Detection of Theileria annulata carrier cattle by PCR.

A simple method for treating bovine blood samples for direct detection of T. annulata in carriers, after polymerase chain reaction (PCR) amplification of small subunit ribosomal RNA (SSU rRNA) gene is described. The threshold of detection of the PCR-assay was an erythrocytic parasitaemia of 0.00008% corresponding to 16 infected bovine erythrocytes. In 50 known carriers, 42 were positive in PCR, in which 8 cattle revealed presence of T. annulata in stained blood smear under microscope.