New diagnostic tools to understand the epidemiology of sheep theileriosis in northern Sudan
In the Sudan animal resources contribution in the national income(GDP) is estimated at 30% ( Hassan, 2003).Ticks and tick- borne diseases are widespread in the country. Theileria are tick transmitted haemoprotozoan parasite infecting wild and domestic Livestock throughout many areas of the world ( Uilenberg et al. 1981). The most economically important species are Theilera parva and Theileria annulata which are both pathogenic to cattle and Theileria lestoquardi which is pathogenic to sheep and goats. Hyalomma anatolicum anatolicum ticks have been shown to transmit the infection to susceptible cattle (Theileria annulata) and sheep( T.lestoquardi). Malignant Olive Theileriosis, which is caused by T.lestoquardi, has recently emerged as an important cause of morbidty and mortality among sheep in the Sudan. Najwa (1986) stated that 68% of sheep examined in Khartoum State were infected with Theileria species. Elghali and Elhussein ( 1995) reported a prevalence of 21.3% and 17.1% in Ed damer province in 1992 and 1993 respectively . Most recently, the prevalence of T. lestoquardi antibodies was determined using IFAT test based on schizont antigen antibodies were found in all sheep grazing areas of the country ( Salih et al 2003).