Cervical human papillomavirus prevalence in 5 continents: meta-analysis of 1 million women with normal cytological findings

Characterization of the human papillomavirus (HPV) integration sites into genital cancers

Oncogenic HPVs have been found frequently integrated into human genome of invasive cancers and chromosomal localization has been extensively investigated in cervical carcinoma. Few studies have analyzed the HPV integration loci in other genital cancers. We have characterized the integration sites of HPV16 in invasive penile carcinoma by means of Alu-HPV-based PCR. Nucleotide sequence analysis of viral-human DNA junctions showed that HPV integration occurred in one case within the chromosome 8q21.3 region, in which the FAM92A1 gene is mapped, and in the second case inside the chromosome 16p13.3, within the intronic region of TRAP1 gene. These results confirm previous observations, summarized in a systematic review of the literature, on the HPV integration events in gene loci relevant to cancer pathogenesis.

Human papillomavirus types in 115,789 HPV-positive women: a meta-analysis from cervical infection to cancer

Genotyping may improve risk stratification of high-risk (HR) human papillomavirus (HPV)-positive women in cervical screening programs; however, prospective data comparing the natural history and carcinogenic potential of individual HR types remain limited. A meta-analysis of cross-sectional HR HPV-type distribution in 115,789 HPV-positive women was performed, including 33,154 normal cytology, 6,810 atypical squamous cells of undetermined significance (ASCUS), 13,480 low-grade squamous intraepithelial lesions (LSIL) and 6,616 high-grade SIL (HSIL) diagnosed cytologically, 8,106 cervical intraepithelial neoplasia grade 1 (CIN1), 4,068 CIN2 and 10,753 CIN3 diagnosed histologically and 36,374 invasive cervical cancers (ICCs) from 423 PCR-based studies worldwide. No strong differences in HPV-type distribution were apparent between normal cytology, ASCUS, LSIL or CIN1. However, HPV16 positivity increased steeply from normal/ASCUS/LSIL/CIN1 (20-28%), through CIN2/HSIL (40/47%) to CIN3/ICC (58/63%). HPV16, 18 and 45 accounted for a greater or equal proportion of HPV infections in ICC compared to normal cytology (ICC:normal ratios = 3.07, 1.87 and 1.10, respectively) and to CIN3 (ICC:CIN3 ratios = 1.08, 2.11 and 1.47, respectively). Other HR types accounted for important proportions of HPV-positive CIN2 and CIN3, but their contribution dropped in ICC, with ICC:normal ratios ranging from 0.94 for HPV33 down to 0.16 for HPV51. ICC:normal ratios were particularly high for HPV45 in Africa (1.85) and South/Central America (1.79) and for HPV58 in Eastern Asia (1.36). ASCUS and LSIL appear proxies of HPV infection rather than cancer precursors, and even CIN3 is not entirely representative of the types causing ICC. HPV16 in particular, but also HPV18 and 45, warrant special attention in HPV-based screening programs.

Prevalence, genotype diversity and determinants of anal HPV infection in HIV-uninfected men having sex with men

BACKGROUND

Anal human papillomavirus (HPV) infection is very common in men having sex with men (MSM), but the available data on its burden and characteristics mainly concern HIV-infected individuals.

OBJECTIVES

This study aimed to assess the prevalence, spectrum of genotypes, and determinants of the anal HPV infection in metropolitan HIV-1 uninfected MSM.

STUDY DESIGN

A cohort of 258 MSM (median age 32 years, IQR 26-39) enrolled at an STI Clinic was screened for anal HPV infection using a highly sensitive PCR-based genotyping method. Medical history and behavioral data were collected.

RESULTS

Overall, 74.8% of the MSM were HPV-positive, with 56.2% of the participants being infected by high-risk (HR) types. A multiple infection was detected in 65.3% of the HPV-positive MSM, with up to 10 different HPV types detected in the same sample. A broad spectrum of infecting HPV types was observed, with 36 different types found overall and HPV16 representing the most common type (17.8%). The lifetime and recent number of sexual partners as well as having receptive anal sex were significantly associated with the anal HPV infection, confirming the role of sexual behavior in risk of HPV infection. However, neither younger age at first intercourse nor inconsistent use of condom was significantly associated with the infection.

