Surra, caused by Trypanosoma evansi, is a re-emerging animal trypanosomosis, which is of special concern for camel-rearing regions of Africa and Asia. Surra decreases milk yield, lessens animal body condition score and reduces market value of exported animals resulting in substantial economic losses. A cross-sectional seroprevalence study of dromedary camels was conducted in Algeria, and major risk factors associated with infection were identified by collecting data on animal characteristics and herd management practices. The seroprevalence of T. evansi infection was determined in sera of 865 camels from 82 herds located in eastern Algeria using an antibody test (card agglutination test for Trypanosomiasis – CATT/T. evansi). Individual and herd seroprevalence were 49.5% and 73.2%, respectively, indicating substantial exposure of camels to T. evansi in the four districts studied. Five significant risk factors for T. evansi hemoparasite infection were identified: geographical area, herd size, husbandry system, accessibility to natural water sources and type of watering. There was no association between breed, sex or age with T. evansi infection. Results of this study provide baseline information that will be useful for launching control programmes in the region and potentially elsewhere.

International audience | Surra, caused by Trypanosoma evansi, is a re-emerging animal trypanosomosis, which is of special concern for camel-rearing regions of Africa and Asia. Surra decreases milk yield, lessens animal body condition score and reduces market value of exported animals resulting in substantial economic losses. A cross-sectional seroprevalence study of dromedary camels was conducted in Algeria, and major risk factors associated with infection were identified by collecting data on animal characteristics and herd management practices. The seroprevalence of T. evansi infection was determined in sera of 865 camels from 82 herds located in eastern Algeria using an antibody test (card agglutination test for Trypanosomiasis - CATT/T. evansi). Individual and herd seroprevalence were 49.5% and 73.2%, respectively, indicating substantial exposure of camels to T. evansi in the four districts studied. Five significant risk factors for T. evansi hemoparasite infection were identified: geographical area, herd size, husbandry system, accessibility to natural water sources and type of watering. There was no association between breed, sex or age with T. evansi infection. Results of this study provide baseline information that will be useful for launching control programmes in the region and potentially elsewhere.

Trypanosomosis is an important disease of dromedary camels caused by the pathogenic protozoan Trypanosoma evansi. This study aimed to compare three different tests for its diagnosis in this species: conventional microscopy, the card agglutination test for trypanosomosis/T. evansi (CATT/T. evansi) and real-time PCR. Whole blood and serum samples collected from 77 dromedary camels of Abu Dhabi, United Arab Emirates, were analysed with the test methods stated. Statistical analysis was done using McNemar’s chi-squared test, and Cohen’s kappa index (κ) was calculated. We obtained results with positivity of 18% (14/77) by microscopy, 22% by CATT (17/77) and 60% (46/77) by real-time PCR, with the chain reaction detecting at a respectively three- and two-fold greater rate than the other techniques. Analysis of the data revealed a relative sensitivity of 30.4% and 37.0% for microscopy and CATT, respectively, compared to real-time PCR. The difference between the real-time PCR’s sensitivity and those of the other methods was statistically significant, with X² values of 30.03 and 20.1, respectively (df = 1 and P = 0.05 in both cases). Agreement of microscopy results with those of with CATT was good (κ = 0.72; 95% CI = 0.62–0.82). Cohen’s kappa index showed fair agreement of real-time PCR with microscopy (κ = 0.26; 95% CI = 0.16–0.36) whereas it was in poor agreement with CATT (κ = 0.09; 95% CI = 0.02–0.15). Real-time PCR was found to be more sensitive than microscopy and CATT.

