Prevalence, incidence and persistence of genital HPV infections in a large cohort of sexually active young women in the Netherlands

Prevalence of Carcinogenic Genotypes of HPV-Infected Women in a Ten-Year Period (2014-2023) in Vojvodina, Serbia

Background and Objectives: Human papillomavirus (HPV) infection and its etiological role in the development of cervical cancer are well established. The cervical cancer mortality rate in Serbia is one of the highest among European countries, and this cancer is the second-leading cause of death in Serbian women aged from 15 to 44. Materials and Methods: This retrospective study was conducted at the Institute of Public Health of Vojvodina. A total of 10,062 cervical specimens from Serbian women were collected and HPV tested in ten years. The study patients were divided into five age groups. HPV genotype testing was performed using a commercial kit to detect 14 high-risk (HR) HPV genotypes. Additionally, cervix cytology data have been available for patients tested in 2022 and 2023. Results: An overall positive rate was found in 43.3% of patients (4356/10,062). A single HPV infection (62.1%) was the main infection pattern. The most frequent HR HPV genotypes were HPV 16, 31, 52, 56, 39, and 51, comprising 62.3% of the detected genotypes, including multiple infections. A significant difference was noted in the HPV prevalence across the different age groups, with a bimodal distribution of HPV infection. The highest prevalence was recorded in the age group ≤ 30 and those after 61 years. Women diagnosed with high-grade squamous intraepithelial lesions (HSIL) were significantly older compared to others. HR HPV is the most prevalent in patients with HSIL cytological findings (76.5%). The most common type, according to age-specific distribution and cytological findings, was HR HPV 16. Conclusions: This study provides comprehensive data on HR HPV distribution among Serbian women, which can serve as a basis for subsequent monitoring of genotypic distribution. It is particularly significant considering they are missing in the updated ICO/IARC Report for Serbia, and the cervical cancer mortality rate in Serbia is one of the highest among European countries.

High prevalence and co-infection of high-risk Human Papillomavirus genotypes among unvaccinated young women from Paraguay

Paraguay launched a human papillomavirus (HPV) vaccination program in 2013, so virological surveillance is important for measuring the impact of HPV vaccines. This study aimed to estimate the type-specific HPV frequency in unvaccinated sexually active women aged 18-25 years in the metropolitan area of Asuncion as a baseline for monitoring the HPV vaccination program. This study included 208 women, attending the Central Laboratory of Public Health between May 2020 and December 2021, were invited for testing through social networks and flyers at local health centers and higher education institutes. All participants who agreed to contribute to the study signed a free, prior, and informed consent form and answered a questionnaire that included basic demographic data and determining factors of HPV infection. Human papillomavirus detection and genotyping were conducted using the CLART HPV2 test (Genomica, Madrid, Spain) that allows the individual identification of 35 genotypes. 54.8% women were positive for any HPV type, with 42.3% positive for high-risk HPV (HR-HPV) types. Several factors were associated with HPV detection including the number of sexual partners, new sexual partners, non-use of condoms, and history of other sexual infections. Moreover, multiple infections were identified in 43.0% of the young women. We detected 29 different viral types present in both single and multiple infections. HPV-58 was the most commonly detected HPV type (14.9%), followed by HPV-16, HPV-51, and HPV-66 (12.3%). We estimated the prevalence of bivalent (16/18), quadrivalent (6/11/16/18), and nonavalent (6/11/16/18/31/33/45/52/58) vaccine types to be 8.2%, 13%, and 38%, respectively. These results reinforce the importance of surveillance studies and provide the first data regarding circulating HPV genotypes in the unvaccinated population in Paraguay, thus generating a baseline to compare future changes in the overall and type-specific HPV prevalence after HPV vaccination.

E6/E7 mRNA Expression of the Most Prevalent High-Risk HPV Genotypes in Cervical Samples from Serbian Women

Cervical cancer caused by persistent infection with HR HPV genotypes is the second leading cause of death in women aged 15 to 44 in Serbia. The expression of the E6 and E7 HPV oncogenes is considered as a promising biomarker in diagnosing high-grade squamous intraepithelial lesions (HSIL). This study aimed to evaluate HPV mRNA and DNA tests, compare the results according to the severity of the lesions, and assess the predictive potential for the diagnosis of HSIL. Cervical specimens were obtained at the Department of Gynecology, Community Health Centre Novi Sad, Serbia, and the Oncology Institute of Vojvodina, Serbia, during 2017-2021. The 365 samples were collected using the ThinPrep Pap test. The cytology slides were evaluated according to the Bethesda 2014 System. Using a real-time PCR test, HPV DNA was detected and genotyped, while the RT-PCR proved the presence of E6 and E7 mRNA. The most common genotypes in Serbian women are HPV 16, 31, 33, and 51. Oncogenic activity was demonstrated in 67% of HPV-positive women. A comparison of the HPV DNA and mRNA tests to assess the progression of cervical intraepithelial lesions indicated that higher specificity (89.1%) and positive predictive value (69.8-78.7%) were expressed by the E6/E7 mRNA test, while higher sensitivity was recorded when using the HPV DNA test (67.6-88%). The results determine the higher probability of detecting HPV infection by 7% provided by the mRNA test. The detected E6/E7 mRNA HR HPVs have a predictive potential in assessing the diagnosis of HSIL. The oncogenic activity of HPV 16 and age were the risk factors with the strongest predictive values for the development of HSIL.

Rapid elimination of cervical cancer while maintaining the harms and benefits ratio of cervical cancer screening: a modelling study

BACKGROUND

Human papillomavirus (HPV) vaccination and intensifying screening expedite cervical cancer (CC) elimination, yet also deteriorate the balance between harms and benefits of screening. We aimed to find screening strategies that eliminate CC rapidly but maintain an acceptable harms-benefits ratio of screening.

METHODS

Two microsimulation models (STDSIM and MISCAN) were applied to simulate HPV transmission and CC screening for the Dutch female population between 2022 and 2100. We estimated the CC elimination year and harms-benefits ratios of screening for 228 unique scenarios varying in vaccination (coverage and vaccine type) and screening (coverage and number of lifetime invitations in vaccinated cohorts). The acceptable harms-benefits ratio was defined as the number of women needed to refer (NNR) to prevent one CC death under the current programme for unvaccinated cohorts (82.17).

RESULTS

Under current vaccination conditions (bivalent vaccine, 55% coverage in girls, 27.5% coverage in boys), maintaining current screening conditions is projected to eliminate CC by 2042, but increases the present NNR with 41%. Reducing the number of lifetime screens from presently five to three and increasing screening coverage (61% to 70%) would prevent an increase in harms and only delay elimination by 1 year. Scaling vaccination coverage to 90% in boys and girls with the nonavalent vaccine is estimated to eliminate CC by 2040 under current screening conditions, but exceeds the acceptable NNR with 23%. Here, changing from five to two lifetime screens would keep the NNR acceptable without delaying CC elimination.

