Overall characteristics of women with multiple HPV results among gynecological outpatients
We enrolled 45,149 individuals who fulfilled the enrollment requirements to examine the prevalence of HPV infection in the study area. Of these, only 10.01% (N=4521) of individuals underwent two or more HPV tests in a 24-month period (Fig. 1). Of the individuals who underwent multiple HPV tests, 76.97% (N=3272) underwent two tests. The number of HPV tests per woman ranged from one to eight. The average age was 40.09±10.30 y. The groups were separated based on age as follows: < 30, 30–39, 40–49, 50–59, and > 60 y. The proportion of individuals in these age categories was 15.86%, 34.97%, 30.55%, 15.00%, and 3.63%, respectively. 39.50 Of those who underwent retesting for HPV, 39.50% had a single infection and 16.55% had multiple infections (Table 1). 42.00 Of the individuals who tested positive for HPV, 42.00% were HR HPV carriers and 14.05% were LR HPV carriers (Table 1).
Overall characteristics of HPV incidence
Among women who underwent another HPV test during a 24-month period, the overall incidence rates of HPV, 2vHPV, 4vHPV, and 9vHPV were 36.84% (95% confidence interval: 34.72% - 38.96%), 4.43% (3.52% - 5.33%), 5.64% (4.62% -6.65%), and 18.42% (16.71% - 20.13%), respectively (Table 2). Age groups 30-39 and 40-49 accounted for the bulk of incident infections. The top five HPV subtypes by incidence frequency were 52, 51, 81, 58, and 16 (Fig. 2a). For HR-HPV, the incidence rates of the first three HPV subtypes were 5.59% (HPV 52), 3.72% (HPV 51), and 3.37% for (HPV 58), respectively. For the LR HPV, the incidence rate of the first three HPV subtypes was 3.47% (HPV 81), 2.67% (HPV 43), and 2.52% (HPV 42), respectively (Fig. 2a). Women who had another HPV test between 0–6, 6–12, 12–18, and 18–24 months after their first test had overall incidence rates of any kind of HPV of 13.14%, 15.60%, 8.76%, and 11.83%, respectively (Fig. 3). The most frequent subtypes of incident infections in the 0–6-and 6–12 month time intervals were HPV 52, 51, 58, and 53. Extended screening intervals were associated with higher incidence rates of HPV 16 and 39. Among all women retested at different intervals, the four most prevalent LR HPVs were HPV81, HPV42, HPV43, and HPV44. With longer retesting intervals, there was a progressive increase in the incidence of HPV 42, indicating that HPV42 may take a longer time to clear.
Overall characteristics of HPV persistence
The overall persistent rates of any HPV, 2vHPV, 4vHPV, and 9vHPV among women who had another HPV test during a 24-month period were 55.56% (95% confidential interval: 53.62%-57.50%), 7.10% (6.10%-8.10%), 7.93% (6.88%-8.98%), and 28.57% (26.81%-30.33%), respectively (Table 3). The proportions of persistent positive infections in age groups <30, 30-39, 40-49, 50-59, and ≥60 were 56.60%, 49.94%, 49.43%, 69.23%, and 78.99%, respectively. Age-related increases in persistent HPV infections have been considerable. According to the frequency of persistence, the top five HPV subtypes were 42, 52, 58, 81, and 56 (Fig. 1b). The first three HPV subtypes for HR HPV had persistence rates of 47.83% (HPV 52), 46.88% (HPV 58), and 41.18% (HPV 56). The first three HPV subtypes for LR HPV had persistence rates of 51.82% (HPV 42), 45.65% (HPV 81), and 32.93% (HPV 44) (Fig. 1b). Between 0–6, 6–12, 12–18, and 18–24 months after their initial test, women who underwent another HPV test showed persistence rates for all HPV types of 12.57%, 13.26%, 6.62%, and 6.37%, respectively (Fig. 4). It is evident from the time interval results that among the HR HPVs, persistent infections were longer for HPV 58 and 52. For LR HPV, HPV42 and 81 showed longer durations of persistent infection.
Overall characteristics of HPV clearance
Among women who underwent another HPV test within a 24-month period, the overall clearance rates for any HPV, 2vHPV, 4vHPV, and 9vHPV were 74.43%(95% confidential interval: 72.73%-76.13%), 13.46%(12.13%-14.79), 17.68%(16.19%-19.17%), and 44.44%(42.50%-46.37%), respectively (Table 4). In age groups <30, 30-39, 40-49, 50-59, and ≥60, the percentage of clearance rates among HPV positive individuals was 77.87%, 76.66%, 75.64%, 67.55%, and 62.18%, correspondingly. The HPV clearance rate decreased progressively with age. HPV 26, 83, 11, 82, and 44 were the top five HPV subtypes that were the most easily eradicated (Fig. 1b). The top three HR HPV subtypes with the lowest clearance rates were 58(53.66%), 52(53.99%), and 35(62.50%). HPV 42(56.93%), 81(62.50%), and 43(85.15%) were the three LR HPV subtypes with the lowest clearance rates. The majority of HPV infections cleared rapidly, with two-thirds cleared within a year (Fig. 5).