Field evaluation of PCR assays for the diagnosis of tropical theileriosis in cattle and water buffaloes in Egypt

The study evaluated the usefulness of specific PCR assays for the diagnosis of tropical theileriosis caused by Theileria annulata in Egypt using Microscopic Examination (ME) for comparison. Blood samples from 258 animals comprising both sick and apparently healthy cattle and water buffaloes were examined for the presence of Theileria infection by ME using Giemsa-stained blood smears and the prevalence was 18.6% (48/258). To evaluate the usefulness of PCR assays for the identification Theileria sp. and T. annulata, 30 bovine blood samples selected from the 258 animals were tested by both PCR assays and ME and ME identified 9/30 (30%), whereas the PCR assay for Theileria sp. was more sensitive which identified 21/30 (70%). Of these 21 Theileria positive samples, 15 were identified as infected with T. annulata by specific PCR assay for T. annulata. This study demonstrated that specific PCR assays are more sensitive and accurate for the clinical diagnosis of tropical theileriosis.