CONCLUSIONS

The present findings highlight the need to create a more significant awareness about the risk of anal HPV infection among HIV-uninfected MSM and warrant the investigation of possible anal intraepithelial lesions, particularly in view of the increasing anal cancer incidence in high-risk populations.

A 'snip' in time: what is the best age to circumcise?

BACKGROUND

Circumcision is a common procedure, but regional and societal attitudes differ on whether there is a need for a male to be circumcised and, if so, at what age. This is an important issue for many parents, but also pediatricians, other doctors, policy makers, public health authorities, medical bodies, and males themselves.

DISCUSSION

We show here that infancy is an optimal time for clinical circumcision because an infant's low mobility facilitates the use of local anesthesia, sutures are not required, healing is quick, cosmetic outcome is usually excellent, costs are minimal, and complications are uncommon. The benefits of infant circumcision include prevention of urinary tract infections (a cause of renal scarring), reduction in risk of inflammatory foreskin conditions such as balanoposthitis, foreskin injuries, phimosis and paraphimosis. When the boy later becomes sexually active he has substantial protection against risk of HIV and other viral sexually transmitted infections such as genital herpes and oncogenic human papillomavirus, as well as penile cancer. The risk of cervical cancer in his female partner(s) is also reduced. Circumcision in adolescence or adulthood may evoke a fear of pain, penile damage or reduced sexual pleasure, even though unfounded. Time off work or school will be needed, cost is much greater, as are risks of complications, healing is slower, and stitches or tissue glue must be used.

SUMMARY

Infant circumcision is safe, simple, convenient and cost-effective. The available evidence strongly supports infancy as the optimal time for circumcision.

Sexual behavior and high-risk human papillomavirus in 15- to 22-year-old Lithuanian women

We determined the risk of high-risk human papillomavirus (HR-HPV) infection in 169 15- to 22-year-old sexually active Lithuanian women attending two outpatient clinics in Vilnius. The Digene(®) Hybrid Capture II DNA test was used to test for HR-HPV infection on material collected by cervical swabs. The findings were compared with the pattern of sexual behavior as given in questionnaire replies. The overall risk of HR-HPV was 23.1%, but 60.0% in adolescents ≤15 years old. Mean age at first intercourse was 17.1 years; 73.5% of women had only had one sexual partner and 24.5% more than one. The risk of HR-HPV was higher in women with more than one sexual partner, and related to being a smoker and to early age at the first intercourse. Our results confirm that smoking, early coitarche, multiple sexual partners and unprotected vaginal intercourse are related to the risk of HR-HPV infection in young women.

Subtype distribution of human papillomavirus in HIV-infected women with cervical intraepithelial neoplasia stages 2 and 3 in Botswana

Human papillomavirus (HPV) vaccines containing types 16 and 18 are likely to be effective in preventing cervical cancer associated with these HPV types. No information currently exists in Botswana concerning the HPV types causing precancerous or cancerous lesions. Our goal was to determine the prevalence of HPV types associated with precancerous cervical intraepithelial neoplasia (CIN) stages 2 and 3 in HIV-infected women in Gaborone, Botswana. HIV-infected women referred to our clinic with high-grade intraepithelial lesion on the Pap smear were enrolled in the study. HPV typing was only performed if the histopathology results showed CIN stage 2 or 3 disease using linear array genotyping (CE-IVD, Roche Diagnostics). One hundred HIV-infected women were identified with CIN stages 2 or 3 between August 11, 2009 and September 29, 2010. Eighty-two of 100 women enrolled had coinfection by multiple HPV subtypes (range, 2 to 12). Of the remaining 18 women, 14 were infected with a single high-risk subtype and 4 had no HPV detected. Overall, 92 (92%) women were infected with at least 1 high-risk HPV subtype, and 56 were coinfected with more than 1 high-risk HPV type (range, 2 to 5). Fifty-one (51%) women had HPV subtypes 16, 18, or both. HPV 16 and 18 are the most common types in HIV-infected women with CIN 2 or 3 in Gaborone, Botswana, suggesting that the implementation of HPV vaccination programs could have a significant impact on the reduction of cervical cancer incidence. However, given the relative lack of knowledge on the natural history of cervical cancer in HIV-infected women and the significant prevalence of infection and coinfection with other high-risk HPV types in our sample, the true impact and cost-effectiveness of such vaccination programs need to be evaluated.

