Search

Trypanosoma evansi is a unicellular protozoan responsible for causing a disease known as “surra,” which is found in different regions of the world and primarily affects horses and camels. Few information is known about virulence factors released from the parasite within the animals. The organism can secrete extracellular vesicles (EVs), which transport a variety of molecules, including proteins. Before being considered exclusively as a means for eliminating unwanted substances, extracellular vesicles (EVs) have emerged as key players in intercellular communication, facilitating interactions between cells, host cells, and parasites, and even between parasites themselves. Thus, they may be used as potential biomarkers. This study aimed to assess the induction of EVs production by Ca+2, conduct a proteomic analysis of the EVs released by T. evansi, and identify epitopes that could serve as biomarkers. The findings indicated that Ca+2 is not an effective promoter of vesiculation in T. evansi. Furthermore, the proteomic analysis has identified multiple proteins that have been investigated as biomarkers or vaccine antigens, previously. A total of 442 proteins were identified, with 7 of them specifically recognizing 9 epitopes that are unique to T. evansi. At least one of these epitopes of TevSTIB805.9.11580 have been previously identified, which increases the possibility of further investigating its potential as a biomarker. [ABSTRACT FROM AUTHOR]

Trypanosomosis due to Trypanosoma evansi (surra) is one of the most important diseases with a significant impact on camel health and production. Trypanosoma-induced immunosuppression mechanisms, which are key factors of disease pathogenesis, have been characterized in several animal species. The present study investigated, therefore, the impact of trypanosomosis on the immunophenotype of blood leukocytes in camels. For this, the relative and absolute values of blood leukocyte populations, their expression pattern of cell surface molecules, and the numbers of the main lymphocyte subsets were compared between healthy camels and camels with clinical symptoms of chronic surra and serological evidence of exposure to Trypanosoma infection. Leukocytes were separated from the blood of healthy and diseased camels, labeled with fluorochrome-conjugated antibodies, and analyzed by flow cytometry. Compared to healthy camels, the leukogram of diseased camels was characterized by a slightly increased leukocyte count with moderate neutrophilia and monocytosis indicating a chronic inflammatory pattern that may reflect tissue injury due to the long-lasting inflammation. In addition, the analysis of lymphocyte subsets revealed a lower number and percentage of B cells in diseased than healthy camels. In vitro incubation of camel mononuclear cells with fluorochrome-labeled T. evansi revealed a higher capacity of camel B cells than T cells to bind the parasite in vitro. Furthermore, cell viability analysis of camel PBMC incubated in vitro with T. evansi whole parasites but not the purified antigens resulted in Trypanosoma-induced apoptosis and necrosis of camel B cells. Here we demonstrate an association between trypanosomosis in camels and reduced numbers of blood B cells. In vitro analysis supports a high potential of T. evansi to bind to camel B cells and induce their elimination by apoptosis and necrosis. [ABSTRACT FROM AUTHOR]

Surra is a zoonotic disease caused by Trypanosoma evansi (T. evansi), which affects a wide variety of animals worldwide. The disease has a severe impact on the productivity, health, and working capacity of camels and causes mortality and extensive economic losses if not diagnosed early. This is the first comprehensive report on the prevalence of T. evansi infection in dromedaries in Balochistan province. In the present study, 393 blood samples (indigenous, n = 240; imported, n=153) were collected from one-humped camels (Camelus dromedarius) and were tested by molecular methods to estimate the prevalence of T. evansi in three districts (Pishin, Nushki, and Lasbella) of Balochistan province. The overall prevalence of T. evansi among examined camel samples was 28.24% (95% confidence interval (CI): 24.02–32.89%). The risk of T. evansi infection in adult camels (> 10 years) is higher than that in young ones (odd-ration (OR) = 2.7; 95% CI: 1.3357–5.3164%). Moreover, male camels were six times more likely to get an infection than female camels. The detection of T. evansi infection in camels sampled in summer and spring was 3.12- and 5.10-fold higher, respectively, than in camels sampled in winter. In conclusion, our findings showed a high rate of T. evansi infection in camels from the three districts. Our study emphasizes the need for a strict surveillance program and risk assessment studies as prerequisites for control measures. [ABSTRACT FROM AUTHOR]

