Piroplasms of domestic animals in the Macedonia region of Greece. 1. Serological cross-reactions

Seroprevalence and risk factors of tropical theileriosis in smallholder asymptomatic large ruminants in Egypt

Knowledge of the prevalence and epidemiological determinants of tropical theileriosis in large ruminants, particularly in the asymptomatic carrier, is crucial for designing and implementing effective host-specific control measures. This study aimed to estimate the seroprevalence of tropical theileriosis in asymptomatic cattle and water buffaloes and identify the potential risk factors of theileriosis in large ruminants raised under smallholder-production system in Egypt. A cross-sectional study was conducted in five districts of the Sharkia governorate from March 2019 to February 2020. In total, 350 serum samples were collected from cattle and water buffaloes under smallholder-production system and tested for Theileria annulata antibodies using the indirect antibody fluorescence test (IFAT). Data on species, host characteristics, presence of ticks, season, and districts were collected at sampling using a questionnaire. A multivariable mixed-effects logistic regression model was built to determine the potential risk factors associated with T. annulate seropositivity of the animals. The overall apparent seroprevalence of T. annulata in 350 tested animals was 70%. In the univariable analyses, cattle compared to buffaloes, younger animals compared to older ones, animals with ticks on their bodies, and warmer seasons were all associated with a higher likelihood of seropositive results in the study population while sex of the animals was not associated with seropositivity. The final multivariable model showed that animals with ticks on their bodies had 3.5× higher odds of seropositivity than those with no ticks (P < 0.001), and warmer seasons were associated with the higher odds of infection compared to winter (P = 0.003). The high seroprevalence of tropical theileriosis in the study region indicates that the disease is endemic among smallholders of large ruminants. The identified risk factors of T. annulata-seropositivity in asymptomatic carrier animals provides evidence-based guidance for adopting effective intervention measures.

Molecular characterization and phylogenetic study of Theileria sp. parasites detected in cattle from the Moscow region of Russia

Theileriae are obligate intracellular protozoan parasites which are transmitted by ixodid ticks and infect both wild and domestic ruminants worldwide. Theileriosis causes significant economic losses to the livestock industry in many countries due to the high morbidity and mortality in cattle herds. In Russia, information concerning prevalence of Theileria spp. in cattle is very limited. This study reports on molecular characterization and phylogenetic analysis of Theileria spp. parasites detected in cattle from the Moscow region of Russia. Phylogenetic analysis based on the full length 18S rRNA gene revealed that the Russian Theileria parasites belong to the Theileria orientalis / Theileria buffeli / Theileria sergenti group and share a common genotype with T. buffeli Marula from Kenya, T. buffeli isolates from Japan and South Korea, T. orientalis isolate from Australia and T. sergenti isolate from Japan, which belong to the pathogenic Chitose genotype.

Sensitivity and specificity of piroplasm indirect fluorescent antibody test and PCR for Theileria annulata infection in clinically asymptomatic large ruminants using Bayesian latent class analysis

There is limited information about the accuracy of molecular and serological diagnostic assays for tropical theileriosis in asymptomatic carrier large ruminants. This study has estimated the sensitivity (Se) and specificity (Sp) of PCR and an indirect fluorescent antibody test (IFAT) in the diagnosis of tropical theileriosis in cattle and buffaloes via a Bayesian latent class analysis (BLCA) framework. Blood samples were collected from 70 cattle and water buffaloes (Bubalus bubalis) raised under a smallholder production system in different Egyptian localities. T. annulata infection status was detected by PCR, and IFAT and the test results were subjected to BLCA without assuming the existence of a reference test. Our findings showed that the performance of PCR was superior to that of IFAT. PCR showed a higher Se [0.83 (95% PCI: 0.63-0.98)] in comparison to IFAT [0.72 (95% PCI: 0.68-0.75)]. Similarly, PCR showed a higher Sp [0.95 (95% PCI: 0.77-1.00)] than IFAT [0.82 (95% PCI: 0.80-0.84)]. Se and Sp of the two tests did not differ by species implying that the diagnostics' performance for T. annulata infection in bovines is the same regardless of the species under consideration. In conclusion, PCR outperforms IFAT in the detection of T. annulata infection and can thus be applied to routine control of tropical theileriosis in endemic situations where cattle and buffaloes are kept under traditional smallholder production systems.

