RESUMO
To compare the immunologic techniques with the conventional staining methods [mainly modified Ziehl-Neelsen, MZN], 93 children [65 immunocompromised and 28 immunocompetent] potentially at risk of Cryptosporidium parvum were studied. Using MZN, a prevalence of 10.7% in diarrheic children was found. ELISA coproantigen and detection of 23 kDa band of immunoblotting by serum IgG were sensitive and specific. They gave 85.7% sensitivity, 100% specificity, 100% diagnostic accuracy, 100% positive predictive value and 98.9% negative predictive value. ELISA detection of serum IgG gave 85.7% sensitivity, 97.7% specificity, 96.8% diagnostic accuracy, 75% positive predictive value and 98.9% negative predictive value. So, it was concluded that 23 kDa band determined by ELISA is a valuable sensitive and specific mean of diagnosing cryptosporidiosis, as this antigen is a consistent target of the humoral immune response