Prevalence of human papillomavirus cervical infection in an Italian asymptomatic population

Recent Advances on Prediction of Human Papillomaviruses Risk Types

BACKGROUND

Some studies have shown that Human Papillomavirus (HPV) is strongly associated with cervical cancer. As we all know, cervical cancer still remains the fourth most common cancer, affecting women worldwide. Thus, it is both challenging and essential to detect risk types of human papillomaviruses.

METHODS

In order to discriminate whether HPV type is highly risky or not, many epidemiological and experimental methods have been proposed recently. For HPV risk type prediction, there also have been a few computational studies which are all based on Machine Learning (ML) techniques, but adopt different feature extraction methods. Therefore, we conclude and discuss several classical approaches which have got a better result for the risk type prediction of HPV.

RESULTS

This review summarizes the common methods to detect human papillomavirus. The main methods are sequence- derived features, text-based classification, gap-kernel method, ensemble SVM, Word statistical model, position- specific statistical model and mismatch kernel method (SVM). Among these methods, position-specific statistical model get a relatively high accuracy rate (accuracy=97.18%). Word statistical model is also a novel approach, which extracted the information of HPV from the protein "sequence space" with word statistical model to predict high-risk types of HPVs (accuracy=95.59%). These methods could potentially be used to improve prediction of highrisk types of HPVs.

CONCLUSION

From the prediction accuracy, we get that the classification results are more accurate by establishing mathematical models. Thus, adopting mathematical methods to predict risk type of HPV will be the main goal of research in the future.

Human papillomavirus genotypes distribution among Gabonese women with normal cytology and cervical abnormalities

BACKGROUND

Cervical cancer is one of the most common tumors affecting women with a disproportionate mortality occurring in developing countries. Despite the high prevalence of cervical cancer and cervical neoplasia in Gabon, few studies have been performed to evaluate the prevalence and determinants of HPV infection in this country. The aim of this study was to determine the HPV prevalence and distribution in a population of Gabonese women with normal cytology and cervical abnormalities.

METHODS

A total of 200 cervical samples collected in the "Departement d'Anatomie et de Cytologie Pathologiques" of the "Faculté de Medecine et des Sciences de la Santé" in Libreville, Gabonwere analyzed. Cytological status was classified according to Bethesda 2001. Nested polymerase chain reaction (PCR) using consensus degenerate PCR primers (MY09/11 and GP5+/6+) was performed for the detection of HPV DNA and HPV typing was done by DNA sequencing.

RESULTS

Cytological analysis showed that 87 % of women had normal cytology (n = 174/200). Among the 26 women with cytological abnormalities, predominance (61.5 %; 16/26) of low grade squamous intraepithelial lesion (LSIL) was found and no cervical cancer case was detected. Overall, HPV DNA was detected in 60 % of women (120/200). With respect to the cytological status, HPV DNA was found in 57.5 % of women with normal cervix and 76.9 % of women with abnormal cytology. HPV genotyping was performed on 114 HPV positive cases and revealed the presence of 11 distinct genotypes: 16, 18, 33, 31, 56, 6, 66, 70, 35, 45 and 81. The high risk type HPV 16 was the most common genotype found in all cytological categories. Six HPV positive samples could not be typed by DNA sequencing, probably due to multiple HPV infection. Evaluation of possible risk factors showed that HPV infection was related positively with number of sexual partners (≥3, OR = 2.3; 95 % CI, 1.3-4.3), history of sexually transmitted infection (Chlamydia, OR = 1.9; 95 % CI, 1.01-3.4) and marital status (single, OR = 2.0; 95 % CI, 1.1-3.5).

CONCLUSION

The prevalence of HPV infection among Gabonese women is high. Our findings highlight the need to set up a national program to fight cervical cancer, combining Pap smear test and HPV testing, to improve cervical cancer prevention in Gabon.

