PREVALENCE OF TICK-VECTORS OF THEILERIA ANNULATA INFESTING THE ONE-HUMPED CAMELS IN GIZA, EGYPT

Abstract

Theileria are obligate intracellular protozoan parasites transmitted by hard ticks that cause severe and mild infections in their vertebrate hosts. The objective of the present study was to identify the possible tick vector of Theileria spp. and to determine the prevalence of camel theileriosis in Birqash market, Giza, Egypt. These camels are previously imported from Sudan and Somalia. A total of 298 nomadic one - humped camels in the study area were selected by simple random sampling technique during the period from December 2014 to November 2015. A total of 1540 ticks were collected, four ixodid tick species; Hyalomma dromedarii, Amblyomma lepidum, Amblyomma variegatum, and Rhipicephalus pulchellus were found on camels. It was observed that H. dromedarii recorded the highest prevalence (69%), followed by A. lepidum (8%), A. variegatum (3%) and R. pulchellus (2%). Using light microscope Hyalomma dromedarii was the most tick carrier of Theileria spp. which recorded 1.3% (20/1540) Theileria infection. The highly prevalence rates for all ticks were monitored during the summer season. The molecular detection of Theileria annulata in Geimsa-stain positive H. dromedarii ticks was performed by the PCR using primer set N516/N517 derived from the gene encoding the 30 kDa major merozoite surface antigen. This primer set amplified T. annulata in H. dromedarii at 750 bp. Thus the presence of H. dromedarii on camels in thefield have dangerous inclusive for animal health and to some extent humans. To reduce thesedangerous effects, strategic control methods could be used in the control of ticks.