Clinical Pathology, Immunopathology and Advanced Vaccine Technology in Bovine Theileriosis: A Review

Theileriosis is a blood piroplasmic disease that adversely affects the livestock industry, especially in tropical and sub-tropical countries. It is caused by haemoprotozoan of the Theileria genus, transmitted by hard ticks and which possesses a complex life cycle. The clinical course of the disease ranges from benign to lethal, but subclinical infections can occur depending on the infecting Theileria species. The main clinical and clinicopathological manifestations of acute disease include fever, lymphadenopathy, anorexia and severe loss of condition, conjunctivitis, and pale mucous membranes that are associated with Theileria-induced immune-mediated haemolytic anaemia and/or non-regenerative anaemia. Additionally, jaundice, increases in hepatic enzymes, and variable leukocyte count changes are seen. Theileria annulata and Theileria parva induce an incomplete transformation of lymphoid and myeloid cell lineages, and these cells possess certain phenotypes of cancer cells. Pathogenic genotypes of Theileria orientalis have been recently associated with severe production losses in Southeast Asia and some parts of Europe. The infection and treatment method (ITM) is currently used in the control and prevention of T. parva infection, and recombinant vaccines are still under evaluation. The use of gene gun immunization against T. parva infection has been recently evaluated. This review, therefore, provides an overview of the clinicopathological and immunopathological profiles of Theileria-infected cattle and focus on DNA vaccines consisting of plasmid DNA with genes of interest, molecular adjuvants, and chitosan as the most promising next-generation vaccine against bovine theileriosis.

Infection with Babesia canis in dogs in the Algiers region: Parasitological and serological study

Background and Aim:

Canine babesiosis is a vector-borne disease transmitted by ticks of the Ixodidae family. The effects of infection in dogs can range from the subclinical to the severe lethal form. This study aimed to make an original contribution to the knowledge of circulating species of Babesia spp. in dogs in the region of Algiers as well as mechanisms and risk factors for their transmission.

Materials and Methods:

An epidemiological study was carried out on 189 blood samples taken from dogs from April 2015 to January 2016. The samples taken underwent parasitological by Giemsa-stained blood smear and serological analyzes by indirect fluorescent antibody test (IFAT). The ticks were looked on all the dogs taken.

Results:

Giemsa-stained blood smears revealed the presence of two groups of parasites of the genus Babesia: Large Babesia (3/25, 12%) and small Babesia (22/25, 88%). The IFAT at a dilution of 1/32 showed an overall seroprevalence with Babesia canis of 17.98% (95% confidence interval 11.53-22.46). The distribution of the antibody titers for the positive samples showed that of the 34 positive sera with a titer ≥1/32, 28 sera remained positive at a dilution of 1/64 (14.81%), 22 at a dilution of 1/128 (11.64%) and 15 sera remained positive at a dilution of 1/256 (7.93%). Although seroprevalence varied according to canine population (20% and 19.49% in pet dogs and canine pound dogs, respectively, and 6.66-0% in farm dogs and hunting dogs, respectively), statistical analysis showed no significant differences between populations. The antibody titers obtained after several dilutions showed that 22 canine pound dog sera remained positive at a dilution of 1/128 compared to pet dogs and farm dogs which ceased to be positive at the dilution of 1/64. The comparison between the two diagnostic methods showed a strong agreement between the parasitological examination by blood smear and the serological method by IFAT. However, IFAT was much more sensitive. The analysis of risk factors, which may influence B. canis seroprevalence, has shown the influence of age, tick presence, and season. Finally, of the 242 ticks collected from a total of 59 dogs, only one tick species was identified , Rhipicephalus sanguineus.

Conclusion:

This study indicates a frequent circulation of species of Babesia in the dog in the Algiers region and R. sanguineus was the only tick identified.

