Prevalence of HPV high and low risk types in cervical samples from the Italian general population: a population based study

Update on Effects of the Prophylactic HPV Vaccines on HPV Type Prevalence and Cervical Pathology

Most national prophylactic HPV vaccination programs started in approximately 2008, with either the bivalent Cervarix HPV16/18 or quadrivalent Gardasil (HPV6/11/16/18) vaccines, which were then followed by introduction of the nonavalent Gardasil 9 (HPV6/11/16/18/ 31/33/45/52/58) vaccine from 2015. Since that time, these products have demonstrated their ability to prevent infection with vaccine-covered HPV types and subsequent development of HPV-related cervical and genital pathologies. The data indicate that vaccination of young girls prior to sexual debut is more effective than vaccination of older HPV+ve women. Although some studies have shown a decline in the prevalence of vaccine-covered HPV types, there are national and regional differences in overall vaccine efficacy. Furthermore, several recently published studies show an increase in the prevalence of non-vaccine-covered HPV types in vaccinated populations, which is indicative of HPV type-replacement. It is also notable that vaccine-related changes in HPV type prevalence spread between vaccinated and unvaccinated women at the same geographical location-presumably via sexual transmission. In conclusion, it is not yet clear what effect dissemination of vaccine-associated changes in HPV type prevalence will have on vaccine efficacy and cervical pathology, particularly in mixed populations of vaccinated and unvaccinated women. However, it is very clear these observations do underscore the need for long-term continuation of cervical screening combined with regular reassessment of testing practices.

Comparison of HPV Testing and Colposcopy in Detecting Cervical Dysplasia in Patients With Cytological Abnormalities

AIM

The aim of the study was to compare the diagnostic value of HPV testing and colposcopy in patients with abnormal cytology results.

PATIENTS AND METHODS

A total of 186 women with cytological abnormalities were included in the study. The patients underwent colposcopy examinations and DNA HPV testing of cervical smear with genotyping.

RESULTS

The HPV test was demonstrated to be more sensitive (79.4%) than specific (60.2%) and was more sensitive than colposcopy for detecting CIN changes (79.4% vs. 73.7%). Combined tests achieved a high sensitivity (90.9%) and negative predictive value (96.1%) in detecting patients with CIN2+ and demonstrated the highest positive predictive value (77.3%) for detecting CIN1+. Colposcopy had a very good specificity (83.5%) and positive predictive value (71.2%) in finding CIN1+ cases.

CONCLUSION

HPV tests showed a higher sensitivity than colposcopy, but colposcopy results presented higher specificity. Combining HPV testing and colposcopy proved to be the most efficient method for detecting CIN lesions.

Prevalence of "unclassified" HPV genotypes among women with abnormal cytology

Background

High risk human papillomaviruses (HPVs) have been unequivocally recognised as the necessary cause of squamous intraepithelial lesions (SIL) and invasive carcinoma of the cervix. The distribution and the role of unclassified risk HPV genotypes in cervical neoplasia has not been fully elucidated.

Methods

Liquid-based cytological samples were collected from 337 women referred for colposcopy following an abnormal cytological diagnosis. HPV DNA was detected by broad-spectrum PCR and genotypes identified by nucleotide sequencing analysis and reverse line blot (RLB).

Results

The overall frequency of HPV infection was 36.5% (35 out of 96) in samples negative for intraepithelial lesions or malignancy (NILM), 80% (181 out of 226) in low grade SIL and 93.3% (14 out of 15) in high grade SIL (P < 0.001). Thirty-five different genotypes were identified among the 230 HPV-positive cases. The Group 1 oncogenic viruses (HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 and 59) were found in 21.9, 46.5, and 86.7% of NILM, low grade SIL and high grade SIL, respectively. The Group 2A, including the probably oncogenic virus HPV68, was found in 1 and 0.8% of NILM and low grade SIL, respectively. The Group 2b possibly oncogenic HPVs (HPV34, 53, 66, 67, 70, 73, 82 and 85) were found in 4.2, 21.7 and 26.7% of NILM, low grade SIL and high grade SIL, respectively. The unclassified viruses (HPV12, 42, 54, 55, 61, 62, 81, 83, 84, 89, 90, 91) were detected in 8.3 and 14.6% of NILM and low grade SIL, respectively, and never in high grade SIL.

Conclusions

Group 1 HPVs were mainly prevalent in high grade SIL and low grade SIL while Group 2B were equally distributed among the two groups. The dominant frequency of unclassified HPVs in low grade SIL and NILM and their rarity in high grade SIL suggests their marginal role in cervical neoplasia of the studied population.

Monitoring vaccine and non-vaccine HPV type prevalence in the post-vaccination era in women living in the Basilicata region, Italy

Background

A large free-of-charge quadrivalent HPV (qHPV) vaccination program, covering four cohorts annually (women 11, 14, 17 and 24 years), has been implemented in Basilicata since 2007. This study evaluated vaccine and non-vaccine HPV prevalence 5-7 years post-vaccination program implementation in vaccinated and unvaccinated women.

Methods

This population-based, cross-sectional study was conducted in the public screening centers of the Local Health Unit in Matera between 2012 and 2014. Cervical samples were obtained for Pap and HPV testing (HC2, LiPA Extra® assay) and participants completed a sociodemographic and behavioral questionnaire. Detailed HPV vaccination status was retrieved from the official HPV vaccine registry. HPV prevalence was described overall, by type and vaccination status. The association between HPV type-detection and risk/protective factors was studied. Direct vaccine protection (qHPV vaccine effectiveness [VE]), cross-protection, and type-replacement were evaluated in cohorts eligible for vaccination, by analyzing HPV prevalence of vaccine and non-vaccine types according to vaccination status.