CONCLUSIONS

De-intensifying CC screening in vaccinated cohorts leads to little or no delay in CC elimination while it substantially reduces the harms of screening. Therefore, de-intensifying CC screening in vaccinated cohorts should be considered to ensure acceptable harms-benefits ratios on the road to CC elimination.

Predictors of Human Papillomavirus Seropositivity in Appalachian Women Aged 18 to 26 Years

BACKGROUND

Key informants of the Appalachian community questioned whether their unique environmental stressors would alter their immune response to human papillomavirus (HPV) infections. The primary aim of this study is to determine predictors of HPV seroprevalence to at least 1 of the 4 vaccine-related HPV types before vaccination using a psychoneuroimmunologic model in Appalachian women.

METHOD

Women aged 18 to 26 years (n = 185) who had not received HPV vaccination provided cervical HPV DNA and blood samples. Human papillomavirus DNA was identified through Hybrid Capture 2 assay and then genotyped for HPV types 6, 11, 16, and 18 by Roche Linear Array. Competitive Luminex Immunoassay measured the type-specific antibodies to HPV types 6, 11, 16, and 18 in milli-Merck units per milliliter. Nine psychoneuroimmunology scales measuring attributes of stress were self-completed.

RESULTS

Human papillomavirus DNA was detected in 50% (92/183) of participants, with only 14% (26/183) positive for HPV-6/11/16/18 DNA. Seropositivity for at least one anti-HPV-6/11/16 or 18, on the other hand, was present in 35% (64/183) of women, with only 10% (19/183) concomitantly infected and seropositive for the vaccine-related types. The Perceived Stress Scale was not a strong predictor of HPV seropositivity.

CONCLUSIONS

Both HPV infection and vaccine-related HPV type seropositivity is common among Appalachian women aged 18 to 26 years. The anticipated effect of environmental stressors on HPV seropositivity was not seen when multiple predictors were considered.

Incidence, persistence and clearance of cervical human papillomavirus among women in Guangdong, China 2007-2018: A retrospective cohort study

BACKGROUND

Previous studies showed the incidence, persistence and clearance of cervical human papillomavirus (HPV) among women varies from regions. There is no study on dynamic changes of HPV infection among women in Guangdong.

METHODS

It is a retrospective cohort study that included gynecological outpatients aged ≥15 years and retested for HPV within 24 months in Guangdong Women and Children Hospital to estimate HPV incidence, persistence and clearance. Outcomes were estimated through the proportion of HPV incidence, persistence and clearance in HPV-negative or HPV-positive women. Moreover, we examined HPV incidence, persistence and clearance among women who retested in four calendar periods: 0-6, 6-12, 12-18, 18-24 months after the first test.

RESULTS

33,328 gynecological outpatients were included in our study. Incidence rates of any HPV, high-risk (HR) HPV and low-risk (LR) HPV were 10.58%, 8.68% and 4.83%. The most common incident HR HPV were HPV52 (2.69%), HPV16 (1.23%) and HPV58 (1.23%). Persistence rates of any HPV, HR HPV and LR HPV were 47.55%, 42.77% and 33.88%. HPV52 (42.33%), HPV58 (40.74%) and HPV68 (32.36%) were commonly found persistent types. And clearance rates of any HPV, HR HPV and LR HPV were 52.44%, 57.23% and 66.12%.The lowest clearance rates were observed for HPV52 (57.67%), HPV68 (67.64%) and HPV39 (68.56%). HPV incidence and persistence were higher among women aged 15-19 years and ≥55 years. HPV incidence and persistence were found higher among women who retested within 6 months than others in other periods.

CONCLUSIONS

HPV52, 58, 68, and 39 were the more likely to cause incident and persistent infection, and less likely to be cleared among women in Guangdong. HPV incidence and persistent infection were higher among women aged both younger and older women compared to middle aged women. HPV retesting period may impact the detection of HPV incidence, persistence and clearance.

Measuring vaccine effectiveness against persistent HPV infections: a comparison of different statistical approaches

BACKGROUND

Persistent high-risk human papillomavirus (HPV) infection is endorsed by the World Health Organization as an intermediate endpoint for evaluating HPV vaccine effectiveness/efficacy. There are different approaches to estimate the vaccine effectiveness/efficacy against persistent HPV infections.

METHODS

We performed a systematic literature search in Pubmed to identify statistical approaches that have been used to estimate the vaccine effectiveness/efficacy against persistent HPV infections. We applied these methods to data of a longitudinal observational study to assess their performance and compare the obtained vaccine effectiveness (VE) estimates.

RESULTS

Our literature search identified four approaches: the conditional exact test for comparing two independent Poisson rates using a binomial distribution, Generalized Estimating Equations for Poisson regression, Prentice Williams and Peterson total time (PWP-TT) and Cox proportional hazards regression. These approaches differ regarding underlying assumptions and provide different effect measures. However, they provided similar effectiveness estimates against HPV16/18 and HPV31/33/45 persistent infections in a cohort of young women eligible for routine HPV vaccination (range VE 93.7-95.1% and 60.4-67.7%, respectively) and seemed robust to violations of underlying assumptions.

CONCLUSIONS

As the rate of subsequent infections increased in our observational cohort, we recommend PWP-TT as the optimal approach to estimate the vaccine effectiveness against persistent HPV infections in young women. Confirmation of our findings should be undertaken by applying these methods after longer follow-up in our study, as well as in different populations.

Prevalence, genotype distribution and risk factors of cervical HPV infection in Yangqu, China: a population-based survey of 10086 women

Human papillomavirus(HPV) infection is a necessary factor for the development of cervical cancer. The HPV vaccine is currently available, but there is still a lack of large-scale research on the distribution and risk factors of HPV. The aim of this study is to investigate the genotype distribution and risk factors of HPV infection in Yangqu which is located in North China. This study enrolled 10086 women aged <65 years from Yangqu County. HPV genotypes were identified via standard HPV DNA testing. The overall prevalence of HPV infection was 8.92%. The prevalence of high-risk HPV types was 8.80%, and it was 0.38% for low-risk HPV types. Single genotype infection accounted for 67.91% in HPV-positive cases. The most common HPV genotypes were HPV-16, -52, and -58. HPV-18 was only the 11th most common type in HPV-positive cases. Women ≥50 years of age had the highest prevalence rate of HPV, and women <30 years had the lowest prevalence rate. The distribution of HPV genotypes also varied among the three age groups: <30, 30-49, and ≥50 years. The risk factors that contributed to the rate of HPV infection included low educational level, low income, smoking, age at first sexual encounter <23 years old, and number of births ≥3 times. This large routine clinical practice report of HPV prevalence and genotype distribution revealed the characteristics of HPV infection-type distributions in Shanxi Province, which should be considered in formulating comprehensive prevention strategies including vaccination for cervical cancer in China.

