Overall and type-specific HPV prevalence. A total of 164,137 women were involved in the present study, including 118,484 females in the OG and 45,653 females in the HFG. Of the 164,137 cases, 28,480 women were positive for HPV, with an overall HPV infection rate of 17.35%. The positive cases accounted for 19.10% (22,626/118,484) of the OG and 12.82% (5,854/45,653) of the HFG, respectively. The HPV infection rate of the OG was significantly higher than that of the HFG (P<0.01).
A total of 27 HPV genotypes were identified in the present study (Table 1). The total number of positive HPV genotypes was 37,106, among which 29,703 were from the OG, with a per capita carrying rate of 0.25 (29,703/118,484). A total of 7,403 positive HPV genotypes were noted in the HFG, with a per capita carrying rate of 0.16 (7,403/45,653).
In total, HPVs 52 (3.29%), 58 (1.96%), 53 (1.87%), 16 (1.67%), and 61 (1.34%) were the five most prevalent HPV genotypes. The five most common genotypes were HPV 52, 58, 16, 53, and 61 in the OG, and the five most common genotypes were HPV 52, 53, 58, 61, and 81 in the HFG (Fig. 1). The percentage of positive detection for each HPV type was analyzed over a total period of 5 years (Fig. 2). The six most common genotypes, namely HPV 52 (14.54%), 58 (8.68%), 53 (8.27%), 16 (7.40%), 61 (5.94%), and 81 (5.76%), accounted for ~50% of all infection types (Fig. S1).
Genotype-specific prevalence of HR-HPV. HR-HPV was detected in 26,568 individuals, with a total infection rate of 16.19% (26,568/164,137). The HR-HPV infection rate of the OG and the HFG was 18.08% (21,424/118,484) and 11.27% (5,144/45,653), respectively. The HR-HPV infection rate of the OG was significantly higher than that of the HFG (P<0.01).
The most prevalent HR-HPV genotypes were HPV 52 (3.29%, 5,397/164,137), followed by HPV 58 (1.96%, 3,220/164,137), HPV 53 (1.87%, 3,070/164,137), HPV 16 (1.67%, 2,746/164,137), and HPV 39 (1.19%, 1,947/164,137).
Distribution characteristics of single and multiple HPV infections. The frequency and number of HPV infections are shown in Table 2. Among women with a single HPV infection, HR-HPV infection accounted for 74.33% (12,867/17,286) in the OG and for 70.33% (3,273/4,654) in the HFG (P>0.01). Among women with multiple HPV infections, the multiple infections with the HR-HPV rate accounted for 93.39% (4,987/5,340) of the population in the OG and for 92% (1,104/1,200) of the population in the HFG (P>0.01).
Multiple and single HPV genotypes accounted for 40.87% (15,166/37,106) and 59.13% (21,940/37,106) of all positive types, respectively. Single infections and multiple infections were identified across all genotypes (Fig. 2). The prevalence of HPV 16, 39, 52, and 58 in the single infection group was higher than that of the multiple infection group (P<0.01).
Time trends of prevalence and genotype of HPV. The prevalence of HPV in Wenzhou from 2015 to 2020 was analyzed; the infection rate of the OG and the HFG indicated almost the same trend (Fig. 3A). The total prevalence of HPV indicated a significant decrease from 23.35% in 2015 to 13.71% in 2017. Subsequently, the infection rate slowly increased to 18.35% in 2020. The number of HPV genotyping tests increased every year during the period 2015-2019. However, the percentage of HPV testing decreased in 2020 due to the COVID-19 lockdown (Fig. 3B).
The majority of the viral infection types were consistent with the general trend of HPV-positive infection; however, certain genotypes exhibited an increasing or decreasing trend change every year (Fig. 4).
Age-specific prevalence and genotype of HPV. All the participants were stratified into 8 groups based on their age. The age-specific prevalence of HPV was calculated (Table 3). The overall age-specific prevalence of HPV exhibited two peaks. The following infection rates were noted for the specific age groups: 44.65%, 19.79%, 15.14%, 15.90%, 19.76%, 27.35%, 23.04%, and 15.87% (Fig. 5). The first peak corresponded to 44.65% in the 10-19 age group. The prevalence of the infection decreased to 19.79% in the 20-29 age group and continuously increased to 27.35% in the 60-69 age group. The lowest prevalence (under 16%) was found in the 30-49 age group and the majority of the samples were obtained from women corresponding to that age stage range. Two infection peaks corresponding to subjects under 20 and between 60 and 69 years of age were noted in the OG, while only one infection peak was noted in the 60-79 age group in the HFG.
The age-specific percentage of the HPV genotype in the positive cases was analyzed (Table S1). The data indicated that young subjects under the age of 20 infected with HPVs 6, 11, 16, 18, and 52 were the main subjects infected, accounting for nearly 50% of the total infection cases. The infection rates of HPVs 6 and 11 were significantly higher in the aforementioned age group (<20 years of age) than those of the other age groups, while HPV 53 infected a significantly lower number of subjects in the <20-year group compared with that of the other age groups.
The overall risk of the six most common HR-HPV genotypes (HPV 52, 58, 53, 16, 39, and 18) was increased with age. However, the individual genotypes indicated different trends in relation to age (Fig. 6).