Epidemiology of HPV infection among Mexican women with normal cervical cytology

Human papillomavirus infection: low-risk and high-risk genotypes in women in Catania, Sicily

INTRODUCTION

Human papillomavirus (HPV) infection has been strongly and consistently associated with cervical carcinoma and its cytologic precursors, such as squamous intraepithelial lesions. A cross-sectional survey was conducted with the aim of estimating the prevalence of cervical HPV infection in women attending a service of colposcopy in Catania, Eastern Sicily, Italy.

METHODS

The prevalence of type-specific HPV was examined in women with negative colposcopic results and cervical intraepithelial neoplasia grades 1, 2, or 3, with the aim of providing some cross-sectional figures on the local epidemiology of HPV infection.

RESULTS

Human papillomavirus DNA was found in 62.1% of women with negative colposcopic results and in 73.2% with positive colposcopic results. Among high-risk types, a predominance of HPV-16 (51.5% of infected women) was shown followed by HPV-56 (29.7%). An age-related pattern was described with a peak in HPV prevalence among women younger than 25 years, followed by the expected decline in prevalence and a second characteristic peak in the perimenopausal or postmenopausal years, useful to design future control strategies.

CONCLUSIONS

The age-related pattern of HPV prevalence and the presence of uncommon high-risk genotypes and their role in the pathogenesis of cervical cancer need to be addressed by specific epidemiologic studies to design large-scale screening programs and multivalent vaccine strategies.

Prevalence of human papillomavirus genotypes, and mucosal IgA anti-viral responses in women with cervical ectopy

BACKGROUND

Data on the prevalence of different human papillomavirus (HPV) genotypes and the associated mucosal immune response in women with cervical ectopy are scarce.

OBJECTIVE

To assess the prevalence of different HPV genotypes and the mucosal anti-viral immune response in cervical ectopy.

STUDY DESIGN

Detection and typing of HPV DNA was determined in 141 women with cervical ectopy, 272 cytologically normal controls and 98 low-grade squamous intraepithelial lesions (LSIL) by PCR and direct sequencing. Mucosal IgA antibodies to HPV16 and HPV18 were evaluated in cervical mucus by ELISA.

RESULTS

The prevalence of HPV in cervical ectopy was higher (73.7%) than that observed in control samples (30.5% in endocervix, and 1.8% in exocervix), but similar to the prevalence in LSIL (62.2%). Typing showed that the overall distribution frequency concerned 14 different genotypes, with HPV18 being the most prevalent in cervical ectopy (53.9%), whereas HPV16 predominated in LSIL (38.7%). High-risk HPV genotypes were 2.2 times more frequent in cervical ectopy than in the normal endocervix (p<0.0001). HPV infection in cervical ectopy patients was accompanied by a mucosal IgA-antibody response. Antibody reactivity to HPV18 was significantly higher than the response to HPV16.

CONCLUSION

Cervical ectopy is a risk factor for infection with high-risk HPV genotypes, in particular HPV18. Our results emphasize the need of further studies to clarify the oncogenic potential of this virus in cervical ectopy.

Human papillomavirus infection in Honduran women with normal cytology

Objective

This study was aimed at estimating type-specific HPV prevalence and its cofactors among Honduran women with normal cytology in order to provide valuable information to health policymakers about the epidemiology of this important sexually transmitted infection.

Methods

A total of 591 women with normal cytology from Tegucigalpa, Honduras were interviewed and tested for HPV using the SPF10 LiPA25. A structured epidemiological questionnaire was administered to each woman.

Results

The overall HPV prevalence was 51%. Twenty-three types of HPV were detected; HPV 16, 51, 31, 18, and 11 were the most common. The highest prevalence of cancer associated HPV types (15.0%) was found in the women less than 35 years. Besides the association with age, the main independent predictors of HPV infection were the lifetime number of sexual partners and having a low socioeconomic status and less than 5 previous Pap smears.

Conclusions

In the population studied, there was a broad diversity of HPV infections, with high-risk types being the most common types detected. The establishment of a well-characterized population with regard to the community prevalence of type-specific HPV infection will provide a valuable baseline for monitoring population effectiveness of an HPV vaccine.

Differences in the risk of cervical cancer and human papillomavirus infection by education level

BACKGROUND

Cervical cancer risk is associated with low education even in an unscreened population, but it is not clear whether human papillomavirus (HPV) infection follows the same pattern.

METHODS

Two large multicentric studies (case-control studies of cervical cancer and HPV prevalence survey) including nearly 20 000 women. GP5+/GP6+ PCR was used to detect HPV.

RESULTS

Education level was consistently associated with cervical cancer risk (odds ratio (OR) for 0 and >5 years vs 1-5 years=1.50, 95% confidence interval (CI): 1.25-1.80 and 0.69, 95% CI: 0.57-0.82, respectively, P for trend <0.0001). In contrast, no association emerged between education level and HPV infection in either of the two IARC studies. A majority of the women studied had never had a Pap smear. The association between low education level and cervical cancer was most strongly attenuated by adjustment for age at first sexual intercourse and first pregnancy. Parity and screening history (but not lifetime number of sexual partners, husband's extramarital sexual relationships, and smoking) also seemed to be important confounding factors.

CONCLUSION

The excess of cervical cancer found in women with a low socio-economic status seems, therefore, not to be explained by a concomitant excess of HPV prevalence, but rather by early events in a woman's sexually active life that may modify the cancer-causing potential of HPV infection.

Human papilloma virus and esophageal carcinoma in a Latin-American region

AIM: To investigate the presence of high-risk human papilloma virus (HPV) in esophageal squamous cell carcinomas (ESCCs) in a non-selected Mexican population.

METHODS: Cases with a pathological diagnosis of squamous cell carcinoma of the esophagus were obtained from Department of Pathology files, at the National Cancer Institute in Mexico City during the period between 2000 and 2008. Slides from each case were reviewed and cases with sufficient neoplastic tissue were selected for molecular analysis. DNA was extracted from paraffin-embedded tissue samples for polymerase chain reaction analysis to detect HPV DNA sequences. Demographic and clinical data of each patient were retrieved from corresponding clinical records.