A million africans a year dying from cancer by 2030: what can cancer research and control offer to the continent?

In Africa, there were an estimated 681,000 new cancer cases and 512,000 deaths in 2008. Projections to 2030 show a startling rise, with corresponding figures of 1.27 million cases and 0.97 million deaths resulting from population growth and aging alone. The figures make no assumptions about incidence rates which may increase due to the further introduction of tobacco and a more westernized lifestyle. The current situation in many parts of Africa with respect to health care systems suggests that improved cancer treatment would be an insufficient response to this increasing burden. Much could be achieved through cancer prevention by applying current knowledge about major risk factors and the natural history of the disease. For example, vaccination against hepatitis B virus and human papilloma viruses would prevent the occurrence of two of the most common cancers in Africa, liver and cervix, respectively, in the long-term. Strong measures to prevent the widespread introduction of tobacco must be a priority. Early detection and treatment of cervical and breast cancers using approaches applicable now in Africa would provide immediate value, as would the management of human immunodeficiency virus (HIV) infection in respect to HIV-associated malignancies. In parallel, further research is needed into the causes of cancer and the barriers to implementation of promising prevention strategies. Underpinning all is the need for African governments to look forward and prioritize cancer through national cancer control plans, to invest in public health infrastructure and to ensure the adequate training and support for people in cancer prevention and control. Given this core commitment from within Africa, international partners can provide complementary support in a cooperation that permits action now to mitigate the impending tragedy of cancer in the continent of Africa.

Treatment of HPV infection-associated cervical condylomata acuminata with 5-aminolevulinic acid-mediated photodynamic therapy

The aim of this study was to investigate the efficacy of 5-aminolaevulinic acid (ALA)-mediated photodynamic therapy (PDT) in treatment of human papillomavirus (HPV)-associated cervical condylomata. A total of 56 patients with cervical and external condylomata lesions were recruited for this open-label study. HPV genotyping of exfoliated cells collected from the cervix and external lesions was performed. Cervical lesions were treated with PDT by applying ALA gel (10%) to the surface of the cervix for 4 h followed by irradiating with a 635 nm laser at 100 J cm(-2). PDT was repeated at 2-week intervals if lesion and HPV infection remained. Patients were followed up for 6-24 months. Genotyping analysis revealed four HPV subtypes (HPV6, 11, 16 and 18). The overall complete remission rate of 1-4 sessions of treatments was 98.2% and the corresponding HPV clearance rate was 83.9%. Ten cases showed complete removal of cervical lesions and HPV infection after a single treatment. Recurrence rate was 3.6%. Adverse effects were minimal and no structural complications were reported. In conclusion, topical ALA PDT is safe and effective for eradicating cervical HPV infection and eliminating condylomata lesion. Its definitive role in treating cervical condylomata deserves further investigation.

Multiple human papillomavirus infections and type competition in men

BACKGROUND

There is little information on multiple human papillomavirus (HPV) infections and the potential for type competition in men, yet competition may impact the type-specific efficacy of HPV vaccination.

METHODS

Among 2702 uncircumcised men in Kisumu, Kenya, who were seronegative for human immunodeficiency virus, the observed numbers of HPV types detected were compared with the expected number, which was simulated under the assumption of independent infections. To assess the potential for HPV type competition, adjusted odds ratios for pairwise combinations of prevalent HPV type infections were estimated using semi-Bayesian methods.

RESULTS

Half of all men were HPV positive, of whom 57% had multiple HPV types. We observed men without HPV infection and with ≥4 HPV types more often than expected if infections were independent. No negative associations between individual HPV types were observed. HPV types 31, 39, 56, 58, and 59 were positively associated with both carcinogenic vaccine types HPV-16 and HPV-18 (2-sided P value <.05).

