A cumulative case-control study of risk factor profiles for oncogenic and nononcogenic cervical human papillomavirus infections

Human papillomaviruses (HPVs) play an essential role in the etiology of cer vical cancer, but besides an established role for sexual transmission, litt le is known about other risk factors for HPV infection. Risk factors for no noncogenic, oncogenic, and HPV 16 cervical infections were investigated usi ng a cumulative case-control approach nested in an ongoing cohort study of low income women from Sao Paulo, Brazil. HPV DNA was detected and typed by the MY09/11 PCR protocol. Risk factor information was obtained via intervie ws. In a case-control analysis, we compared women who harbored infections w ith exclusively nononcogenic types (n = 123), exclusively oncogenic types ( n = 94), and any HPV 16 (n = 60) to women remaining HPV-negative (n = 512) throughout 1 year of follow-up. A strong negative association was found bet ween age and oncogenic infections, but not with nononcogenic infections. Or al contraceptive use was strongly and exclusively associated with oncogenic and HPV 16 infections. Markers of sexual activity were associated with all types of infections, although with varying strengths. Our results suggest some important differences in the epidemiological correlates of HPV infecti on according to oncogenicity that may have implications for the planning of specific preventive strategies aiming at reduction of cervical cancer risk .