Histopathological method for diagnosis of cryptosporidiosis using monoclonal antibodies.

A monoclonal antibody directed against the oocyst wall of Cryptosporidium parvum was produced which strongly reacted with 25 strains of the parasite. This antibody was assessed for use in a diagnostic immunoperoxidase assay performed on tissue sections. It permitted an intense and specific staining of the parasite in five biopsies positive for Cryptosporidium parvum fixed with routine techniques. The procedure described may be useful in screening mucosal biopsies from immunosuppressed patients.