Cost-Effectiveness Analysis of Universal Human Papillomavirus Vaccination Using a Dynamic Bayesian Methodology: The BEST II Study

BACKGROUND

Human papillomavirus (HPV) plays a role in the development of benign and malign neoplasms in both sexes. The Italian recommendations for HPV vaccines consider only females. The BEST II study (Bayesian modelling to assess the Effectiveness of a vaccination Strategy to prevent HPV-related diseases) evaluates 1) the cost-effectiveness of immunization strategies targeting universal vaccination compared with cervical cancer screening and female-only vaccination and 2) the economic impact of immunization on various HPV-induced diseases.

OBJECTIVE

The objective of this study was to evaluate whether female-only vaccination or universal vaccination is the most cost-effective intervention against HPV.

METHODS

We present a dynamic Bayesian Markov model to investigate transmission dynamics in cohorts of females and males in a follow-up period of 55 years. We assumed that quadrivalent vaccination (against HPV 16, 18, 6, and 11) is available for 12-year-old individuals. The model accounts for the progression of subjects across HPV-induced health states (cervical, vaginal, vulvar, anal, penile, and head/neck cancer as well as anogenital warts). The sexual mixing is modeled on the basis of age-, sex-, and sexual behavioral-specific matrices to obtain the dynamic force of infection.

RESULTS

In comparison to cervical cancer screening, universal vaccination results in an incremental cost-effectiveness ratio of €1,500. When universal immunization is compared with female-only vaccination, it is cost-effective with an incremental cost-effectiveness ratio of €11,600. Probabilistic sensitivity analysis shows a relatively large amount of parameter uncertainty, which interestingly has, however, no substantial impact on the decision-making process. The intervention being assessed seems to be associated with an attractive cost-effectiveness profile.

CONCLUSIONS

Universal HPV vaccination is found to be a cost-effective choice when compared with either cervical cancer screening or female-only vaccination within the Italian context.

High prevalence of abnormal cervical smears in a hospital cohort of French women beyond the upper age limit screening program

OBJECTIVE

To determine the prevalence of cytological abnormalities and high risk Human PapillomaVirus (hrHPV) in cervical smears from French women aged over 65 years who attended the referent Gynecology Clinic of the Besançon University Hospital.

METHODS

Between 2002 and 2012, 796 French women aged 66-99 years were cotested for cytology and hrHPV by Hybrid Capture 2 (hc2). hc2-positive cases were subjected to real time PCR for specific HPV 16/18/45 genotyping. Women with normal Pap smears and positive for hrHPV were followed-up every 12 months.

RESULTS

Cytological abnormalities were detected in more than 30% of women and cervical cancers (CC) in 2.9% of women. Benign lesions were more frequent in women aged 66-75 years while (pre)-malignant lesions were preferentially found in women over 76. The prevalence of hrHPV was 22.7%. HPV 16 was the most frequent (23.8%), followed by HPV 45 (7.7%) and HPV 18 (3.9%). The rate of hrHPV increased with the lesion severity and HPV 16 was identified in 50% of CC. Among the followed-up women, those who developed CIN3 were HPV16 positive at study entry.

CONCLUSION

The study provides important estimates of the prevalence of cervical abnormalities and hrHPV positivity in a French hospital based-population over 65. Findings suggest to consider this high risk population in regards to cervical cancer.

High prevalence of oncogenic HPV-16 in cervical smears of asymptomatic women of eastern Uttar Pradesh, India: a population-based study

In developing countries like India, occurrence of Human papillomavirus (HPV) in cervical cancer as well as in the asymptomatic population was observed to be very high. Studies on HPV prevalence have been conducted in different parts of the country but no data were available from the eastern region of Uttar Pradesh (UP). The present study aimed to determine the status of HPV prevalence and its association with different socio-demographic factors in this population. Prevalence of HPV was investigated in a total of 2424 cervical scrape samples of asymptomatic women. Primer sets from L1 consensus region of viral genome were used to detect the presence of HPV, and the positive samples were genotyped by sequencing. Univariate binary logistic regression analysis was used to evaluate association of socio-demographic factors with HPV. 9.9% of the clinically asymptomatic women were found to be infected with HPV comprising 26 different genotypes. Among HPV-positive women, 80.8% showed single infection, while 15.4% harboured multiple infections. HPV-16 (63.7%) was the most prevalent, followed by HPV-31 (6.7%), HPV-6 (5.4%), HPV-81 (4.6%) and HPV-33 (4.2%). Significant association of HPV with non-vegetarian diet (P less than 0.05) and rural residential areas (P less than 0.01) were observed. High prevalence of HPV-16 in asymptomatic women of this population, a frequency comparable to invasive cervical cancers, highlights an urgent need for a therapeutic HPV vaccine covering HPV-16 and other high-risk types to provide protection against the disease.

