ABSTRACT
Objective To understand the various HPV types and the factors influencing their distribution among women with normal cervical cytology in the Shanghai area, to provide basic data for cervical cancer prevention and vaccine use.Methods A questionnaire-based survey was conducted among 3 372 married women in the Shanghai area. A PCR reverse dot blot (PCR-RDB) method was adopted for HPV genotyping of cervical exfoliated cell samples from 3 206 women. Odds ratio (OR) for HPV infection were analyzed using logistic regression. Results Of the 3 206 women investigated, 669 (20.87%) were positive for HPV infection. The highest incidence of HPV infections was seen in the age groups of 55-59 years, 50-54 years and 45-49 years, with the rates of positive detection being 27.67%, 21.65%, and 21.55%, respectively. While 70.4% of the positive cases had a single infection, 29.6% showed multiple infections. In cases with multiple infections, double infection was predominant (20.63%). The top five high-risk gene types were HPV52(3.65%),HPV53(2.71%),HPV51(2.03%),HPV58(1.87%),and HPV16 (1.40%). The top three low-risk gene types were HPV81 (2.03%), HPV42 (1.43%), and HPV55 (1.31%). Among the women with HPV infections,there were 483 having medium-high-risk HPV infection.There were significant differences in the age,the age at first sexual activity,sexual activities per week,education,and alcohol consumption between HPV positive and HPV negative patients. Age stratification showed that the infection rates in the 55-59 years old group were significantly higher than that in the other age groups(χ2=15.349, P=0.000). Both single factor and multivariate non-conditional logistic regression analyses showed that higher education and the start of sexual activity at a later age were protective factors for medium-high-risk HPV infection,with regression coefficients of-0.165 and-0.08,respectively (P<0.01) in the multivariate analysis. The risk factors included age between 55- 59 years, menstrual status (menopause), sexual activity (≥3 times per week) and alcohol consumption. High-risk HPV infections also had the same risk factors,and the odds ratios were 1.558,1.275,and 1.678,respectively(P<0.01).However, 55-59 years of age and alcohol consumption are independent risk factors for medium-high risk HPV infection. Conclusions High-risk HPV in women of Shanghai is commonly caused by HPV52, HPV53, HPV51,HPV58,and HPV16.The high-risk group includes women who are 55-59 years old.While drinking is an independent risk factor for medium-high risk HPV infection, a moderate sex life and delayed age at first sex can reduce the risk of high-risk HPV infections.