In an investigation conducted in student health clinic patients, the polymerase chain reaction was used to detect human papillomavirus (HPV) DNA, thereby allowing measurement of the prevalence of HPV infection and study of the association between HPV infection and risk factors for cervical cancer. Of 159 women eligible to participate, 105 (66%) provided a specimen of cervical cells for HPV typing, and also answered an interviewer-administered questionnaire which sought information on risk factors for cervical cancer. Nucleic acid extracted from cervical cells was screened with primers for HPV types 6, 11, 16, 18, 33 and with an HPV Consensus primer. Overall, the prevalence of HPV infection was 18.1%, while for HPV-6/11 it was 2.9% and for HPV-16/18 it was 10.5%. There were statistically significant increases in risk of HPV infection with a history of ever having smoked cigarettes (overall, and for HPV-16 alone) and with a history of usually having sexual intercourse during menstrual periods (overall, but not for HPV-16), and these associations were independent of the effects of age at first sexual intercourse and number of sexual partners. The latter 2 variables, as well as the total number of occasions of sexual intercourse, a history of anal intercourse, and a history of ever having used oral contraceptives, were not associated with statistically significant alterations in risk of HPV infection.

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To determine the prevalence of cervical human papillomavirus (HPV) infection and risk factors in young women from Brazil, Canada, and the USA. Cross-sectional study in 3204 healthy women, aged 15 to 25 years. Cervical samples were collected for cytology and for HPV DNA detection (SPF 10-LiPA 25 system). Serum samples were collected for the measurement of HPV-16 and HPV-18 antibodies by enzyme-linked immunosorbent assay. Risk factors were obtained through a questionnaire. Overall, 26.6% of women had DNA detected for at least 1 HPV type. The prevalence for oncogenic HPV types was 21.7% (25% in Brazil, 16.9% in Canada, and 19.1% in the USA). HPV-16 was the most prevalent oncogenic type (5.2%). The next most common oncogenic HPV types were 51 (3.3%), 52 (3.3%), 31 (2.9%), 66 (2.3%), and 39 (2.0%). Multiple oncogenic types were detected in one-third of the infections. The prevalence of HPV-16 and/or HPV-18 infections detected by DNA and/or enzyme-linked immunosorbent assay was 24.8%. The majority of women (85%) had a normal cervical cytology. Sexual behavior was the main determinant for HPV-16/18 infections and squamous intraepithelial lesions. The prevalence of HPV oncogenic infections was high and linked to sexual behavior. Strategies to reduce the burden of oncogenic HPV infection, such as prophylactic vaccination programs, are likely to impact the burden of disease due to cervical precancer and cancer.