Endemic instability of ovine babesiosis in Turkey: A country-wide sero-epidemiological study

Ovine babesiosis is an endemic tick-borne disease of small ruminants in the Middle East, European, and some African and Asian countries, including Turkey. This study assessed whether the endemic status of this disease was stable or instable, which is important for disease control efforts. For this aim, 4115 sheep blood samples were collected from 81 cities in the seven geographical regions of Turkey. The diagnosis of Babesia ovis was made using microscopic and serological techniques. Thin blood smears were prepared from anticoagulated venous blood. Serum samples were screened for specific antibodies using an enzyme-linked immunosorbent assay (ELISA) and indirect fluorescent antibody test (IFAT). Recombinant Babesia ovis secreted antigen 1 (rBoSA1) was used in the ELISA. The antigen slides used in the IFAT were prepared from the B. ovis-infected blood at a high level of parasitemia (5 %). The animals were divided into three groups according to their age: group I (one to six months), group II (6-12 months), and group III (older than one year). The endemic status of B. ovis was determined according to the inoculation rate (h value) calculations. Babesia spp. merozoites were observed in 40 (0.97 %) of the slides. Seropositivity rates were 29.89 % (1230/4115) and 49.16 % (2023/4115) by the ELISA and IFAT, respectively. According to the IFAT results, 31.7 %, 33.6 %, and 52.8 % of the animals were seropositive in groups I, II, and III, respectively. The inoculation rates of the animals indicated that the endemic status of ovine babesiosis was mostly instable throughout the country. Endemic stability was found only in group I from four regions (Central Anatolia, Eastern Anatolia, Aegean, and Mediterranean). Based on these results, the risk of clinical infection due to tick infestation was high when the maternal immunity and non-specific age resistance weakens or disappears. Thus, vaccination is needed to protect sheep against B. ovis infections in Turkey.

An appraisal of oriental theileriosis and the Theileria orientalis complex, with an emphasis on diagnosis and genetic characterisation

Oriental theileriosis, a tick-borne disease of bovids caused by members of the Theileria orientalis complex, has a worldwide distribution. Globally, at least 11 distinct genotypes of T. orientalis complex, including type 1 (chitose), type 2 (ikeda), type 3 (buffeli), types 4 to 8, and N1-N3, have been described based on the sequence of the major piroplasm surface protein (MPSP) gene. Of these 11 genotypes, mainly ikeda and chitose are known to be pathogenic and cause considerable morbidity (including high fever, anaemia, jaundice and abortion), production losses and/or mortality in cattle. Mixed infections with two or more genotypes of T. orientalis is common, but do not always lead to a clinical disease, posing challenges in the diagnosis of asymptomatic or subclinical forms of oriental theileriosis. The diagnosis of oriental theileriosis is usually based on clinical signs, the detection of piroplasms of T. orientalis in blood smears, and/or the use of serological or molecular techniques. This paper reviews current methods used for the diagnosis of T. orientalis infections and the genetic characterisation of members of the T. orientalis complex, and proposes that advanced genomic tools should be established for investigations of these and related haemoparasites.

Important hemoprotozoan diseases of livestock: Challenges in current diagnostics and therapeutics: An update

Hemoprotozoan parasites pose a serious threat to the livestock population in terms of mortality, reduced milk yield and lowered draft power. Diagnosis of these diseases often poses a challenging task. Needless to say that impact of disease in health and productivity is huge though a fair economic assessment on the quantum of economic loss associated is yet to be worked out from India. The diagnosis of hemoprotozoan infections largely depends on various laboratory-based diagnostic methods as the clinical manifestations are often inconspicuous and non-specific. Traditional diagnostic methods rely on microscopical demonstration of infective stages in blood or tissue fluids. However, it is laborious, lesser sensitive, and cannot differentiate between morphologically similar organisms. Recent development in the technologies has opened new avenues for improvement in the accurate diagnosis of parasitic infections. Serological tests are simple, fast but lack specificity. With advent of molecular techniques, as DNA hybridization assays, polymerase chain reaction and its modifications ensure the detection of infection in the latent phase of the disease. Nucleic acid-based assays are highly sensitive, free from immunocompetence and can differentiate between morphologically similar parasites. With the advent of newer diagnostics complemented with traditional ones will be of huge help for targeted selective treatment with better chemotherapeutic agents.