Trypanosoma evansi, the causative agent of "surra" is enzootic in Iran. The current study aimed to detect T. evansi in horses from different regions of Iran using morphological, serological, and molecular methods. In 2021, 400 blood samples were collected from horses in eight regions. Eighty horses showed clinical signs such as cachexia (n = 64), fever (n = 36), foot edema (n = 40), and abdominal edema (n = 32), and 320 horses appeared healthy. All samples from the studied regions were evaluated for the presence of trypanosomes using direct analysis of blood smears, mercuric chloride, and PCR-based tests. In total, 12% (95% CI: ± 3.1%), 21% (95% CI: ± 3.9%), and 21% (84) of animals were positive for Trypanosoma in microscopic, serologic, and molecular analyses, respectively. All animals positive for SSU rDNA PCR were from Qom, Semnan, and Golestan regions. Further molecular analyses on 84 PCR-positive horses revealed that 29 horses scored positive in PCR using primers of trypanozoon species and 5 scored positive in PCR using primers of Trypanosoma evansi type A. All samples (n = 5) were from Qom region. The 205-bp fragments of T. evansi RoTat 1.2VSG (accession numbers: ON017789-93) analyzed and compared to other isolates sequence from GenBank BLAST search. It has close similarities with isolates from Pakistan, Egypt, Malaysia, Kenya, and India. Data herein demonstrated that horses from Iran were at high risk of T. evansi infection. Comprehensive control programs, such as those based on the application of repellants and traps, and also, compliance with quarantine standards are recommended for minimizing the risk of the infection. [ABSTRACT FROM AUTHOR]

Trypanosoma evansi is a causative agent of chronic wasting and fatal disease of livestock and wild animals known as surra. In this study, repurposing approach based on drug target was used to investigate the efficacy of kinase inhibitors (Barasertib-HQPA, BAR and Palbociclib isethionate, PAL) and protease inhibitors (Z-pro-prolinal, Z-PRO and Leupeptin hemisulphate, LEU) against T. evansi in HMI-9 medium. BAR, PAL and Z-PRO exhibited IC50 values of 13.52 µM, 0.6375 µM and 63.20 µM against T. evansi in terms of growth inhibition, in the contrary, LEU failed to exhibit a significant growth inhibition at any time interval. Furthermore, oligopeptidase B and aurora kinase genes of T. evansi were targeted to determine the effect of these drugs on quantitative mRNA expression, which showed significant (p < 0.01) up-regulation of both genes in the BAR and PAL-exposed population at 12 h of exposure, whereas, Z-PRO showed only significant (p < 0.05) up-regulation of aurora kinase gene at 12 h interval. In cytotoxicity assay, BAR exhibited 52% and 41% cytotoxicity at 50 μM concentration (about five folds the IC50 value) on equine PBMC's and Vero cell line, respectively. Similarly, the cytotoxicity of 25% and 24% were recorded at 10 μM concentration (about ten folds to the IC50 value) of PAL in equine PBMC's and Vero cell line, respectively. Of these, BAR and PAL, which were found effective under in vitro trials, raised the longevity of mice at higher doses during in vivo trials. Data generated showed that kinase inhibitors have higher potential to explore therapeutic molecules against surra organism. [ABSTRACT FROM AUTHOR]

African animal trypanosomosis (nagana) is becoming prevalent beyond its traditionally defined geographical boundaries in African tsetse belts. However, knowledge of clinically important trypanosomes and infection rate in non-tsetse hematophagous flies and domestic animals are limited. This study characterized the potential mechanical vectors, their host feeding patterns, and trypanosome infection in them and domestic animals outside the tsetse belt in northern Kenya. Field-trapped flies and blood from camels, cattle, donkeys, goats, and sheep were screened for trypanosome infection by microscopy and polymerase chain reaction (PCR) of the internal transcribed spacer 1 region. Blood-fed specimens were analysed using PCR-HRM and/or sequencing of 16S rRNA gene to identify vertebrate blood-meal host sources. Hippobosca camelina, Stomoxys calcitrans, Tabanus spp., and Pangonia rueppellii were identified as potential vectors of trypanosomes outside the tsetse belt in Marsabit County. The trypanosome species, Trypanosoma vivax, T. evansi, T. brucei, and T. congolense were recovered in biting flies as well as in camels (Camelus dromedarius). The diversity of parasites in the biting flies was similar to that detected in the tsetse fly Glossina pallidipes collected from the tsetse-infested Shimba Hills, in coastal Kenya, suggesting a wide geographic distribution of the trypanosomes in Kenya. The biting flies fed on camels, cattle, goats, and sheep. Furthermore, we identified diverse clinical outcomes based on PCV (anemia), heamorrhagia) associated with infection with disparate Trypanosoma species. Thus, infection of flies and camels by diverse Trypanosoma species could contribute to the complex epidemiology of observed trypanosomosis in camels. [ABSTRACT FROM AUTHOR]

