PCR-Based Detection of Trypanosoma evansi Infection in Semi-Captive Asiatic Black Bears (Ursus thibetanus)

Clinical signs, viz lethargy, increased heart rate and reduced appetite, making trypanosomiasis a possible differential diagnosis, were found in five out of twenty semi-captive Asiatic black bears (Ursus thibetanus) in a sanctuary, located in Kund, District Sawabi, KPK, Pakistan. Microscopic examination of blood samples of bears expressing clinical signs and symptoms revealed the presence of haemoflagellates, which was found to be trypanosomes. Subsequently, the PCR technique was exploited to screen for the presence of trypanosomal species in all bears’ blood samples. Blood samples from 20 individual bears were screened using three sets of primers specific to Trypanosoma evansi species. Three primer pairs used are equally effective in successful detection of the parasite. Two out of five, diseased bears diedprior to any trypanosoma specific medication while the rest were given an administered dose of Melarsomine (Immiticide). The treated bears survived and were assured to be aparasitemic on post-treatment examination after six weeks.