IgA and IgM anti-Naegleria fowleri antibodies in human serum and saliva

Antibodies from IgA and IgM classes that recognize Naegleria fowleri (Nf) p roteins were detected by the ELISA assay in serum and saliva from three gro ups of people: (i) subjects with upper respiratory tract infections (URTI) living in the parasite-endemic area, (ii) healthy persons from the same are a, and (iii) healthy persons from a parasite-nonendemic area. In serum and in saliva the titers of IgA antibodies to Naegleria fowleri in the group of patients with URTI was significantly higher than that of the healthy group in the parasite-endemic area; also the titers of IgM antibodies in serum w ere significantly higher in patients. On the contrary, in saliva the antibo dies were higher in healthy people from the parasite-endemic area. In all c ases the subjects from the parasite-nonendemic area had lower antibody tite rs in serum and saliva.