Purpose: Surra is an economically important livestock disease in many low- and middle-income countries, including those of Northern Africa. The disease is caused by the biting fly-transmitted subspecies Trypanosoma brucei evansi, which is very closely related to the tsetse-transmitted subspecies T. b. brucei and the sexually transmitted subspecies T. b. equiperdum. At least two phylogenetically distinct groups of T. b. evansi can be distinguished, called type A and type B. These evolved from T. b. brucei independently. The close relationships between the T. brucei subspecies and the multiple evolutionary origins of T. b. evansi pose diagnostic challenges. Methods: Here we use previously established and newly developed PCR assays based on nuclear and mitochondrial genetic markers to type the causative agent of recent trypanosome infections of camels in Southern Algeria. Results/conclusion: We confirm that these infections have been caused by T. b. evansi type A. We also report a newly designed PCR assay specific for T. b. evansi type A that we expect will be of diagnostic use for the community. [ABSTRACT FROM AUTHOR]

High cytotoxicity and increasing resistance reports of existing chemotherapeutic agents against T. evansi have raised the demand for novel, potent, and high therapeutic index molecules for the treatment of surra in animals. In this regard, repurposing approach of drug discovery has provided an opportunity to explore the therapeutic potential of existing drugs against new organism. With this objective, the macrocyclic lactone representative, ivermectin, has been investigated for the efficacy against T. evansi in the axenic culture medium. To elucidate the potential target of ivermectin in T. evansi, mRNA expression profile of 13 important drug target genes has been studied at 12, 24, and 48 h interval. In the in vitro growth inhibition assay, ivermectin inhibited T. evansi growth and multiplication significantly (p < 0.001) with IC50 values of 13.82 μM, indicating potent trypanocidal activity. Cytotoxicity assays on equine peripheral blood mononuclear cells (PBMCs) and Vero cell line showed that ivermectin affected the viability of cells with a half-maximal cytotoxic concentration (CC50) at 17.48 and 22.05 μM, respectively. Data generated showed there was significant down-regulation of hexokinase (p < 0.001), ESAG8 (p < 0.001), aurora kinase (p < 0.001), casein kinase 1 (p < 0.001), topoisomerase II (p < 0.001), calcium ATPase 1 (p < 0.001), ribonucleotide reductase I (p < 0.05), and ornithine decarboxylase (p < 0.01). The mRNA expression of oligopeptidase B remains refractory to the exposure of the ivermectin. The arginine kinase 1 and ribonucleotide reductase II showed up-regulation on treatment with ivermectin. The ivermectin was found to affect glycolytic pathways, ATP-dependent calcium ATPase, cellular kinases, and other pathway involved in proliferation and maintenance of internal homeostasis of T. evansi. These data imply that intervention with alternate strategies like nano-formulation, nano-carriers, and nano-delivery or identification of ivermectin homologs with low cytotoxicity and high bioavailability can be explored in the future as an alternate treatment for surra in animals. [ABSTRACT FROM AUTHOR]

