Infection and cervical intraepithelial neoplasia

The impact of sexually transmitted diseases (STDs) on the development of ce rvical intraepithelial neoplasia (CIN) has been increasingly recognized ove r the last 20 years. Much attention has been focused on human papillomaviru s (HPV) and the potential for screening for certain HPV types alongside sta ndard cervical cytology in the hope of identifying those females at particu lar risk of developing high grade CIN or invasive carcinoma. Some infection s, for example herpes simplex virus (HSV), have been heavily investigated i n the past as they were thought to be involved in the development of CIN bu t were subsequently discounted. Also discounted as causes of CIN are Neisse ria gonorrhoeae (NG) and Chlamydia trachomatis (CT). These infections were found to be associated with higher rates of CIN in early studies but transp ired to be markers for the presence of other infections and pathology and t herefore not themselves directly responsible for cytological changes. The r ole of bacterial vaginosis (BV) is the focus of several current investigati ons, not only in the genesis of CIN but also in the development of other gy necological and obstetric conditions and complications. Evidence to implica te Trichomonas vaginalis (TV) in the genesis of CIN is conflicting, but the re is some evidence that it may exert its influence in a similar way to tha t hypothesized for BV, ie via abnormal amines. It is well known that there is a high level of concordance of STDs whereby the presence of one infection greatly increases the likelihood of there bei ng one or more others present. There may be a synergism between some infect ions with regard to the causation of GIN, although the evidence for this is putative. Presented here is an overview of current and previous research i n the field of lower genital tract infection as it relates to the developme nt of GIN.