Results

Overall, 2793 women (18-50 years) were included, 1314 of them having been in birth cohorts eligible for the HPV vaccination program (18- to 30-year-old women at enrolment). Among the latter, qHPV vaccine uptake was 59% (at least one dose), with 94% completing the schedule; standardized qHPV type prevalence was 0.6% in vaccinated versus 5.5% in unvaccinated women (P <0.001); adjusted VE against vaccine type infections was 90% (95% CI: 73%-96%) for all fully vaccinated women and 100% (95% CI not calculable) in women vaccinated before sexual debut. No statistically significant difference in overall high-risk HPV, high-risk non-vaccine HPV, or any single non-vaccine type prevalence was observed between vaccinated and unvaccinated women.

Conclusions

These results, conducted in a post-vaccine era, suggest a high qHPV VE and that a well-implemented catch-up vaccination program may be efficient in reducing vaccine-type infections in a real-world setting. No cross-protective effect or evidence of type-replacement was observed a few years after HPV vaccine introduction.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-2945-8) contains supplementary material, which is available to authorized users.

Six years genotype distribution of Human Papillomavirus in Calabria Region, Southern Italy: a retrospective study

BACKGROUND

Although analysis of the Human papillomavirus (HPV) genotype spread in a particular area has a crucial impact on public health and prevention programmes, there is a lack of epidemiological data regarding HPV in the Calabria region of Italy. We therefore update information on HPV age/genotype distribution by retrospectively analysing a cohort of women, with and without cervical lesions, living in Calabria, who underwent HPV DNA testing; moreover, we also evaluated HPV age/genotype distribution in a subset of patients with cervical lesions.

METHODS

Cervical scrape specimens obtained from 9590 women (age range 20-75 years) from January 2010 to December 2015 were tested for HPV DNA. Viral types were genotyped by Linear Array HPV Genotyping® test (Roche, USA) at the Clinical Microbiology Operative Unit of six hospitals located in four provinces of the Calabria region. Cervical scrape specimens were also used to perform Pap smears for cytological analysis in a subset of 405 women; cytological classification of the samples was performed according to the Bethesda classification system.

RESULTS

A total of 2974 women (31%) (C.I. 95% 30.09-31.94) were found to be HPV DNA positive for at least one (57.3%) or several (42.7%) HPV genotypes. Of single genotype HPV infections, 46.5% and 36.4 % were classed as high-risk (HR, Group 1) and low-risk (LR, Group 3) respectively, while 16.9% were classed as probably/possibly carcinogenic and 0.2% undetermined risk. Stratified by age, total HPV distribution, showed the highest prevalence within the range 30-39 years (37.2%), while single genotype infection distribution displayed a peak in women from the age range 20-29 years (37.5%). The most common high-risk HPV type was HPV 16 (19.1%), followed by HPV 31 (9.1%).

CONCLUSIONS

We provide epidemiological data on HPV age/genotype distribution in women living in the Calabria region with or without cytological abnormalities, further to the enhancement of HPV screening/prevention programmes for the local population.

Cervical cancer screening in women vaccinated against human papillomavirus infection: Recommendations from a consensus conference

In Italy, the cohorts of women who were offered Human papillomavirus (HPV) vaccination in 2007/08 will reach the age (25years) for cervical cancer (CC) screening from 2017. The simultaneous shift from cytology-based screening to HPV test-based screening gives the opportunity for unprecedented reorganisation of CC prevention. The ONS (National Screening Monitoring Centre) Directive and the GISCi (Italian Group for Cervical Screening) identified the consensus conference as the most suitable method for addressing this topic. A summary of consensus recommendations is reported here. The main objective was to define the best screening methods in girls vaccinated against HPV and the knowledge required for defining evidence-based screening strategies. A Jury made recommendations about questions and proposals formulated by a panel of experts representative of Italian scientific societies involved in CC prevention and based on systematic reviews of literature and evidence. The Jury considered changing the screening protocols for girls vaccinated in their twelfth year as appropriate. Tailored screening protocols based on vaccination status could be replaced by "one size fits all" protocols only when a herd immunity effect has been reached. Vaccinated women should start screening at age 30, instead of 25, with HPV test. Furthermore, there is a strong rationale for applying longer intervals for re-screening HPV negative women than the currently recommended 5years, but research is needed to determine the optimal screening time points. For non-vaccinated women and for women vaccinated in their fifteenth year or later, the current protocol should be kept.

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.

Overview of the benefits and potential issues of the nonavalent HPV vaccine

HPV-related diseases affect anogenital and oropharyngeal regions, heavily affecting the psychosexual dimension of both male and female individuals. HPV vaccination programs based on a bivalent or quadrivalent vaccine have opened broad perspectives for primary prevention. A nonavalent HPV vaccine (9vHPV), covering nine genotypes (HPV6, HPV11, HPV16, HPV18, HPV31, HPV33, HPV45, HPV52, and HPV58), might provide further improvement in terms of direct protection. In the present report, efficacy and safety data from 9vHPV vaccine development programs are examined. Efficacy data come from a pivotal trial, which was conducted among women aged 16-26 years randomly assigned to receive either the 9vHPV or the quadrivalent HPV (4vHPV) vaccine. The 9vHPV vaccine was shown to have potential benefits as compared with 4vHPV, increasing the overall estimated rate of prevention to 90% for cervical cancer and up to 80% for precancerous cervical lesions. For all other HPV-related pre-invasive and invasive lesions, 9vHPV showed potentially greater disease reduction, depending on the anatomic region examined. Thus, the 9vHPV vaccine shows clinical potential for the prevention of HPV-related diseases in both sexes. Future adoption of 9vHPV will depend on factors including market price, cost-effectiveness data, use of a two-dose schedule, and safety and efficacy monitoring in real-life programs.

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.