Trypanosoma evansi, a hemoflagellate protozoan parasite, causes wasting disease called surra in wide range of animals. Although the organism has been reported from various parts of India, data generated from organized epidemiological study is still in infancy in majority states of India. In the present study, livestock of Himachal Pradesh, India, was targeted for epidemiological investigation of T. evansi infections. A total of 440 equines and 444 cattle serum samples were collected from four agro-climatic zones. Furthermore, serum samples of 280 buffaloes from three different agro-climatic zones of Himachal Pradesh were also collected and evaluated for the presence of T. evansi infection by indirect ELISA. Data generated showed higher prevalence in buffalo (23.57%) followed by cattle (22.52%) and equines (1.82%). Disease was found to be more prevalent (P < 0.01) in cattle of lower altitude as compared to those of higher altitudes. No significant variation was seen in prevalence of disease on the basis of age and sex of the animals. Serum biochemical analysis revealed increased levels of BUN in T. evansi–infected equines. Levels of liver function enzymes such as ALT/GGT and AST were found to be significantly elevated (P < 0.01) in seropositive animals whereas glucose levels were significantly lower in surra-seropositive animals as compared to seronegative animals. Immunoblot analysis of whole cell lysate (WCL) antigen of T. evansi using surra-seropositive samples of equines showed immunodominant bands in the range of 100–25 kDa. Bovine-seropositive samples recognized polypeptide bands in the range of 85–32 kDa, including protein clusters of 52–55 and 48–46 kDa. Polypeptide cluster of 62–66 kDa was found common in seropositive samples of bovines and equines from all agro-climatic zones. T. evansi was found to be highly prevalent in livestock of Himachal Pradesh, and thus, there is dire need for designing of proper control strategies against surra. [ABSTRACT FROM AUTHOR]

Surra is a parasitic disease caused by Trypanosoma evansi and transmitted non-cyclically by biting flies. The disease significantly affects the health, productivity, and market value of camels thereby constituting a major constraint to food safety, security, and economy. This is the first study on the prevalence of surra in northwestern Nigeria, using a range of diagnostic tests along the parasitological-serological-molecular continuum hence, emphasizing it as a major enzootic risk for camels in Nigeria. In this cross-sectional study, 600 blood samples were collected from camels at major abattoirs in northwestern Nigeria and evaluated for the prevalence of T. evansi using parasitological (Giemsa staining), serological (CATT/T. evansi), and molecular (VSG-PCR and sequencing) methods. The overall prevalence of surra recorded in this study was 5.3%, 11.5%, and 22.5% using Giemsa-stained blood smears, CATT/T. evansi, and VSG-PCR respectively. However, higher prevalence rates at 6.0%, 13.7%, and 26.7% by Giemsa-stained blood smears, CATT/T. evansi, and VSG-PCR were recorded in Katsina State compared with results from Kano State. A significantly (p < 0.05) higher prevalence by VSG-PCR was observed when compared with both parasitological and serological methods used. Although age and body condition scores were associated (p < 0.05) with surra prevalence in sampled camels, no seasonal association (p > 0.05) was recorded. Sequencing of the VSG region of Trypanosoma spp. Further confirmed the presence of T. evansi as the aetiological agent of surra from the sampled camels. Findings from this study call for the implementation of adequate control measures aimed at reducing the impact of T. evansi infections on camel production in Nigeria. [ABSTRACT FROM AUTHOR]

Trypanosoma evansi is a flagellated, extracellular haemoprotozoan parasite infecting a wide range of mammalian hosts including dromedaries, cattle, equines and dogs cause disease surra. Carrier animals with sub-clinical infection cause significant monetary losses to livestock holders and therefore detection of infection status using molecular diagnostic techniques becomes important in order to control the disease. In the current study cattle, buffalo, goat, pig and dog samples from three northeastern states of India-Assam, Mizoram and Tripura were screened to determine the prevalence of surra. A total of 1702 samples including 795 from Assam, 678 from Mizoram and 229 from Tripura were screened by CATT/T. evansi test out of which 16.8%, 27.1% and 22.3% samples in respective states were found to have antibodies against T. evansi. DNA detection of T. evansi by PCR amplification targeting VSG gene revealed the molecular prevalence of surra in Assam, Mizoram and Tripura as 8.5%, 7.5% and 4.4% respectively. The analysis of amplified partial VSG sequences showed 99% similarity within an animal species whereas 86–94% similarity was observed among different species of animals revealing the homogeneity. The study established the prevalence of surra in different species of animals in the three northeastern states of India-Assam, Mizoram and Tripura and this study is the first report of T. evansi infection in pig and goat from India. [ABSTRACT FROM AUTHOR]