HPV16 whole genome minority variants in persistent infections from young Dutch women

BACKGROUND

Chronic infections by one of the oncogenic human papillomaviruses (HPVs) are responsible for near 5% of the global cancer burden and HPV16 is the type most often found in cancers. HPV genomes display unexpected levels of variation when deep-sequenced. Minor nucleotide variations (MNVs) may reveal HPV genomic instability and HPV-related carcinogenic transformation of host cells.

OBJECTIVES

The objective of this study was to investigate HPV16 genome variation at the minor variant level on persisting HPV16 cervical infections from a population of young Dutch women.

STUDY DESIGN

15 HPV16 infections were sequenced using a whole-HPV genome deep sequencing protocol (TaME-seq). One infection was followed over a three-year period, eight were followed over a two-year period, three were followed over a one-year period and three infections had a single sampling point.

RESULTS AND CONCLUSIONS

Using a 1% variant frequency cutoff, we find on average 48 MNVs per HPV16 genome and 1717 MNVs in total when sequencing coverage was >100 × . We find the transition mutation T > C to be the most common, in contrast to other studies detecting APOBEC-related C > T mutation profiles in pre-cancerous and cancer samples. Our results suggest that the relative mutagenic footprint of HPV16 genomes may differ between the infections in this study and transforming lesions. In addition, we identify a number of MNVs that have previously been associated with higher incidence of high-grade lesions (CIN3+) in a population study. These findings may provide a starting point for future studies exploring causality between emerging HPV minor genomic variants and cancer development.

Assessing the cost-effectiveness of HPV vaccination strategies for adolescent girls and boys in the UK

BACKGROUND

Human papillomavirus (HPV) is the most widespread sexually transmitted infection worldwide. It causes several health consequences, in particular accounting for the majority of cervical cancer cases in women. In the United Kingdom, a vaccination campaign targeting 12-year-old girls started in 2008; this campaign has been successful, with high uptake and reduced HPV prevalence observed in vaccinated cohorts. Recently, attention has focused on vaccinating both sexes, due to HPV-related diseases in males (particularly for high-risk men who have sex with men) and an equity argument over equalising levels of protection.

METHODS

We constructed an epidemiological model for HPV transmission in the UK, accounting for nine of the most common HPV strains. We complemented this with an economic model to determine the likely health outcomes (healthcare costs and quality-adjusted life years) for individuals from the epidemiological model. We then tested vaccination with the three HPV vaccines currently available, vaccinating either girls alone or both sexes. For each strategy we calculated the threshold price per vaccine dose, i.e. the maximum amount paid for the added health benefits of vaccination to be worth the cost of each vaccine dose. We calculated results at 3.5% discounting, and also 1.5%, to consider the long-term health effects of HPV infection.

RESULTS

At 3.5% discounting, continuing to vaccinate girls remains highly cost-effective compared to halting vaccination, with threshold dose prices of £56-£108. Vaccination of girls and boys is less cost-effective (£25-£53). Compared to vaccinating girls only, adding boys to the programme is not cost-effective, with negative threshold prices (-£6 to -£3) due to the costs of administration. All threshold prices increase when using 1.5% discounting, and adding boys becomes cost-effective (£36-£47). These results are contingent on the UK's high vaccine uptake; for lower uptake rates, adding boys (at the same uptake rate) becomes more cost effective.

CONCLUSIONS

Vaccinating girls is extremely cost-effective compared with no vaccination, vaccinating both sexes is less so. Adding boys to an already successful girls-only programme has a low cost-effectiveness, as males have high protection through herd immunity. If future health effects are weighted more heavily, threshold prices increase and vaccination becomes cost-effective.

Detoxification therapy of traditional Chinese medicine for genital tract high-risk human papillomavirus infection: A systematic review and meta-analysis

BACKGROUND

Persistence of high-risk human papillomavirus (hr-HPV) infections is the most critical risk factor for cervical intraepithelial neoplasia (CIN) and cervical cancer (CC). Treatment of persistent oncogenic HPV-positive women after 12-24 months follow-up is still controversy. Detoxification therapy of Chinese medicine (DTCM) has been conducted recently. However, the conclusions are still unclear. We planned to conduct a systematic review and meta-analysis to explore DTCM in the treatment of persistent hr-HPV infections.

METHODS

Nine electronic databases were systematically searched from their inception to 30 September 2018. Randomized controlled trials comparing DTCM with follow-up or placebo were included. Risk of bias was assessed by the Cochrane 'Risk of Bias' tool. Review Manager 5.3 was used for statistical analyses. Relative ratios (RR) and 95% confidence intervals were used for dichotomous data, and the mean difference (MD) was used for continuous data. We assessed the quality of trials by the GRADE.

RESULTS

Seventeen RCTs from 2011 to 2018 with 1906 participants were included. The evidence showed that DTCM had a pooled efficacy difference in favor of increasing the HPV clearance rate compared to placebo groups (RR = 2.62, 95% CI 1.28 to 5.33, very low quality) and follow-up groups (RR = 1.88, 95% CI 1.60 to 2.22, low quality). The median HPV persistence tended to decline from 50% within six months to 41.5% at 12 months, and 31.5% at 24 months. A significantly increased regression rate of CIN was found in the DTCM compared with placebo groups (RR = 3.61, 95% CI 1.21 to 10.83, very low quality) and follow-up groups (RR = 1.79, 95% CI 1.31 to 2.45, very low quality). Additionally, we found DTCM have an impact on TNF-α (MD = 2.99, 95% CI 1.90 to 4.07; very low quality), IFN-α (MD = 3.47, 95% CI 2.42 to 4.52; very low quality), CD4+/CD8+ cells (MD = 0.21, 95% CI 0.05 to 0.37; very low quality) compared with follow up groups in some trials with small sample sizes. The major adverse events were genital mucosal irritation symptoms (10%, 5/50).

CONCLUSIONS

DTCM have favorable outcomes on improving the HPV clearance rate, increasing the regression rate of CIN, and impacting the proportion of some immune cells and cytokine levels. However, most of the evidence was of low quality. Any future high-quality trials and a more extended follow-up period of 24 months or more should be performed.

Ten years of HPV vaccination in the Netherlands: current evidence and future challenges in HPV-related disease prevention

INTRODUCTION

Girls-only vaccination against human papillomavirus (HPV) type 16 and 18 was implemented in the Netherlands in 2009. Despite the evidence of the efficacy against precancerous lesions, cross-protection induced by the vaccine and a greater potential for cancer prevention than cervical cancer only, vaccine coverage in the girls-only program has remained below target levels.

AREAS COVERED

In this paper, we review the literature from the Netherlands on the effectiveness and cost-effectiveness of HPV vaccination since vaccine introduction, give an account of the coverage, safety and effectiveness of HPV vaccination as has been reported in the Dutch surveillance program and discuss challenges of the current HPV vaccination program.

EXPERT COMMENTARY

Girls-only HPV vaccination may confer a substantial health gain in HPV-related disease prevention. However, vaccine coverage declined remarkably recently possibly related to safety concerns, limiting the benefits from girls' vaccination and increasing the potential additional benefit of sex-neutral HPV vaccination. Considering the emergence of novel vaccination and screening options and the change from cytology- to HPV-based screening in 2017, further research is required to inform decisions on the optimization of an integrated vaccination and screening program.