RESULTS: HPV was detected in 15 (25%) of ESCCs. HPV-16 was the most frequently observed genotype, followed by HPV-18; HPV-59 was also detected in one case. Unfortunately, HPV genotype could not be established in three cases due to lack of material for direct sequencing, although universal primers detected the presence of HPV generic sequences. No low-risk HPV genotypes were found nor was HPV-16/18 co-infection. HPV presence in ESCC was not significantly associated with gender, age, alcohol consumption, smoking, anatomic location, or histologic grade. All patients belonged to low and very low socioeconomic strata, and were diagnosed at advanced disease stage. Male patients were most commonly affected and the male:female ratio in HPV-positive ESCC increased two-fold in comparison with HPV-negative cases (6.5:1 vs 3.1:1).

CONCLUSION: High prevalence of high-risk HPV in ESCC in Mexico does not support the hypothesis that HPV-associated ESCC is more common in areas with higher ESCC incidence rates.

Human Leukocyte Antigens I and II Haplotypes Associated With Human Papillomavirus 16-Positive Invasive Cervical Cancer in Mexican Women

Infection with human papillomavirus (HPV), mainly HPV type 16, is the major etiologic factor associated with cervical cancer (CC), but HPV infection alone is not sufficient for progression of precursor lesions. Host genetic susceptibility may lead to abnormal immune response resulting from virus persistence. Several studies have suggested a possible association with specific human leukocyte antigen (HLA) class I and II alleles and CC, but results are not consistent. The association of genetic HLA class I (A and B) and HLA class II (DR*B1 and DQ*B1) haplotypes with HPV16-positive CC (n = 104) and base population controls (n = 104) was evaluated in this Mexican population study. Sequence-specific primer HLA genes were determined by polymerase chain reaction (PCR)-based methods in peripheral blood cell counts (PCR sequence-specific oligonucleotides). The cervical swabs of 208 women were tested for HPV16 by Hybrid Capture II. Allele and haplotype HLA frequencies, Hardy-Weinberg tests, and a haplotype homogeneity test were estimated using the Arlequin software v. 3.01. Odds ratio (OR) was calculated to compare cases and control women. Consistent associations across other studies in women with CC and infected by HPV16 were observed for HLA-DRB1*15 (OR, 3.9; 95% CI, 1.6-10.2) and the haplotype DRB1*15 DQB1*0602 (OR, 4.1; 95% CI, 1.4-12.7) compared with control women. The HLA-A2-B44-DR4-DQ*0302, HLA-A24-B35-DR16-DQ*0301, and HLA-A2-B40-DR4-DQ*0302 haplotypes showed a positive association with CC (OR, >1), whereas HLA-A2-B39-DR4-DQ*0302, HLA-A24-B35-DR4-DQ*0302, and HLA-A68-B40-DR4-DQ*0302 showed a negative association (OR, <1). These results support the hypothesis that some HLA class I and II haplotypes could be involved with susceptibility for developing CC.

Abbreviations:

Cervical Cancer-CC, confidence interval-CI, human leukocyte antigens-HLA, human papillomavirus-HPV, odds ratio-OR, polymerase chain reaction-PCR, relative risk-RR, relative light units-RLU, ribonucleic acid-RNA, sequence-sensitive oligonucleotide-SSO

Human papillomavirus profile of women in Belize City, Belize: correlation with cervical cytopathologic findings

Cervical carcinoma is the most common cancer among Belizean women; however, data regarding the frequency of human papillomavirus (HPV) genotypes and their association with cervical cancer are nonexistent. We therefore included HPV genotyping as part of a week-long cervical cancer screening campaign conducted in Belize City in 2007. Conventional Papanicolaou smears with Hybrid Capture (HC) 2 HPV testing were performed on 463 women. All HC2-positive samples were genotyped using a developmental GP5+/GP6+ polymerase chain reaction-coupled Luminex assay for 2 low-risk and 18 high-risk HPV types. The prevalence of high-risk HPV was 15.6% in the total population, 10.1% in those with normal cytologic findings, and 93.3% in women with a high-grade squamous intraepithelial lesion. Of patients with HPV infections, 35% had multiple types (5.4% of the total group). Of all women and of women with normal cytologic findings, 5.2% and 2.8%, respectively, had HPV16 or 18. For all women, HPV16, 18, 56, and 52 were present in decreasing order of frequency. HPV11 was present in only one patient, and none had HPV6. HPV16 was found in 47% of high-grade squamous epithelial lesions; however, no case of HSIL had HPV18 or 45. HPV35 and HPV58 were the next most common types in high-grade squamous intraepithelial lesion, each occurring in 20% of cases of high-grade squamous intraepithelial lesion, followed by HPV31 in 13.3%. Although women younger than 25 years old were underrepresented, these data suggest that the HPV profile of this cohort of Belizean women differs somewhat from that in the region. In addition, these data are of importance with regard to the development of HPV vaccines that will be used in less developed countries, where care should be taken not to implement vaccination at the cost of basic screening and diagnostic services.

Prevalence and age distribution of human papillomavirus infection in a population of Inuit women in Nunavik, Quebec

OBJECTIVES

Our aim was to study the prevalence and age distribution of human papillomavirus (HPV) infection among Inuit women in Nunavik, northern Quebec, a population at high risk of cervical cancer.

METHODS

We recruited a cohort of Inuit women seeking routine care and living primarily in four communities of the Nunavik region. Pap smears were done and cervical specimens were tested for HPV-DNA using the PGMY-Line blot assay.