Prevalence and Associated Risk Factors of Human Papillomavirus in Healthy Skin Specimens Collected from Rural Anyang, China, 2006-2008

Skin infections with cutaneous human papillomavirus (HPV) have been linked to the development of non-melanoma skin cancer, in which mucosal HPV may also play a crucial role. However, systematic investigations of the distribution and associated factors of HPV infection in healthy skin of the general population are scarce. HPV DNA from palmar exfoliated cells of 2,087 individuals was detected by FAP6085/64 and SPF1/GP6+ primers followed by sequencing. A total of 338 papillomavirus types were detected, with HPV-3, HPV-57, and HPV-49 being the most dominant types. The overall prevalence for HPV DNA on skin was 79.92% and for alpha-, beta-, and gamma-HPV were 27.07%, 38.76%, and 29.56%, respectively. Having multiple lifetime sexual partners (adjusted odds ratio 1.60), being a migrant worker (adjusted odds ratio 2.05, reference: farmers), and frequent bathing (Ptrend = 0.001) were associated with alpha-HPV DNA presence. Advancing age increased the detection risk of beta-HPV (Ptrend = 0.001). Higher education (Ptrend = 0.017) and frequent bathing (Ptrend = 0.001) were positively related to gamma-HPV positivity. This study demonstrates that alpha-HPV commonly exists on healthy skin of the general population in rural China, and alpha- and gamma-HPV infections are related to certain behaviors, different from beta-HPV infection. These findings are crucial to better understanding the biology of HPV infection and may be suggestive of the potential transmission of these viruses.

Epidemiological patterns of cervical human papillomavirus infection among women presenting for cervical cancer screening in North-Eastern Nigeria

Background

Sub-Saharan countries including Nigeria have the highest burden of Human Papillomavirus (HPV) infection in the world. Most studies on HPV surveillance in Nigeria were done in the southern part of the country. Geographical and socio-cultural diversity of Nigeria makes these data unlikely to be universally representative for the entire country. Northern Nigeria especially the North-East carries a higher prevalence of cervical cancer and many of its risk factors. The region may be harbouring a higher prevalence of HPV infection with a possibility of different genotypic distribution. This study was carried out to determine the burden and confirm the predominant HPV genotypes among women presenting for cervical cancer screening at the Federal Teaching Hospital Gombe (FTHG), North-eastern, Nigeria.

Methods

The study was an observational hospital based cross sectional study among women who presented for cervical cancer screening in FTHG. A total of 209 consenting women were tested for cervical HPV infection using PCR. DNA sequencing was carried out on positive samples to determine the prevalent HPV genotypes.

Results

The prevalence of cervical HPV infection among the participants with mean age of 39.6 ± 10.4 years was 48.1 %. The five most predominant genotypes were 18, 16, 33, 31 and 35, with prevalence of 44.7 %, 13.2 %, 7.9 %, 5.3 % and 5.3 % respectively. Other genotypes observed were 38, 45, 56, 58, 82 and KC5. Multiple HPV infections were detected among 7.9 % of participants. Risk factors such as level of education (X² = 15.897; p = 0.007), age at sexual debut (X² = 6.916; p = 0.009), parity (X² = 23.767; p = 0.000), number of life time sexual partners (X² = 7.805; p = 0.005), age at first pregnancy (X² = 10.554; p = 0.005) and history of other malignancies (X² = 7.325; p = 0.007) were found to have a statistically significant association with HPV infection.

Conclusion

This study identified a high burden of HPV infection in Northern Nigeria while also confirming HPV 18 and 16 as the most predominant genotypes. It further justifies the potential benefit of the currently available HPV vaccines in the area. A larger and community based study is however recommended for better representation of the area.

Electronic supplementary material

The online version of this article (doi:10.1186/s13027-015-0035-8) contains supplementary material, which is available to authorized users.

Changes in cervical cancer incidence following the introduction of organized screening in Italy

OBJECTIVE

To quantify the impact of organized cervical screening programs (OCSPs) on the incidence of invasive cervical cancer (ICC), comparing rates before and after activation of OCSPs.

METHODS

This population-based investigation, using individual data from cancer registries and OCSPs, included 3557 women diagnosed with ICC at age 25-74years in 1995-2008. The year of full-activation of each OCSP was defined as the year when at least 40% of target women had been invited. Incidence rate ratios (IRRs) with 95% confidence intervals (95% CIs) were calculated as the ratios between age-standardized incidence rates observed in periods after full-activation of OCSPs vs those observed in the preceding quinquennium.

RESULTS

ICC incidence rates diminished with time since OCSPs full-activation: after 6-8years, the IRR was 0.75 (95% CI: 0.67-0.85). The reduction was higher for stages IB-IV (IRR=0.68, 95% CI: 0.58-0.80), squamous cell ICCs (IRR=0.74, 95% CI: 0.64-0.84), and particularly evident among women aged 45-74years. Conversely, incidence rates of micro-invasive (stage IA) ICCs increased, though not significantly, among women aged 25-44years (IRR=1.34, 95% CI: 0.91-1.96). Following full-activation of OCSPs, micro-invasive ICCs were mainly and increasingly diagnosed within OCSPs (up to 72%).

CONCLUSION(S)

Within few years from activation, organized screening positively impacted the already low ICC incidence in Italy and favored down-staging.

HPV prevalence and risk of pre-cancer and cancer in regular immigrants in Italy: results from HPV DNA test-based screening pilot programs

ᅟ: Immigrants from low- and medium-income countries have a higher risk of cervical cancer due both to barriers in access to screening and to higher human papillomavirus (HPV) prevalence. In the near future many screening programmes in industrialised countries will replace Pap test with HPV as primary test. In order to plan future interventions, it is essential to understand how the HPV screening performs in immigrant women.