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

Background

This multicenter study describes the type-specific prevalence of HPV infection in the general population from central and southern Italy, comparing the data with previously published Italian studies.

Methods

Women aged from 25 to 65 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

3817 women had a valid HCII test: 350 of them (9.2%) were positive for HR probes, 160 (4.2%) for LR probes, while 57 women were positive for both. Multiple infections were detected in 97 HR HPV positive women. The most common types were HPV 16 (3%), 31 (1.2%), 51 (1%). HPV6 ranked fifth (0.6%), HPV18 ranked tenth (0.5%) and HPV11 sixteenth (0.3%).

In Sardinia the prevalence of high-risk infection was 13%, significantly higher than the mean value (p < 0.00005).

The distribution of the most frequent types did not significantly differ by centre (p = 0.187) and age (p = 0.085).

Conclusions

Because cervical cancer incidence and Pap test coverage is lower in southern than in northern Italy, a lower prevalence of high-risk infections in the general population was expected in the south. However, prevalence detected in this study for the south of the country is slightly but significantly higher than the rest of Italy. The consequence may be an epidemic of cervical cancer in the next decades if adequate screening programs are not implemented there.

Prevalence and genotype identification of human papillomavirus in women undergoing voluntary cervical cancer screening in Molise, central Italy

We examined the prevalence of HR- and LR-HPV by Linear Array genotyping test in 299 women aged 18-63 years who consecutively visited Molise Region main hospitals for routine Pap smear between February and August 2008. Ninety women were positive for any HPV (30.1%), and 66 for any HR-HPV (22.1%). The most prevalent HR-HPV types were HPV 16 (22.2% of all women with HPV infection), HPV 53 (14.4%), and HPV 66 (14.4%). HPV infections increased from 15.8% in the 18-20 years group to 50.0% in the 21-23 years group and then decreased to 9.1% in those aged 50 years or more (p=0.008). Multiple HPV infections were observed in 15.7% of the study sample (52.2% of all HPV positive). There is a significantly higher prevalence of multiple infections in 18-32 years group women (24.5%) compared with females aged 33 years or more (6.8%) (p<0.005). Current smokers were at increased risk of HPV infection (44.2% of HPV infections compared with 23.5% in never smokers, and 25.3% of multiple HPV infections compared with 11.3%; p=0.001). HR-HPV infections were higher in women never been pregnant (27.1% compared with 7.7%; p=0.001). Oral contraceptive use was completely unrelated to infection. Among the 122 women who had both cytological examination and HPV results, multiple HR-HPV types were found in 36.8% of those with abnormal cervical findings, and in 13.6% of those with normal cervical findings (p=0.05). The results of the present investigation provide further evidence for the notion that cervical HPV infection is more widespread than previously suggested.

Epidemiology and genotype distribution of human papillomavirus (HPV) in women of Sardinia (Italy)