RESULTS

From January 2002 until December 2007, 629 women were recruited into the study and had their cervical specimens tested. Of 554 women with complete results, the overall and high-risk HPV prevalence were 28.9% and 20.4%, respectively. Multiple-type infections were observed in 40% of HPV-positive subjects. The most common HPV type was HPV-16 (n = 31), and other common high-risk types included HPV-31, HPV-58, and HPV-52. The most prevalent papillomavirus species were alpha-9 (60% of infections), alpha-3 (44%), and alpha-7 (31%). Age-specific prevalence of low-risk HPV, high-risk HPV, and overall HPV showed a U-shaped curve. Of women with baseline cytology, 6.5% had an abnormal result, either atypical squamous cells of undetermined significance, low-grade squamous intraepithelial lesion (LSIL), or high-grade intraepithelial lesion (HSIL). HPV-16, HPV-31, and HPV-58 were some of the most common high-risk types detected in both LSIL and HSIL specimens.

CONCLUSIONS

Overall and high-risk HPV prevalence was elevated in this population of Quebec Inuit women when compared with other populations that have been studied in Canada. Different HPV types seem to be important as contributors to the overall burden of infection and to the presence of cervical abnormalities, which may have implications for developing cervical screening and vaccination programs.

Correlation between IL-10 gene expression and HPV infection in cervical cancer: a mechanism for immune response escape

The present study was performed to determine IL-10 expression in cervical tissues in Mexican women according to the severity of the malignity and its association with HPV infection. IL-10 expression showed a clear tendency to increase during the different cervical cancer stages: 37% in LGSIL; 62% in HGSIL; and 84% in cancer. However, all the patients that expressed IL-10 were HPV positives; we found an association with HPV 16. These results suggest a clear relationship between IL-10, HPV and the stage of cervical cancer disease; this event could contribute to the immunosuppressive micro-environment in the tumor site.

Prevalence of human papillomavirus genotypes in women from a rural region of Puebla, Mexico

OBJECTIVE

To determine the prevalence of human papillomavirus (HPV) genotypes 6, 11, 16, 18, and 31 in Mexican women living in rural areas of Puebla, Mexico and to evaluate risk factors associated with cervical neoplasm in this population.

METHODS

A cross-sectional study was conducted in 326 women at the General Hospital of Metepec, Puebla. Cervical samples were obtained using a cytobrush and tested for HPV genotypes by PCR assays using type-specific primers. A questionnaire was completed regarding gynecological, obstetric, and sexual behavior of the patients.

RESULTS

The overall prevalence of HPV infection was 25.4%, with two peaks of higher HPV prevalence in those aged 18-24 and 55-64 years. The individual genotype prevalences were: 9.6% HPV6, 4.8% HPV11, 54.2% HPV16, 37.3% HPV18, and 9.6% HPV31. Number of pregnancies was the most important risk factor associated with cervical cancer.

CONCLUSIONS

HPV16 was the most common type found in all cervical lesions. Genotype 16 or 18 was detected in patients with a diagnosis of cervical cancer. We found two peaks of age-specific HPV prevalence similar to findings reported worldwide.

Epidemiology of Human Papilloma Virus (HPV) in Cervical Mucosa

In a worldwide scenario, human papillomavirus (HPV) infection is the second leading cause of cancer-related morbidity and mortality among women due to its very close association with cervical cancer. More than 100 different types of HPV genotypes have been characterized to date. Among these, approximately 24 HPV genotypes specifically infect the genital and oral mucosal system. The mucosal HPVs are most frequently sexually transmitted, and they are responsible for the most common sexually transmitted diseases throughout the world. In a majority of the cases, oncogenic/nononcogenic HPV infections spontaneously clear by themselves without any medical intervention. However, a persistent and long-term HPV infection usually leads to cervical cancer, which remains difficult to treat. In recent years, advance understanding of the structure of HPV and its pathogenesis has led to a variety of new treatments to combat HPV-related diseases, including a Food and Drug Administration-approved HPV vaccine that is very effective in young women. To effectively use this HPV vaccine worldwide, a clear understanding of HPV genotypes in different geographical populations is imperative. In this chapter, we have focused briefly on HPV genotypes and HPV prevalence in the women of different geographical populations.

Risk factors for human papillomavirus exposure and co-factors for cervical cancer in Latin America and the Caribbean

The incidence of cervical cancer in Latin America and the Caribbean (LAC) is among the highest in the world. Because there are major demographic shifts happening in LAC countries (population growth, urbanization and ageing) cervical cancer incidence and mortality will likely continue to be a significant public health problem. Overall human papillomavirus (HPV) prevalence in the LAC general population has been found to be 2-fold higher than the average worldwide prevalence. The large HPV and cancer burden may be explained by the highly prevalent HPV variants of HPV types -16 and 18, which have an increased oncogenic potential. Given the major mode of transmission of genital HPV is sexual, certain, patterns of sexual behaviour (early age at first sexual intercourse, number of sexual partners and sexual behaviour of the partner) are associated with an increased risk of HPV genital acquisition. Although HPV infection is necessary for carcinogenesis, certain co-factors (high parity, long term use of oral contraceptives, smoking and co-infection with the human immunodeficiency virus (HIV)) help in the progression from infection to cancer. Many studies that have contributed to this evidence have been carried out in LAC and are reviewed and summarised in this article. Since HPV vaccines will likely take years to implement, and many more years to show impact on disease, cervical cancer screening programmes remain as the key intervention to control disease in LAC in the years to come.