A review of Theileria diagnostics and epidemiology

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Serological and molecular assays exist for most economic important Theileria species.

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Molecular assays are constantly being improved with regard to sensitivity and specificity.

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The concept of what constitute a Theileria species impacts on accurate diagnostics.

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Analytical specificity of molecular assays are >800 000 parasites/L blood.

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Parasitemia ranges may determine practical limits of detection.

An extensive range of serological and molecular diagnostic assays exist for most of the economically important Theileira species such as T. annulata, T. equi, T. lestoquardi, T. parva, T. uilenbergi and other more benign species. Diagnostics of Theileria is considered with regard to sensitivity and specificity of current molecular and serological assays and their use in epidemiology. In the case of serological assays, cross-reactivity of genetically closely related species reduces the use of the gold standard indirect fluorescent antibody test (IFAT). Development of antigen-specific assays does not necessarily address this problem, since closely related species will potentially have similar antigens. Even so, serological assays remain an important line of enquiry in epidemiological surveys. Molecular based assays have exploded in the last decade with significant improvements in sensitivity and specificity. In this review, the current interpretation of what constitute a species in Theileria and its impact on accurate molecular diagnostics is considered. Most molecular assays based on conventional or real-time PCR technology have proven to be on standard with regard to analytical sensitivity. However, consideration of the limits of detection in regard to total blood volume of an animal indicates that most assays may only detect >400,000 parasites/L blood. Even so, natural parasitaemia distribution in carrier-state animals seems to be above this limit of detection, suggesting that most molecular assays should be able to detect the majority of infected individuals under endemic conditions. The potential for false-negative results can, however, only be assessed within the biological context of the parasite within its vertebrate host, i.e. parasitaemia range in the carrier-state that will support infection of the vector and subsequent transmission.

A sero-epidemiological survey of Chinese Babesia motasi for small ruminants in China

Babesia motasi BQ1 (Lintan) was first isolated from Haemaphysalis qinghaiensis collected in Gannan Tibet Autonomous Region, Gansu province in April 2000. In this study, a total of 3,204 serum samples from small ruminants in 22 provinces located in different districts of China were tested for antibodies against merozoite antigens from cultured B. motasi BQ1 (Lintan) by enzyme-linked immunosorbent assay. This method can survey the prevalence of low-pathogenic Chinese B. motasi. The results of this survey indicated that the average positive rate was 43.5 %, and the positive rates of investigated provinces were significantly different from 6.1 to 91.0 %, and the infections had been found in all provinces investigated. Our data provide large important information regarding the current sero-prevalence of B. motasi in China.

The use of different diagnostic tools for Babesia and Theileria parasites in cattle in Menofia, Egypt

Bovine piroplasmosis is caused by tick-borne hemoprotozoans of the genera Babesia and Theileria and is the most prevalent in tropical and subtropical countries, causing a major economic impact worldwide. In the current study, a total of 405 cattle of different ages, sexes, and breeds were randomly sampled for surveying and diagnosis of babesiosis and theileriosis using three methods: direct microscopy (blood smears), indirect fluorescent antibody test (IFAT) and polymerase chain reaction (PCR). Giemsa-stained blood smears revealed that, out of 405 examined cattle, 33 (8.15 %) were infected with Babesia sp. and 65 (16.05 %) with Theileria sp. (total number of infected cattle was 98). Mixed infection was seen in 11 (2.72 %) animals. Moreover, application of the three diagnostic assays on 158 randomly sampled cattle indicated that 17 (10.76 %) and 33 (20.89 %) were positive for Babesia and Theileria spp. by the direct smear technique, 25 (15.82 %) and 33 (20.89 %) by IFAT (fluorescence was greenish yellow for Babesia and yellowish for Theileria), and 20 (12.66 %) and 38 (24.05 %) by PCR. Using primers specific for Babesia and Theileria spp., we found that diagnostic bands appeared at ~350 and ~370 bp, respectively indicating the presence of these piroplasms. Statistically, there was a non-significant difference of the positivity in response to the three techniques; thus, any of these methods can be described as useful for diagnosing blood parasites in both domesticated animals and birds. On the basis of the obtained results, it could be concluded that direct microscopy can be used in acute infections, whereas IFAT and PCR are useful in chronicity.