CONCLUSIONS

Men who were HPV infected were likely to test positive for >1 HPV type. Cross-sectional associations between individual HPV types were positive and did not appear to be type-specific. Thus, we did not identify HPV types that are candidates for potential HPV type competition in men.

Human papillomavirus deoxyribonucleic acid testing in developed countries

Cervical cancer has been largely eliminated in developed countries with the implementation of cytology-based screening programmes that depend on a call-recall system, followed by colposcopy and biopsy, treatment of precancerous lesions and follow up. With the discovery that persistent infection with high-risk human papillomavirus types is necessary for the development of cervical cancer, several tests for human papillomavirus deoxyribonucleic acid have been developed that can identify women at risk. Human papillomavirus deoxyribonucleic acid testing is more sensitive and only slightly less specific than cytology for detecting cervical intraepithelial neoplasia. It is also more reproducible, with the potential for self-sampling. Human papillomavirus genotyping, messenger RNA analysis and other biomarkers can help to further stratify this group and diminish referrals to colposcopy. Initially, human papillomavirus testing was used as an adjunct to cytology for triage of borderline cases, but evidence has shown its superiority as a screening method and in the follow up of women treated for cervical intraepithelial neoplasia.

The epidemiology of human papillomavirus infection in HIV-positive and HIV-negative high-risk women in Kigali, Rwanda

Background

The prevalence, incidence and persistence of human papillomavirus (HPV) types in sub-Saharan Africa are not well established. The objectives of the current study are to describe (predictors of) the epidemiology of HPV among high-risk women in Kigali, Rwanda.

Methods

HIV-negative, high-risk women were seen quarterly for one year, and once in Year 2. HIV serostatus, clinical, and behavioral information were assessed at each visit, HPV types at Month 6 and Year 2, and other sexually transmitted infections (STI) at selected visits. HPV prevalence was also assessed in HIV-positive, high-risk women.

Results

Prevalence of any HPV was 47.0% in HIV-negative women (median age 25 years) compared to 72.2% in HIV-positive women (median age 27 years; OR 2.9, 95% CI 1.9-4.6). Among HIV-negative women, cumulative incidence of high-risk (HR)-HPV was 28.0% and persistence 32.0% after a mean period of 16.6 and 16.9 months, respectively. Prior Chlamydia trachomatis and Neisseria gonorrhoeae infection, concurrent low-risk (LR)-HPV infection and incident HSV-2 were associated with HR-HPV prevalence among HIV-negative women; prior C. trachomatis infection and co-infection with LR-HPV and HPV16-related HPV types with HR-HPV acquisition. HPV16-related types were the most prevalent and persistent.

Conclusions

High HPV prevalence, incidence and persistence were found among high-risk women in Kigali. HPV52 had the highest incidence; and, together with HPV33 and HPV58, were strongly associated with acquisition of other HR-HPV types in HIV-negative women.

Next Generation Cancer Protection: The Bivalent HPV Vaccine for Females

Nearly a half a million women throughout the world develop cervical cancer every year Parkin and Bray ("Chapter 2. The burden of HPVrelated cancers," Vaccine, vol. 24, no. 3, pp. S11-S25, 2006); 80% of these women are in countries without a quality-assured cytology screening program. It is in this setting that Cervarix could reduce the incidence of cervical cancer to about 9.5/100,000 women. New evidence indicates that this might be able to be accomplished with a single dose of Cervarix, a great advantage to public health implementation programs Kreimer et al. ("Proof-of-principle evaluation of the efficacy of fewer than three doses of a bivalent HPV16/18 vaccine, The Journal of the National Cancer Institute, vol. 103, no. 19, pp. 1444-1451, 2011). In countries with screening programs, adenocarcinoma is the most difficult to detect and treat with later-stage presentation and higher mortality Smith et al. ("The rising incidence of adenocarcinoma relative to squamous cell carcinoma of the uterine cervix in the United States-a 24-year population-based study," Gynecologic Oncology, vol. 78, no. 2, pp. 97-105, 2000) and Gunnell et al. ("A longitudinal Swedish study on screening for squamous cell carcinoma and adenocarcinoma: evidence of effectiveness and overtreatment," Cancer Epidemiology Biomarkers and Prevention, vol. 16, no. 12, pp. 2641-2648, 2007). With additional cross-protection to HPV 31, 33, and 45 and protection against HPV 16 and 18 lasting at least 9.4 years, Cervarix may reduce adenocarcinomas in screened populations by more than 90%. This paper will detail the evidence about the efficacy, immunogenicity, and safety of Cervarix in the studied populations contrasting public health goals with individual health options.