METHODS

We conducted a survey on the main performance indicators from some of the HPV DNA-based pilot programmes in Italy, comparing regular immigrant women, identified as women resident in Italy who were born abroad, with women who were born in Italy. All the programmes applied the same protocol, with HPV as stand-alone test starting for women of 25 or 35 to 64 years of age. Cytology triage is performed for positive women; those ASC-US or more severe are referred directly to colposcopy; negative women are referred to repeat HPV after one year.

RESULTS

Overall, 162,829 women were invited, of whom 22,814 were born abroad. Participation was higher for Italy-born than born abroad (52.2% vs. 43.6%), particularly for women over 45 years. HPV positivity rate was higher in immigrants: 7.8% vs. 6.1%, age-adjusted Relative Risk (age-adj RR) 1.18, 95% confidence interval (95% CI) 1.13-1.22. The proportion of women with positive cytology triage was similar in the two groups (42%). Cervical Intraepithelial Neoplasia (CIN) grade 2 or more severe detection rate was higher for born abroad (age-adj RR 1.65, 95% CI 1.45-1.89). The difference was stronger when considering only CIN3 or more severe (age-adj RR 2.29, 95% CI 1.90-2.75). Both HPV positivity and CIN2 or more severe detection rate had a different age curve in born abroad compared with Italy-born: in the former, the risk was almost flat, while in the latter it declined rapidly with age.

CONCLUSION

Compliance with HPV screening is lower for migrant women, who are affected by higher HPV positivity and CIN3 cancer detection rates.

Specific genotypes of human papillomavirus in 125 high-grade squamous lesions and invasive cervical cancer cases from Congolese women

BACKGROUND

Knowledge on HPV prevalence and genotype distribution in HSIL and ICC is highly essential for the introduction of an effective vaccination program and appropriate epidemiological monitoring of viral ecology before and after vaccination in Congo. This study aimed to determine the specific-HPV genotypes in HSIL and ICC among women in southwestern Congo.

METHODS

125 archival paraffin-embedded biopsy collected between 2008 and 2012 and histologically diagnosed were investigated. DNA extraction was performed using the phenol/chloroform method. HPV search was performed by nested-PCR using MY09/MY11 and GP5+/GP6+ consensus primers followed by direct sequencing.

RESULTS

The mean age of participants was 44.3 ± 8.2 years. Overall, HPV prevalence was 89.6% (112/125) with all high-risk genotypes. HPV-DNA was detected in 81.5% (53/65) of HSIL and 98.3% (59/60) of ICC. HPV 16 the most common genotype was detected in 47.1% (25/53) of HSIL and 52.5% (31/59) of ICC. Other types identified were: HPV 33 (22.6%), HPV 18 (15%), HPV 31 (11.3%) and HPV 69 (3.7%) in HSIL, and HPV 33 (28.8%), HPV 18 (11.8%), HPV 31 (5%) and HPV 35 (1.7%) in ICC. Knowing that the ADC accounted for 6.7% (4/60) of ICC cases, HPV 18 was identified in 25% (1/4) of these cases against 75% (3/4) for HPV 16.

CONCLUSION

Our study showed that HPV 16, 33, 18 and 31 were the four most common genotypes in women with HSIL and ICC. These findings indicate that current vaccines against HPV could help to reduce the burden of cervical cancer in Congo.

High-risk human papillomavirus in Galicia, Spain: prevalence and evaluation of the sample representativeness

BACKGROUND

The prevalence of high-risk genotypes of the human papillomavirus (HR-HPV) in Galicia remained unknown before the introduction of the HPV vaccine. The objective of this study was to estimate this prevalence in non-vaccinated women when vaccination against HR-HPV started. Sample representativeness was also evaluated.

METHODS

Female volunteers aged 16-64 years, residents in Galicia, Spain, completed a questionnaire and provided biological samples for a virological study and for cytology. The sample was weighted; prevalence rates were estimated and are shown with 95% confidence intervals.

RESULTS

Virological results were available for 1703 women. HR-HPV prevalence was 10.1%, decreasing notably at ages above 30 years. HPV-16 was the most frequent genotype and 3.6% of women were infected by more than one genotype. No adjustment was necessary to generalize the results of the study.

CONCLUSIONS

In Galicia in 2009 there would be 96 400 women aged 16-64 years infected with HR-HPV. It is possible to estimate HR-HPV prevalence in a population starting from a volunteer sample.

Clinical prediction based on HPV DNA testing by hybrid capture 2 (HC2) in combination with liquid-based cytology (LBC)

Primary screening by HPV DNA testing is an effective method for reducing cervical cancer and has proven more sensitive than cytology. To advance this approach, many molecular methods have been developed. Hybrid capture 2 provides semi-quantitative results in ratios of relative light units and positive cutoff values (RLU/ PC). Twenty-five thousand and five patients were included in this study to analyze the correlation between the ratio of RLU/PC and stage of cervical dysplasia. The results show that the RLU/PC ratios ranged from 0-3500 while almost normal cases, ASC-US and ASC-H, had values below 200. Of those samples negative for cytology markers, 94.6% were normal and their RLU/PC ratios were less than 4. With an RLU/PC ratio greater than 4 and less than or equal to 300, the percentages in all age groups were normal 53.6%, LSIL 20.2%, ASC-US 17.2%, HSIL 6.13%, ASC-H 2.72%, and AGC 0.11%, respectively. In contrast, 64.0% of samples with a RLU/ PC ratio greater than 300 and less than or equal to 3500 were LSIL. These results should contribute to cost effective cervical cancer management strategies. Further studies of associations with particular HPV genotypes would be useful to predict the risk of progression to cancer.