Diminazene diaceturate (DIM) and isometamidium chloride hydrochloride (ISMM) have been widely used for the treatment of animal trypanosomosis. We evaluated the efficacy of standard doses of DIM and ISMM followed by their double doses for the treatment of Trypanosoma evansi in experimentally infected mice. A T. evansi strain obtained from a naturally infected camel in Afar was used. 25 swiss white mice randomly divided in to five groups were inoculated with 0.2 mL of blood containing 103 trypanosomes. At the peak of parasitemia (≈ 2 weeks post infection), groups A and B were treated with the standard dose (3.5 mg/kg body weight [BWT]) of DIM; groups C and D were treated with the standard dose (0.5 mg/kg BWT) of ISMM; and group E served as infected control. In the DIM standard dose groups, relapses and peak parasitemia were observed 20- and 25-days post treatment respectively. Similarly, relapses and peak parasitemia were observed 21- and 27-days post treatment in the ISMM standard dose groups. All mice in the control group died within two weeks post infection. Following relapses, mice were treated with the double doses of DIM (7 mg/kg BWT) or ISMM (1 mg/kg BWT). Parasitemia was not detected for 3 months following the double dose treatments. Following dexamethasone administration for 7 days, all but one mouse in the DIM group remained negative for another month. In general, although the T. evansi strain was resistant to the standard doses of DIM and ISMM their double doses completely cleared the infection. [ABSTRACT FROM AUTHOR]

Trypanosoma evansi, an extracellular haemoflagellate, has a wide range of hosts receptive and susceptible to infection, in which it revealed highly inconsistent clinical effects. Drugs used for the treatment of trypanosomosis have been utilized for more than five decades and have several problems like local and systemic toxicity. In the present investigation, imatinib and sorafenib were selected as drugs as they are reported to have the potential to cause reactive oxygen species (ROS)–mediated effect in cancer cells. Both have also been reported to have potential against T. brucei, T. cruzi and Leishmania donovani. To date, imatinib and sorafenib have not evaluated for their growth inhibitory effect against T. evansi. Imatinib and sorafenib showed significant (p < 0.001) inhibition on parasite growth and multiplication with IC50 (50% inhibitory concentration) values 6.12 μM and 0.33 μM respectively against T. evansi. Both the drug molecules demonstrated for the generation of ROS in T. evansi and were found up to 65% increased level of ROS as compared with negative control in the axenic culture system. Furthermore, different concentrations of imatinib and sorafenib were found non-toxic on horse peripheral blood mononuclear cells and Vero cell lines. Also, in conclusion, our results demonstrated that imatinib- and sorafenib-induced generation of ROS contributed inhibitory effect on the growth of Trypanosoma evansi in an axenic culture system. [ABSTRACT FROM AUTHOR]

Our previous studies report epidemics of non-tsetse-transmitted equine trypanosomosis in Mongolia. However, the current status of non-tsetse-transmitted equine trypanosomosis endemicity remains to be clarified in some parts of Mongolia. We previously reported the potential application of rTeGM6-4r-based diagnostic tools, an rTeGM6-4r-based immunochromatographic test (ICT) and an enzyme-linked immunosorbent assay (ELISA), in the serological surveillance of equine trypanosomosis in Mongolia. In the present study, the utility of the rTeGM6-4r-based ICT was validated. The rTeGM6-4r-based ICT accurately diagnosed positive reference sera that had been prepared from dourine horses in Mongolia, similarly to the rTeGM6-4r-based ELISA. The diagnostic performance of the rTeGM6-4r-based ICT was maintained when the strips were preserved for at least 2 months under dry conditions. The ICT detected 42 positive serum samples from a total of 1701 equine sera that had been collected from all 21 provinces of Mongolia. The κ-value, sensitivity and specificity of rTeGM6-4r-based ICT were 0.58, 50.0% (95% CI, 37.7-62.3%) and 99.3% (95% CI, 98.7-99.6%), respectively, in comparison to the rTeGM6-4r-based ELISA. Our field-friendly rTeGM6-4r-based ICT was found to be useful for the serological diagnosis of non-tsetse-transmitted equine trypanosomosis in rural areas of Mongolia. [ABSTRACT FROM AUTHOR]

