Human papillomavirus infection in Shanxi Province, People's Republic of China: a population-based study

Abstract

To investigate the prevalence of, and risk factors for, cervical infection with human papillomavirus (HPV) in the rural province of Shanxi, People's Republic of China, which has relatively high cervical cancer mortality rates, we interviewed and obtained cervical cell samples from 662 women aged 15 -59 years. A total of 24 different HPV types were identified using a GP5 þ /6 þ -based PCR assay able to detect 44 different HPV types. Human papillomavirus prevalence was 14.8% overall and 9.6% among women without cervical abnormalities (14.2 and 8.9%, respectively, age standardised to the world standard population). Multiple-type infections accounted for 30.6% of all infections. By far the most commonly found type was HPV16 (5.7% of all women and 38.8% of HPV-positive women), followed by HPV 58, 52, 33 and 18. Unlike most previous studies published, HPV prevalence was lower among women younger than 35 years (8.7%) than those older than 35 years (17.8%). High-risk HPV types predominated in all age groups. Although low-risk HPV types were rare in young women, they became more common with increasing age. 92.3% of women with cervical intraepithelial neoplasia grade 3 were infected with high-risk HPV types, but none with low-risk types only. No significant difference in HPV positivity was observed by educational level, sexual habits, reproductive history or use of contraceptive methods in this rural lowincome Chinese population.

Human papillomavirus infection in women with and without cervical cancer in Nepal

“…The agespecific curve of HPV prevalence in Nepal resembled the flat age curves reported previously in some low-resource countries in Asia and Africa [15][16][17][18]24], albeit at a lower level of HPV prevalence. It clearly differed, on the other hand, from the steep decrease in HPV prevalence seen by age in high-and medium-resource countries in Europe, the Americas, and Asia [23,25].…”

“…The major finding of this present study, the first undertaken in Nepal, is that the burden of HPV infection in the general population (8.6%) is somewhat lower than that observed in previous studies performed using the same HPV testing protocol in neighboring countries (e.g., 17% in Tamil Nadu, India, [15] and 15-18% range in three provinces in China [16][17][18]), and much less than in the high-risk areas in Asia and Africa (e.g., 35% in Mongolia [19] and 51% in Guinea [20]). Nevertheless, HPV prevalence remained greater than that in other areas in Asia (e.g., 2% in Hanoi, Vietnam [21], 4% in Songkla, Thailand [22]), and in Europe [23].…”

“…As in previous IARC HPV prevalence surveys in Asia [15][16][17][18], the gynecological exam was acceptable only to married women, so, the HPV prevalence estimate represents that in married women only. Nevertheless, age at first marriage (median = 17 years, intraquartile range [15][16][17][18][19] was relatively early, and 91% of participants reported an age at first sexual intercourse that was the same as, or greater than, age at first marriage, suggesting that marriage is a good proxy for sexual activity in this population.…”

“…Of note, the relationship between education level and HPV prevalence in previous IARC surveys in Asia included inverse [25] and direct associations [21,22] as well as no relationship [16].…”

“…Nevertheless, age at first marriage (median = 17 years, intraquartile range [15][16][17][18][19] was relatively early, and 91% of participants reported an age at first sexual intercourse that was the same as, or greater than, age at first marriage, suggesting that marriage is a good proxy for sexual activity in this population. HPV16/18 prevalence, however, was highest among older women.…”