Efficacy of the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine in women aged 15-25 years with and without serological evidence of previous exposure to HPV-16/18

In the Phase III PATRICIA study (NCT00122681), the human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine (Cervarix(®), GlaxoSmithKline Biologicals) was highly efficacious against HPV-16/18 infections and precancerous lesions in women HPV-16/18 deoxyribose nucleic acid (DNA) negative and seronegative at baseline. We present further data on vaccine efficacy (VE) against HPV-16/18 in the total vaccinated cohort including women who may have been exposed to HPV-16/18 infection before vaccination. In women with no evidence of current or previous HPV-16/18 infection (DNA negative and seronegative), VE was 90.3% (96.1% confidence interval: 87.3-92.6) against 6-month persistent infection (PI), 91.9% (84.6-96.2) against cervical intraepithelial neoplasia (CIN)1+ and 94.6% (86.3-98.4) against CIN2+ [97.7% (91.1-99.8) when using the HPV type assignment algorithm (TAA)]. In women HPV-16/18 DNA negative but with serological evidence of previous HPV-16/18 infection (seropositive), VE was 72.3% (53.0-84.5) against 6-month PI, 67.2% (10.9-89.9) against CIN1+, and 68.8% (-28.3-95.0) against CIN2+ [88.5% (10.8-99.8) when using TAA]. In women with no evidence of current HPV-16/18 infection (DNA negative), regardless of their baseline HPV-16/18 serological status, VE was 88.7% (85.7-91.1) against 6-month PI, 89.1% (81.6-94.0) against CIN1+ and 92.4% (84.0-97.0) against CIN2+ [97.0% (90.6-99.5) when using TAA]. In women who were DNA positive for one vaccine type, the vaccine was efficacious against the other vaccine type. The vaccine did not impact the outcome of HPV-16/18 infections present at the time of vaccination. Vaccination was generally well tolerated regardless of the woman's HPV-16/18 DNA or serological status at entry.

p53 degradation activity, expression, and subcellular localization of E6 proteins from 29 human papillomavirus genotypes

Human papillomaviruses (HPVs) are the etiological agents of cervical cancer and other human malignancies. HPVs are classified into high- and low-risk genotypes according to their association with cancer. Host cell transformation by high-risk HPVs relies in part on the ability of the viral E6 protein to induce the degradation of p53. We report the development of a cellular assay that accurately quantifies the p53 degradation activity of E6 in vivo, based on the fusion of p53 to Renilla luciferase (RLuc-p53). This assay was used to measure the p53 degradation activities of E6 proteins from 29 prevalent HPV types and variants of HPV type 16 (HPV16) and HPV33 by determining the amount of E6 expression vector required to reduce by half the levels of RLuc-p53 (50% effective concentration [EC₅₀]). These studies revealed an unexpected variability in the p53 degradation activities of different E6 proteins, even among active types whose EC₅₀s span more than 2 log units. Differences in activity were greater between types than between variants and did not correlate with differences in the intracellular localization of E6, with most being predominantly nuclear. Protein and mRNA expression of the 29 E6 proteins was also examined. For 16 high-risk types, spliced transcripts that encode shorter E6*I proteins of variable sizes and abundances were detected. Mutation of the splice donor site in five different E6 proteins increased their p53 degradation activity, suggesting that mRNA splicing can limit the activity of some high-risk E6 types. The quantification of p53 degradation in vivo represents a novel tool to systematically compare the oncogenic potentials of E6 proteins from different HPV types and variants.

