Virulence of Entamoeba histolytica according to the Strains in Korea I. Comparison of Indirect Fluorescent Antibody Test and Immobilization Test for the Sero-Diagnosis of Amoebiasis

ABSTRACT

Indirtct fluorescent antibody and immobilization tests on Eatamoeba histolytica have been carried out using the sera of 84 Cheju-islanders, a highly endemic area of amebiasis in Korea. The sera were divided into seven groups; 1) liver abscess (E. histolytica in liver), 2) liver abscess (E. histolytica in stool), 3) liver abscess (E. histolytica not demonstrated by examinations of abscess and stool), 4) hepatomegaly (E. histolytica in stool), 5)hepatomegaly (E. histolytica not found in stool), 6) cyst carrier, symptomless healthy individuals and 7) control group. 1. The indirect fluorescent antibody test, 100 per cent of cases with group 1 and group 2, 40 per cent with group 3 and group 4, 33.3 per cent with group 5, 50 per cent with group 6 and 5.9 per cent with control group were found positive at 116 or higher. Higher titers were manifested in proved liver abscess, but lower titres were in cyst carrier and control group. 2. The immobilization test, 100 per cent of sera in group 1, 2 and 3, 8O per cent in group 4, 90.5 per cent in group 5, 40 per cent in cyst carrier and 23.5per cent in control group showed positive. 3. Both tests were positive in all sera of group 1 and 2, six sera out of 15 in group 3, four out of 10 in group 4, seven out of 21 in group 5, two out of 10 in cyst carriers and one out of 17 in controls. 4. Indirect F-A titers were not correlated with the rate of immobilization. Therefors it is suggestive that the two methods will be preferable for the diagnosis of suspicious cases of amoebiasis.