Comparison of ELISA, radioimmunoassay and stool examination for Schistosoma mansoni infection

Publisher Website
Google Scholar
Abstract
A comparison was made of the sensitivity and specificity of four diagnostic tests for Schistosoma mansoni infection in a community of 516 untreated persons in St. Lucia, West Indies. Prevalence of infection as obtained by: (i) the Bell filtration technique was 44·4% (one filter) and 63·2% (three filters); (ii) the Kato thick smear, 60·2%; (iii) by radioimmunoassay (RIA), 73·3%; and (iv) enzyme-immunoassay (ELISA) 70·9%. The age distribution of persons serologically positive but parasitologically negative showed these to be mostly children and persons 40 years old and over. By means of a statistical test due to Cochrane, it was concluded that there was no evidence to indicate a difference between paired serological tests and paired parasitological tests in their diagnostic capability. There was a very significant difference between the Bell technique and the other three tests. The ELISA emerged as a less satisfactory test than the RIA or the Kato thick smear. The levels of sensitivity and specificity of each test were measured by Armitage's “J” index. The reliability of the Bell filtration technique was 64%, of the ELISA 68%, of the RIA 78% and of the Kato 85%.