A trial of the validity of genital smears and cultures with gonococcal vaccine provocation in diagnosing genital gonorrhoea in women

In Russia the diagnosis of gonorrhoea in women relied on microscopy, justified by the hypothesis that sensitivity increases using 'provocation' techniques. The aim was to test the value of Gonovaccine as provocation in women who would have received it normally. Cervical specimens from 204 women were tested by culture and a ligase chain reaction (LCR) assay before the women were randomized to receive provocation or not. Further cervical specimens were obtained 24, 48 and 72 hours later for microscopy, culture and LCR tests. In both provocation and non-provocation arms, 24 women were positive for gonorrhoea by the LCR assay. Test-by-test, sensitivity of microscopy was 30% in the provocation arm and 13% in the control arm (P = 0.0407, Fisher's exact test). Patient-by-patient, sensitivity of microscopy was 50% in the provocation arm, but only 25% in the control arm (P = 0.0675, Fisher's exact test). The cost per case was greater ($214) using provocation with microscopy than culture and microscopy at the first visit ($150). Thus, although Gonovaccine provocation doubled the sensitivity of microscopy in detecting gonococci, the internationally recommended protocol of microscopy and culture at first visit should be adopted as routine practice in Russia. The findings raise questions about the pathogenesis and natural history of gonorrhoea.