ECHINOCOCCUS-GRANULOSUS - A SEROEPIDEMIOLOGICAL SURVEY IN NORTHERN ISRAEL USING AN ENZYME-LINKED-IMMUNOSORBENT-ASSAY

Following an intensive health education programme, 8651 finger-prick b lood samples, 4122 from a predominantly adult group attending a primar y care clinic and 4529 from schoolchildren, were collected in Tamra, n orthern Israel. An enzyme-linked immunosorbent assay (ELISA) for immun oglobulin G (IgG) was used to detect anti-Echinococcus granulosus anti bodies, using both crude and purified antigens. The seroprevalence in the adult group was 0.48% (20/4122); optical density values were 0.1-0 .14 in 10 subjects, 0.15-0.19 in 9, and greater than or equal to 0.2 i n one; prevalences did not differ significantly between males and fema les or among age groups. Twenty-six of the schoolchildren (0.57%) were seropositive, 23 with optical densities of 0.1-0.14, one of 0.15-0.19 , and 2 greater than or equal to 0.2. A high correlation was observed between ELISA positivity and both positivity in the are 5 immunoelectr ophoresis test and the presence of a high titre in the indirect immuno fluorescence assay. Cross reactivity was observed with sera from schis tosomiasis and ancylostomiasis patients, using both crude and purified echinococcal antigens. The results indicated that the IgG ELISA, usin g both crude and purified antigens, was very useful for seroepidemiolo gical screening for echinococcosis, and that this condition is an emer ging disease in northern Israel.