Comparison of diagnostic methods to detect piroplasms in asymptomatic cattle

This study was carried out to compare different diagnostic techniques to reveal the presence of piroplasms in asymptomatic cattle kept at pasture. Nineteen blood samples were collected from animals of two different areas of Emilia Romagna Region of Italy and processed for microscopic observation, PCR, serological test (IFAT) for Babesia bovis and Babesia bigemina antibodies and in vitro cultivation. The cultures were performed on both bovine and ovine erythrocytes. Seventeen blood smears (89%) were positive for piroplasms, while PCR was positive on 18 samples (95%). DNA sequencing of 18S rRNA identified the piroplasms as Theileria spp. In vitro cultures were successful for 6 samples (32%) cultured on bovine blood and subsequent identified these as Babesia major by PCR. On IFAT analyses of 16 samples, 36.8% resulted positive for B. bovis and 31.6% positive for B. bigemina. These results show, in the same animals, the co-infection with Babesia spp. and Theileria spp.; the detection of B. major was possible only using the in vitro cultures.

A survey for piroplasmids in horses and Bactrian camels in North-Eastern Mongolia

Equine piroplasmosis caused by Babesia caballi and Theileria equi is widespread in Asia. The presence of these haemozoans in Mongolia was previously confirmed in domestic as well as in reintroduced Przewalski horses in which they cause significant pathology. The data on occurrence of piroplasms from Bactrian camels in Asia is lacking. A total of 192 horses, 70 Bactrian camels, and additional 16 shepherd dogs from the Hentiy province were included in our study. No clinical signs typical for piroplasmid infection were observed during the field survey. Microscopic examination revealed the presence of T. equi in blood smears from 67% of examined horses, with camels and dogs being negative. A two step PCR approach was used to detect piroplasms in peripheral blood. In the first "catch all" PCR reaction, amplification of the 496 bp-long fragment of the SSU rRNA gene enabled the detection of Babesia and Theileria spp. Second round multiplex PCR reaction used for species discrimination allowed the amplification of T. equi- and B. caballi-specific 340 bp and 650 bp-long regions of the SSU rRNA, respectively. This assay detected T. equi in 92.7% of horses, while the infections with B. caballi and dual infections were rare. In both PCR setups, camels and dogs were negative indicating that in the studied region, these hosts do not share piroplasms with horses.

Development and evaluation of two nested PCR assays for the detection of Babesia bovis from cattle blood

We developed and evaluated two nested polymerase chain reaction (nPCR) assays for the diagnosis of Babesia bovis infection in cattle based on two membrane protein genes from B. bovis, BBOV_IV005650 (BV5650) and BBO_IV008970 (BV8970). The specificities and sensitivities of the tests were compared with B. bovis Rhoptery associated protein 1 gene (RAP-1) nPCR. The specificity of the tests was 100% for B. bovis DNA. The sensitivities of nPCR to B. bovis from the in vitro cultured parasites were as low as 10(-8)%, 10(-6)%, and 10(-7)% parasitemia for BV5650, BV8970, and RAP-1 nPCR, respectively. The nPCR detected as little as 1 fg genomic DNA per test for BV5650 and 100fg per test for both BV8970 and RAP-1 genes. For field applications, the sensitivity was evaluated to a total of 165 field samples from Ghana, Mongolia, Brazil and Japan. The nPCR assay of BV5650 was the most sensitive for the detection of B. bovis from the field samples. The BV5650 nPCR assay provides a good diagnostic tool for laboratory diagnostic assessment of B. bovis infection in cattle worldwide.