Human Papillomavirus Infection and Cervical Neoplasia among Migrant Women Living in Italy

Human papillomavirus (HPV) infection is highly prevalent in women migrating from countries where cervical screening is not implemented. The variety of HPV genotypes, their prevalence and the association with cervical abnormalities has been investigated by several groups in women moving mainly from Eastern Europe, Africa, and Southern Asia to Italy. All studies are concordant on the elevated rate of HPV infection among immigrants, which is four times higher than that observed among age-matched Italian women. The HPV prevalence among short-term migrants and characterization of viral variants showed that the high prevalence of HPV reflects either individual lifestyle or high prevalence of HPV in the country of origin. The high burden of HPV infection correlates very well with the high incidence of cervical cancer in migrant women. In fact, during the years 2000-2004 the cervical cancer incidence in women from Central and Eastern Europe and living in Central Italy was 38.3 per 100,000, which is statistically significant higher than that of native Italian women (6 per 100,000). In this study, we pooled together the results of three independent studies originally designed to assess the distribution and the prevalence of HPV genotypes among 499 immigrant women living in Southern Italy. A total of 39 mucosal HPV genotypes were identified. The 12 genotypes (HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, and 59) classified as carcinogenic to humans (group 1) accounted for >80% of all infections. HPV16 was the most common viral type in all groups with frequency rates ranging from 15.4% in Africa to 51.1% in Eastern and Southern European HPV-positive women. The high prevalence of oncogenic HPVs and cervical cancer risk among migrant women, together with the lower participation in screening programs, demands for an urgent implementation of preventive strategies to increase screening and vaccine coverage and viral monitoring of uncommon HPV genotypes potential spreading in settled population.

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.

Difference in overall and age-specific prevalence of high-risk human papillomavirus infection in Italy: evidence from NTCC trial

BACKGROUND

Although among women a decreasing prevalence of human papillomavirus (HPV) infection with increasing age has been consistently observed in high-resource countries, different age profiles have been reported elsewhere.

METHODS

We compared the age profile of high-risk (HR)-HPV prevalence in nine different areas of Northern and Central Italy by studying the women recruited in the intervention arm of the New Technologies in Cervical Cancer study and tested by Hybrid Capture 2. Differences in the age-distribution of HPV infection were investigated in each centre by the joinpoint approach in a logistic model. 46,900 women aged 25 to 60 years were included in the analysis.

RESULTS

The HR-HPV age-standardised (on Italian population) prevalence ranged from 5.7% (Trento) to 10.3% (Ravenna). HR-HPV prevalence decreased as a logistic function of increasing age in 6 of 9 centres (Trento, Verona, Florence, Bologna, Imola, and Viterbo). The effect of age on HR-HPV prevalence slopes did not differ significantly among these 6 centres, whereas significant heterogeneity in intercepts (p < 0.001) was found, reflecting different overall HR-HPV prevalence between centres. One significant joinpoint was observed in 2 centres (Padua and Ravenna), indicating that the decrease in HR-HPV prevalence by age was better described using a function composed with two logistic segments. In Padua HR-HPV prevalence decreased only slightly up to 39 years but showed a steep downturn thereafter. In Ravenna HR-HPV prevalence decreased steeply down to 45 years of age and then showed a plateau. Finally, in Turin two significant joinpoints were observed: prevalence decreased only after age 29 and showed a plateau after age 39.

CONCLUSIONS

Our results showed substantial differences in overall and age-specific HR-HPV prevalence across Italian areas. These findings may be related to different timing of changes in sexual behaviours across regions. Age-specific HR-HPV prevalence in Italy does not support an influence of age per se.

Prevalence of high-risk HPV types and associated genital diseases in women born in 1988/89 or 1983/84--results of WOLVES, a population-based epidemiological study in Wolfsburg, Germany

BACKGROUND

High-risk human papilloma virus (HR-HPV) infection is associated with the development of cervical cancer. HPV vaccination reduces the risk of developing malignant lesions and is expected to change the dynamics of HPV transmission. Data from non-vaccinated women may provide an important benchmark to allow the impact of HPV vaccination programs to be assessed.This study was designed to prospectively determine the changing dynamics of HR-HPV infection and associated genital diseases in young women, most of whom were non-vaccinated.

METHODS

Data from a population-based cohort study, comprising women of two predefined birth cohorts (women born in 1983/84 or 1988/89), were analyzed between 19 October 2009 and 31 December 2010 to determine risk factors for high-risk HPV infection and the association between specific HR-HPV types and atypical Pap smear test results. HPV status was determined by Hybrid Capture 2 (HC2) assay and genotyping.

RESULTS

The prevalence of HR-HPV was 22.8% in the 1983/84 cohort (150/659) and 23.7% in the 1988/99 cohort (142/599). Only the number of sexual partners was a significant risk factor for HPV infection (odds ratios 22.687 and 6.124 for more than five versus one partner 84 cohort,/84 and 1988/89 cohorts, respectively) in multivariate analysis. HPV16 positive-women were significantly more likely to have abnormal Pap smears of any degree than HPV16-negative women (22.0% versus 3.61%, p < 0.0001 for the 1983/84 cohort and 9.09% versus 2.52%, p = 0.0482 for the 1988/89 cohort). CIN3 was diagnosed in six women 84 cohort,/84 cohort and two in the 1988/89 cohort. All women with CIN3 tested positive for HC2-HR and all six CIN3 cases 84 cohort,/84 cohort tested positive for HPV16. In the 1988/89 cohort, the rate of HPV16 infection was significantly lower in vaccinated than non-vaccinated women (1.59% versus 8.88%; p = 0.003).

CONCLUSIONS

HR-HPV infection was highly prevalent in both cohorts and associated with an increased risk of abnormal Pap smears and biopsy proven CIN2+. HPV16 infection was associated with a high risk of clinically relevant lesions. HPV vaccination significantly decreased the risk of HPV16 infection.

