Comparison of Gram Stain and Pap Smear Procedures in theDiagnosis of Bacterial Vaginosis

Abstract

Objective: The purpose of this study was to examine the characteristics of Gram stain versus Pap smear in diagnosis of bacterial vaginosis (BV). Methods: One-thousand and sixty women were enrolled in this study. All cases with symptoms of BV were determined by Amsel's criteria, which were accepted as the gold standard for diagnosis of BV. Pap smear and Gram stain evaluations were compared according to Amsel's criteria, without viewing the clinical results of the patients. Gram stain and Pap smear results were determined as negative or positive according to Amsel's criteria. Sensitivity, specifity and positive predictive values were calculated. Results: After accepting the cases that were diagnosed as BV according to Amsel's criteria as reference cases, the sensitivity of the Gram stain method was calculated as 97% and the sensitivity of the Pap smear method as 93%. Similar specificity rates were obtained with both methods in diagnosis of BV related to the clinical results. There were no statistically significant differences in diagnosis of BV between these two groups. Conclusion: If Amsel's criteria are accepted as the gold standard for diagnosis of BV, Gram stain and Pap smear methods will give similar results in diagnosis.

Prevalence of Bacterial Vaginosis and Comparison of the Efficacy of Gram Stain and Pap Smears in Its Detection

“…6 the sensitivity of the Gram stain method was calculated as 97% and the sensitivity of the Pap smear method as 93% which is different from our findings.One of the most important complications of bacterial vaginosis is cervical dysplasia. It is hypothesized that bacterial vaginosis could be important in the development of neoplasia of the cervix, because the abnormal microflora in this condition produce carcinogenic nitrosamines.…”

Significance of a Diagnosis of Microorganisms on Pap Smear

“…The vaginal flora shifts from the dominant aerobic Lactobacillus to predominantly anaerobic organisms including G. vaginalis, Bacteroides species, Mobiluncus species, and Mycoplasma hominis [44,45]. Under normal circumstances, lactobacilli produce an acidic medium in the vagina by the production of hydrogen peroxide, which transforms glycogen to lactic acid.…”

“…This lactic acid suppresses the growth of other organisms. However, if the balance is tipped away from the lactobacilli, they are replaced by anaerobes [44].…”

“…The criterion standard for the clinical diagnosis was first described by Amsel et al [46] and has been repeated in numerous works. Three of the 4 objective signs must be present: (1) a milky homogenous vaginal discharge, (2) a vaginal pH higher than 4.5, (3) a fishy odor with the addition of KOH (whiff test), and (4) clue cells on a saline wet mount [44,47,48]. Bacterial vaginosis has been implicated in preterm labor, premature rupture of the membranes, chorioamnionitis, puerperal endometritis, pelvic inflammatory disease, postoperative vaginal cuff cellulitis, and urinary tract infection [48].…”

“…The Pap smear was also specific, with a range of 94% to 98%. Each of the studies concluded that the Pap smear would give accurate diagnostic results [44,45,48]. A large study was undertaken by Giacomini et al [47] in 1997.…”