PREVALENCE AND INFECTION PATTERN OF TRYPANOSOMA EVANSI IN CAMELS IN MID-EASTERN SUDAN E.A. ELAMIN * , M.O.A. EL BASHIR AND E.M.A. SAEED Department of Parasitology, Faculty of Veterinary Science, University of Khartoum, PO Box 32, Khartoum North, Sudan *Present address: Department of Microbiology and Parasitology, College of Veterinary Medicine and Animal Resources, King Faisal University, PO Box 1757, Al- Ahsa 31982, Saudi Arabia ABSTRACT Elamin, E.A., El Bashir, M.O.A. and Saeed, E.M.A., 1998. Prevalence and infection pattern of Trypanosoma evansi in camels in mid-Eastern Sudan. Tropical Animal Health and Production, 30(2), 107^114. The antigen detection enzyme immunoassay (AgELISA) in conjunction with parasitological examina- tion of blood were used to study the enzootic situation of cameline trypanosomiasis in mid-Eastern Sudan. A one year survey showed that the infection is endemic among pastoral camels with a prevalence of 5.4% based on parasitological examination and 31.3% based on AgELISA. The infection rate was higher during the dry period (November to May) than the wet season. Young camels had a much lower infection rate as detected by parasitological techniques, but not with AgELISA. A lower prevalence of infection was detected by bu¡y coat technique (BCT) in herds of camels raised by nomads compared with those kept by agropastoralists and in camels located in the southern districts of mid- Eastern Sudan. INTRODUCTION Approximately 20% of the world camel population, some 3 000 000 animals, is found in the Sudan. Camels are an important source of meat, milk and hair, and are used for transportation and draught power. Camels provide foreign currency from their export to North Africa and the Middle East. Their main owners are pastoralists in northern Sudan and although many are still nomadic, an increasing number are settling as agropastoralists into large agricultural schemes in eastern Sudan and are keeping camels on the products and residues of sorghum (Abu Sin, 1988). However, both settled and nomadic systems of husbandry commonly share pastures in northern Butana during the rainy season. Recently a severe drought, which a¡ected most of northern Sudan, has increased the importance of camels compared to cattle and sheep. The major constraint to camel productivity in the Sudan is trypanosomiasis caused by Trypanosoma evansi. Currently, diagnosis is based on clinical signs and/or parasitological con¢rmation of infection, but clinical signs are not pathognomonic and detection of trypanosomes in the blood is frequently di¤cult. Recently, the enzyme-linked immunosorbent assay (ELISA) has been used to detect circulating antigens in camels. Tropical Animal Health and Production, 30 (1998) 107^114 # 1998 Kluwer Academic Publishers. Printed in the Netherlands 107