Capturing sexual contact patterns in modelling the spread of sexually transmitted infections: Evidence using Natsal-3

BACKGROUND

Understanding the spread of sexually transmitted infections (STIs) in a population is of great importance to the planning and delivery of health services globally. The worldwide rise of HIV since the 1980's, and the recent increase in common STIs (including HPV and Chlamydia) in many countries, means that there is an urgent need to understand transmission dynamics in order to better predict the spread of such infections in the population. Unlike many other infections which can be captured by assumptions of random mixing, STI transmission is intimately linked to the number and pattern of sexual contacts. In fact, it is the huge variation in the number of new sexual partners that gives rise to the extremes of risk within populations which need to be captured in predictive models of STI transmission. Such models are vital in providing the necessary scientific evidence to determine whether a range of controls (from education to screening to vaccination) are cost-effective.

METHOD AND RESULTS

We use probability sample survey data from Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) to determine robust distributions for the rate of new partnerships that involve condomless sex and can therefore facilitate the spread of STIs. Different distributions are defined depending on four individual-level characteristics: age, sex, sexual orientation, and previous sexual experience. As individual behaviour patterns can change (e.g. by remaining in a monogamous relationship for a long period) we allow risk-percentiles to be randomly redrawn, to capture longer term behaviour as measured by Natsal-3. We demonstrate how this model formulation interacts with the transmission of infection by constructing an individual-based SIS-P (Susceptible-Infected-Susceptible-Protected) transmission model for the spread of a generic STI, and observing overall population demographics when varying the transmission probability within a partnership, recovery rate and the level of population protection (e.g. from vaccination where applicable).

Screening for persistent high-risk HPV infections may be a valuable screening method for young women; A retrospective cohort study

Introduction

Screening of young women is often discouraged because of the high risk of unnecessary diagnostics or overtreatment. Multiple countries therefore use cytology instead of high risk human papillomavirus (hrHPV)-testing as screening method for young women because of the limited specificity of hrHPV-testing. The objective of this study was to investigate how hrHPV screening before the age of 30, can be used to reduce the future prevalence of high-grade cervical lesions in young women.

Methods

We retrospectively analyzed follow-up data from a cohort study on HPV prevalence in unscreened Dutch women aged 18–29 years. Women performed multiple self-collected cervico-vaginal samples for HPV detection and genotyping. At least one valid cervical pathology result was obtained from 1,018 women. Women were categorized as hrHPV negative, cleared- or persistent hrHPV infection. Anonymized follow-up data for each group was obtained. Composite outcome measures were defined as; normal, low-grade squamous intraepithelial lesion (LSIL) or high-grade squamous intraepithelial lesion (HSIL). The association between prior hrHPV status and cytology and histology outcome was analyzed.

Results

After exclusion, a pathology result was registered for 962 women. The prevalence of HSIL was 19.3% in women with a persistent HPV infection at a younger age. This is significantly higher (p<0,001) compared with the HSIL prevalence of 1.5% in HPV-negative women, and 3.1% (n = 8) in women who cleared the hrHPV infection in the past.

Conclusion

Women with a persistent hrHPV infection in their 20s, show an increased prevalence of HSIL lesions in their early 30s. Screening for persistent hrHPV infections, instead of cytology screening before the age of 30, can be used to reduce the future prevalence of cervical cancer in young women.

Age-Structured Population Modeling of HPV-related Cervical Cancer in Texas and US

Human papillomavirus (HPV)-related cervical cancer is a major public health threat to women, with >10,000 new cases diagnosed annually in the United States between 2008 and 2012. Since HPV vaccines can protect against ~80% of HPV-associated cervical cancers, the economic and epidemiological impacts of HPV vaccination have been extensively investigated, particularly at the national level. However, vaccination policies are state-specific, and state-level models are required for state-specific policy decisions. This study adapted an age-structured population model to describe the dynamics of HPV-related cervical cancer in Texas, with model parameters calibrated for Texas. The Year 2000 parameter set was the start point, and the model's predictions from 2001-2010 were well matched with the real incidence numbers in 23 age groups, suggesting the validity of the model. Application of the model to the Year 2010 parameter set predicted that, over the next 10 decades, incidence would decrease rapidly within the first decade and more slowly thereafter. Sensitivity analysis determined the impact of selected parameters (e.g., vaccine coverage rate) on future disease incidence. When compared with the US parameter sets, the Texas population was more sensitive to changes in HPV transmission and vaccination (e.g., ~8% difference in the predicted disease decline).

Detection and Genotyping of HPV DNA in a Group of Unvaccinated Young Women from Colombia: Baseline Measures Prior to Future Monitoring Program

In 2012, Colombia launched human papillomavirus (HPV) vaccination program for girls ages 9 to 12, and in 2013, the target age was expanded to 9 to 17 years. Monitoring the changes of HPV infection prevalence among young women has been proposed as an endpoint for early assessment of HPV vaccination programs. However, the data on HPV prevalence in young ages are very limited. The purpose of this study was to determine the prevalence of HPV infection and the distribution of genotypes in a group of nonvaccinated women ages 18 to 25 years old in three Colombian cities as baseline for the monitoring of the HPV national vaccination program. A total of 1,782 sexually active women were included. Cervical smear samples were collected to perform the Pap smear and HPV DNA detection using a Linear Array HPV assay. Of the 1,782 specimens analyzed, 60.3% were positive for any HPV type; 42.2% were positive for high-risk HPV (HR-HVP) types, and 44.4% for low-risk HPV (LR-HPV) types. Multiple and single infections were identified in 37.1% and 23.2% of samples, respectively. HR-HPV types -16, -52, and -51 were the most predominant with proportions of 11.3%, 7.92%, and 7.9%, correspondingly. The prevalence for HR-HPV 16/18 was 14.4%. HR-HPV prevalence in women with abnormal cytology (75.16%) was higher than in women with normal cytology (38.6%). In conclusion, a high prevalence of HR-HPV was observed among younger women. This HPV type-specific prevalence baseline may be used to monitor postvaccination longitudinal changes and to determine its impact on HPV-related disease incidence in Colombia population. Cancer Prev Res; 11(9); 581-92. ©2018 AACR.