The human papillomavirus (HPV) infection is necessary for the development of cervical cancer. Our study aims to evaluate the rate of HPV circulation in our population, to identify the prevalent genotypes and to establish correlation with cervical abnormalities. Furthermore, the awareness of women about HPV issues was investigated. This study included 864 women attending the Oncologic Prevention Service for their routine Pap test screening or the Health Promotion Mother-Child Service for counselling about sexual activity, from July 2006 to September 2007. All the participants gave their informed consent to be enrolled in the study and were invited to fill in a questionnaire about the socio-cultural state, sexual activity and awareness about HPV. The women samples were tested for HPV-DNA and HPV genotypes: any type of HPV-DNA was detected in 31.0% of the women; single or multiple infections sustained by HPV-16 or HPV-18 represented 43.5% of all HPV infections, accounting for infections in 11.8% of the recruited women. The HPV and high-risk HPV (HR-HPV) prevalence significantly declined in women older than 46 years. The Pap test result was available in 490 women; 48.1% of the Pap test positive women had also an HPV infection and among these 22.7% were infected by HPV-16 and/or HPV-18 genotype, while 51.9% (94/181) were HPV negative. The analysis by binary logistic regression showed that genotype 16 and/or 18 is a risk factor for the Pap positive test with a odds ratio (OR) of 2.9 (95% C.I. 1.4-5.9) and 3.6 (95% C.I. 1.58-8.42) respectively, while age is a protective factor (OR 0.97, C.I. 95% 0.96-0.99); furthermore, the mean age at the first sexual intercourse and the mean number of partners since the beginning of sexual activity, were statistically associated with the risk of HPV infection. More than half of women were aware about HPV, its sexual transmission and of its correlation with cervix cancer. Our findings evidenced that HPV infection is frequent in women aged 18-46 years in Sardinia and particularly that 16 and 18 HPV genotypes are detectable in more than 40% of the infected women. The proportion of women informed about HPV issues is sufficient to guarantee an aware approach to HPV vaccination.

Advantages and pitfalls of the polymerase chain reaction in the diagnosis of esophageal ulcers in AIDS patients

HIV-1-infected patients frequently have opportunistic esophageal infections which, when associated with severe immunodeficiency, can be attributed to unusual pathogens. The clinical presentation of several esophageal diseases is similar and the best method for a specific diagnosis of these patients has not been well defined. To evaluate the role of the polymerase chain reaction (PCR) in the etiologic definition of esophageal ulcers in HIV-1-infected patients, 96 esophageal biopsies from 79 HIV-1-infected patients were processed by PCR using specific primers for cytomegalovirus (CMV), herpes virus (HSV), human papilloma virus (HPV), HIV-1, Mycobacterium tuberculosis, Mycobacterium avium, Mycobacterium intracellulare, Treponema pallidum, and Haemophilus ducreyi. The PCR results were compared to the histopathologic results. Seventy-nine patients were studied (mean age: 34 years; 62% men; median CD4 + T cell = 103.59 cells/microl (range 1-795.2 cells/microl). The most common endoscopic findings were as follows: esophageal candidiasis (37.1%), esophageal ulcers (24.7%), esophagitis (11.2%), and lugol-negative areas (10.1%). The histopathologic findings in the esophageal ulcers (22 biopsies) were non-specific inflammation (31.8%), HSV (36.4%), Candida (13.6%), CMV (13.6%), or HPV disease (4.5%). In the esophageal ulcer biopsies, the PCR results were negative in 27.6% of cases, and positive for HIV (65.5%), CMV (31%), HPV (20.7%), HSV (10.3%), and H. ducreyi (6.9%). The histopathologic examination did not identify a pathogen or identified only Candida in 15 biopsies of esophageal ulcers. PCR was positive in ten (66.7%) and negative in five (33.3%) of these biopsies (idiopathic ulcers). PCR detected: HIV (53.3%), CMV (20%), HPV (13.3%), and H. ducreyi (6,7%). PCR detected more etiologic agents in esophageal ulcers than histopathology and was able to detect unusual pathogens. On the other hand, sometimes more than one pathogen was detected in the esophageal ulcers, making it difficult to reach an accurate diagnosis. This finding indicates the need for more studies to evaluate the benefit of this method in the routine evaluation of esophageal ulcer biopsies in HIV-1-infected patients.

Cervical infections by multiple human papillomavirus (HPV) genotypes: Prevalence and impact on the risk of precancerous epithelial lesions