Prevalence, acquisition, and clearance of cervical human papillomavirus infection among women with normal cytology: Hawaii Human Papillomavirus Cohort Study

Few natural history studies of cervical human papillomavirus (HPV) incidence and duration have been conducted among older women, especially from multiethnic populations. Viral and nonviral determinants of HPV acquisition and clearance were examined among 972 sexually active women, ages 18 to 85 years, recruited from clinics on Oahu, Hawaii, and followed for a mean duration of 15 months (range, 2-56 months). Interviews and cervical cell specimens for cytology and HPV DNA detection by PCR, using the PGMY09/PGMY11 primer system, were obtained at baseline and at 4-month intervals. The prevalence of cervical HPV infection was 25.6% at study entry. A total of 476 incident genotype-specific infections were observed during the follow-up period. The incidence of high-risk (HR) HPV types (9.26 per 1,000 woman-months) was similar to low-risk (LR) HPV types (8.24 per 1,000 woman-months). The most commonly acquired HR-HPV types were HPV-52, HPV-16, and HPV-31; and their incidence was increased significantly with a coexisting cervical HPV infection. Cervical HPV acquisition decreased with age, income, and long-term use of oral contraceptives and increased with number of sexual partners, use of hormonal creams, alcohol drinking, and condom use by a sexual partner. Cohort participants cleared 265 of the 476 incident infections during follow-up. LR-HPV infections cleared more rapidly than did HR-HPV infections (median, 180 days versus 224 days). Clearance times were enhanced among older women and women with multiple infections. Our data suggest several viral and nonviral determinants of cervical HPV acquisition and clearance that might be used in cervical cancer prevention programs.

Cervical carcinoma in Southern Mexico: Human papillomavirus and cofactors

BACKGROUND

This study was conducted to determine human papillomavirus (HPV) types in women with cervical cancer (CC) and normal cervical cytology in the Southern region of Mexico, and to know the contribution of HPV types and cofactors in cervical cancer etiology.

METHODS

A case-control study was performed in 133 women with CC and 256 controls. HPV detection was done by MY09/11 and GP5+/GP6+ PCR systems and typing by restriction fragment length polymorphism or DNA sequencing.

RESULTS

HPV was found in 100% of CC and 35.5% of controls. The genotype distribution in CC was: HPV 16 (66.8%), 18 (9%), 31 (7.5%), 45 (4.5%), 58 (3.7%), 69 (3%), 52 (1.6%), 6, 11, 33, 56, and 67 (0.8% each). Among controls, HPV 33 followed by HPV 16 were the most frequent. Cervical cancer was associated with HPV 16 (OR=573.5), HPV 18 (OR=804.4), and undetermined risk HPV (types 67 and 69) (OR=434.3). Age at first intercourse <16 years (OR=9.6) and > or =3 births (OR=16) were significant risk factors for CC.

CONCLUSIONS

HPV 16, by far, is the most frequent type in CC, HPV 16 and 18 are responsible for 75.8% of the CC cases and high-risk HPV for 94.7%, which is useful data to take into account in vaccination programs. HPV 33 is the most frequent type in controls and high-risk HPV are more common than low-risk HPV.

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 of genital HPV infection among women screened for cervical cancer]

OBJECTIVE

To assess the prevalence of high-risk genital human papillomavirus (HPV) infection by age group and risk factors associated.

METHODS

Cross-sectional study in a sample of 2,300 women (15-65 years old) who self-referred to cervical cancer screening in Sao Paulo and Campinas, Southeastern Brazil, between February 2002 and March 2003. An epidemiological questionnaire was applied and cervical specimens were obtained for cytology and hybrid capture II test (HCII) for HPV detection. Statistical analysis included Pearson Chi-square and unconditional multiple logistic regression model (forward likelihood ratio).

RESULTS

High-risk genital HPV infection prevalence in this sample was 17.8% and age distribution was as follows: 27.1% (<25 years), 21.3% (25-34 years), 12.1% (35-44 years), 12.0% (45-54 years) and 13.9% (55-65 years). Subjects with the highest number of lifetime sexual partners had the highest rates of genital HPV infection. To be living with a partner, aged 35 to 44 years, and former smokers were protective factors. High-risk genital HPV infection was 14.3% in normal cytology, 77.8% in high grade squamous intraepithelial lesions and in the two cases (100%) of cervical cancer.

CONCLUSIONS

High-risk HPV prevalence was high in the sample studied. The highest prevalence of HPV infection was seen in women under 25 years old and then a new increase was seen over the age of 55 and the highest rates were found among those with many sexual partners during their lifetime.

Prevalence of human papillomavirus in Indonesia: a population-based study in three regions

Cervical cancer is the most common cancer among women in the Indonesian population, yet little is known about the prevalence of human papillomavirus (HPV). We investigated age-specific prevalence of HPV types and possible risk factors of HPV positivity in a population-based sample of 2686 women, aged 15–70 years, in Jakarta, Tasikmalaya, and Bali, Indonesia. The overall HPV prevalence was 11.4%, age-standardized to the world standard population 11.6%. The most prevalent types found were HPV 52, HPV 16, HPV 18, and HPV 39, respectively, 23.2, 18.0, 16.1, and 11.8% of the high-risk HPV types. In 20.7% of infections, multiple types were involved. Different age-specific prevalence patterns were seen: overall high in Jakarta, and in Tasikmalaya, and declining with age in Bali. The number of marriages was most associated with HPV positivity (OR 1.81 95% CI 1.31–2.51)). Remarkably, in Indonesia HPV 16 and HPV 18 are equally common in the general population, as they are in cervical cancer. HPV 52 was the most prevalent type in the general population, suggesting that this type should be included when prophylactic HPV vaccination is introduced in Indonesia.

Seroprevalence of 34 human papillomavirus types in the German general population

The natural history of infections with many human papillomavirus (HPV) types is poorly understood. Here, we describe for the first time the age- and sex-dependent antibody prevalence for 29 cutaneous and five mucosal HPV types from 15 species within five phylogenetic genera (alpha, beta, gamma, mu, nu) in a general population. Sera from 1,797 German adults and children (758 males and 1,039 females) between 1 and 82 years (median 37 years) were analysed for antibodies to the major capsid protein L1 by Luminex-based multiplex serology. The first substantial HPV antibody reactions observed already in children and young adults are those to cutaneous types of the genera nu (HPV 41) and mu (HPV 1, 63). The antibody prevalence to mucosal high-risk types, most prominently HPV 16, was elevated after puberty in women but not in men and peaked between 25 and 34 years. Antibodies to beta and gamma papillomaviruses (PV) were rare in children and increased homogeneously with age, with prevalence peaks at 40 and 60 years in women and 50 and 70 years in men. Antibodies to cutaneous alpha PV showed a heterogeneous age distribution. In summary, these data suggest three major seroprevalence patterns for HPV of phylogenetically distinct genera: antibodies to mu and nu skin PV appear early in life, those to mucosal alpha PV in women after puberty, and antibodies to beta as well as to gamma skin PV accumulate later in life.