Animal trypanosomosis is a devastating parasitic disease that is of economic importance to livestock production. The infection includes animal African trypanosomosis, surra, and dourine. The treatment is based solely on few compounds that were discovered decades ago and which are associated with severe toxicity. Furthermore, it is likely that the parasite has developed resistance towards them. Thus, there is an urgent need for new, accessible, and less toxic drugs. Azithromycin is an antibiotic with documented efficacy against Toxoplasma, Babesia, and Plasmodium. The current study investigated its effects against animal trypanosomes. An in vitro system was used to determine the trypanocidal effects of azithromycin against Trypanosoma congolense, Trypanosoma brucei brucei, and Trypanosoma evansi, and cytotoxicity in Madin-Darby bovine kidney (MDBK) and NIH 3T3 cells. Furthermore, the trypanocidal effects of azithromycin were investigated in T. congolense-infected mice. In vitro, azithromycin had an IC of 0.19 ± 0.17; 3.69 ± 2.26; 1.81 ± 1.82 μg/mL against T. congolense, T. b. brucei, and T. evansi, respectively. No cytotoxic effects were observed in MDBK and NIH 3T3 cells. The efficacy of orally administered azithromycin was investigated in short-term and long-term treatment protocols. Although the short-term treatment protocol showed no curative effects, the survival rate of the mice was significantly prolonged ( p < 0.001) in comparison to the control group. The long-term treatment yielded satisfying curative effects with doses of 300 and 400 mg/kg achieving 80 and 100% survival, respectively. In conclusion, long-term oral azithromycin treatment has trypanocidal effects against T. congolense. [ABSTRACT FROM AUTHOR]

Trypanosoma evansi, the aetiological agent of Surra affects a wide range of livestock and wild animals in India. In the present study, we studied intra- and inter species genetic variability in the transferrin receptor encoding gene regions (ESAG6/7 gene region) of T. evansi isolates by cloning, sequencing and phylogenetic study collected from camel, cattle, donkeys and ponies from North-Western and Central India. The nucleotide sequence variation of ESAG6/7 gene region between Indian T. evansi isolates was up to 17.7% and amino acid sequence variation was up to 31%. Twenty nine clones from six T. evansi isolates from geographical regions of India were included into Clade 1, 5, 6, 7 and 9 consisting of ESAG6 variants reported among T. evansi isolates from South-east Asia and South America. The cladogram indicated a relation between the host species and the genetic variability in the hyper-variable region of ESAG6 gene. Analysis of the Indian ESAG6 variants and their respective Clade positions presented a host specific distribution indicating homogenous parasite population in their respective animal hosts. [ABSTRACT FROM AUTHOR]

Trypanosoma ( Trypanozoon) evansi is a causative agent of the dreadful mammalian disease trypanosomiasis or 'Surra' and carried as a latent parasite in domestic cattle but occasionally proves fatal when transmitted to horses and camel. Sporadic outbreak of 'Surra' to different animals (beside their natural hosts) reminds that T. evansi may be zoonotic, as their close relative cause sleeping sickness to human being. This haemoflagellate is mechanically transmitted by horse fly and its effect on different host varies depending on certain factors including the effectiveness of transmission by mechanical vector, the suitability and susceptibility of the host as well as most importantly the ability of the disease establishment of parasite to adapt itself to the host's resistance, etc. The course of the disease caused by T. evansi is similar to that of human sleeping sickness caused by T. ( T.) brucei gambiense. The target organs and symptoms show close similarity. T. evansi can successfully be transmitted among unnatural hosts i.e., other classes of vertebrates, like chicken. In transmission experiments, the unnatural hosts may sometimes induce profound changes in the biology of trypanosomes. Hence, in present study the observations are the biology of different morphological changes of T. evansi as well as its ability of disease formation within some heterologous mammal viz., albino rat, guineapig, bandicoot, mongoose, domestic cat and common monkey. Blood smears of infected albino rats, bandicoot, and mongoose revealed only monomorphic form. Interestingly, blood smears of infected cat and monkey, T. evansi shows slender trypomastigote form and short intermediate form whereas organ smears shows other two forms of haemoflagellate viz., sphaeromastigote and amastigote form. The haemoflagellate maintains a common reproductive cycle in all the experimental heterologous hosts whereas disease symptoms differ. T. evansi infected cat and monkey shows nervous symptoms. Infected monkey expresses some symptoms similar to that of human sleeping sickness disease. Thus the paper highlights zoonotic potentialities of T. evansi. [ABSTRACT FROM AUTHOR]

