With the aim to evaluate the circulating cathodic antigen (CCA) levels in relation to
the different clinical phases of Schistosoma sp. infection a sandwich ELISA using
monoclonal antibody 5H11 was performed. The sera of three groups of 25 Brazilian patients
with acute, intestinal and hepatosplenic forms of S. mansoni infection were tested and
compared to a non-infected control group. Patients and control groups were matched for age
and sex and the number of eggs per gram of feces was equally distributed among the three
patient groups. Sensitivity of 100%, 72%, 52% of the assay was observed for the intestinal,
hepatosplenic and acute toxemic groups respectively. The specificity was 100%. Intestinal and
hepatosplenic groups presented CCA levels significantly higher in comparison to those
observed for acute patients (F-ratio = 2,524; p = 0.000 and F-ratio = 6,314; p = 0.015
respectively). There was no significant difference of CCA serum levels between hepatosplenic
and intestinal groups (F-ratio = 1,026; p = 0.316).
