent Hylaeamys megacephalus yielded an Anaplasma sp. genotype (partial 16S rRNA gene) 99% similar to multiple Anaplasma spp. genotypes around the world. The blood of three rodents of the species Calomys callosus were positive for a novel Hepatozoon sp. agent, phylogenetically related (18S rDNA gene) to distinct Hepatozoon genotypes that have been detected in rodents from different parts of the world. One marsupial (Monodelphis domestica) and three rodents (Thrichomys pachyurus) were positive to novel piroplasmid genotypes, phylogenetically (18S rDNA gene) related to Theileria bicornis, Cytauxzoon manul, and Cytauxzoon felis. The present study provides the first molecular detection of Hepatozoon sp. and piroplasmids in small mammals in Brazil. Additionally, we expanded the distribution of O. guaporensis to Brazil, since this tick species was previously known to occur only in Bolivia.

Transplacental transmission of bovine tick-borne pathogens: Frequency, co-infections and fatal neonatal anaplasmosis in a region of enzootic stability in the northeast of Brazil

Bovine tick-borne disease (TBD) constitutes a worldwide group of diseases that result in great losses for dairy and beef cattle. With regard to the epidemiological profile of the diseases, the importance of transplacental transmission is still not very well understood. The aim of this study was to determine the transplacental transmission of TBD agents (Anaplasma marginale, Babesia bovis and B. bigemina) in a herd of dairy cattle that had been naturally infected in an area of enzootic stability in northeastern Brazil. Blood for serology of the three agents was collected from cows within 120 days of gestation and serology, haemogram and nPCR assays were performed after birth. Blood was collected from the calves within 3h of birth, and haemogram and nPCR assays were performed in all animals. Pre-colostrum serology was achieved in 34 animals. The Student's t-test was used to compare the haemogram results between animals that were positive and negative for the haemoparasites. The cows were seropositive for all agents in at least one of the examinations. We detected 15 cases of vertical transmission of A. marginale, 4 of B. bovis and 2 of B. bigemina in the 60 cows. In infected animals, co-infection was detected for A. marginale and B. bovis in 1 of 60 calves, and a triple infection was detected in one other calf. Fatal neonatal anaplasmosis was observed in 1 of 15 calves, in which death occurred within 24h of birth. From the results, we concluded that transplacental transmission of TBD agents occurs, including in cases of co- and triple-infection. Such transplacental transmission can cause neonatal death, increasing the importance of this form of epidemiological transmission and suggesting its role as a cause of undiagnosed neonatal death.

Bovine babesiosis and anaplasmosis complex: diagnosis and evaluation of the risk factors from Bahia, Brazil

Direct diagnoses were made by using - blood smears and nested PCR (nPCR) tests on 309 blood samples from crossbred dairy cattle in the municipality of Ibicaraí, Bahia. From diagnostic blood smear slides, the observed parasitic frequencies were 31.1% for Anaplasma marginale and 20.4% for Babesia sp. From nPCR diagnoses, they were 63% for A. marginale, 34% for Babesia bigemina and 20.4% for Babesia bovis. There were significant differences (P <0.01) between the two diagnostic methods (nPCR and blood smear slides). The compliance obtained from the kappa test was 0.41 and 0.48 for A. marginale and Babesia sp., respectively. The tick samples from the six farms analyzed using nPCR were only positive for A. marginale. Evaluation of the risk factors relating to the presence of ticks and the age of the animals showed that there was a significant association (P <0.01) with the frequency of animals infected with both pathogens. Therefore, under the conditions studied, nPCR proved to be a good tool for diagnosing the agents of the bovine babesiosis and anaplasmosis complex because of its sensitivity and specificity in comparison with blood smears. The municipality of Ibicaraí is an area with endemic prevalence of bovine babesiosis and anaplasmosis confirmed by nPCR and A. marginale is the main agent of the disease.