Cervical human papillomavirus infection among female sex workers in southern Vietnam

Background

Cervical cancer is the most frequently diagnosed malignancy among women in southern Vietnam where its incidence is one of the highest observed worldwide.

Results

Cervical HPV DNA infection was measured in a cross-sectional sample of 282 female sex workers (FSW) in Soc Trang province in southern Vietnam. HPV DNA was detected in 85% of FSW and prevalence did not vary by age. Thirty-five HPV genotypes were detected; HPV 52 was the most common type. Half of HPV-positive women were infected with oncogenic types and 37% were infected with multiple genotypes. The prevalence of oncogenic HPV infection was lower among FSW with more formal education (adj. prevalence ratio = 0.63, 95% CI 0.42–0.93), those servicing 25 or more clients per month (adj. PR = 0.66 95% CI 0.48–0.92), and those engaging in withdrawal prior to ejaculation (adj. PR = 0.68, 95% CI 0.53–0.87). Oncogenic HPV prevalence was higher among FSW with regular male partners who had other female partners (adj. PR = 1.75, 95% CI 1.34–2.28) and FSW who were HIV+ (adj. PR = 1.42, 95% CI 1.08–1.88).

Conclusion

Our results demonstrate that although cervical HPV infection is extremely common among FSW in southern Vietnam, prevalence varies by education level, sexual activity, habits of regular partners, and HIV status.

Detection of human papillomavirus DNA by DNA chip in breast carcinomas of Korean women

It remains unclear whether there is an association between human papillomavirus (HPV) infection and human breast cancer. The aim of this study was to investigate the presence of HPV DNA in breast carcinomas of Korean women and to examine the possible association between HPV and breast cancer development. For this purpose, HPV DNAs from 154 patients, including 123 patients with breast carcinoma and 31 with intraductal papilloma, and nipple tissue from 27 cancer patients were examined using the DNA chip method. HPV DNA was detected in 8 breast carcinomas (6.5%) but in no intraductal papilloma. All detected HPV genotypes were of high-risk groups. There was a slightly increased incidence in papillary carcinomas (11.5%) and invasive ductal carcinomas with adjacent intraductal papillomas (11.8%) compared to the other histological subtypes (3.2-4.3%), although the difference was not statistically significant (p = 0.126). The presence of HPV DNA was not correlated with specific prognostic predictors of disease. High-risk HPV DNA sequences were present in 6.5% of Korean patients with breast tumors. However, this study could not demonstrate whether or not such HPVs directly contribute to the development of breast cancer.

Safety, immunogenicity, and efficacy of quadrivalent human papillomavirus (types 6, 11, 16, 18) L1 virus-like-particle vaccine in Latin American women

The prevalence of HPV infection in Latin America is among the highest in the world. A quadrivalent (types 6/11/16/18) human papillomavirus L1 virus-like-particle vaccine has been shown to be 95-100% effective in preventing HPV 6/11/16/18-related cervical and genital disease in women naive to vaccine HPV types. A total of 6,004 female subjects aged 9-24 were recruited from Brazil, Mexico, Colombia, Costa Rica, Guatemala and Peru. Subjects were randomized to immunization with intramuscular (deltoid) injections of HPV vaccine or placebo at enrollment (day 1), month 2 and month 6. Among vaccinated subjects in the per-protocol population from Latin America, quadrivalent HPV vaccine was 92.8 and 100% effective in preventing cervical intraepithelial neoplasia and external genital lesions related to vaccine HPV types, respectively. These data support vaccination of adolescents and young adults in the region, which is expected to greatly reduce the burden of cervical and genital cancers, precancers and genital warts.

Smoking and human papillomavirus infection: pooled analysis of the International Agency for Research on Cancer HPV Prevalence Surveys

BACKGROUND

Smoking increases the risk of squamous-cell carcinoma of the cervix, but it is not clear whether smoking increases the risk of acquisition or persistence of human papillomavirus (HPV) infection.

METHODS

Information on smoking was collected from 10 areas in four continents among population-based, age-stratified random samples of women aged 15 years or older. HPV testing was performed using PCR-based enzyme immunoassay. Unconditional logistic regression was used to estimate odds ratios (OR) and corresponding 95% confidence intervals (CI) of being HPV-positive by smoking habits, adjusted for age and lifetime number of sexual partners.

RESULTS

Ten thousand five hundred and seventy-seven women (mean age 41.4 years) were included. Among current smokers, the risk of being HPV-positive increased with smoking intensity, after allowing for lifetime number of sexual partners: ORs for <5, 5-14 and >/=15 cigarettes per day were 1.21 (95% CI 0.95-1.54), 1.39 (95% CI 1.04-1.87) and 2.01 (95% CI 1.32-3.08), respectively, as compared with never-smokers. The risk among former smokers (OR = 0.95, 95% CI 0.73-1.23) was similar to that among never-smokers. Analyses stratified by lifetime number of sexual partners showed a significant trend in risk only for women with one lifetime sexual partner.

CONCLUSIONS

Our study suggests that current, though not former, smoking is associated with an increased prevalence of HPV, after allowance for sexual covariates. Among current smokers, HPV prevalence increased with smoking intensity, but a clear dose-response relationship was exclusively seen among women who declared one lifetime sexual partner.

