RISK-FACTORS FOR HPV DNA DETECTION IN MIDDLE-AGED WOMEN

Background and Objectives: Strong epidemiologic evidence indicates tha t human papillomavirus (HPV) is the main etiologic factor of cervical cancer. A few cohort studies suggest that most HPV infections are tran sient in young women and that persistent HPV infections are more commo n in older women. Little is known about the determinants of persistent HPV infections. The present study was aimed at increasing our knowled ge about these determinants. Goals: To identify risk factors for genit al HPV DNA detection among cytologically normal middle-aged women. Stu dy Design: Eight hundred ten women who participated as control subject s in three case-control studies on cervical cancer in Spain, Colombia, and Brazil were included in this study. After an interview, women und erwent a gynecologic examination with collection of exfoliated cells f or a Papanicolaou smear and HPV DNA detection. Human papilloma virus D NA was detected by polymerase chain reaction (PCR)-based hybridization techniques. Results: The HPV positivity rate was 10.5% in the whole p opulation, but was higher in the areas with high incidence of cervical cancer (17% in Brazil and 13% in Colombia) than in Spain (4.9%), whic h is a low-risk area for cervical cancer. Age was related to the preva lence of HPV DNA in Brazil, but not in Spain and Colombia. In univaria te analyses in all three countries, the prevalence of HPV DNA was posi tively associated with the number of lifetime sexual partners and inve rsely associated with the levels of family income and with age at firs t sexual intercourse. There were four times increase in the odds ratio (OR) or HPV infection in women who had six or more lifetime sexual pa rtners compared with those with one or less. The use of any kind of co ntraceptive tended to decrease the OR for HPV detection. Their ORs ran ged from 0.44 (barrier methods) to 0.48 (oral contraceptives). In Spai n and Colombia, antibodies against Chlamydia trachomatis were positive ly associated with the prevalence of HPV DNA. In a final multivariate model, the positive associations with lifetime number of sexual partne rs, socioeconomic status, and C. trachomatis persisted. Conclusions: T hese results support the sexual transmission of HPV and suggest that s ocioeconomic status and antibodies to C. trachomatis are independent p redictors of HPV detection in middle-aged cytologically normal women.