Risk factors for incident cervical human papillomavirus infection in women in a high-risk area for cervical cancer

Human papillomavirus (HPV) is the sexually-transmitted etiologic agent of cervical cancer. Despite screening programs, cervical cancer remains too common, particularly in developing countries. Various correlates of prevalent infections have been identified. However, the determinants of incident infections have never been studied.Data were collected during a prospective cohort study conducted in Brazil. Incidence density rates of infection were calculated and determinants of incident infection were identified using Cox regression models. Analyses were done for HPV types classified into low-risk and high-risk depending on their association with cervical neoplasia.The incidence density rates were 9.3 and 7.6 per 1000 women-months respectively for low-risk and high-risk HPV infection. Independent positive associations were found between the time of first occurrence of low-risk infection and age, number of sexual partners in the past 5 years, education level and use of non-commercial hygienic absorbents. The first occurrence of high-risk infection was independently predicted by age, age at first sexual intercourse, condom use (negative associations) and by the number of sexual partners in the past year (positive association). Elucidation of the dynamics of infection is a first step towards implementation of public health programs for reducing the risk of cervical cancer