The epidemiology of oral human papillomavirus infection in healthy populations: A systematic review and meta-analysis

Human papillomavirus (HPV) is a potentially oncogenic sexually transmitted infection. As the incidence of oropharyngeal cancer (OPC) caused by oral HPV infections is rising, further investigation into the natural history of such infections is needed. This systematic review and meta-analysis aimed to synthesize data on the prevalence, incidence, clearance, and persistence of oral HPV infections in healthy individuals. A systematic review of literature published between January 1995 and August 2017 was conducted using Ovid MEDLINE, PubMed, Embase, and the Cochrane Library. Meta-analysis of prevalence and incidence data was conducted. Clearance and persistence data were extracted. Sixty-six studies met the inclusion criteria. Meta-analysis demonstrated an overall prevalence of 7.7% for all types of HPV and 1.4% for high-risk HPV16. The overall incidence was 4.38 cases per 1000 person-months for all HPV types and 0.92 cases per 1000 person-months for HPV16. This systematic review and meta-analysis demonstrated that oral HPV infection has a lower prevalence and incidence than cervicogenital HPV infection in healthy individuals. Nonetheless, oral HPV is still an important concern, given its oncogenicity and the rising incidence of oropharyngeal cancer. Consistency of methodology will allow for better future comparisons, particularly of infection clearance and persistence.

High Whole-Genome Sequence Diversity of Human Papillomavirus Type 18 Isolates

Background: The most commonly found human papillomavirus (HPV) types in cervical cancer are HPV16 and HPV18. Genome variants of these types have been associated with differential carcinogenic potential. To date, only a handful of studies have described HPV18 whole genome sequencing results. Here we describe HPV18 variant diversity and conservation of persistent infections in a longitudinal retrospective cohort study. Methods: Cervical self-samples were obtained annually over four years and genotyped on the SPF10-DEIA-LiPA₂₅ platform. Clearing and persistent HPV18 positive infections were selected, amplified in two overlapping fragments, and sequenced using 32 sequence primers. Results: Complete viral genomes were obtained from 25 participants with persistent and 26 participants with clearing HPV18 infections, resulting in 52 unique HPV18 genomes. Sublineage A3 was predominant in this population. The consensus viral genome was completely conserved over time in persistent infections, with one exception, where different HPV18 variants were identified in follow-up samples. Conclusions: This study identified a diverse set of HPV18 variants. In persistent infections, the consensus viral genome is conserved. The identification of only one HPV18 infection with different major variants in follow-up implies that this is a potentially rare event. This dataset adds 52 HPV18 genome variants to Genbank, more than doubling the currently available HPV18 information resource, and all but one variant are unique additions.

Whole-Genome Sequencing and Variant Analysis of Human Papillomavirus 16 Infections

Human papillomavirus (HPV) is a strongly conserved DNA virus, high-risk types of which can cause cervical cancer in persistent infections. The most common type found in HPV-attributable cancer is HPV16, which can be subdivided into four lineages (A to D) with different carcinogenic properties. Studies have shown HPV16 sequence diversity in different geographical areas, but only limited information is available regarding HPV16 diversity within a population, especially at the whole-genome level. We analyzed HPV16 major variant diversity and conservation in persistent infections and performed a single nucleotide polymorphism (SNP) comparison between persistent and clearing infections. Materials were obtained in the Netherlands from a cohort study with longitudinal follow-up for up to 3 years. Our analysis shows a remarkably large variant diversity in the population. Whole-genome sequences were obtained for 57 persistent and 59 clearing HPV16 infections, resulting in 109 unique variants. Interestingly, persistent infections were completely conserved through time. One reinfection event was identified where the initial and follow-up samples clustered differently. Non-A1/A2 variants seemed to clear preferentially (P = 0.02). Our analysis shows that population-wide HPV16 sequence diversity is very large. In persistent infections, the HPV16 sequence was fully conserved. Sequencing can identify HPV16 reinfections, although occurrence is rare. SNP comparison identified no strongly acting effect of the viral genome affecting HPV16 infection clearance or persistence in up to 3 years of follow-up. These findings suggest the progression of an early HPV16 infection could be host related.

IMPORTANCE Human papillomavirus 16 (HPV16) is the predominant type found in cervical cancer. Progression of initial infection to cervical cancer has been linked to sequence properties; however, knowledge of variants circulating in European populations, especially with longitudinal follow-up, is limited. By sequencing a number of infections with known follow-up for up to 3 years, we gained initial insights into the genetic diversity of HPV16 and the effects of the viral genome on the persistence of infections. A SNP comparison between sequences obtained from clearing and persistent infections did not identify strongly acting DNA variations responsible for these infection outcomes. In addition, we identified an HPV16 reinfection event where sequencing of initial and follow-up samples showed different HPV16 variants. Based on conventional genotyping, this infection would incorrectly be considered a persistent HPV16 infection. In the context of vaccine efficacy and monitoring studies, such infections could potentially cause reduced reported efficacy or efficiency.

Human Papillomavirus Genotype-Specific Persistence and Potential Risk Factors among Korean Women: Results from a 2-Year Follow-up Study

Purpose

High-risk human papillomavirus (HPV) infection progression should be considered a critical factor for preventing cervical cancer, although most infections are transient and rarely persist. This study aimed to examine the specific types of HPV infections, their change patterns, and the potential risk factors among Korean women.

Materials and Methods

We included 4,588 women who visited hospitals in Busan and Suwon for cervical cancer screening, and 1,224 of thesewomen attended a 2-yearfollow-up. Infection statuswas evaluated using HPV DNA testing (Hybrid Capture 2) and genotyping testing (Linear Array). Data regarding the potential risk factors for HPV infection were collected by trained nurses using structured questionnaires.

Results

Among the 1,224 women (mean age, 47 years), 105 women (8.6%) were HPV-positive at baseline. HPV infections had been cleared among 92 women (87.6%) within 2 years. Only 13 infections (12.4%) were remained, and the 10 cases of them are high-risk HPV types including genotype 33, 45, 16, 35, and 52. Among women who were negative at baseline, the HPV incidence was 4.8%. The HPV incidence was marginally associated with having multiple sexual partners (odds ratio, 2.0; 95% confidence interval, 1.0 to 3.9), although it was not significantly associated with HPV persistence.

Conclusion

Most HPV infections (88%) among Korean women were cleared within 2 years, with only a small number of persistent infections. The persistent HPV genotypes were different in our study, compared to those from previous studies. Having multiple sexual partners was associated with acquiring a HPV infection, but not with persistence.

Persistence of type-specific human papillomavirus infection among Daqing City women in China with normal cytology: a pilot prospective study

Persistence of high-risk human papillomavirus (HPV) represents the necessary cause of cervical cancer. Researching natural history of HPV infection is important to identify high-risk population of cervical cancer. Since HPV infection is population-specific, the findings in western populations could not be simply extended to Chinese and Asian females. This study investigated the type-specific persistence of HPV and related factors among Daqing City women in China. A total of 1759 women aged 18–80 years were enrolled at baseline. Cervical cell specimens were collected for cytological examination and HPV detection. HPV-positive individuals with normal cytology were followed up after 12 months. The results showed that HPV prevalence was 8.64% at baseline, of which 85 HPV-positive cases with normal cytology were followed up. The one-year type-specific persistence of HPV and high-risk types were 34.12% (29/85) and 34.25% (25/73), respectively. The top three high-risk types were HPV16 (7/17, 41.18%), HPV18 (5/8, 62.50%) and HPV58 (7/15, 46.67%). Age > 50 years was significantly associated with a higher risk of HPV persistence compared to ≤ 50 (OR = 2.73; 95% CI: 1.07, 6.93). In conclusion, approximately one-third of Daqing City women with HPV infection had at least one-year viral persistence, most of which were high-risk types. Older age represents a risk factor of HPV persistence.