Detecção sorológica e molecular de Anaplasma marginale em búfalos na Ilha de Marajó, Pará

O objetivo do estudo foi testar a prevalência sorológica e molecular de Anaplasma marginale em búfalos do municipio de Soure, Ilha de Marajó, estado do Pará, Brasil. Para a pesquisa sorologica foram selecionados randomicamente 800 animais e para a pesquisa molecular 50 destes animais foram aleatoriamente escolhidos. Para quantificar a prevalência sorológica utilizou-se o ensaio de imunoadsorção enzimático indireto (iELISA) com antígeno total contendo proteínas de superfície externa e para quantificar a prevalência molecular utilizou-se a reação em cadeia da polimerase (PCR), envolvendo a amplificação de fragmento gênico da proteína de superfície maior 5 (MSP5). A prevalência de animais positivos no ELISA para A. marginale foi de 25% (200/800). Na PCR foi detectada a presença de A. marginale em 2% (1/50) dos animais. Embora apenas um animal tenha sido positivo na PCR, observou-se que o mesmo foi negativo no ELISA. A presença do agente, mesmo em baixa prevalência, mostra que os bubalinos podem funcionar como um importante reservatório desse patógeno para os rebanhos bovinos da região norte do Brasil.

Babesiosis and anaplasmosis in dairy cattle in Northeastern Brazil

The goal of this study was to characterize the epidemiological situation and the factors involved in the prevalence of babesiosis and anaplasmosis in cattle in the dairy basin of Parnaíba, Piauí, Brazil. The study was conducted in 22 farms, and collected blood samples from 202 cattle to study serological, molecular and determination of the packed cell volume (PCV). On the farms were applied surveys involving epidemiological aspects. Seroprevalence rates were: Babesia bigemina 52.5%, B. bovis 68.8%, and Anaplasma marginale 89.1%. Of the samples analyzed, 73.3% were reactive for Babesia spp. and A. marginale, showing co-infection. In PCR, B. bigemina and B. bovis were positive in 52.0% and 33.2% respectively, and A. marginale in 76.2%. Of these, 51.5% amplified DNA of Babesia spp. and A. marginale. The semi-intensive management predominated in 68.0% of the farms studied. The clinical history of babesiosis and anaplasmosis, was reported from 73% of the farms. There was no significant difference (p>0.05) between age groups and for the PCV of positive compared with negative animals. The study indicates that in this region is enzootic instability for babesiosis and enzootic stability for anaplasmosis, reinforcing the fact that in Brazil there are areas of enzootic instability, even in tropical regions of the country. The PCR technique was a valuable tool for the diagnosis of these diseases and may be used to characterize a geographic region.

Molecular detection and identification of hemoparasites in pampas deer (Ozotoceros bezoarticus Linnaeus, 1758) from the Pantanal Brazil

Hemoparasites were surveyed in 60 free-living pampas deer Ozotoceros bezoarticus from the central area of the Pantanal, known as Nhecolândia, State of Mato Grosso do Sul, Brazil, through the analysis of nested PCR assays and nucleotide sequencing. Blood samples were tested for Babesia/Theileria, Anaplasma spp., and Trypanosoma spp. using nPCR assays and sequencing of the 18S rRNA, msp4, ITS, and cathepsin L genes. The identity of each sequence was confirmed by comparison with sequences from GenBank using BLAST software. Forty-six (77%) pampas deer were positive for at least one hemoparasite, according to PCR assays. Co-infection occurred in 13 (22%) animals. Based on the sequencing results, 29 (48%) tested positive for A. marginale. Babesia/Theileria were detected in 23 (38%) samples, and according to the sequencing results 52% (12/23) of the samples were similar to T. cervi, 13% (3/23) were similar to Babesia bovis, and 9% (2/23) were similar to B. bigemina. No samples were amplified with the primers for T. vivax, while 11 (18%) were amplified with the ITS primers for T. evansi. The results showed pampas deer to be co-infected with several hemoparasites, including species that may cause serious disease in cattle. Pampas deer is an endangered species in Brazil, and the consequences of these infections to their health are poorly understood.