Trypanosoma evansi is enzootic in camels in Egypt, and water buffaloes act as a reservoir for camel infection. Molecular techniques have contributed towards understanding the epidemiology of T. evansi. Trypanosoma evansi was detected in acute and chronic stages of the disease in male and female mice by polymerase chain reaction (PCR) using two primers. Two experiments were conducted. In experiment I, two groups consisting of 26 female and 26 male mice received 104 trypanosome by I/P inoculation for each mouse. In experiment II, 42 female and 42 male mice were inoculated I/P with 102 trypanosome/mouse. In addition, five mice were kept as uninfected control for each group. Mice were monitored daily for parasitaemia level during the pre-patent period using the micro-haematocrit centrifugation technique (MHCT) and conventional PCR. The primer pairs, (Trypanosoma brucei) TBR1/2 and TeRoTat1.2 (T. evansi Rode Trypanozoon antigen type [RoTat] 1.2), detected the infection after 24 hours earlier than MHCT in both experiments. The course of infection that was detected by MHCT revealed three waves of parasitaemia in female mice and two waves in male mice in the chronic stage of infection. In addition, PCR was able to detect T. evansi in different organs in the chronic stage (i.e. disappearance of parasite from blood). Application of the two primer sets on blood samples from camels showed that all samples were positive by TBR1/2 primers and only 32 of 44 were positive by TeRoTat1.2 primers. Acutely and chronically Trypanosoma-infected mice were detected by PCR in blood and organs. TBR1/2 primers were more sensitive than TeRoTat1.2 primers in detecting Trypanosoma-infected mice, and more reliable in detecting field-infected camels and excluding carrier animals.

Trypanosoma evansi is enzootic in camels in Egypt, and water buffaloes act as a reservoir for camel infection. Molecular techniques have contributed towards understanding the epidemiology of T. evansi. Trypanosoma evansi was detected in acute and chronic stages of the disease in male and female mice by polymerase chain reaction (PCR) using two primers. Two experiments were conducted. In experiment I, two groups consisting of 26 female and 26 male mice received 10(4) trypanosome by I/P inoculation for each mouse. In experiment II, 42 female and 42 male mice were inoculated I/P with 10² trypanosome/mouse. In addition, five mice were kept as uninfected control for each group. Mice were monitored daily for parasitaemia level during the pre-patent period using the micro-haematocrit centrifugation technique (MHCT) and conventional PCR. The primer pairs, (Trypanosoma brucei) TBR1/2 and TeRoTat1.2 (T. evansi Rode Trypanozoon antigen type [RoTat] 1.2), detected the infection after 24 hours earlier than MHCT in both experiments. The course of infection that was detected by MHCT revealed three waves of parasitaemia in female mice and two waves in male mice in the chronic stage of infection. In addition, PCR was able to detect T. evansi in different organs in the chronic stage (i.e. disappearance of parasite from blood). Application of the two primer sets on blood samples from camels showed that all samples were positive by TBR1/2 primers and only 32 of 44 were positive by TeRoTat1.2 primers. Acutely and chronically Trypanosoma-infected mice were detected by PCR in blood and organs. TBR1/2 primers were more sensitive than TeRoTat1.2 primers in detecting Trypanosoma-infected mice, and more reliable in detecting field-infected camels and excluding carrier animals.

Bovine haemoparasites are cosmopolitan in distribution and are known to cause substantial losses to the cattle industry. In spite of their economic importance, there remains a dearth of information on their molecular epidemiology in many parts of the world including Malaysia. To ascertain the molecular prevalence and species co-infection of bovine haemoparasites in the country, blood samples were collected from 1,045 heads of beef and dairy cattle on 43 farms from six geographical zones throughout Peninsular Malaysia. Samples subjected to PCR amplification of parasite species-specific genetic fragments revealed that Anaplasma marginale was the most prevalent haemoparasite (72.6%),followed by Theileria orientalis(49.8%),Candidatus Mycoplasma haemobos ( 47. 0 % ),Babesia bovis(32. 5%), Babesia bigemina (30.5%) and Trypanosomaevansi(17.9%). A high percentage (92.1%) of cattle was infected with either one or more haemoparasites. Triple haemoparasite species co-infection was the most prevalent (25.6%), followed closely by double species co-infection (25.1%). The most common (8.8%) and significantly correlated(rs= 0.250; p<0.01) combination was A. marginale+ T.orientalis. The present study constitutes the first attempt in the country to document the molecular prevalence and species co-infection of bovine haemoparasites over a wide spatial distribution. The data obtained will facilitate treatment, control and prevention measures to improve the local cattle industry.

