Clinical and Molecular detection of Theileria annulata isolated from calves and ticks in Iraq

Bovine theileriosis is an important tick-borne disease caused by intraerythrocytic parasites from genus Theileria. Theileria annulata is the causative agent of tropical theileriosis or Mediterranean theileriosis. This study directed to diagnose theileriosis among calves and ticks in Al-Qasim city, Iraq. Seventy blood samples from seventy calves and seventy ticks were collected in April-August of 2022. These animals were a local breed with clinical signs of theileriosis; lymph node enlargement, fever (40c-41c), palely mucus membrane, loss of appetite; living in different areas of Al-Qasim city. The blood smear was prepared and stained with Giemsa for microscopic examination of T.annulata. Polymerase chain reaction (PCR) assay was performed to detect T.annulata using primer pairs targeted to 18S ribosomal RNA gene. The molecular assays revealed that seventy calves were infected as well as the samples of ticks.