Table 1

Results of comparison of BD ProbeTec strand displacement assay with culture

	SDA +ve	SDA −ve
Initial results Culture +ve	46	2*
Culture −ve	5†	1529

After review of culture results
Of the two SDA negative (−tive) and culture positive (+tive) patients on review one of the +tive cultures was misidentified as N gonorrhoeae* and therefore the sample was re-classified as N gonorrhoeae culture −tive. In the other (female) patient culture was +on the urethral swab only.
†Of the five strand displacement assay (SDA) +tive/culture −tive samples, a retrospective review of stored culture plates showed 4 of these to either have a low level of N gonorrhoeae growth on culture plate or the organism was redesignated as N gonorrhoeae following repeat gram stain/API. In the fifth patient, a follow up culture sample was positive for N gonorrhoeae. Therefore all these 5 patients who were initially SDA +tive /culture −tive were confirmed as GC infected.
Culture +ve	51	1
Culture −ve	1	1529