Detection of Genital HPV Infection Using Urine Samples: a Population Based Study in India

BACKGROUND

Cervical cancer is the second commonest cancer among Indian women and its association with human papilloma virus (HPV) is well established. This preventable cancer accounts for the maximum number of cancer related deaths among rural Indian women. Unlike in developed countries there are no organized cervical cancer screening programmes in India due to lack of resources and manpower.

OBJECTIVE

To detect genital HPV infection using urine samples among asymptomatic rural women in the age group of 18-65 years.

MATERIALS AND METHODS

The study area chosen was Perdoor village in Udupi Taluk, Karnataka State and all the women in the age group of 18-65 years formed the study cohort. A cross sectional study was conducted by house visits and 1,305 women were enrolled in the study. After taking written informed consent a data sheet was filled and early stream random urine samples were collected, transported to a laboratory at 4OC and aliquoted. Samples were tested using nested HPV PCR with PGMY09/11 and GP5+/6+ primers. Positive cases were genotyped by sequence analysis.

RESULTS

Study participants included 1,134 sexually active and 171 unmarried women with a mean age at marriage of 22.1 (SD=3.9) years. Study area showed high female literacy rate of 86.6%. Five urine samples tested positive for HPV DNA (0.4%).

CONCLUSIONS

We found very low genital HPV infection rate among women from monogamous community. This is the first major population based study carried out among asymptomatic rural women to detect genital HPV infectio from Karnataka using urine samples.

Community-Based Prevalence of Genital Human Papilloma Virus (HPV) Infection: a Systematic Review and Meta-Analysis

Introduction:

Cervical cancer probably represents the best-studied human cancer caused by a viral infection and the causal association of this preventable cancer with human papilloma virus (HPV) is well established. Worldwide there is a scarcity of data regarding HPV prevalence with vast differences existing among populations.

Objective:

The aim of this meta-analysis was to determine the community-based HPV prevalence estimates among asymptomatic women from urban and rural set ups and in participants of cancer screening clinics.

Study design:

Systematic review and meta-analysis.

Methods:

PubMed-Medline, CINAHL, Scopus, and Google scholar were systematically searched for studies providing prevalence data for HPV infection among asymptomatic women between 1986 and 2016.

Results:

The final analysis included 32 studies comprising a population of 224,320 asymptomatic women. The overall pooled HPV prevalence was 11% (95% confidence interval (CI), 9%-12%). The pooled HPV prevalence of 11% (95% CI, 9%-11%) was observed among women attending cervical cancer screening clinics. The pooled HPV prevalences were 10% (95% CI 8%-12%) and 11% (95% CI 4%-18%) from urban and rural areas respectively, indicating higher infection rates among the rural women with the least access to cancer screening and cancer care.

Conclusion:

The prevalence rates in this systematic quantitative review provide a reliable estimate of the burden of HPV infection among asymptomatic women from developed as well as developing nations. Rural women and women attending cervical cancer screening programmes feature higher genital HPV prevalences compared to their urban counterparts.

Bias Due to Correlation Between Times-at-Risk for Infection in Epidemiologic Studies Measuring Biological Interactions Between Sexually Transmitted Infections: A Case Study Using Human Papillomavirus Type Interactions

The clustering of human papillomavirus (HPV) infections in some individuals is often interpreted as the result of common risk factors rather than biological interactions between different types of HPV. The intraindividual correlation between times-at-risk for all HPV infections is not generally considered in the analysis of epidemiologic studies. We used a deterministic transmission model to simulate cross-sectional and prospective epidemiologic studies measuring associations between 2 HPV types. When we assumed no interactions, the model predicted that studies would estimate odds ratios and incidence rate ratios greater than 1 between HPV types even after complete adjustment for sexual behavior. We demonstrated that this residual association is due to correlation between the times-at-risk for different HPV types, where individuals become concurrently at risk for all of their partners' HPV types when they enter a partnership and are not at risk when they are single. This correlation can be controlled in prospective studies by restricting analyses to susceptible individuals with an infected sexual partner. The bias in the measured associations was largest in low-sexual-activity populations, cross-sectional studies, and studies which evaluated infection with a first HPV type as the exposure. These results suggest that current epidemiologic evidence does not preclude the existence of competitive biological interactions between HPV types.

The Role of Chlamydia trachomatis in High-Risk Human Papillomavirus Persistence Among Female Sex Workers in Nairobi, Kenya

BACKGROUND

Little is known about risk factors for persistent high-risk human papillomavirus (hrHPV) infection in low-income settings, and prior research has not quantified the relative duration of hrHPV infections stratified by risk factors. We compared the duration of hrHPV infection among female sex workers (FSWs) by exposure to sexually transmitted infections (STIs), using a highly sensitive biomarker assay.

METHODS

From 2009 to 2011, 350 FSWs enrolled in this longitudinal study. Every 3 months, sociodemographic and sexual behavior data were collected via questionnaire, and APTIMA assays were used to detect the rRNA of Chlamydia trachomatis (CT), Neisseria gonorrhea, Trichomonas vaginalis, Mycoplasma genitalium, and messenger RNA of the E6/E7 oncoproteins expressed by hrHPV. Among 173 FSW who were infected with hrHPV during the observation period, accelerated failure time models estimated time ratios (TRs) for duration of hrHPV infection, comparing FSW infected with STIs at baseline to STI-uninfected FSWs.

RESULTS

Median follow-up time was 26.2 months (interquartile range, 18.8-27.5 months). The median duration of hrHPV infection among all FSWs was 9.3 months (95% confidence interval [CI], 9.3-11.5). The duration of hrHPV infection among FSW infected with CT at baseline was greater than that among FSWs who were uninfected (adjusted TR, 1.7; 95% CI, 1.2-2.6). Among FSWs who were coinfected with hrHPV and CT at baseline, the adjusted TR was 3.4 (95% CI, 2.5-5.4) compared with FSWs infected with hrHPV only. No other STI was associated with hrHPV duration.

CONCLUSIONS

Recent or concurrent CT infection was associated with prolonged hrHPV infection among a cohort of Nairobi FSWs. Management of CT could reduce risk for hrHPV persistence.

Elevated Expression of Human Papillomavirus-16/18 E6 Oncoprotein Associates with Persistence of Viral Infection: A 3-Year Prospective Study in China

BACKGROUND

An association between high-risk human papillomavirus (HR-HPV) oncoprotein expression and viral persistence has been suggested by the outcome of etiology studies, but there are no epidemiologic studies evaluating that link.

