Microscopic, Serological and Molecular Screening of Theileria annulata in Camels (Camelus dromedarius) of Saudi Arabia

The present study was aimed to evaluate the prevalence rate of Theileria spp., especially T. annulata, in camels of Taif Governorate, Saudi Arabia. A total of 102 blood samples were collected from camels. Parasitological examination of buffy coat smear, ELISA-IgG, and PCR (targeting 16S rRNA and cytochrome b gene sequences) assays were done for T. annulata infection detection. The results report a high prevalence rate of T. annulata in the examined dromedary’s population using ELISA-IgG (32.4%), followed by targeted PCR (25.5%). Then lower detection was reported by buffy coat Giemsa stained (10.8%). Statistical analysis using one-way ANOVA followed by Tukey’s at P < 0.001 showed signifcant variation in values within different diagnostic tools and age categories. Both females and males were at risk of parasitic infections, but females have a higher incidence (17.6%, 15.7%, 6.8%). Young age (X≤3 years) camels were the most infected category (50.0%, 44.4%, 22.2%) according to age from elder ones. These results could be a baseline for easing a later large-scale epidemiological screening on tropical theileriosis in the camel population in Saudi Arabia.