Merozoite proteins from Babesia sp. BQ1 (Lintan) as potential antigens for serodiagnosis by ELISA

Babesia sp. BQ1 (Lintan) is a Babesia isolated from sheep infested with Haemaphysalis qinghaiensis in China, and is closely related to B. motasi based on the 18S rRNA gene sequence. In the present study, an ELISA was developed with merozoite antigens of Babesia sp. BQ1 (Lintan) (BQMA) purified from in vitro culture. When the positive threshold was chosen as 30% of the antibodies rate, evaluated with 198 negative sera, the specificity was 95.5%. Except for Babesia sp. Tianzhu, there was no cross-reaction between BQMA and positive sera from Babesia sp. BQ1 (Ningxian)-, Babesia sp. Hebei-, Babesia sp. Xinjiang-, Theileria luwenshuni-, T. uilenbergi-, or Anaplasma ovis-infected sheep, which are the dominant haemoparasites of small ruminants in China. Specific antibodies against Babesia sp. BQ1 (Lintan) were produced 1 or 2 weeks post-infection and a high level of antibodies persisted for more than 8 months in experimentally infected sheep. This ELISA was tested on 974 sera collected from field-grazing sheep in 3 counties of Gansu province, northwestern China to evaluate the seroprevalence of Babesia sp. BQ1 (Lintan) infection and the average positive rate was 66.84%. The feasibility of increasing the specificity of this BQMA-based ELISA, by using some BQMA antigens for serodiagnosis is discussed.

Diagnostic real-time PCR assay for the quantitative detection of Theileria equi from equine blood samples

We developed a TaqMan real-time polymerase chain reaction (PCR) assay for the quantitative detection of Theileria equi from the in vitro-cultured parasite and field blood samples collected from horses living in Ghana and Brazil. The detection limit for the assay was determined to be 1.5 parasites/microl per sample, and the quantitative capacity was demonstrated using the in vitro-cultured parasite. For field applications, the real-time PCR assay was compared to a previously established nested PCR assay used as the gold standard for the real-time PCR assay. Of 65 field blood samples, 46 samples were T. equi-positive in the nested PCR assay, while the real-time PCR assay also detected the parasite in all 46 of the nested PCR-positive samples but did not detect T. equi in the remaining 19 negative blood samples. This quantitative real-time PCR assay provides a valuable tool for fast laboratory diagnostic assessment of T. equi infection in horses.

Prevalence of Theileriosis in Red Hartebeest (Alcelaphus buselaphus caama) in Namibia

A total of 23 blood samples from Red Hartebeest and 28 ticks of the subspecies Rhipicephalus evertsi were collected in Namibia during the summer 2003. For a Piroplasmida species, Theileria sp 95.7% of blood and 50.0% of tick samples (all R. e. mimeticus, none of R. e. evertsi were carrying the pathogen) were PCR positive. Sequencing showed infection from a re-emerging mild species of Theileria phylogenetically different from other African Theileria species such as Theileria parva, T. buffeli, T. annulata, T. taurotragi or T. mutans.

Epidemiological study of the prevalence of Babesia divergens in a veterinary practice in the mid-east of France

To assess the epidemiology of Babesia divergens in a veterinary practice based in the mid-east of France ("Monts du Lyonnais"), blood was collected from 254 cattle belonging to 24 herds. To assess the dynamics of the carrier state, six carriers were identified, treated with flumethrin and sampled once every 3 weeks during 6 months. Two different DNA extraction methods were compared. Each sample was tested for the presence of parasites using a PCR-RFLP test based on the 18S rRNA gene. The sensitivity of the test was equivalent to a parasitaemia as low as 10(-5)% (in "Filter Paper" samples) and 10(-6)% in 1 ml blood (extracted using "Matrix"). With the latter method, the rate of detection diminishes in the low parasitaemia range but could probably be improved. This test proved to be very useful in the detection of B. divergens carriers. Serology using IFAT showed 7% of the cattle seropositive, which is suggestive of a disease situation with a low clinical risk level. Analysis of the PCR results suggests a 20% prevalence rate of carriers in the cattle population. The use of the mean parasitaemia is proposed to serve as a babesiosis clinical risk indicator. This approach could also be used in other babesia infections provided the lowest detectable parasitaemia level (threshold level) could be resolved for each parasite species.