A large proportion of human papillomavirus (HPV) infections is sustained by multiple genotypes. The effect of multiple infections on the risk of cervical intraepithelial neoplasia (CIN) and the potential efficacy of vaccine on these infections are controversial. We performed viral typing by SFP(10)-LIPA on a consecutive series of 1,323 women undergoing colposcopy, 69% of whom had cervical biopsy, and correlated CIN severity with the type and number of HPVs. Overall prevalence of HPV-DNA was 68.9%, 97.3% in CIN1, and 98.1% in CIN>/=2. HPV positivity correlated with younger age (35.9 vs. 37.3 years, P = 0.026) and history of CIN (P < 0.001). Multiple types were detected in 44.2% of cases, including 63.1% CIN1 and 80.8% CIN>/=2. Twenty-three different types were detected, HPV-16, 31 and 52 being the most frequent. Infections by HPV-6, 11, 16, or 18 occurred in 59.4% of CIN1 and 71.3% of CIN>/=2. Number of viral types and class of oncogenic risk were linearly correlated with CIN severity (P < 0.0001) by univariate and multivariate analyses controlling for age and history of CIN. The effect of the number of HPV types was maintained after exclusion from the model of infections by HPV-6, 11, 16, and 18. Frequency, distribution, and clinical correlates of multiple HPV infections highlight the importance of assessing individual types in the management and the prediction of outcome of women with abnormal baseline cytology and point to potential limitations in current vaccine strategies.

Multiple human papillomavirus infection and high grade cervical intraepithelial neoplasia among women with cytological diagnosis of atypical squamous cells of undetermined significance or low grade squamous intraepithelial lesions

OBJECTIVE

To evaluate the effect of multiple human papillomavirus (HPV) infection on the prevalence of cervical intraepithelial neoplasia (CIN) among women undergoing colposcopy following a cytological diagnosis of atypical squamous cells of undetermined significance (ASCUS) or low grade squamous intraepithelial lesions (LSIL).

METHODS

HPV type-specific sequences of 15 high-risk and 10 low risk types were detected by the line probe, INNO-LiPA HPV genotyping assay before colposcopic examination and targeted biopsies. Multinomial logistic regression was used to evaluate the effect of multiple infection on pathologic outcome adjusting for confounders.

RESULTS

The prevalence of HPV infection in the 1218 women enrolled was 69.9% (851/1218). HPV 16 (37.4%), 31 (26.1%), 51 (17.4%), 52 (15.7%) and 18 (14%) were the commonest viral types identified. Overall, the rates of multiple infection were 22.5% (153/680) among subjects with negative colposcopy/biopsy, 63.6% (218/343) and 79.5% (155/195) among those with CIN 1 and CIN>or=2, respectively (p for trend <.001). The corresponding rates among subjects uninfected by HPV 16 or 18 were 13.5% (77/572), 57.4% (112/195) and 62% (48/77), respectively (p for trend <.001). In multinomial logistic regression, the odds ratio of CIN>or=2 in multiple high risk as compared to single high risk HPV infection was 4.33 (95% confidence intervals=2.32-7.14) in the overall population and 2.76 (95% confidence intervals=1.36-5.59) among women uninfected by HPV 16 or 18.

CONCLUSIONS

Multiple HPV infection is a significant risk factor for CIN>or=2 among women undergoing colposcopy because of ASCUS/LSIL.

Age-specific prevalence of infection with human papillomavirus in females: a global review

PURPOSE

Global data on age-specific prevalence of human papillomavirus (HPV) infection overall, and for high-risk HPV types 16 and 18, are essential for the future implementation of HPV prophylactic vaccines for cervical cancer prevention.

METHODS

A systematic review of peer-reviewed publications was conducted to summarize worldwide data on genital HPV-DNA prevalence in women. Studies with clear descriptions of polymerase chain reaction or hybrid capture detection assays were included.

RESULTS

A total of 346,160 women were included in 375 studies. Of 134 studies with age-stratified HPV prevalence data (116 low sexual risk populations, 18 high sexual risk populations), over 50% were from Europe and the Middle East (38%) and North America (19%), with smaller proportions from Asia and Australia (21%), Central and South America (11%), and Africa (10%). Across all geographical regions, data on HPV prevalence were generally limited to women over 18 years of age. Consistently across studies, HPV infection prevalence decreased with increasing age from a peak prevalence in younger women (< or =25 years of age). In middle-aged women (35-50 years), maximum HPV prevalence differed across geographical regions: Africa (approximately 20%), Asia/Australia (approximately 15%), Central and South America (approximately 20%), North America (approximately 20%), Southern Europe/Middle East (approximately 15%), and Northern Europe (approximately 15%). Inconsistent trends in HPV prevalence by age were noted in older women, with a decrease or plateau of HPV prevalence in older ages in most studies, whereas others showed an increase of HPV prevalence in older ages. Similar trends of HPV 16 and/or 18 prevalence by age were noted among 12 populations with available data.