METHODS

We performed a 3-year prospective study in which 2,498 Chinese women ages 25 to 65 years were screened by six screening tests, including the Onco E6: Cervical Test (Arbor Vita Corporation) in 2011 (baseline). Six-hundred and ninety women who were positive for any of the tests and a random sample of 164 women with all negative results received colposcopy, and cervical specimens for the cobas 4800 HPV test ("cobas," Roche Molecular Systems) were collected before colposcopy; of this group, 737 cervical specimens were collected to perform cobas and Onco E6: Cervical Test in 2014 (follow-up). Twenty-four cases of HPV16/18 E6 positives and 204 selected controls at baseline, 13 cases of HPV16/18 E6 positive and another 204 selected controls at follow-up were analyzed separately using unconditional logistical regression models to estimate ORs and 95% confidence intervals (CI).

RESULTS

Compared with women who were HPV16 E6 oncoprotein negative at baseline, women in the E6-positive group had a much higher risk of HPV persistence (adjusted OR, 54.64; 95% CI, 7.19-415.09) at 3-year follow-up; a statistically strong association was also found between HPV16/18 HPV persistence and E6 oncoprotein expression detected at follow-up (adjusted OR, 360.57; 95% CI, 28.30-4,593.55).

CONCLUSIONS

A single detection of HPV16/18 E6 oncoprotein expression was strongly associated with viral persistence.

IMPACT

HPV16/18 E6 oncoprotein constitutes a marker for risk of HPV persistence. Cancer Epidemiol Biomarkers Prev; 25(7); 1167-74. ©2016 AACR.

Genetic Diversity in the Major Capsid L1 Protein of HPV-16 and HPV-18 in the Netherlands

Objectives

Intratypic molecular variants of human papillomavirus (HPV) type-16 and -18 exist. In the Netherlands, a bivalent vaccine, composed of recombinant L1 proteins from HPV-16 and -18, is used to prevent cervical cancer since 2009. Long-term vaccination could lead to changes in HPV-16 and -18 virus population, thereby hampering vaccination strategies. We determined the genetic diversity of the L1 gene in HPV-16 and -18 viral strains circulating in the Netherlands at the start of vaccination in order to understand the baseline genetic diversity in the Dutch population.

Methods

DNA sequences of the L1 gene were determined in HPV-16 (n = 241) and HPV-18 (n = 108) positive anogenital samples collected in 2009 and 2011 among Dutch 16- to 24-year old female and male attendees of the sexually transmitted infection (STI) clinics. Phylogenetic analysis was performed and sequences were compared to reference sequences HPV-16 (AF536179) and HPV-18 (X05015) using BioNumerics 7.1.

Results

For HPV-16, ninety-five single nucleotide polymorphism (SNPs) were identified, twenty–seven (28%) were non-synonymous variations. For HPV-18, seventy-one SNPs were identified, twenty-nine (41%) were non-synonymous. The majority of the non-silent variations were located in sequences encoding alpha helix, beta sheet or surface loops, in particular in the immunodominant FG loop, and may influence the protein secondary structure and immune recognition.

Conclusions

This study provides unique pre-vaccination/baseline data on the genetic L1 diversity of HPV-16 and -18 viruses circulating in the Netherlands among adolescents and young adults.

Incidence and persistence of carcinogenic genital human papillomavirus infections in young women with or without Chlamydia trachomatis co-infection

We assessed whether infection with chlamydia increases the incidence of carcinogenic human papillomavirus (HPV) infections and if HPV persistence is affected by chlamydia co-infection. For 1982 women (16–29 years-old) participating in two consecutive rounds of a chlamydia screening implementation trial, swabs were polymerase chain reaction tested to detect chlamydia and 14 carcinogenic HPV genotypes. HPV type-specific incidence and persistence rates were stratified for chlamydia positivity at follow-up. Associations were assessed by multilevel logistic regression analyses with correction for sexual risk factors. HPV type-specific incidence ranged from 1.4% to 8.9% and persistence from 22.7% to 59.4% after a median follow-up of 11 months (interquartile range: 11–12). Differences in 1-year HPV persistence rates between chlamydia -infected and noninfected women were less distinct than differences in HPV incidence rates (pooled adjusted odds ratios of 1.17 [95% CI: 0.69–1.96] and 1.84 [95% CI: 1.36–2.47], respectively). The effect of chlamydia co-infection on HPV-infection risk did not significantly differ by HPV genotype. In conclusion, infection with chlamydia increases the risk of infection by carcinogenic HPV types and may enhance persistence of some HPV types. Although these findings could reflect residual confounding through unobserved risk factors, our results do give reason to explore more fully the association between chlamydia and HPV type-specific acquisition and persistence.

Long-term persistence of oral human papillomavirus type 16: the HPV Infection in Men (HIM) study

Persistent infection with oral HPV16 is believed to drive the development of most oropharyngeal cancers. However, patterns of oral HPV16 persistence remain understudied, particularly among HIV-negative individuals. Oral HPV16 persistence was evaluated among 1,626 participants of the HPV Infection in Men (HIM) Study. Twenty-three oral HPV16-positive men who provided an oral gargle sample on ≥2 study visits were included in the analysis. Archived oral samples from all follow-up visits were tested for HPV16 using Linear Array and INNO-LiPA detection methods. Persistence was evaluated using consecutive HPV16-positive visits held approximately 6 months apart and using the Kaplan-Meier method. Oral HPV16-positive men were aged 18 to 64 years [median, 36 years; interquartile range (IQR), 25-42] and were followed for a median of 44.4 months (IQR, 29.9-49.5). Of 13 incident infections, 4 (30.8%) persisted ≥12 months, 1 (10.0%) persisted ≥24 months, and none persisted ≥36 months [median infection duration, 7.3 months; 95% confidence interval (CI), 6.4-NA)]. Of 10 prevalent infections, 9 (90.0%) persisted ≥12 months, 8 (80.0%) persisted ≥24 months, 4 (57.1%) persisted ≥36 months, and 2 (40.0%) persisted ≥48 months (median infection duration, NA). Twelve-month persistence of incident infections increased significantly with age (Ptrend = 0.028). Prevalent oral HPV16 infections in men persisted longer than newly acquired infections, and persistence appeared to increase with age. These findings may explain the high prevalence of oral HPV observed at older ages. Understanding oral HPV16 persistence will aid in the identification of men at high-risk of developing HPV-related oropharyngeal cancer.

Population- and type-specific clustering of multiple HPV types across diverse risk populations in the Netherlands

In view of possible type replacement upon introduction of human papillomavirus (HPV) vaccination, we aimed to explore patterns of type-specific clustering across populations with various background infection risks. A total of 3,874 women from 3 cross-sectional studies in the Netherlands (in 2007-2009) provided vaginal self-samples, which were tested for 25 HPV genotypes by a sensitive molecular assay (SPF10 line probe assay, DDL Diagnostic Laboratory, Voorburg, the Netherlands). The number of concurrent HPV infections per woman was studied by Poisson regression. Associations between HPV types were investigated by generalized estimating equation analyses. The prevalence of any HPV type was 14% in a population-based study, 54% in a chlamydia screening intervention study, and 73% in a study among attendees of sexually transmitted infection clinics. Overall, multiple HPV infections were detected in 26% of the women. The number of concurrent HPV infections conformed to an overdispersed Poisson distribution, even after correction for known risk factors. Types differed significantly in their tendencies to be involved in coinfections, but no evidence for particular type-type interactions was found. Moreover, the strongest associations were observed in the lowest-risk population and vice versa.We found no indications of pairwise interactions, but our findings do suggest that clustering differs among HPV types and varies across risk groups.