Reverse line blot hybridization used to identify hemoprotozoa in Minorcan cattle

Piroplasmosis, a tick-borne protozoal disease, is an important disease affecting domestic and wild animals. We performed PCR-based reverse line blot hybridization (RLB) assays on blood samples obtained from 133 cattle exposed to ticks in field conditions in Minorca (Balearic Islands, Spain) in three different seasons. The oligonucleotides used were those for Theileria annulata, T. buffeli, T. taurotragi, T. velifera, Babesia bigemina, B. bovis, B. divergens, and B. major. The RLB technique allowed the simultaneous identification of T. annulata, T. buffeli, B. bigemina, and B. bovis as the piroplasms present in cattle in Minorca. Of the 133 animals, only 4 were not infected by any of the studied parasites. The results indicated endemic piroplasm infection in cattle in Minorca; especially important was the presence of T. annulata. The RLB was highly sensitive and allowed the simultaneous detection and identification of the Theileria and Babesia species in carrier cattle, which cannot be achieved by classical identification methods.

Bovine piroplasms in Minorca (Balearic Islands, Spain): a comparison of PCR-based and light microscopy detection

The present study provides the first epidemiological data regarding infection by Theileria and Babesia piroplasms in cattle in Minorca. More than 94% of the studied animals were positive for the presence of Theileria sp., and of those, 41.3% were positive for the presence of Theileria annulata. These results indicate that the prevalence of Mediterranean theileriosis caused by T. annulata is very high in Minorcan dairy farms and that other Theileria sp. are also present in the area. The prevalence of infection was similar throughout the study indicating an endemic situation in this island. The use of PCR resulted in significantly higher efficacy of detection of Theileria sp. compared to microscopical observation (MO) of blood smears and allowed the specific discrimination between pathogenic and non-pathogenic theilerias which cannot be accomplished by traditional diagnosis by MO. Babesia infection in the area was mainly due to Babesia bigemina (6.0% of the studied animals were infected), while one animal (0.75%) was found to be infected by Babesia bovis. It was observed that 31% of animals infected with B. bigemina had a concurrent infection of T. annulata. PCR also resulted in a significantly higher efficacy of detection of Babesia sp. compared to MO when infection levels were higher, towards the end of the study period. The results clearly demonstrate that parasitic infection by piroplasms, especially Theileria sp. is common and endemic in the island of Minorca and that PCR is the optimal approach for the detection and discrimination of these important parasites.

Simultaneous detection of bovine Theileria and Babesia species by reverse line blot hybridization

A reverse line blot (RLB) assay was developed for the identification of cattle carrying different species of Theileria and Babesia simultaneously. We included Theileria annulata, T. parva, T. mutans, T. taurotragi, and T. velifera in the assay, as well as parasites belonging to the T. sergenti-T. buffeli-T. orientalis group. The Babesia species included were Babesia bovis, B. bigemina, and B. divergens. The assay employs one set of primers for specific amplification of the rRNA gene V4 hypervariable regions of all Theileria and Babesia species. PCR products obtained from blood samples were hybridized to a membrane onto which nine species-specific oligonucleotides were covalently linked. Cross-reactions were not observed between any of the tested species. No DNA sequences from Bos taurus or other hemoparasites (Trypanosoma species, Cowdria ruminantium, Anaplasma marginale, and Ehrlichia species) were amplified. The sensitivity of the assay was determined at 0.000001% parasitemia, enabling detection of the carrier state of most parasites. Mixed DNAs from five different parasites were correctly identified. Moreover, blood samples from cattle experimentally infected with two different parasites reacted only with the corresponding species-specific oligonucleotides. Finally, RLB was used to screen blood samples collected from carrier cattle in two regions of Spain. T. annulata, T. orientalis, and B. bigemina were identified in these samples. In conclusion, the RLB is a versatile technique for simultaneous detection of all bovine tick-borne protozoan parasites. We recommend its use for integrated epidemiological monitoring of tick-borne disease, since RLB can also be used for screening ticks and can easily be expanded to include additional hemoparasite species.

