ECHINOCOCCUS-GRANULOSUS ANTIGEN-B AND SEROREACTIVITY IN NATURAL OVINEHYDATIDOSIS

Hydatid cyst fluid from sheep and camels infected with Echinococcus gr anulosus, together with partially purified preparations of hydatid flu id antigen B and a recombinant antigen B product, were tested in an EL ISA for their ability to detect IgG antibodies against E granulosus in the serum of naturally infected sheep. The antibody activity in sera from sheep naturally infected with Taenia hydatigena cysticercosis or Fasciola hepatica was also tested. All the antigen preparations from n ative hydatid cyst fluid were able to detect antibodies in the sera fr om a significant proportion of sheep with natural hydatid cyst infecti on, as identified by inspection at slaughter, although the seroreactiv ity was variable. The native antigen B preparation from camel hydatid cyst fluid gave the highest sensitivity in the ELISA (total 90 per cen t), with 99 per cent specificity. In all cases, the recombinant antige n B was the least sensitive antigen (25 per cent) although it was high ly specific (99 per cent).