Trypanosomiasis positive cases were reported in Sahom Farm Retreatin Gopeng, Perak; with multispecies livestock animals. Nzi and Vavoua traps were applied to survey the population of biting flies; stable flies (Muscidae: Stomoxyinae) and horse flies (Tabanidae)as the vector for surra. Results indicated the presence of Trypanosomiasis infection diagnosed by buffy coat examination, thinblood stained smears and serological test (Surra Sero K-Set test) and identification of its insect vectors. The presence of bothbiting flies provides the missing link between the occurrence of the disease and host or environmental factors precipitatingthe disease. Besides trypanosomiasis in cattle, other parasitic infections were also recorded with heavy infections for liver fluke (Fasciola gigantica ova) and coccidia oocysts. Therefore, some control measures are recommended to eradicate the vectors and to treat infected animals in order to prevent the dissemination ofthe trypanosmiasis.

Surra, caused by Trypanosoma evansi, is a re-emerging animal trypanosomosis, which is of special concern for camel-rearing regions of Africa and Asia. Surra decreases milk yield, lessens animal body condition score and reduces market value of exported animals resulting in substantial economic losses. A cross-sectional seroprevalence study of dromedary camels was conducted in Algeria, and major risk factors associated with infection were identified by collecting data on animal characteristics and herd management practices. The seroprevalence of T. evansi infection was determined in sera of 865 camels from 82 herds located in eastern Algeria using an antibody test (card agglutination test for Trypanosomiasis – CATT/T. evansi). Individual and herd seroprevalence were 49.5% and 73.2%, respectively, indicating substantial exposure of camels to T. evansi in the four districts studied. Five significant risk factors for T. evansi hemoparasite infection were identified: geographical area, herd size, husbandry system, accessibility to natural water sources and type of watering. There was no association between breed, sex or age with T. evansi infection. Results of this study provide baseline information that will be useful for launching control programmes in the region and potentially elsewhere.

Histopathological changes were studied in Swiss albino mice (N:36)which were challenged with the South Indian local strain of Trypanosoma evansi. Each animal was infected with 5×105 trypanosomes intraperitoneally. The animals were examined daily for development of clinical signs and infection status by wet blood-films made from the tail veins. The infected mice were dull and depressed from two days post-infection (DPI) onwards. Systematic post-mortem examination of the infected mice was performed and pathological changes were recorded. The different tissue samples were collected in 10% formalin and were used to study the histopathological changes. Postmortem examination from 3-4 DPI (the maximum period of observation) revealed splenomegaly, hepatomegaly, marked congestion of lungs, presence of fl uid in peritoneal cavity. Histopathologically, heart muscles showed hyaline degenerative changes and haemorrhages. Liver parenchyma revealed congestion of central vein and sinusoids, binucleated hepatocytes and fatty change of hepatic cells. Thickening of interstitial space with mononuclear infiltration, areas of collapse, areas of emphysema, edema and dilated and congested blood vessels were the histopathological changes noticed in the lungs of the infected mice. In the spleen, giant cells aggregation, hyperplasia, thickening of capsule and trabecule were the changes indicating irreversible degeneration. The affected kidney showed inter-tubular hemorrhages in the cortex, medullary hemorrhages, congested glomerulus, atrophied glomerulus, desquamated tubular epithelium and disruption of renal tubules at some places.

Blood protozoan diseases are significant to animal breeding as theyresult in economic loss due to mortality, reduction in production efficiency and increment in drugs usage. This historical retrospective study was carried out to investigate the most significant blood protozoan diseases, their trends as well as the host range diagnosed by Veterinary Research Institute (VRI) from 1931 to 2010 among Malaysian domestic animals. Conventional techniques such as stained thin blood film, whole blood buffy coatexamination and direct wet smears were utilised for diagnosis from 1931 to 2010. Five most common significant blood protozoan diseases from the domestic animals were identified namely, theileriosis,leucocy tozoonosis, pla smod ia sis, babesiosis and trypanosomiasisrespectively. The setting up of a systematic laboratory service in VRI has enabled more cases of blood protozoan infections to be diagnosed and this has inadvertently led to better understanding and control of the diseases thereby improving the livelihood and reducing economic loss of local farmers.