Prevalence and characterization of Trypanosoma species from livestock of Cholistan desert of Pakistan.

Trypanosomiasis is one of the most pathogenic infection of livestock caused by several Trypanosoma species. The current study aims to determine the current prevalence of trypanosomiasis in livestock of Cholistan desert, Pakistan by molecular characterization. A total 272 animals, 61 camels, 59 cattle, 50 goats, 50 sheep and 52 donkeys that were bled and processed for thin smear microscopy, packed cell volume (PCV), DNA extraction, PCR, formol gel test and for cryo preservation. For diagnosis and molecular characterization, three sets of primers including TBR, RoTat 1.2, TRYP4 were used which detect their targets including repeated satellite DNA region, variant surface glycoprotein (VSG) gene and the ITS ribosomal DNA sequence of microbe. According to results, 6.2% animals were positive by microscopy, 51.1% by formol gel, 54.7% by PCV and 36.7% by PCR. The results of this study support the idea that PCR is a sensitive, robustic and reliable technique to diagnose trypanosomiasis and it should be added in conventional setup along with microscopy to avoid false negative and positive results. The PCR based order of prevalence of trypanosomiasis in Cholistani livestock was sheeps>camels>donkeys>goats>cattle. Similary, on the basis of thin smear microscopy the prevalence of trypanosomiasis was donkeys>camels>sheep>goats>cattle. It was observed that Trypanosoma evansi is the most prevalent specie involved in trypanosomiasis in Cholistani livestock.