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Enzyme-linked immunosorbent assay (ELISA) in the detection of IgG antibodies in onchocerciasis using blood collected on filter paper

Abstract:

The enzyme-linked immunosorbent assay (ELISA) for onchocerciasis was performed with a crude saline extract of adult Onchocerca volvulus and 2 types of blood samples from inhabitants in an endemic and a nonendemic area in Guatemala and Venezuela. The ELISA values of blood samples taken on filter paper and of sera obtained by venipuncture showed at high correlation (r=0.948). IgG antibodies in these human blood samples were measured with the ELISA using O. volvulus and O. gutturosa antigens. It was shown that O. gutturosa antigens were as potent with the ELISA as O. volvulus antigens. The results from five surveyed areas revealed that the mean ELISA value of a community closely correlated the corresponding microfilarial (mf) rate. A sex-related difference was evident in the ELISA values in the subjects from moderate and low endemic areas. The mean ELISA values of a population were age-dependent. Many subjects in mf negative subjects from endemic areas had high ELISA values. These false positive cases were thought to be due mainly to low sensitivity of skin biopsy and/or to early infection. These results suggest that the specificity and sensitivity of the ELISA for onchocerciasis are satisfactory.