Association of bacterial vaginosis to atypia in squamous cells of the cervix

Abstract

Considered the sexually transmitted infection (STI) with the highest incidence worldwide, HPV in 1992 was recognized by the WHO as a necessary condition for the development of cervical cancer (CC). Its transmission occurs by direct contact with the squamous epithelium of the skin and mucosa, which can cause benign lesions such as warts and papillomas or malignant lesions such as neoplasia. In balance, the vaginal microbiota consists mainly of gram positive bacilli that have the function of maintaining the health of the genital tract, in addition to preventing infections caused by pathogenic microorganisms. The aim of the present study is to correlate changes in the vaginal microbiota with atypical changes in cervical squamous cells. This is an exploratory literature review of 15 articles found in the search sources Scientific Electronic Library Online (SCIELO), Google Scholar, Lilacs, using keywords “Atypias in Squamous Cells”, “HPV”, “Cancer of the Cervix”, “Vaginal Microbiota”. The imbalance of the normal microbiota can occur due to internal and external factors that provide the total or partial replacement of this environment by other types of bacteria, highlighting the role of Gardnrella vaginalis, which causes bacterial vaginosis (BV). Studies suggest that the presence of BV may be a cofactor for HPV infection. According to some authors, the composition of the vaginal microbiota associated with infection by the HPV virus can be explained by conditions of alkalinization of the vaginal pH, increasing susceptibility to sexually transmitted infections, which automatically increases the risk of HPV infection. In a study carried out in London, it was revealed that women with the presence of BV and, respectively, a reduction in Lactobacillus ssp., associated with the worsening of the disease, represent a greater risk of developing precursor lesions of CC. Given the above, it was possible to establish a relationship between changes in the vaginal microbiota and atypical cellular changes in the cervix. In this way, it was verified the importance of the stable vaginal microbiota for the health of the uterus, and that in conditions of imbalance, it provides an inhospitable environment for the normal microbiota, favoring the proliferation of bacteria that make the vaginal environment susceptible to HPV infections. This, in turn, promotes precursor lesions, which, when not diagnosed and treated in time, can result in the development of invasive cervical lesions.