Evaluating the effectiveness of an inactivated vaccine from Anaplasma marginale derived from tick cell culture

The protective efficacy of an inactivated vaccine from Anaplasma marginale that was cultured in tick cells (IDE8) for use against bovine anaplasmosis was evaluated. Five calves (Group 1) were inoculated subcutaneously, at 21-day intervals, with three doses of vaccine containing 3 × 10(9) A. marginale initial bodies. Five control calves received saline solution alone (Group 2). Thirty-two days after the final inoculation, all the calves were challenged with approximately 3 × 10(5) erythrocytes infected with A. marginale high-virulence isolate (UFMG2). The Group 1 calves seroconverted 14 days after the second dose of vaccine. After the challenge, all the animals showed patent rickettsemia. There was no significant difference (p > 0.05) between the Group 1 and 2 calves during the incubation period, patency period or convalescence period. All the animals required treatment to prevent death. The results suggest that the inactivated vaccine from A. marginale produced in IDE8 induced seroconversion in calves, but was not effective for preventing anaplasmosis induced by the UFMG2 isolate under the conditions of this experiment.

Transmission and epidemiology of zoonotic protozoal diseases of companion animals

Over 77 million dogs and 93 million cats share our households in the United States. Multiple studies have demonstrated the importance of pets in their owners' physical and mental health. Given the large number of companion animals in the United States and the proximity and bond of these animals with their owners, understanding and preventing the diseases that these companions bring with them are of paramount importance. Zoonotic protozoal parasites, including toxoplasmosis, Chagas' disease, babesiosis, giardiasis, and leishmaniasis, can cause insidious infections, with asymptomatic animals being capable of transmitting disease. Giardia and Toxoplasma gondii, endemic to the United States, have high prevalences in companion animals. Leishmania and Trypanosoma cruzi are found regionally within the United States. These diseases have lower prevalences but are significant sources of human disease globally and are expanding their companion animal distribution. Thankfully, healthy individuals in the United States are protected by intact immune systems and bolstered by good nutrition, sanitation, and hygiene. Immunocompromised individuals, including the growing number of obese and/or diabetic people, are at a much higher risk of developing zoonoses. Awareness of these often neglected diseases in all health communities is important for protecting pets and owners. To provide this awareness, this review is focused on zoonotic protozoal mechanisms of virulence, epidemiology, and the transmission of pathogens of consequence to pet owners in the United States.

Molecular and serological prevalence of Anaplasma marginale in cattle of North Central Morocco

A cross sectional study was conducted to investigate the epidemiological distribution of Anaplasma marginale in North Central Morocco. Blood samples from five provinces of Morocco were collected from apparently healthy cattle (n=668) and simultaneously analyzed by a nested polymerase chain reaction (nPCR) assay and competitive enzyme-linked immunosorbent assay (cELISA). The overall prevalence of A. marginale was 21.9% by nPCR and 16.5% by cELISA. The Kappa coefficient between nPCR and cELISA indicated a modest level of agreement (0.54). The prevalence of A. marginale varied significantly according to the province and the month of sampling. However age, gender and breed did not have a significant effect on the prevalence of this pathogen. The highest prevalence of A. marginale was found in the Gharb, a sub-humid area while the lowest was reported in the Saiss, a semi-arid area. These results indicate that an A. marginale infection are widespread in the country and suggests that either or both techniques are excellent tools for epidemiological studies and control programs.

Bartonella and Babesia infections in cattle and their ticks in Taiwan

Bartonella and Babesia infections and the association with cattle breed and age as well as tick species infesting selected cattle herds in Taiwan were investigated. Blood samples were collected from 518 dairy cows and 59 beef cattle on 14 farms and 415 ticks were collected from these animals or in a field. Bartonella and Babesia species were isolated and/or detected in the cattle blood samples and from a selected subset (n=254) of the ticks either by culture or DNA extraction, PCR testing and DNA sequence analysis. Bartonella bovis was isolated from a dairy cow and was detected in 25 (42.4%) beef cattle and 40 (15.7%) tick DNA samples. This is the first isolation of B. bovis from cattle in Asia and detection of a wide variety of Bartonella species in Rhipicephalus microplus. Babesia spp. were detected only on one farm from dairy cows either infected by Babesia bovis (n=10, 1.9%) or B. bigemina (n=3, 0.6%).