HPV Infection in a Cohort of HIV-Positive Men and Women: Prevalence of Oncogenic Genotypes and Predictors of Mucosal Damage at Genital and Oral Sites

The aim of this study was to assess the prevalence of HPV infection and determinants of abnormal cytology in HIV-positive patients. In a cross-sectional study, patients of both sexes, asymptomatic for HPV, underwent anorectal (men)/cervical (women) and oral swabs. Cytology and HPV-PCR detection/genotyping (high- and low-risk genotypes, HR-LR/HPV) were performed. A total of 20% of the 277 enrolled patients showed oral HPV, with no atypical cytology; in men, anal HPV prevalence was 81% with 64% HR genotypes. In women, cervical HPV prevalence was 58% with 37% HR-HPV. The most frequent genotypes were HPV-16 and HPV-18; 37% of men and 20% of women harbored multiple genotypes. Also, 47% of men showed anal squamous intraepithelial lesions (SILs); 6% had high- and 35% low-grade SILs (HSILs/LSILs); 5% had atypical squamous cells of undetermined significance (ASC-US). HR-HPV was independently associated with anal-SIL in men (P = 0.039). Moreover, 37% of women showed cervical SIL: 14 ASC-US, 15 LSILs, 4 HSILs, and 1 in situ cancer. The presence of both LR and HR-HPV in women was independently associated with SIL (P = 0.003 and P = 0.0001). HR-HPV and atypical cytology were frequently identified in our cohort. HPV screening should be mandatory in HIV-infected subjects, and vaccine programs for HPV-negative patients should be implemented.

A cross-sectional study to estimate high-risk human papillomavirus prevalence and type distribution in Italian women aged 18-26 years

Background

Pre-vaccination information on HPV type-specific prevalence in target populations is essential for designing and monitoring immunization strategies for cervical cancer (CC) prevention. Data on HPV prevalence in Italy are available for women over the age of 24 years, target of the population-based CC screening programmes; while data of HPV prevalence in younger ages are very limited. The present study enrolled Italian women aged 18–26 years in order to assess the prevalence and distribution of high-risk (HR) HPV types. Risk-factors correlated with HR-HPV positivity were also described.

Methods

A sample of 2,289 women was randomly selected from the resident population lists of ten Local Health Units (LHUs) located in six Italian Regions scattered across the country; both rural and urban LHUs were involved. Women aged between 18 and 26 years and living in the selected LHUs were included in the study; pregnant women and women who did not speak Italian were excluded. A total of 1,102 women met the inclusion criteria and agreed to participate. Participants were offered pap test and Hybrid-Capture 2 (HC2) test for HR-HPV types and genotyping was performed on positive smears.

Results

Out of 1,094 valid samples, 205 (18.7%) were HR-HPV positive. Women with 2–4 (OR_adj = 4.15, 95%CI: 2.56-6.72) and ≥5 lifetime partners (OR_adj = 10.63, 95%CI: 6.16-18.36) and women who have used any contraceptive in the last six months (OR_adj = 1.67, 95%CI: 1.09-2.54) had a higher risk to be infected; women living with their partner had a lower risk (OR_adj = 0.56, 95%CI: 0.34-0.92) to acquire infection than women living with parents/friends/alone. Among HC2 positive women, HPV16 was the most prevalent type (30.9%), followed by 31 (19.6%), 66 (12.9%), 51 (11.3%), 18 (8.8%), 56 (8.8%). Co-infections of HR-HC2 targeted types were found in 20.4% of positive samples. The HR-HPV prevalence in women with abnormal cytology (52.4%) was significantly higher than in women with normal cytology (14.6%); however 33.0% of HR-HPV infected women had an abnormal cytology.

Conclusion

HR-HPV prevalence in Italian women aged 18–26 years was 19%, higher than what detected for older women, by other studies using the same molecular method and laboratory network; this result supports the choice of electing girls before the sexual debut as the primary target of HPV vaccination. The HPV type distribution found in this study may represent a baseline picture; an accurate post-vaccine surveillance is necessary to early detect a possible genotype replacement. The high prevalence of viral types other than vaccine-HPV types supports the necessity to guarantee the progression of CC screening programmes in vaccinated women.

A cross sectional study of HPV type prevalence according to age and cytology

Background

A cross sectional study to investigate HPV prevalence according to age and cytology.

Methods

Women presenting to a gynaecological outpatient clinic for a Pap smear test were included in the study (n=3177). All women had cervical cytology and HPV testing.

Results

Overall prevalence of any 24 HPV type analysed was 33.1% (95% CI 31.5% to 34.7%) and HPV 16 and HPV 42 were the most frequent (6.7% (95% CI 5.8% to 7.6%), 6.8% (95% CI 5.9% to 7.6%)), in total samples. Multiple HPV infection rate was 12.9% (95% CI 11.8% to 14.1%). High risk HPV (hrHPV) types were present in 27.4% (95% CI 25.8% to 28.9%) of the samples.

HPV prevalence was highest among 14 to 19 y.o (46.6% (95% CI 40.7%-52.4%)) and second highest among 30–34 y.o. (39.7%, 95% CI 35.4%–44%). HPV 16 was highest among 20–24 (9.0% (95% CI 6.4%–11.6%)) and second highest among 50 to 54 y.o. (6.3% (95% CI 2.9% to 9.8%).

In Low-grade Squamous Intraepithelial Lesions (LgSIL) cytology samples, the most frequently detected hrHPV types were: 16 (14.5% (95% CI 12.1% to 16.9%)), 51 (13.0% (95% CI 10.7% to 15.3%)) and 53 (9.1% (95% CI 7.2% to 11.1%)) and in High-grade Squamous Intraepithelial Lesions (HgSIL) were: HPV 16 (37.2% (95% CI 26.5% to 47.9%)), HPV 51 (17.9% (95% CI 9.4% to 26.5%)) and HPV 18 (12.8% (95% CI 5.4% to 20.2%)).