Epidemiology and burden of HPV infection and related diseases: implications for prevention strategies

Human papillomavirus (HPV) infection is a necessary, although not sufficient cause of cervical cancer. Globally, HPV infection accounts for an estimated 530,000 cervical cancer cases (~270,000 deaths) annually, with the majority (86% of cases, 88% of deaths) occurring in developing countries. Approximately 90% of anal cancers and a smaller subset (<50%) of other cancers (oropharyngeal, penile, vaginal, vulvar) are also attributed to HPV. In total, HPV accounts for 5.2% of the worldwide cancer burden. HPVs 16 and 18 are responsible for 70% of cervical cancer cases and, especially HPV 16, for a large proportion of other cancers. Prophylactic vaccination targeting these genotypes is therefore expected to have a major impact on the burden of cervical cancer as well as that of other HPV-related cancers. Over the past 50 years, organized or opportunistic screening with Papanicolaou (Pap) cytology has led to major reductions in cervical cancer in most developed countries. However, due to lack of resources or inadequate infrastructure, many countries have failed to reduce cervical cancer mortality through screening. HPV DNA testing recently emerged as a likely candidate to replace Pap cytology for primary screening. It is less prone to human error and more sensitive than Pap in detecting high-grade cervical lesions. For countries with national vaccination programs, HPV testing may also serve as a low cost strategy to monitor long term vaccine efficacy. Introduction of well organized vaccination and screening programs should be a priority for all countries. Increased support from donors is needed to support this cause.

Human papillomavirus, cancer and vaccination

PURPOSE OF REVIEW

HIV-positive men and women are at greater risk of human papillomavirus (HPV)-related cancers compared with the general population. This study describes recent findings in HPV-related cancers and precancerous lesions and discuss the potential benefit of recently developed prophylactic HPV vaccines.

RECENT FINDINGS

Despite improving access to antiretroviral therapy (ART), particularly in developing countries, the incidence of cervical cancer has not declined and the incidence of anal cancer is still rising in HIV-infected individuals. HIV appears to affect the history of HPV infection, and the distribution of genotypes detected in precancerous lesions in HIV-infected women is not similar to that of the general population. The use of the quadrivalent HPV vaccine has been shown to prevent cervical precursor lesions caused by the vaccine types in women in the general population. Safety and immunogenicity studies of the quadrivalent HPV vaccine in HIV-infected individuals are underway. Efficacy has to be proven in the context of both a different epidemiology of HPV infection and of immunosuppression.

SUMMARY

Recent data imply that the issue of HPV-related cancers will not decline in HIV-infected individuals. Therefore, efficacy studies of HPV vaccines are sorely needed in the setting of HIV.

Human papillomavirus prevalence among indigenous and non-indigenous Australian women prior to a national HPV vaccination program

BACKGROUND

Indigenous women in Australia have a disproportionate burden of cervical cancer despite a national cervical screening program. Prior to introduction of a national human papilloma virus (HPV) vaccination program, we determined HPV genotype prevalence by Indigenous status and residence in remote areas.

METHODS

We recruited women aged 17 to 40 years presenting to community-based primary health services for routine Pap screening across Australia. A liquid-based cytology (LBC) cervical specimen was tested for HPV DNA using the AMPLICOR HPV-DNA test and a PGMY09/11-based HPV consensus PCR; positive specimens were typed by reverse hybridization. We calculated age-adjusted prevalence by weighting to relevant population data, and determined predictors of HPV-DNA positivity by age, Indigenous status and area of residence using logistic regression.

RESULTS

Of 2152 women (655 Indigenous), prevalence of the high-risk HPV genotypes was similar for Indigenous and non-Indigenous women (HPV 16 was 9.4% and 10.5%, respectively; HPV 18 was 4.1% and 3.8%, respectively), and did not differ by age group. In younger age groups, the prevalence of other genotypes also did not differ, but in those aged 31 to 40 years, HPV prevalence was higher for Indigenous women (35% versus 22.5%; P < 0.001), specifically HPV clades α5 (OR = 2.1, 95% CI 1.1 to 4.3) and α7, excluding type 18 (OR 1.9, 95% CI 1.1 to 3.3). In multivariate analysis, detection of any HPV genotype was strongly associated with smoking and Pap-test abnormalities, with both risk factors more common among Indigenous women.