Epidemiology of bovine anaplasmosis in dairy herds from Costa Rica

Bovine anaplasmosis is endemic and occurs in almost all areas of livestock production of Costa Rica. The aim of this study was to determine the seroprevalence and risk factors of anaplasmosis in dairy farms of Costa Rica by the recombinant truncated MSP-5 (rMSP-5) enzyme-linked immunosorbent assay (ELISA). Serum samples were obtained from 733 cattle from 20 commercial dairy herds of Costa Rica. The overall seroprevalence was 37.2% and herd seroprevalence ranged from 20.0 to 72.0%. The age-specific seroprevalence was 49.3% in young and 33.4% in adult animals. The main risk factors associated with seroprevalence were season of occurrence of clinical cases (rainy season) (OR=22.8), presence of tabanids (OR=9.5) and stable flies (OR=6.2), stable flies control measures (OR=3.2), non-use of ear tattoos (OR=2.8), interval of veterinary visit (≤ 60 days) (OR=2.7), altitude of the farms (<800 masl) (OR=2.6) and age (<2 years) (OR=1.8). The results indicated that exposure of cattle to Anaplasma marginale is common in dairy herds of Costa Rica and endemic instability situation probably is due to inadequate vector control.

Detection of antibodies against Babesia bovis and Babesia bigemina in calves from the region of Araguaína, State of Tocantins, Brazil

The aim of this study was to determine the seroprevalence of antibodies against B. bovis and B. bigemina in calves from the region of Araguaína, State of Tocantins, Brazil. In this research we used sera obtained from 506 calves, from both genders and of 8 to 24 months old, to detect antibodies by indirect Enzyme-Linked Immunosorbent Assay (ELISA-test). Statistical analysis of the data was performed using the Chi-square (χ2) test with Yates correction. The seroprevalence obtained was 90.5 and 91.7% for B. bigemina and B. bovis, respectively, characterizing the region as an area of enzootic stability for the species analyzed. The seroprevalence to B. bovis showed higher positivity among calves 19-24 months old.

IgG and IgG2 antibodies from cattle naturally infected with Anaplasma marginale recognize the recombinant vaccine candidate antigens VirB9, VirB10, and elongation factor-Tu

Anaplasma marginale is an important vector-borne rickettsia of ruminants in tropical and subtropical regions of the world. Immunization with purified outer membranes of this organism induces protection against acute anaplasmosis. Previous studies, with proteomic and genomic approach identified 21 proteins within the outer membrane immunogen in addition to previously characterized major surface protein1a-5 (MSP1a-5). Among the newly described proteins were VirB9, VirB10, and elongation factor-Tu (EF-Tu). VirB9, VirB10 are considered part of the type IV secretion system (TFSS), which mediates secretion or cell-to-cell transfer of macromolecules, proteins, or DNA-protein complexes in Gram-negative bacteria. EF-Tu can be located in the bacterial surface, mediating bacterial attachment to host cells, or in the bacterial cytoplasm for protein synthesis. However, the roles of VirB9, VirB10, and TFSS in A. marginale have not been defined. VirB9, VirB10, and EF-Tu have not been explored as vaccine antigens. In this study, we demonstrate that sera of cattle infected with A. marginale, with homologous or heterologous isolates recognize recombinant VirB9, VirB10, and EF-Tu. IgG2 from naturally infected cattle also reacts with these proteins. Recognition of epitopes by total IgG and by IgG2 from infected cattle with A. marginale support the inclusion of these proteins in recombinant vaccines against this rickettsia.