Conclusions

In the population studied, HPV 16 and 51 were the most frequent detected hrHPV types. HPV positivity, hrHPV and multiple HPV types infections were higher in young women, while HPV prevalence declined with increasing age and presented two peaks a higher (14–19 y.o.) and a lower one (30–34 y.o.) These results may contribute to the creation of a national screening programme.

Prevalence of human papillomavirus infection in Italian and immigrant women

Human papillomavirus (HPV) is the most common sexually transmitted agent worldwide. Prevalence varies according to the geographic regions, and is highest in developing countries. Geographic differences exist also in the detection rate of oncogenic types in malignant cervical lesions. In this study, the prevalence of HPV infection as well as the spectrum of HPV types was evaluated in Italian and immigrant women of the urban area of Rome. Several risk factors (age at first intercourse, number of partners, smoking, pregnancy, age at first pregnancy, contraception, education, and menarche) were taken into consideration. Overall, there was a high prevalence of HPV infection in the two groups studied. No significant differences were observed in the spectrum of HPV types detected. HPV 16 and 18 were the types detected more frequently in both groups. Interestingly, HPV 54 and 70 were found only in the immigrants. Whether this finding reflects a recent introduction of these HPV types in the population studied remains to be established. Monitoring of HPV types in the population is advisable, especially in countries like Italy which is a destination and a gateway for immigrants directed towards north and central Europe. The introduction of high risk HPV variants may have a clinical impact and affect the diagnostic procedures.

Cervical biopsies and cytological smears - a comparison of sample materials in HPV diagnostics

BACKGROUND

Cervical cancer is causally related to cervical infections by oncogenic human papillomavirus (HPV) genotypes. To improve the quality of diagnosis evaluation of screening methods and their HPV type detection rate is an important part for this item.

OBJECTIVES

Two different cervical specimens of the same patients were analysed simultaneously with molecular HPV subtyping methods to find the most sensitive sample material for cervical cancer screening.

STUDY DESIGN

Biopsy specimens and cytological smears of the cervix of 443 patients were analysed for human papilloma virus (HPV) subtyping by a macroarray from Chipron, Germany, which allows a differentiation of 16 high and 16 low risk types. Results were compared for reliability and differences were studied.

RESULTS

Both sample material groups showed HPV conformity of 70%, 23% more subtypes could be detected in smears in contrary to biopsies but only 6% vice versa. 14 biopsies and 7 smears were HPV negative although the concerning second sample type of the patients was HPV positive. HPV 16 as one of the most relevant subtypes in cervical cancer pathogenesis was missed in the biopsies' group with 34.3% out of 35 HPV 16 positive smear cases, whereas only one smear failed to discover this subtype contrariwise.

CONCLUSION

Comparison of the examination results shows that subtyping of smear samples is able to detect more subtypes than by biopsy specimens. The probability to underdiagnose HPV 16 and to get a false negative result in bioptic sample material favours smear as method of choice for HPV subtyping.

Oncogenic human papillomavirus genital infection in southern Iranian women: population-based study versus clinic-based data

BACKGROUND

Epidemiological studies on genital human papilloma viruses infection (HPVs) in general population are crucial for the implementation of health policy guidelines for developing the strategies to prevent the primary and secondary cervical cancer. In different parts of Iran, there is a lack of population-based studies to determine the prevalence of HPV in the general population. The aim of this population-based study is to compare the prevalence rate of genital HPV infection among reproductive women with our previous clinic-based data, which showed a prevalence rate of 5% in women in southern Iran.

RESULTS

Using general primers for all genotypes of HPV, of 799 randomly selected women, five (0.63%, 95% CI 0.23-1.55%) tested positive for HPV DNA. Overall, seven different HPV genotypes were detected: six types (16, 18, 31, 33, 51 and 56) were carcinogenic, or "high risk genotypes" and one genotype (HPV-66) was "probably carcinogenic."

CONCLUSIONS

In a population-based study, the prevalence of HPV infection among southern Iranian women was lower than that observed worldwide. However, our gynaecological clinic-based study on the prevalence of HPV infection showed results comparable with other studies in the Middle East and Persian Gulf countries. Since gynaecological clinic-based data may generally overestimate HPV prevalence, estimates of prevalence according to clinic-based data should be adjusted downward by the population-based survey estimates.

Comparison of HPV sign genotyping test with INNO-LiPA HPV genotyping extra assay on histologic and cytologic cervical specimens

An accurate tool for viral typing is important for management of patients with human papillomavirus (HPV) infection and to monitor HPV vaccine efficacy. This study evaluated the performance of the HPV sign® Genotyping Test by analyzing 87 archival cervical specimens and compared results with historical data by INNO-LiPA HPV Genotyping Extra assay. There was a substantial concordance for HPV detection in clinical samples (k 0.66), with an overall agreement rate of 85.1%. The genotyping overall agreement, considering one by one the HPV infection detected, was 95.7%. The HPV sign test showed, however, lower sensitivity than INNO-LiPA for HPV 31, 53, and 66. On the other hand, The HPV16 sensitivity was higher for HPV sign (90.0%, confidence interval [CI] 0.79-1.01) than for INNO-LiPA (83.3%, CI 0.70-0.97). Furthermore, HPV sign allowed identifying the presence of HPV16 intratype variants. In conclusion, HPV sign is a promising method for HPV genotyping and has revealed advantages in detecting a broad spectrum of HPV types and variants.

