Differentiating normal from abnormal rates of genital epithelial findings in vaginal microbicide trials

Candidate vaginal microbicides could cause genital irritation, which in turn could facilitate HIV transmission instead of preventing it. While genital epithelial findings are documented in a standardized manner in most microbicide trials, little is known about background rates and predictors for many types of genital findings.

A secondary analysis was conducted using data from a Phase II expanded safety study of the candidate microbicide Carraguard gel (Population Council, NY, USA) in Thailand. Genital findings were identified by visual inspection of the cervix, vaginal walls and external genitalia during pelvic exams prior to gel use (screening and enrollment) and during gel use (at 2 weeks and Months 1-12). Women were interviewed about potential risk factors for genital findings at every visit and tested routinely for sexually transmitted and vaginal infections.

A total of 258 genital findings were identified in 152 woman-years of follow-up. Genital findings were positively associated with older age, increased parity, self-report of genital symptoms, positive HSV-2 serology, bacterial vaginosis by Nugent scoring and the presence of a genital finding at baseline. Furthermore, vaginal findings were positively associated with vaginal practices and yeast infections. Genital findings were negatively associated with use of hormonal contraception, inconsistently associated with frequency of sex and applicator use, and not associated with condom use.

Several factors that are common in women of reproductive age account for the background rate of genital epithelial findings in this population.