Frequency of antibodies to Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax and Borrelia burdgorferi in cattle from the northeastern region of the state of Pará, Brazil

Babesiosis, anaplasmosis, and trypanosomosis are relevant diseases, potentially causing morbidity in cattle, leading to economic losses. Borreliosis is import as a potential zoonosis. The objective of this study was to determine, by indirect enzyme-linked immunosorbent assay (ELISA), the frequency of seropositive cattle to Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma vivax and Borrelia burgdorferi in cattle from the Northeastern region of Pará, Brazil. Sera samples from 246 female adult cattle from municipalities of Castanhal and São Miguel do Guamá were used. Crude antigens ELISAs were used to detect antibodies to all agents, except to A. marginale, to which an indirect ELISA with recombinant major surface 1a protein (MSP1a) antigen was used. Overall frequencies of seropositive animals were: B. bigemina - 99.2%; B. bovis - 98.8%; A. marginale - 68.3%; T. vivax - 93.1% and B. burgdorferi - 54.9%. The frequencies of seropositive cattle to B. bovis and B. bigemina suggest a high rate of transmission of these organisms by tick in the studied region, which can be classified as enzootically stable to these hemoprotozoans. The low frequency of seropositive cattle to A. marginale may be attributed to a lower sensitivity of the recombinant antigen ELISA utilized or a distinct rate of inoculation of this rickettsia by ticks, as compared with Babesia sp. transmission. The high frequency of seropositive cattle to T. vivax indicates that this hemoprotozoan is prevalent in herds from the Northeastern region of Pará. The rate of animal that showed homologues antibodies to B. burgdorferi indicates the presence of the tickborne spirochaetal agent in the cattle population in the studied region.

Detection of Babesia bigemina in cattle of different genetic groups and in Rhipicephalus (Boophilus) microplus tick

Babesia bigemina infections were investigated in four genetic groups of beef cattle and in Rhipicephalus (Boophilus) microplus engorged female ticks. Blood samples and engorged female ticks were collected from 15 cows and 15 calves from each of the following genetic groups: Nelore, Angus x Nelore, Canchim x Nelore, and Simmental x Nelore. Microscopic examination of blood smears and tick hemolymph revealed that merozoites of B. bigemina (6/60) as well as kinetes of Babesia spp. (9/549) were only detected in samples (blood and ticks, respectively) originated from calves. PCR-based methods using primers for specific detection of B. bigemina revealed 100% infection in both calves and cows, regardless the genetic group. Tick infection was detected by nested-PCR amplifications showing that the frequency of B. bigemina was higher (P<0.01) in female ticks collected from calves (134/549) than in those collected from cows (52/553). The frequency of B. bigemina was similar in ticks collected from animals, either cows or calves, of the four genetic groups (P>0.05).

Comparison between indirect enzyme-linked immunosorbent assays for Anaplasma marginale antibodies with recombinant major surface protein 5 and initial body antigens

Indirect enzyme-linked immunosorbent assays (ELISAs) based on recombinant major surface protein 5 (rMSP5) and initial body (IB) antigens from a Brazilian isolate of Anaplasma marginale were developed to detect antibodies against this rickettsia in cattle. Both tests showed the same sensitivity (98.2%) and specificities (100% for rMSP5 and 93.8% for IB ELISA) which did not differ statistically. No cross-reactions were detected with Babesia bigemina antibodies, but 5 (rMSP5 ELISA) to 15% (IB ELISA) of cross-reactions were detected with B. bovis antibodies. However, such difference was not statistically significant. Prevalences of seropositive crossbred beef cattle raised extensively in Miranda county, state of Mato Grosso do Sul, Brazil, were 78.1% by rMSP5 ELISA and 79.7% by IB ELISA. In the analysis of sera from dairy calves naturally-infected with A. marginale, the dynamics of antibody production was very similar between both tests, with maternal antibodies reaching the lowest levels at 15-30 days, followed by an increase in the mean optical densities in both ELISAs, suggesting the development of active immunity against A. marginale. Results showed that all calves were seropositive by one-year old, characterizing a situation of enzootic stability. The similar performances of the ELISAs suggest that both tests can be used in epidemiological surveys for detection of antibodies to A. marginale in cattle.