International correlation between human papillomavirus prevalence and cervical cancer incidence

Data from population-based human papillomavirus (HPV) surveys in regions of low, intermediate, and high cervical cancer incidence were used to study the ecologic correlation between high-risk HPV prevalence and cervical cancer incidence. All the surveys were conducted by the IARC according to a standardized protocol for the collection of female population samples and detection of HPV DNA using PCR assay in a central laboratory. Cervical cancer incidence data were extracted, when available, from a cancer registry covering the surrounding or nearby area of the prevalence survey. Thirteen areas were included in this analysis. The relation between high-risk HPV prevalence and cervical cancer incidence was investigated within 10-year age groups from age 25 to 65 years. A Poisson regression model was used to predict cervical cancer incidence from HPV prevalence, and the strength of the correlation was assessed using Spearman's rank correlation coefficient. The rank correlation was weakest in women ages 25 to 34 years and strongest in women ages 55 to 64 years. In addition, the prevalence of high-risk HPV was not able to predict cervical cancer incidence accurately in every country. Nevertheless, our data raise a concern about the cervical cancer burden in areas where reliable cervical cancer statistics do not exist but where the prevalence of high-risk HPV in women over age 45 is high.

Prevalence of high-risk human papillomavirus types in Mexican women with cervical intraepithelial neoplasia and invasive carcinoma

Background

Prevalence of high risk (HR) human papillomavirus (HPV) types in the states of San Luis Potosí (SLP) and Guanajuato (Gto), Mexico, was determined by restriction fragment length-polymorphism (RFLP) analysis on the E6 ~250 bp (E6-250) HR-HPV products amplified from cervical scrapings of 442 women with cervical intraepithelial neoplasia and invasive carcinoma (280 from SLP and 192 from Gto). Fresh cervical scrapings for HPV detection and typing were obtained from all of them and cytological and/or histological diagnoses were performed on 383.

Results

Low grade intraepithelial squamous lesions (LSIL) were diagnosed in 280 cases (73.1%), high grade intraepithelial squamous lesions (HSIL) in 64 cases (16.7%) and invasive carcinoma in 39 cases (10.2%). In the 437 cervical scrapings containing amplifiable DNA, only four (0.9%) were not infected by HPV, whereas 402 (92.0%) were infected HR-HPV and 31 (7.1%) by low-risk HPV. RFLP analysis of the amplifiable samples identified infections by one HR-HPV type in 71.4%, by two types in 25.9% and by three types in 2.7%. The overall prevalence of HR-HPV types was, in descending order: 16 (53.4%) > 31 (15.6%) > 18 (8.9%) > 35 (5.6) > 52 (5.4%) > 33 (1.2%) > 58 (0.7%) = unidentified types (0.7%); in double infections (type 58 absent in Gto) it was 16 (88.5%) > 31 (57.7%) > 35 (19.2%) > 18 (16.3%) = 52 (16.3%) > 33 (2.8%) = 58 (2.8%) > unidentified types (1.0%); in triple infections (types 33 and 58 absent in both states) it was 16 (100.0%) > 35 (54.5%) > 31 (45.5%) = 52 (45.5%) > 18 (27.3%). Overall frequency of cervical lesions was LSIL (73.1%) > HSIL (16.7%) > invasive cancer (10.2%). The ratio of single to multiple infections was inversely proportional to the severity of the lesions: 2.46 for LSIL, 2.37 for HSIL and 2.15 for invasive cancer. The frequency of HR-HPV types in HSIL and invasive cancer lesions was 16 (55.0%) > 31 (18.6%) > 35 (7.9%) > 52 (7.1%) > 18 (4.3%) > unidentified types (3.6%) > 33 (2.9%) > 58 (0.7%).

Conclusion

Ninety percent of the women included in this study were infected by HR-HPV, with a prevalence 1.14 higher in Gto. All seven HR-HPV types identifiable with the PCR-RFLP method used circulate in SLP and Gto, and were diagnosed in 99.3% of the cases. Seventy-one percent of HR-HPV infections were due to a single type, 25.9% were double and 2.7% were triple. Overall frequency of lesions was LSIL (73.1%) > HSIL (16.7%) > invasive cancer (10.2%), and the ratio of single to multiple infections was inversely proportional to severity of the lesions: 2.46 for LSIL, 2.37 for HSIL and 2.15 for invasive cancer. The frequency of HR-HPV types found in HSIL and invasive cancer was 16 (55.0%) > 31 (18.6%) > 35 (7.9%) > 52 (7.1%) > 18 (4.3%) > unidentified types (3.6%) > 33 (2.9%) > 58 (0.7%). Since the three predominant types (16, 31 and 18) cause 77.9% of the HR-HPV infections and immunization against type 16 prevents type 31 infections, in this region the efficacy of the prophylactic vaccine against types 16 and 18 would be close to 80%.

Human papillomavirus: molecular and cytologic/histologic aspects related to cervical intraepithelial neoplasia and carcinoma

Cervical cancer is unique among human cancers because it was the first cancer discovered to be virtually solely attributable to the effects of an infectious agent. Numerous epidemiologic and laboratory studies have confirmed a strong causal association between human papillomavirus infection and the development of premalignant and malignant lesions of the uterine cervix, and human papillomavirus-mediated malignant transformation is an ideal model system for the study of virally mediated carcinogenesis. Neoplastic transformation of affected cervical epithelium appears to be a direct consequence of the unregulated overexpression of viral oncoproteins that have central roles in the normal viral replicative cycle. This review is focused on the mechanisms that regulate the normal papillomavirus life cycle and on the mechanisms that appear to have central roles in malignant transformation of the cervical mucosa.

Lifestyle and socio-demographic factors associated with high-risk HPV infection in UK women

The world age-standardised prevalence of high-risk HPV (hrHPV) infection among 5038 UK women aged 20–59 years, with a low-grade smear during 1999–2002, assessed for eligibility for TOMBOLA (Trial Of Management of Borderline and Other Low-grade Abnormal smears) was 34.2%. High-risk HPV prevalence decreased with increasing age, from 61% at ages 20–24 years to 14–15% in those over 50 years. The age-standardised prevalence was 15.1, 30.7 and 52.7%, respectively, in women with a current normal, borderline nuclear abnormalities (BNA) and mild smear. In overall multivariate analyses, tertiary education, previous pregnancy and childbirth were associated with reduced hrHPV infection risk. Risk of infection was increased in non-white women, women not married/cohabiting, hormonal contraceptives users and current smokers. In stratified analyses, current smear status and age remained associated with hrHPV infection. Data of this type are relevant to the debate on human papillomavirus (HPV) testing in screening and development of HPV vaccination programmes.

