Molecular Detection of Animal Trypanosomes in Different Animal Species in the Visayas Region of the Philippines

PURPOSE

Animal trypanosomosis is one of the most important parasitic diseases significantly affecting the Philippine economy. It is considered by the government to be the second most important disease of livestock after fasciolosis. A PCR-based molecular survey for trypanosomes in different animals in Bohol, Philippines, was performed to assess the prevalence of trypanosomosis in the area during the rainy and dry season.

METHODS

A total of 269 blood samples were collected in two batches in rainy and dry season from different animal species in Ubay Stock Farm in Ubay, Bohol, the Philippines, including 151 samples from water buffaloes, 76 samples from cattle, 35 samples from goats, and 7 samples from horses. DNA was subsequently extracted from these blood samples, and two different PCR assays were employed to detect and identify trypanosomes DNA including ITS1 PCR and CatL PCR.

RESULTS

Animal trypanosomes, Trypanosoma evansi and Trypanosoma theileri, were detected in water buffalo (37.7%) [95%CI: 30.4 - 45.7], cattle (44.7%) [95%CI: 34.1 - 55.9], and goats (34.3%) [95%CI: 20.8 - 50.8]. Only T. evansi was detected in horses (28.6%) [95% CI: 8.2 - 64.1]. No clinical signs were observed in all positive animals.

CONCLUSION

This highlights the importance of domestic animals that can be infected with no signs but may act as reservoir animals and transmit trypanosomosis to susceptible animals. This study supports the importance of regular surveillance to estimate the prevalence of the disease, emphasizing its various dynamics in the affected areas and supporting efficient intervention measures.

First molecular detection and identification of Trypanosoma evansi in goats from Cebu, Philippines using a PCR-based assay

The increasing number and severity of surra outbreaks in the Philippines led the government to consider it as the second most important disease of livestock in the country. It is one of the most economically important animal parasitic diseases and has been reported in several animal species, including water buffaloes, cattle, and horses in different regions of the Philippines. However, it has not yet been reported in Cebu, the usual gateway of livestock trade in the area that raises 6% of the 3.75 million goats in the country. In the current study, a PCR-based assay was conducted for the molecular detection and characterization of Trypanosoma evansi in goats in Cebu. A total of 251 goats were randomly sampled from four farms. DNA was extracted and ITS1-PCR was applied to detect different trypanosomes in goats. Eighty-five out of the 251 (33.9%) samples tested positive for T. evansi, two of which were also positive for T. theileri-like trypanosome. The detection rate of T. evansi was slightly higher in male goats (38.3%) than in females (32.5%), and in younger goats (34.5%) than in adults (33.5%). The findings, however, did not differ significantly to suggest any association between sex and age with T. evansi infection in goats. The detection of T. evansi and T. theileri-like trypanosome in goats was confirmed by sequence analysis of ITS1 region. To our knowledge, this is the first report on the molecular detection and identification of caprine T. evansi infection in Cebu, Philippines.

Prevalence and risk factor analysis of bovine hemoplasma infection by direct PCR in Eastern Hokkaido, Japan

The prevalence and risk factors of 2 bovine hemoplasma species-Mycoplasma wenyonii (Mw) and "Candidatus Mycoplasma haemobos" (CMh)-were examined by direct PCR using whole blood samples collected from 343 cattle in Eastern Hokkaido, Japan. The sensitivity of the direct PCR assay was 10-fold higher than the standard PCR assay, detecting 5 copies of bovine hemoplasma DNA per reaction. An epidemiological survey of sampling location, living conditions, age and bovine leukemia virus antibody was performed to assess infection risk factors. The prevalence rates were 38.5% for Mw and 39.1% for CMh, respectively, with an overall prevalence rate of 64.7% for all bovine hemoplasma infections. Significant differences were found in sampling location, living conditions and age. Compared with pastured cattle, farmed cattle were significantly more susceptible to infection with total hemoplasma species (P<0.001), and were particularly susceptible to CMh (P<0.001). Cattle that were 1-3 years of age were more susceptible to infection with hemoplasma compared with other age groups. Bovine leukemia virus infection status was not significantly associated with hemoplasma infections. Blood examination revealed significantly lower RBC, Hb, and PCV levels, and a higher MCV in infected cattle than in noninfected cattle.