Studies on the specific immunodiagnosis of cystic echinococcosis in camels using enzyme-linked immunosorbent assay

Abstract

Cystic echinococcosis (CE) is of increasing public health and socio-economic concern because of the large morbidity rates and produced high economic losses in the livestock industry. The objective of the current research was to study the reliability of indirect ELISA in detecting CE, based on two different types of crude antigens of camel origin; protoscolex and germinal layer antigens from hydatid cyst. Blood samples were collected from 284 (125 slaughtered and 159 live camels). Out of 125 slaughtered camels examined visually, 55 (44%) were found to have hydatid cysts. Of them, 52/125 (41.6%) and 3/125 (2.4%) harboured hydatid cysts in lungs and livers respectively. Fertile lung cysts were 32.8%; 26.9% were sterile, while 40.3% of lung and liver cysts were calcified. The sensitivity of ELISA was 83% and 46.5% when protoscolex and germinal layer antigens were used, respectively. The respective specificity of antigens of protoscolex and germinal layer was 70.3% and 41.7%. The protoscolex antigen showed higher accuracy (73.6%) compared to the germinal layer antigen (52.8%). The cross reactivity of these antigens were evaluated with antigens and hyperimmune sera of CE and Fasciola spp. and Haemonchus contortus using ELISA. The results showed also weak immu-nogenic potency of each antigen with Fasciola spp. hyperimmune sera at dilution 1:50 while hyperimmune sera of Haemonchus contortus did not bind any antigen.