The enzyme-linked immunosorbent assay (ELISA) in the laboratory diagnosis of gonorrhoea. A comparative evaluation.

An enzyme-linked immunosorbent assay (ELISA) was used to detect levels of antibodies to Neisseria gonorrhoeae in 100 male patients with suspected gonorrhoea attending a clinic for sexually transmitted diseases. Although significantly higher antibody levels were detectable in patients with clinically diagnosed gonorrhoea confirmed by laboratory tests, positive results were also obtained in 26% of the control subjects, who were presumed to be healthy. Serum anticomplement activity was present in 8% of the subjects with false-positive results, while tests for rheumatoid factor were positive in 14%. However, these problems could be eliminated to a certain extent by including a negative control or background well for each serum sample. Because the ELISA was found to be of high sensitivity and moderate specificity it is concluded that it is a useful serodiagnostic test for gonorrhoea.