Combining cervical and anal-canal specimens for gonorrhea on a single culture plate

Abstract

To reduce the cost of detecting gonorrhea, the effect on diagnostic sensitivity of combining 2 culture specimens on the same plate of modified Thayer-Martin medium was studied using specimens from 7787 women seen consecutively in the clinic. There was no significant difference (P > 0.05) between 1 cervical and 1 anal-canal specimen placed on separate plates (C,A) and these 2 specimens combined but spaced apart on a single plate (C/A), or between 2 cervical specimens combined but spaced apart on the same (C/C) and C/A. C/C, C/A and C,A have equivalent diagnostic sensitivities. C/A detected 5.68% more women with gonorrhea than did a single cervical culture (C) (P < 0.001). If C/A were to replace C,A for culture specimens from women seen in venereal disease clinics and C for specimens taken and cultured outside of venereal disease clinics, gonorrhea control programs in the USA could realize substantial savings.