The diagnostic performance of classical molecular tests used for detecting human papillomavirus

Cervical samples were evaluated for human papillomavirus (HPV) presence using the hybrid capture-2 (HC2) assay and the polymerase chain reaction (PCR) with three different primer sets (GP5+/6+, MY09/11 and pU1M/2R). PCR results were compared to HC2 and results of all assays were compared to cytological and colposcopy findings. Post-test probability was assessed in individual assays and test combinations. HPV-DNA prevalence was 36.5% with HC2 and 55.2% with PCR. MY09/11 detected HPV-DNA in 38% of samples, GP5+/6+ in 19.1% and pU1M/2R in 16.4%. pU1M/2R and HC2 had the highest concordance (75.31%, k=0.39 in the whole population; 74.1%, k=0.5 in women with abnormal cytology). pU1M/2R had the best diagnostic performance, including optimal post-test probabilities and cervical abnormality detection (individually or in a panel of tests). Women positive for pU1M/2R may be at higher risk of disease progression; the assay performance when combined with a Pap smear in cervical cancer screening programs should be evaluated.

High prevalence of human papillomavirus infection in Eastern European and West African women immigrants in South Italy

Surveillance of human papillomavirus (HPV) prevalence and genotype distribution in migrant women from middle and low-income countries to developed countries is limited. The aim of this study was to analyze the spectrum of HPV genotypes and prevalence of cervical abnormalities in women emigrated mainly from Eastern Europe and West Africa and living in Southern Italy. The study included 233 migrant and 98 Italian-born women who self-referred to two gynecological outpatient clinics in the Campania region. Cervical specimens were subjected to cytological examination and viral testing by broad spectrum PCR. The prevalence rates of HPV infection were 57.9% and 94.1% among migrant and 19.4% and 88.5% among Italian women with normal and abnormal cytology respectively. HPV infection was detected in 56.1% of Southern and Eastern European, 62.5% of Central and South American, 55.5% of West African, and 73.3% of Southern Asian women with normal cervix. Among the 140 HPV-positive migrants, a total of 28 mucosal HPV genotypes were identified of which 11 types (HPV16, 18, 31, 33, 35, 39, 45, 51, 52, 56, and 58), epidemiological classified as carcinogenic to humans (group 1), accounted for 73.4% of all infections. As expected, HPV16 was the most common viral type in all groups with frequency rates ranging from 12.5% in African to 30.1% in Eastern and Southern European women. In conclusion, the estimated prevalence of HPV infection among migrant women is very high, probably reflecting either lifestyle or high incidence of HPV in their country of origin. The implementation of vaccination strategies and cervical cancer surveillance are critical for women in this risk group.

Comparison of clinical performance of Abbott RealTime High Risk HPV test with that of hybrid capture 2 assay in a screening setting

Randomized trials have produced sound evidence about the efficacy of screening with human papillomavirus (HPV) DNA tests in reducing cervical cancer incidence and mortality. We evaluated the clinical performance and reproducibility of the Abbott RealTime High Risk (HR) HPV test compared with that of the HR hybrid capture 2 (HC2) assay as assessed by a noninferiority score test. A random sample of 998 cervical specimens (914 specimens of cervical intraepithelial neoplasia less severe than grade 2 [<CIN2] and 84 specimens of cervical intraepithelial neoplasia grade 2 or more severe lesions [≥CIN2]), collected in the Florence and Catania cervical Cancer Screening Programs from women aged 25 to 64 and already tested by HR HC2, were retested with the Abbott RealTime HR HPV test. Absolute specificity was 92.3% (95% confidence interval [CI], 90.4 to 94.0) and 92.6% (95% CI, 90.7 to 94.2) for the Abbott RealTime HR HPV test and the HR HC2, respectively. Absolute sensitivity was 96.4% (95% CI, 89.9 to 99.3) and 97.6% (95% CI, 91.7 to 99.7) for the Abbott RealTime HR HPV test and the HR HC2, respectively. The noninferiority score test revealed that the clinical sensitivity and specificity of the Abbott RealTime HR HPV test were not inferior (P = 0.004 and 0.009, respectively) to those of HR HC2. Overall agreement between the two assays was 96.5%, with a k value of 0.86 (CI 95%, 0.82 to 0.91). We evaluated the intralaboratory reproducibility by retesting 521 samples at least 4 weeks after the first test; the crude agreement between the first and second test was 98.5%, with an overall k value of 0.97 (CI 95%, 0.95 to 0.99). This test fully satisfies the requirements of a primary cervical cancer screening test. This assay differentiates between HPV16, HPV18, and non-HPV16/18 types in every specimen, but how to use this information in a screening setting still is unclear.

Distribution of high and low risk HPV types by cytological status: a population based study from Italy

Background

HPV type distribution by cytological status represents useful information to predict the impact of mass vaccination on screening programs.

Methods

women aged from 25 to 64 who attended cervical cancer screening in five different Italian regions were tested for HPV infection with Hybrid Capture II (HCII) low and high risk probes. Women repeating Pap-test upon unsatisfactory or positive results, or as a post-treatment and post-colposcopy follow-up analysis, were excluded from our study. High risk (HR) HPV positive samples were typed using GP5+/GP6+ primed PCR, followed by Reverse Line Blot for 18 high/intermediate risk HPV types, while low risk (LR) HPV positive samples were tested with type specific primers for HPV6 and HPV11.

Results

3410 women had a valid HCII and Pap-test. The prevalence of HR and LR infections was 7.0% and 3.6%, 29.1% and 13.7%, 68.1% and 31.9%, 60.0% and 0.0%, 65.0% and 12.0%, for negative, ASC-US, L-SIL, ASC-H and H-SIL cytology, respectively. The fraction of ASC-US+ cytology due to HPV 16 and 18 ranged from 11.2 (HPV 16/18 alone) to 15.4% (including HPV 16/18 in co-infection with other virus strains), and that due to HPV 6 and 11 ranged from 0.2% (HPV 6/11 alone) to 0.7% (including HPV 6/11 in co-infection with other LR virus strains).

Conclusions

mass vaccination with bivalent or quadrivalent HPV vaccine would modestly impact on prevalence of abnormal Pap-test in screening.