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.

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.

A cross-sectional study aimed at investigating the species diversity of fly vectors and estimating the prevalence of bovine trypanosomosis was carried out from October 2009 to May 2010 in selected settlement areas of the Hawa-Gelan district in the western Wollega zone of Ethiopia. Standard methods of sampling and identification were employed for both entomological and parasitological examination. Three species of the genus Glossina (Glossina pallidipes, Glossina morsitans submorsitans and Glossina fuscipes) and two genera of biting flies (Stomoxys and Tabanus) were caught and identified. The overall apparent density of Glossina species caught was 10.5 flies per trap per day, with a higher proportion of female flies (57.2%). Out of a total 389 cattle examined, 42 (10.8%; 95% CI: 7.89% – 14.3%) were found infected with trypanosomes. Three trypanosome species were detected in the study area, namely Trypanosoma congolense (54.8%), Trypanosoma brucei (23.8%) and Trypanosoma vivax (21.4%). The prevalence of trypanosomosis was found to be significantly (p < 0.05) higher in cattle with poor body condition. There was an association between mean packed cell volume (PCV) and the occurrence of parasitaemia (χ2 = 49.5, p < 0.05). About 95.2% of cattle that were positive for trypanosomes had a PCV less than the lower limit for cattle. Considering the current result, bovine trypanosomosis seems to be a serious constraint for agricultural activities in the settlement areas of the Hawa-Gelan district and seems to be associated with the presence of Glossina species. Therefore, application of control methods through community involvement to reduce the Glossina species infestation level is likely to increase animal productivity.

Bovine trypanosomosis displays various epidemiological aspects in various areas. In some instances the disease has a high prevalence in animals with high impact on production whereas in other cases the disease has a low impact on production despite a high level of infection in animals. In addition epidemiological changes are frequently observed in various areas and are related to many factors including the vectors, the host, the parasites, the environment as well as the livestock management. However the implication of these factors in these changes is not fully elucidated. In eastern Zambia, factors predicting the establishment of severe infection in cattle are all present. However trypanosomosis occurring in cattle in this area has a low impact on livestock production. Several studies on the characterisation of trypanosome strains circulating in domestic and wild animals have been conducted in order to clarify the epidemiology of this disease in this area. These studies aimed at evaluating genetic and biological characteristics of these strains including their virulence profiles, their transmissibility by tsetse flies, their resistance to drugs and interference between different strains. In this review these findings are analysed in order to elucidate the implication of trypanosome strain variability in the distribution and the expression of this disease in the study area. The evolutionary trends of the situation occurring in this study area are also explained. Use of these findings is the context of disease control in the study area is further discussed.

Trypanosomosis is a parasitic disease that causes serious economic losses in livestock, especially in sub-Saharan countries. This study was conducted from October 2010 to March 2011 in the Diga and Sasiga districts of the East Wollega zone in western Ethiopia to determine the prevalence of bovine trypanosomosis and its vectors. A total of 386 blood samples were collected from randomly selected animals. Packed cell volume (PCV) was determined and samples were examined for the presence of trypanosomes using the buffy coat technique. Out of 386 blood samples, 8.55% tested positive for trypanosomes. The majority of the infections were caused by Trypanosoma congolense (72.73%), followed by Trypanosoma vivax (27.27%). There were no statistically significant differences (p > 0.05) between districts, altitudes, sexes and ages, but the prevalence was significantly higher (p < 0.05) in cattle which were in poor body condition. The mean PCV value of infected animals (21.45 ± 3.62 s.d.) was significantly lower (p < 0.05) than that of non-infected animals (26.60 ± 4.60 s.d.). A total of 1151 flies were caught by deploying 21 monoconical shaped traps. Of these flies, 822 (71.42%) were Glossina, whilst the remaining flies were either Stomoxys (17.20%) or Tabanus (11.38%). The overall apparent densities of tsetse and biting flies were 1.45 and 0.58 flies per trap per day, respectively. In conclusion, this study confirmed that trypanosomes and their vectors are prevalent and still pose a threat to cattle production in the area. Therefore, proper strategies have to be designed and implemented to minimise their effect on livestock production.

The study is the result of analyzing 16 895 blood smears of cattle collected at 180 sites in the provinces of Manica, Sofala, Zambézia and Tete in Mozambique. Of the blood smears 73.9 % were from Manica, 11.8 % from Tete, 8.5 % from Sofala and 5.8 % from Zambézia; 75.6 % of these were collected from smallholder cattle. Infections with trypanosomes were highest in smallholder cattle from Sofala Province with 36.8 % of the 872 blood smears examined positive for trypanosomes, and lowest in cattle of commercial farmers in Manica Province with only 6.2 % of 2 252 blood smears being positive. Trypanosoma congolense was the predominant species, followed by Trypanosoma vivax and Trypanosoma brucei sensu lato. Trypanosoma brucei, which also infects humans, was more frequent in the districts of Buzi, Mutarara and Morrumbala with 15.1 %, 10.5 % and 9.8 % of all examined cattle in 2005 being infected with it, respectively. The results show a significant increase in the infection rate with trypanosomes compared with results obtained in previous years by the Regional Veterinary Laboratory in Manica Province and by the Regional Tsetse and Trypanosomiasis Control Programme in Zambézia, Tete and Sofala provinces.