Detection of IgG Anti-Giardia duodenalis Antibodies in Sera by Indirect Immunofluorescence and Western Blotting Assays.

Constant exposure to Giardia infection throughout a lifetime can maintain high levels of specific antibodies in serum, even without active infection. Moreover, proteins found in intestinal amoebas may hinder the serological diagnosis of giardiasis in endemic areas due to cross-reactivity, which can be partially solved using Giardia low molecular weight proteins.