Bacterial vaginosis and cervical intraepithelial neoplasia.

METHODS

In an attempt to investigate an association between the finding of clue cells in Papanicolaou-stained (PAP) smears and cervical intraepithelial neoplasia (CIN), a total of 6150 smears from 1976 were re-investigated.

RESULTS

Clue cells representing bacterial vaginosis were present in 10% of the PAP-smears. CIN II and III alone, as well as all CIN cases, were more common in women with bacterial vaginosis (p < 0.001). Histologically CIN III/carcinoma in situ was found in nine patients with and in 16 patients without bacterial vaginosis. The relative risk of having CIN III/carcinoma in situ if the women had bacterial vaginosis was 5.0 with 95% confidence interval of 2.2-11.6.

CONCLUSIONS

The possibility exists that bacterial vaginosis is in some way associated with the development of cervical intraepithelial neoplasia, i.e. as a cofactor to human papilloma virus. Therefore, bacterial vaginosis must be taken in consideration in future studies on CIN.