A study was made to determine the prevalence of camel trypanosomosis (surra) and its associated risk factors in Borena zone, southern Ethiopia during 2013-2014. A total of 2400 blood samples were collected and examined by the buffy coat and thin blood film laboratory methods, and data were analyzed using the SPSS statistical software. The overall prevalence of camel trypanosomosis in the area was found to be 2.33 %. Prevalence was significantly different among the surveyed districts ( P = 0.000), the pastoral associations ( F = 6.408, P = 0.000), altitudinal divisions ( P = 0.000), age groups ( P = 0.034), and between animals possessing packed cell volume (PCV) values greater than 25 % and less than 25 % ( P = 0.000); whereas, prevalence of the disease was not statistically significantly different between the sexes ( P = 0.311) and among the body condition score groups ( P = 0.739). The PCV of trypanosome positive and trypanosome negative camels differ significantly ( P = 0.001), and prevalence of trypanosomosis was seen to be negatively correlated with packed cell volume ( r = −0.069, P = 0.000) revealing the effect of camel trypanosomosis on anemia state of parasitized animals. In conclusion, camel trypanosomosis is a serious and economically important disease hampering camel production and productivity in southern Ethiopia. Further studies involving more sensitive molecular techniques to reveal the precise magnitude of the disease and to identify the vector species of the parasite are recommended. [ABSTRACT FROM AUTHOR]

Surra is caused by infection with the protozoal parasite, Trypanosoma evansi. This parasite was transmitted mechanically by biting flies which is widespread in camels in the world. The aim of this study is to determine the prevalence of T. evansi in camels in Rafsanjan, Kerman province, southeast of Iran. In this study, 95 suspected camels were randomly selected in 2011. Blood samples were taken from deep blood vessels. Thin and thick blood smears were prepared in laboratory. Blood smears were stained by Giemsa and studied under a light microscope. The positive blood samples were also used for further molecular analysis. Data were analyzed using SPSS 17.0 software and P ≤ 0.05 was considered as statistical difference. A total of 95 camels were examined for infection with T.evansi using parasitological and molecular methods. The overall prevalence of infection was 2.1 %. It was found that the frequency of infection was significantly higher ( P < 0.05) in age group >6 years old than the corresponding younger camels. However, there was no significant difference when the gender was considered. PCR technique confirmed the two infected cases were T. evansi. Results of the present study indicated that surra is present in Rafsanjan county, Kerman province in an infection rate of 2.1 % in camels. To our knowledge, this is the first study reported from this province. Further investigations are needed to focus on vectors and to evaluate the risk factors. [ABSTRACT FROM AUTHOR]

In Venezuela, horses are indispensable for extensive cattle raising, and extensive cattle raising prevails in all regions. This determines the numerical relationship between horses and cattle ( r = 0.93) to be relatively constant nationwide. At regional level, the average extension of cattle ranches varies greatly. However, in relation to the area covered by pastures, the numbers of horses ( r = 0.95) and cattle ( r = 0.93) are relatively uniform nationwide. Water buffalo occupy small fractions of the territory; therefore, their numbers are related to the area of pastures less strongly ( r = 0.56). There is no information on the numerical relationship between the numbers of horses and water buffalo. In the Llanos region of the country, equine trypanosomiasis is responsible for a high mortality in horses, causing considerable financial losses to cattle ranches. So far, such losses have not been assessed. For this region, in 2008, it can be calculated that: (1) with no treatment, losses owing to horse mortality caused by this hemoparasitosis would have amounted to US$7,486,000; (2) the diagnosis and treatment of affected horses would have required an investment of US$805,000; and (3) in terms of horses saved, this investment would have resulted in benefit of US$6,232,000. Therefore, for every monetary unit invested, there would be a benefit 7.75 times greater, this ratio being applicable to any year and all regions of the country. It follows that the profitability of investing in the diagnosis and treatment of equine trypanosomiasis is guaranteed. [ABSTRACT FROM AUTHOR]