Tristeza parasitária bovina na região sul do Rio Grande do Sul: estudo retrospectivo de 1978-2005

Foi realizado um estudo retrospectivo dos casos de tristeza parasitária bovina (TPB) ocorridos no sul do Rio Grande do Sul, área de influência do Laboratório Regional de Diagnóstico (LRD) da Faculdade de Veterinária da Universidade Federal de Pelotas entre 1978 e 2005. De um total de 4.884 materiais de bovinos provenientes de necropsias realizadas e órgãos ou sangue enviados ao laboratório 231 (4,7%) tiveram o diagnóstico de TPB. Desses 231 surtos foram resgatados os dados de 221 diagnósticos dos quais 91 (41,1%) foram causados por Babesia bovis, 11 (4,9%) por Babesia bigemina, e 65 (29,41%) por Anaplasma marginale. Em outros 33 (14,93%) surtos de babesiose não foi informada a espécie de Babesia e em 21 (9,5%) surtos foi detectada infecção mista por Babesia sp e A. marginale. Os índices gerais médios de morbidade, mortalidade e letalidade, resgatados em 149 dos 221 surtos da doença, foram de 11,17%, 6,81% e 70,04%, respectivamente. Verificou-se que, na região estudada, a maioria dos surtos ocorre durante os meses de verão e outono, e que os animais com um a três anos de idade são os mais afetados. Os sinais clínicos nos surtos caracterizaram-se por apatia, orelhas caídas, debilidade, febre, anorexia e emagrecimento. Os valores de hematócrito eram baixos. Hemoglobinúria foi frequentemente observada nos casos de babesiose. Sinais neurológicos estavam presentes nos casos de babesiose por B. bovis e se caracterizaram por transtornos da locomoção, tremores musculares, agressividade e quedas com movimentos de pedalagem. As lesões macroscópicas principais relatadas nos casos de babesiose foram esplenomegalia, hepatomegalia, fígado amarelo, hemoglobinúria, icterícia, hemorragias cardíacas e bile espessa. Congestão do córtex cerebral foi relatada nos casos de babesiose por B. bovis. Nesta região, com população de bovinos de aproximadamente 2.630.000 cabeças as perdas anuais por morte de bovinos pela enfermidade podem ser estimadas em 6.220 cabeças por ano representando um prejuízo econômico anual aproximado de R$3.732.000,00 evidenciando a necessidade de medidas preventivas que evitem a exposição de animais desprote-gidos aos agentes da TPB.

The development of an enzyme-linked immunosorbent assay for Trypanosoma vivax antibodies and its use in epidemiological surveys

There are data indicating that the distribution of Trypanosoma vivax in the Brazilian territory is expanding with potential to reach other areas, where the vectors are present. The detection of anti-trypanosomal antibodies in serum provides important information of the trypanosomal status in cattle herds. For this reason, an enzyme-linked immunosorbent assay (Tv-ELISA-Ab) with crude antigen from one Brazilian isolate of T. vivax was developed and evaluated. The sensitivity and specificity were respectively 97.6 and 96.9%. In the evaluation of cross-reactions, three calves inoculated with T. evansi trypimastigotes blood forms showed optical densities (OD) under the cut-off during the whole experimental period, except one at 45 days post-inoculation. With relation to Babesia bovis, B. bigemina, and Anaplasma marginale, which are endemic hemoparasites in the studied area, the cross-reactions were shown to be 5.7, 5.3, and 1.1%, respectively. The first serological survey of Pantanal and state of Pará showed that T. vivax is widespread, although regions within both areas had significantly different prevalences. Therefore, this Tv-ELISA-Ab may be a more appropriate test for epidemiological studies in developing countries because the diagnostic laboratories in most countries may be able to perform an ELISA, which is not true for polymerase chain reaction.