Abstract
BACKGROUND: Prevalence information is lacking on human papillomavirus types 16 and 18 (HPV-16/18) infection in cervical tissues of women residing in Riyadh, Saudi Arabia. In addition, there are no observations on progression to cervical intraepithelial neoplasia (CIN). SUBJECTS AND METHODS: Pap smear and HPV-16/18 DNA detection by PCR followed by Southern blotting was performed on 120 subjects (Saudi and other Arab nationals) during routine gynecological examination. Some HPV-positive subjects were followed for 4 years, by Pap smear every 6 months and by HPV DNA detection at the end of 4 years. RESULTS: Overall HPV-16/18 prevalence was 31.6%. HPV-16 prevalence alone was 13.3%, HPV-16 as a mixed infection with HPV-18 was 15%, and all HPV-16 was 28.3%. HPV-18 alone was 3.3%, HPV-18 as a mixed infection with HPV-16 was 15%, and all HPV-18 was 18.3%. Ten subjects had cervical abnormalities with the Pap smear test, six of whom were HPV-16/18 positive, 1 with HPV-16, 1 with HPV-18, and 4 with a mixed infection of HPV-16/18. Of all 23 HPV-16/18-positive subjects, either as individual or mixed infection, followed for 4 years, 7 showed abnormal cytology, 6 at initial examination and 1 during follow-up. Of these 7, 6 reverted to normal without treatment and 1 was treated and became normal after 3 years. None of the subjects progressed to CIN-III. CONCLUSION: A high prevalence of HPV-16/18 was found, but with a low rate of progression to CIN. A significant association with abnormal cytology was found only in patients with HPV-16/18 mixed infection.