Serological diagnosis of Oesophagostomum infections.

A sensitive and specific enzyme-linked immunosorbent assay (ELISA) is described to diagnose human infection with Oesophagostomum bifurcum. In an ELISA using crude soluble antigen, prepared from adult O. bifurcum, many cross reactions occurred when measuring IgG titres in patients with other helminth infections. An ELISA based on the detection of specific IgG4, however, had a specificity of over 95%. The sensitivity of the IgG4 ELISA was difficult to assess because a reliable parasitological diagnosis is not available. The IgG4-ELISA described seems to be a powerful new tool to study the distribution of this little known but locally very common nematode parasite.