CONCLUSION

Although we found no difference in the prevalence of HPV16/18 among Australian women by Indigenous status or, for Indigenous women, residence in remote regions, differences were found in the prevalence of risk factors and some other HPV genotypes. This reinforces the importance of cervical screening as a complement to vaccination for all women, and the value of baseline data on HPV genotype prevalence by Indigenous status and residence for the monitoring of vaccine impact.

Sequence imputation of HPV16 genomes for genetic association studies

BACKGROUND

Human Papillomavirus type 16 (HPV16) causes over half of all cervical cancer and some HPV16 variants are more oncogenic than others. The genetic basis for the extraordinary oncogenic properties of HPV16 compared to other HPVs is unknown. In addition, we neither know which nucleotides vary across and within HPV types and lineages, nor which of the single nucleotide polymorphisms (SNPs) determine oncogenicity.

METHODS

A reference set of 62 HPV16 complete genome sequences was established and used to examine patterns of evolutionary relatedness amongst variants using a pairwise identity heatmap and HPV16 phylogeny. A BLAST-based algorithm was developed to impute complete genome data from partial sequence information using the reference database. To interrogate the oncogenic risk of determined and imputed HPV16 SNPs, odds-ratios for each SNP were calculated in a case-control viral genome-wide association study (VWAS) using biopsy confirmed high-grade cervix neoplasia and self-limited HPV16 infections from Guanacaste, Costa Rica.

RESULTS

HPV16 variants display evolutionarily stable lineages that contain conserved diagnostic SNPs. The imputation algorithm indicated that an average of 97.5±1.03% of SNPs could be accurately imputed. The VWAS revealed specific HPV16 viral SNPs associated with variant lineages and elevated odds ratios; however, individual causal SNPs could not be distinguished with certainty due to the nature of HPV evolution.

CONCLUSIONS

Conserved and lineage-specific SNPs can be imputed with a high degree of accuracy from limited viral polymorphic data due to the lack of recombination and the stochastic mechanism of variation accumulation in the HPV genome. However, to determine the role of novel variants or non-lineage-specific SNPs by VWAS will require direct sequence analysis. The investigation of patterns of genetic variation and the identification of diagnostic SNPs for lineages of HPV16 variants provides a valuable resource for future studies of HPV16 pathogenicity.

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.

Worldwide burden of cervical cancer in 2008

BACKGROUND

The knowledge that persistent human papillomavirus infection is the main cause of cervical cancer has resulted in the development of assays that detect nucleic acids of the virus and prophylactic vaccines. Up-to-date and reliable data are needed to assess impact of existing preventive measures and to define priorities for the future.

MATERIALS AND METHODS

Best estimates on cervical cancer incidence and mortality are presented using recently compiled data from cancer and mortality registries for the year 2008.

RESULTS

There were an estimated 530,000 cases of cervical cancer and 275,000 deaths from the disease in 2008. It is the third most common female cancer ranking after breast (1.38 million cases) and colorectal cancer (0.57 million cases). The incidence of cervical cancer varies widely among countries with world age-standardised rates ranging from <1 to >50 per 100,000. Cervical cancer is the leading cause of cancer-related death among women in Eastern, Western and Middle Africa; Central America; South-Central Asia and Melanesia. The highest incidence rate is observed in Guinea, with ∼6.5% of women developing cervical cancer before the age of 75 years. India is the country with the highest disease frequency with 134,000 cases and 73 000 deaths. Cervical cancer, more than the other major cancers, affects women <45 years.

CONCLUSIONS

In spite of effective screening methods, cervical cancer continues to be a major public health problem. New methodologies of cervical cancer prevention should be made available and accessible for women of all countries through well-organised programmes.

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.