Serosurvey on theileriosis in Awassi sheep in Syria

A serological survey using indirect fluorescent antibody test (IFAT) for Theileria spp. infection of sheep has been carried out from 1994 to 1997 in the provinces Daraa, Hama, Homs and Latakia in Syria. The results revealed a mean seroprevalence of 59.9% without significant differences between years (p = 0.57) and provinces (p = 0.126).

Seroprevalence of Babesia ovis in sheep in Catalonia, northeastern Spain

An indirect fluorescent antibody test (IFAT) was developed in order to detect antibodies against Babesia ovis in different sheep flocks from Catalonia, northeastern Spain. Of the total 2174 sera included in the study, 133 (6.1%) were positive. Considerable differences in seroprevalence were detected depending on the geographical areas from which the animals originated. This must have been a consequence of the presence or absence of the vector tick, Rhipicephalus bursa, the distribution of which depends upon the bioclimate and vegetation present in the different areas studied. Even within those areas which afford suitable conditions for the presence of Rh. bursa ticks, and therefore in which positive titres were found, great differences in seroprevalence were detected among different flocks.

Seroprevalence of Babesia ovis in Spanish ibex (Capra pyrenaica) in Catalonia, northeastern Spain

A serologic survey was carried out in order to detect antibodies against Babesia ovis in a large population of Spanish ibex (Capra pyrenaica) from a hunting reserve in Catalonia, northeastern Spain. For this purpose, an indirect fluorescent antibody test (IFAT) was developed using a B. ovis isolate of ovine origin as antigen. Of the total 475 sera tested, 155 (32.6%) showed titres between 1:160 and 1:1280 and were considered positive. These results reveal that exposure of Spanish ibex to B. ovis is common in the studied area. No significant differences could be detected when comparing season or year of capture and age or sex of the animals in positive and negative samples. A high proportion of low titres was found in comparison to those reported by other researchers in sheep in Spain; this could be a consequence of the existence of some minor antigenic differences between B. ovis of domestic sheep and that found in Spanish ibex.

Piroplasms of domestic animals in the Macedonia region of Greece. 3. Piroplasms of small ruminants

A study was carried out on piroplasms of small ruminants in the Macedonia region of Greece. During 1984-1985, 721 serum samples were collected from sheep in 49 localities and 487 from goats in 43 localities. Blood smears were also prepared from 26 sheep and eight goats in 16 localities. The prevalence of positive IFA titres for sheep and goat sera, respectively, was: 24.6% and 0.6% for Theileria ovis, 52.1% and 36.4% for Babesia ovis, 10.5% and 4.2% for Babesia motasi, 12.6% and 6.6% for Babesia crassa. Many of the positive reactions, specially for the large Babesia species, B. motasi and B. crassa, probably resulted from cross-reactions and the presence of these two species is doubtful. Antibodies against B. ovis were found in animals from more than 90% of the localities. T. ovis was also common, but it was confined essentially to sheep. The examination of Giemsa stained blood smears revealed the presence of T. ovis and B. ovis in sheep, and Anaplasma ovis in a goat.

Piroplasms of domestic animals in the Macedonia region of Greece. 2. Piroplasms of cattle

A study was carried out on piroplasms of cattle in the Macedonia region of Greece. During 1984-1986, 602 serum samples were collected from cattle in 33 localities. Blood smears were also prepared from 50 of the animals in 13 localities. The indirect fluorescent antibody (IFA) test revealed that 41.4% of cattle sera were positive to Theileria orientalis, 2.0% to Theileria annulata, 21.6% to Babesia bovis, 15.2% to Babesia bigemina, 5.1% to Babesia major and 2.7% to Babesia divergens. Some of the positive titres were probably due to cross reactions. T. orientalis was widely distributed. T. annulata was limited to a small number of foci. B. bigemina and B. bovis, often present together, were widespread, whereas B. major was only present in a small number of localities. No convincing evidence of B. divergens infection was found. By examination of Giemsa stained blood smears T. orientalis, T. annulata and a Babesia sp. were detected.