Prevalence and risk factors of human papillomavirus infection types 16/18/45 in a cohort of French females aged 15-23 years

Investigation of the prevalence and risk factors of human papillomavirus (HPV) infection is the basis for developing prophylactic strategies against cervical cancer, especially for young women. This study aimed to assess the prevalence and risk factors of HPV infection among a cohort of sexually active young French women eligible for catch-up vaccination. Between 1997 and 2007, 2163 women aged 15-23 years attending consultations at the department of gynecology in the Hospital of Besançon (France) were screened for high risk HPV (HR HPV) infection. Risk factors were investigated through a questionnaire sent to all participants in 2010. HPV DNA was detected by HC2 and Probe Set assays. The overall prevalence for HR HPV and HPV16, 18 and/or HPV45 was 44.6% (95% CI, 42.5-46.7%) and 19% (95% CI, 17.3-20.7%), respectively. The response rate to the questionnaire was 22.6%. The prevalence of independent risk factors (age older than 19, smoking, and oral contraception) for HPV 16/18/45 infection in this population was less than 20%. Based on this study, HPV vaccination should be offered not only to teenage girls, but also to young women, regardless of their sexual activity.

Prevalence of human papillomavirus in young Italian women with normal cytology: how should we adapt the national vaccination policy?

BACKGROUND

Human Papillomavirus (HPV) is the most common sexually transmitted infection. In Italy, HPV vaccination is now offered free of charge to 12-year-old females. However, some regional health authorities have extended free vaccination to other age-groups, especially to girls under 18 years of age. We conducted a multicentre epidemiological study to ascertain the prevalence of different genotypes of HPV in young Italian women with normal cytology, with the aim of evaluating the possibility of extending vaccination to older females.

METHODS

The study was performed in 2010. Women aged 16-26 years with normal cytology were studied. Cervical samples were analyzed to identify the presence of HPV by PCR amplification of a segment of ORF L1 (450 bp). All positive HPV-DNA samples underwent viral genotype analysis by means of a restriction fragment length polymorphism assay.

RESULTS

Positivity for at least one HPV genotype was found in 18.2% of the 566 women recruited: 48.1% in the 16-17 age-class, 15.4 in the 18-20 age-class, 21.9% in the 21-23 age-class, and 15.5% in the 24-26 age-class; 10.1% of women were infected by at least one high-risk HPV genotype. HPV-16 was the most prevalent genotype. Only 4 (0.7%), 4 (0.7%) and 3 (0.5%) women were infected by HPV-18, HPV-6 and HPV-11, respectively. Of the HPV-DNA-positive women, 64.1% presented only one viral genotype, while 24.3% had multiple infections. The HPV genotypes most often involved in multiple infections were high-risk. A high prevalence was noted in the first years of sexual activity (48.1% of HPV-DNA-positive women aged 16-17 years); HPV prevalence subsequently declined and stabilized.The estimate of cumulative proportions of young women free from any HPV infection at each age was evaluated; 93.3% and 97.1% of 26 year-old women proved free from HPV-16 and/or HPV-18 and from HPV-6 and/or HPV-11, respectively.

CONCLUSIONS

Our findings confirm the crucial importance of conducting studies on women without cytological damage, in order to optimise and up-date preventive interventions against HPV infection, and suggest that vaccinating 26-year-old females at the time of their first pap-test is to be recommend, though this issue should be further explored.

Understanding HPV tests and their appropriate applications

Greater understanding of the role played by human papillomavirus (HPV) in the causation of disease has led to the development of an increasing number of HPV tests with different characteristics. The bewildering choice facing healthcare professionals and providers is daunting. Clearly, HPV testing is no longer simply of research interest, but can provide information that can be used for individual patient management and at the population level for cervical screening and vaccine surveillance. This review aims to provide the background to the development of HPV tests, to explain the different technologies and to discuss the challenges of the application of these optimally in the varied contexts of disease management. Few HPV tests are approved for clinical use and it is important that clinicians understand which test can be utilized, in what circumstances, with what specimens and the meaning of the report issued. HPV testing is no longer applicable only to cervical disease, and we have suggested additional areas, such as the oropharynx, in which HPV testing services might be implemented in the near future. New tests will continue to emerge and we have identified some of the indirect measures of HPV activity, or biomarkers, that could help in the risk stratification of HPV infection and associated disease. The challenges relating to the optimal application of the various HPV technologies are compounded by the lack of evidence regarding their performance in vaccinated populations. Currently published work, including modelling studies, has been undertaken in non-immunized populations. We therefore end by addressing the issues regarding appropriate strategies and tests for immunized populations.

High HPV-51 prevalence in invasive cervical cancers: results of a pre-immunization survey in North Sardinia, Italy

Background

Human Papilloma virus (HPV) is recognized as the etiological agent of benign and malignant ano-genital lesions. The most prevalent genotypes associated with cervical carcinoma are HPV-16 and -18 worldwide. However, recent studies have emphasized the role of other genotypes, such as HPV-51, in the pathogenesis of cervical dysplasia. The aim of the study was to estimate the burden of HPV-51 infection in invasive cervical malignant lesions in Northern Sardinia, Italy.

Methods/Principal Findings

An observational, retrospective, prevalence, mono-center study was carried out to evaluate the presence of HPV genotypes in tissues biopsies of cervical lesions (CIN-1, CIN-2, CIN-3 and invasive carcinoma) gathered from 1996 to 2009. Biological samples were collected from women admitted consecutively to a tertiary university hospital situated in Sassari, Italy. Molecular methods were used to identify 28 oncogenic HPV types. A total of 155 formalin-fixed and paraffin-embedded cervical tissue samples were analyzed. Approximately half of the cervical lesions were classified as invasive carcinoma. HPV-DNA was detected in 71% of the samples, with a higher frequency (100%) in those categorized as invasive neoplasia. Mono- or co-infections were demonstrated in 45.8% and 25.8% of the cervical samples, respectively. Overall, the most prevalent HPV types were -16 (49%) and -51 (19.4%), with an increased frequency of detection associated with the severity of the cervical lesions.

Conclusions/Significance

This survey highlights for the first time the relevant role of HPV-51 infection in the pathogenesis of invasive cervical cancer prior to the introduction of a vaccination program. Although a selection bias could have influenced the results, other recent studies have described the impact of HPV-51. This remarkable epidemiological element should be carefully evaluated, particularly in the view of opting for preventive vaccines, whose cross-protection patterns determine their efficacy in protecting against infection from HPV types that are not included in the vaccine itself.