Cytologic diagnosis of atypical squamous cells of undetermined significance in perimenopausal and postmenopausal women

BACKGROUND

The authors have noted that in cervical cytology specimens from perimenopausal and postmenopausal women, the diagnosis of atypical squamous cells of undetermined significance (ASC-US), as defined in the Bethesda system, is often not associated with a clinically evident lesion on follow-up. Reflex human papillomavirus (HPV) testing provides an opportunity to distinguish cytologic features of significance from those within the spectrum of benign cellular change in this age group.

METHODS

Liquid-based preparations that were diagnosed as ASC-US between January 2003 and July 2005 at Emory University Hospital were identified from the computer files. The results of HPV-DNA testing were recorded. Two hundred four Papanicolaou tests from perimenopausal women (n = 81, 40-49 years) and postmenopausal women (n = 123, >50 years) were reviewed in a blinded fashion.

RESULTS

HPV-DNA results were available for 903 of 1044 patients diagnosed as ASC-US. Overall, 323 results (35.8%) were positive, 510 results (56.6%) were negative, and 70 results (7.8%) were indeterminate. In addition, 73% of ASC-US specimens in patients aged > or =40 years were negative for HPV DNA. The HPV-DNA detection rate dropped from 60% in the group ages 10 to 19 years to approximately 18% in the group aged >50 years. A review of HPV-negative cases in the group aged >40 years showed squamous cells with random nuclear enlargement and slight hyperchromasia that likely were interpreted as ASC-US (based on the cells that were dotted by the original reviewer). Nuclear grooves were frequent in these nuclei; and cytoplasmic halos, when present, usually were perinuclear.

CONCLUSIONS

HPV-DNA detection in cervical cytology specimens has an inverse relation to patient age. A diagnosis of ASC-US in perimenopausal and postmenopausal women is likely to result in a negative HPV-DNA test in a significant proportion of patients. Enlarged nuclei with nuclear grooves and slight hyperchromasia are possibly the cause of ASC-US overdiagnosis in this age group.

A comparative profile of the prevalence and age distribution of human papillomavirus type 16/18 infections among three states of India with focus on northeast India

Human papillomavirus (HPV) DNA in cervical scrape samples of married women from Manipur (n= 692) and Sikkim (n= 415) in northeast India was determined and compared with that of women from West Bengal (n= 1112) in eastern India by polymerase chain reaction. HPV prevalence was lower in Manipur (7.4%) than in Sikkim (12.5%), which was closely followed by West Bengal (12.9%). HPV18 was predominant in Manipur (2.03%) and strikingly lower (0.2%) in Sikkim and West Bengal (0.9%), while the reverse was true for HPV16. The proportion of HPV16/18 infections in Manipur (3.3%, 22/672) and Sikkim (3.89%, 14/359) were comparable and significantly lower compared to that in West Bengal (7.8%, 79/1007) among women having normal cervical cytology. Such prevalence was similar among all age groups in Manipur: increased with age for women in Sikkim and dropped with age for those in West Bengal similar to that reported previously. At age < or =30 years, HPV16/18 prevalence in Manipur (3.3%) and Sikkim (2.5%) was comparable but was significantly lower (P < 0.05) in contrast to that in West Bengal (8.8%). Among abnormal cytologic lesions, HPV16/18 infections were significantly higher than in normals (P= 0.000) both in Sikkim (14.3%) and West Bengal (20.9%) and absent in Manipur. Such prevalence was noted among women in Sikkim aged >30 years and equally among those in West Bengal aged < or =30 or >30 years. Thus, women from northeast India, particularly from Manipur, appear less susceptible to HPV16/18 infection and related cervical lesions compared to those from West Bengal, where such proneness was prominently evident at age < or =30 years.

Age-specific detection of high risk HPV DNA in cytologically normal, computer-imaged ThinPrep Pap samples

OBJECTIVE

Recent cervical cancer screening guidelines for women over age 30 seek to improve the sensitivity of cytology by incorporating high-risk (HR) human papillomavirus (HPV) DNA testing into the screening algorithm, a recommendation based largely on data that utilized the conventional Pap smear and were not stratified by patient age. Data on the rate of HR HPV among women over age 30 undergoing liquid-based Pap test screening are limited. The objective of this study was to determine the rate of HR HPV DNA positivity in women ages 30 and over with a cytologically negative liquid-based Pap test result.

METHODS

Consecutive residual ThinPrep Pap samples from women with a cytologically negative result following computer-assisted screening were tested for HR HPV using the Hybrid Capture 2 (HC2) method. All HC2-positive samples were additionally tested with the Linear Array (LA) HPV Genotyping Test.

RESULTS

1000 cytologically negative specimens from women aged 30 to 45 years (38.9+/-4.7 years) were evaluated. The overall HC2 HR HPV positivity rate in this age group was 3.9% (confidence interval 2.8-5.3%). When stratified by age group, the rate was inversely proportional to age (ages 30-35: 6.7%; 36-40: 3.0%; 41-45: 2.6%) and lower than most previous reports (1-17%). Some of the cases that were positive for HR HPV by HC2 were negative by LA, or showed only low-risk virus.

CONCLUSIONS

The HR HPV rates in women ages 30-45 with a cytologically negative, computer-imaged ThinPrep test result are low. If these findings are confirmed in future studies, the added benefit of HPV testing to liquid-based cytology for women ages 30 and over should be critically evaluated.

