Development of a Species-Specific qPCR Assay for Theileria annulata Detection and Its Molecular Surveillance in Kazakhstan

Abstract

Simple Summary Theileria annulata is a tiny parasite that infects the blood of cattle and causes a serious illness called tropical theileriosis, which is common in Kazakhstan and many other warm-climate countries. Infected animals can become very sick, produce less milk and meat, and sometimes die, causing real financial harm to farmers. Older laboratory methods for finding this parasite, based on examining blood under a microscope, often miss mild infections. In this study, we designed a new, highly accurate genetic test that directly detects the parasite’s DNA in a blood sample. We used this test to check blood from cattle in ten regions of Kazakhstan and found the parasite in four of them. We also compared the genetic makeup of the parasites we found with parasites previously reported in Kazakhstan and China and found them to be closely related. Our new test detected more true infections than the traditional microscope method. These results give veterinarians and animal-health authorities a faster, more reliable tool to find infected cattle early, track how the disease spreads across the country, and take timely action to protect herds and reduce losses for farmers.