DISCUSSION

Genital HPV infection in women is predominantly acquired in adolescence, and peak prevalence in middle-aged women appears to differ across geographical regions. Worldwide variations in HPV prevalence across age appear to largely reflect differences in sexual behavior across geographical regions. Further studies of HPV prevalence in adolescents are needed for all geographic regions.

Prevalence and genotypes identification of human papillomavirus infection in a population of South Italy

BACKGROUND

A limited number of human papillomavirus (HPV) types account for the majority of invasive cervical cancer cases.

OBJECTIVES

To assess, in a southern Italian region, where HPV infection had not yet been investigated, the prevalence of type-specific HPV infection.

STUDY DESIGN

Multiplex PCR was used to test cervical specimens from 871 asymptomatic women.

RESULTS

The HPV infection rate was 23.1%, with the highest prevalence being observed in women aged 20-30 years (32.6%). Type 16 was the most frequent HPV type detected either in mono-infected (39.8%) or in multi-infected (46.3%) women.

CONCLUSIONS

The HPV infection rate was higher than reported from other Italian areas. Our results further emphasise the importance of vaccinations to immunize females before they acquire HPV infection.

HPV vaccine efficacy in preventing persistent cervical HPV infection: a systematic review and meta-analysis

INTRODUCTION

We performed a pooled analysis of randomised clinical trials (RCT) on HPV vaccine efficacy in preventing cervical persistent infection.

METHODS

We carried out a bibliographic search on electronic databases and we selected RCT to perform the meta-analyses.

RESULTS

We selected five studies. The first meta-analysis, including all studies, showed an important reduction of the risk of infection from HPV 16 in vaccinated cohort [RR 0.10 (95% CI: 0.07-0.15)]. The second and third meta-analyses, including only studies on bivalent and tetravalent vaccines, showed a RR of 0.13 (95% CI: 0.09-0.20) for HPV 16 infections and a RR of 0.22 (95% CI: 0.13-0.38) for HPV 18 ones.

DISCUSSION

HPV vaccine efficacy in preventing persistent infection is high but there is the need for further studies on the duration of immunization and long-term vaccine efficacy.

Prevalence and risk factors of HPV infection among high-risk rural and urban Lithuanian women

AIMS

To investigate the prevalence, persistence and risk factors of high oncogenic risk human papillomavirus (HPV) among urban and rural women of reproductive age coming to consult a gynaecologist.

METHODS

A prospective cohort study in urban (Kaunas) and rural (Marijampole) regions of Lithuania. The data were collected in 8 healthcare institutions from women seeking consultation of gynaecologists using a questionnaire for finding out demographic, social, behavioural and biomedical factors. HPV DNA was determined by molecular hybridization method (hybrid capture version II) determining HPV of high oncogenic risk.

RESULT

1,120 women participated in the study. The prevalence of high-risk HPV among the studied women was 25.1%. It was higher among the urban women than among the rural women. The prevalence of high-risk HPV was increased if the subjects had 2 or more sexual partners during the last 12 months (OR 2.81; 95% CI 1.83-4.32), were 19 years of age or younger (OR 2.68; 95% CI 1.47-4.91), were smoking (OR 1.81; 95% CI 1.16-2.81), and had secondary or lower education level (OR 1.43; 95% CI 1.01-2.04). This infection was obviously associated with high- and low-grade squamous intraepithelial changes of the cervix (OR 1.66, 95% CI = 1.08-2.53).

CONCLUSION

The incidence rate for cervical cancer in Lithuania is one of the highest in comparison with other European countries. HPV infection was also particularly common in the studied population. About one-fourth of the women were infected with high-risk HPV infection. Young and less educated women were found to be the group that was most exposed to HPV, and therefore public health interventions and education seem to be essential in programs aimed at reducing the incidence of cervical cancer.