The Falcon assay screening test-
enzyme-linked
immunosorbent assay (FAST-ELISA) and the
enzyme-linked immunoelectrotransfer blot (EITB) technique were used to test human sera with Dracunculus medinensis adult worm
antigen in order to assess their potential value in the immunodiagnosis of
dracunculiasis. The human sera used were from patients with prepatent and patent D. medinensis
infections or from patients infected with other nematodes (Onchocerca volvulus and Loa loa) or trematodes (Schistosoma mansoni and S. haematobium), as well as uninfected Nigerian and Puerto Rican normal controls. In the FAST-ELISA, the sera from prepatent and patent
dracunculiasis patients gave the highest absorbance values relative to normal human sera. The highest cross-reactivity was observed with
onchocerciasis sera; no cross-reactivity was seen with sera from individuals with
loiasis or
schistosomiasis mansoni or haematobia. By the EITB, sera from
dracunculiasis patients specifically recognized a 16 kDa
protein (Dm 16) and
antibodies to Dm 16 disappeared 2 months after worm extraction. Recognition of Dm 16 occurred from the late prepatent stage.
A 17 kDa
protein (Dm 17) was also recognized by
dracunculiasis sera, but
antibodies to Dm 17 disappeared more slowly and were present 1 year after recovery. The 16 kDa and 17 kDa
antigens of D. medinensis may be useful in the immunodiagnosis of
dracunculiasis.