Antibodies to gonococcal pili in women with asymptomatic gonorrhoea. Diagnostic value of the ELISA for testing women attending an STD clinic.
The diagnostic efficacy of an enzyme-linked immunosorbent assay (ELISA) using gonococcal pili 6650 as antigen was studied in asymptomatic women attending an STD clinic. Of the 182 women studied, gonorrhoea was diagnosed in 29%. The value of the ELISA was calculated on the basis of four arbitrary cut-off points in the test. The best predictive values for a positive result (PV(+)) were obtained at an absorbance value of A greater than or equal to 1.15 and A greater than or equal to 1.30 and that for a negative result at A greater than or equal to 0.85. When patients with a history of gonorrhoea were excluded, the PV(+) rose only at A greater than or equal to 1.15 (not at A greater than or equal to 1.30) and the PV(-) rose slightly. To be of use in the diagnosis of gonorrhoea in asymptomatic patients the ELISA should be used as follows: the result is positive at A greater than or equal to 1.15 and negative at A less than 0.85, the PV(+) then being 0.52 and the PV(-) 0.85. Whenever sera give a result between A = 0.85 and A = 1.15, the test should be repeated.
D000907:Antibodies, Bacterial / Q000032:analysis*; D000942:Antigens, Bacterial / Q000276:immunology; D002353:Carrier State / Q000175:diagnosis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D010861:Fimbriae, Bacterial / Q000276:immunology; D006069:Gonorrhea / Q000175:diagnosis* / Q000276:immunology / Q000635:transmission; D006801:Humans; D009344:Neisseria gonorrhoeae / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial