Molecular and parasitological detection of Trypanosoma evansi in Camels in Ismailia, Egypt

Abstract

Trypanosoma evansi (T. evansi) is an endemic disease of camels and other domestic animals in Egypt. This study aimed to determine the prevalence of clinical and sub-clinical T. evansi infection among camels in Ismailia, Egypt, as well as survey their owners for T. evansi infection. The diagnostic sensitivity of three different PCR assays for detection of T. evansi in blood samples was evaluated. Blood samples were collected from 100 camels and 20 of their owners in the Ismailia governorate. Results revealed that the percentage of infected of camels with T. evansi vary with the detection method, ranging from 10% to 46% by PCR compared to 12% by microscopic examination of stained blood smears. Targeting the highly repeated sequence of mini-chromosome satellite DNA (TBR1/2 primer set) was more often seen in the PCR method (46% positive) compared to targeting ITS 1 (16% positive) or RoTat 1.2 VSG (10% positive) sequences. A partial sequence of RoTat 1.2 VSG gene was identical to the T. evansi sequences reported from India and Kenya, but varied similarity was seen when aligned with Egyptian T. evansi sequences. None of the camel owners were positive for T. evansi by microscopic examination of stained blood smears or PCR assays. PCR assay based on TBR sets is useful in the diagnosis and control disease and reducing economic losses.