Human papillomavirus-specific viral types are common in Mexican women affected by cervical lesions

Cervical cancer (CC) is the most common in Mexican female population. The human papillomavirus (HPV) 16 and 18 frequencies in worldwide may be different due to geographical distribution. We analyzed the prevalence of HPV types and determinated their association in cervical lesion in a Mexican population. One hundred fifty-nine normal cervical smears, 95 low-grade squamous intraepithelial lesions (LGSIL), 59 high-grade squamous intraepithelial lesions (HGSIL), and 108 CC samples of the patients were collected. HPV types were determined by sequencing. We detected 11 high-risk types, four low-risk types, three not determinated, and two probably high risk. HPV were present in 12%, 57%, 88%, and 92% from normal, LGSIL, HGSIL, and CC samples, respectively. HPV 16 was the most common in all cervical lesions (71.6% in CC). HPV 58 was present in 18.6% of HGSIL, and the HPV 18 in 4.6% of CC. The 76% of all detected viruses belong to A9 species branch. Control women showed high percentage of HPV high-risk infection, suggesting that this is a high-risk group. High frequency of HPV 16 compared with a low incidence of HPV 18 was observed. HPV 58 is frequently detected in HGSIL but low frequency is found in CC. These findings might be considered for HPV screening.

Prevalence of human papillomavirus types in women screened by cytology in Germany

Incidence and mortality rates of cervical cancer are higher in Germany than in other Western European countries. Type-specific human papillomavirus (HPV) distribution was investigated for the first time in Germany in an epidemiological study including 8,101 women. Women above the age of 30 years, self-referring for cervical cancer screening, were enrolled in two study centers in Hannover (Northern Germany) and Tübingen (Southern Germany). Participants were screened by the Pap smear and the hybrid capture 2 (HC2) test using the high-risk probe. All samples that were positive by the HC2 test were genotyped using the prototype PGMY09/11 PCR line blot assay. Most women in the study population had a negative Pap smear (96.7%). Prevalence of high-risk type HPV detected by HC2 was 6.4% and prevalence of carcinogenic types detected by PGMY09/11 was 4.3%. Of the PGMY09/11 PCR-positive women, 70.2% had a single infection, 28.1% had multiple infections and 1.7% remained uncharacterized. 32 different HPV types were detected using PGMY09/11 PCR. HPV 16, 31, 52, 51, 18, and 45 were the most common carcinogenic types in the study population. Among women with histologically confirmed high-grade lesions HPV 16, 45, 58, 18, 31, 33, and 52 were the predominant types. These results provide valuable information for the management of HPV infections in Germany, both in terms of future strategies of screening and vaccination.

Genomic diversity of human papillomavirus genotype 53 in an ethnogeographically closed cohort of white European women

Human papillomavirus (HPV) genotype 53 is classified taxonomically in alpha HPV genus-species 6, together with HPV-30, HPV-56, and HPV-66 and is considered to be one of three "probable high-risk" HPV genotypes. Recent worldwide comparison of 44 isolates of HPV-53 showed the existence of nine long control region (LCR) genomic variants, which formed a phylogenetic tree with two deep dichotomic branches. In order to investigate further the genomic diversity of HPV-53, a total of 94 isolates of HPV-53 obtained from an ethnogeographically closed cohort of 70 white European women was analyzed. The identification and characterization of HPV-53 genomic variants was based on analysis of three different HPV genomic regions: LCR, E6 and E7. A higher genomic diversity of HPV-53 was identified in the ethnogeographically closed cohort of white European women than has been reported previously on isolates collected worldwide. Altogether, 19 HPV-53 genomic variants, composed of 13 LCR, 13 E6, and 5 E7 genomic variants, were identified. Eleven out of 13 LCR, all E6, and four out of five E7 genomic variants were described for the first time. The present study confirmed dichotomic phylogeny of HPV-53 described previously and, in addition, showed for the first time that after a dichotomic split, both groups of HPV-53 genomic variants formed star-like phylogenetic clusters. In women with persistent HPV-53 infection, HPV-53 genomic variants remained unchanged for up to 51 months. In rare cases, infection with multiple HPV-53 genomic variants is possible. Taking into account the results of this and previous studies, at least 26 different HPV-53 genomic variants exist today.

Persistent human papillomavirus infection is associated with a generalized decrease in immune responsiveness in older women

The development of cervical cancer and its precursors are linked to persistent infection with oncogenic types of human papillomavirus (HPV). Host immune responses seem to be determinants of risk for this disease. However, little is known about the immunologic determinants of HPV persistence. Here, we examined the association between lymphoproliferative responses to antigens/mitogens and persistent HPV infection in women older than 45 years. Women included in this study were participants in a 10,000-woman population-based cohort study of cervical neoplasia in Costa Rica. Women older than 45 years and HPV DNA positive at a screening visit were selected as cases (n = 283). We selected a comparably sized control group of HPV DNA-negative women, matched to cases on age and time since enrollment (n = 261). At an additional clinical visit, women were cytologically and virologically rescreened, and cervical and blood specimens were collected. Proliferative responses to phytohemagglutinin (PHA), influenza virus (Flu), and HPV16 virus-like particle (VLP) were lower among women with persistent HPV infection [median counts per minute (cpm): 72,849 for PHA, 1,241 for Flu, and 727 for VLP] than for the control group (median cpm: 107,049 for PHA, 2,111 for Flu, and 2,068 for VLP). The decreases were most profound in women with long-term persistence and were only observed for the oldest age group (>/=65 years). Our results indicate that an impairment in host immunologic responses is associated to persistent HPV infection. The fact that effects were evident for all studied stimuli is suggestive of a generalized effect.

Variations in the age-specific curves of human papillomavirus prevalence in women worldwide

An inverse relationship between age and human papillomavirus (HPV) prevalence has been reported in many developed countries, but information on this relationship is scarce in many other parts of the world. We carried out a cross-sectional study of sexually active women from the general population of 15 areas in 4 continents. Similar standardised protocols for women's enrolment, cervical specimen collection and PCR-based assays for HPV testing were used. HPV prevalence in different age groups was compared by study area. 18,498 women aged 15-74 years were included. Age-standardised HPV prevalence varied more than 10-fold between populations, as did the shape of age-specific curves. HPV prevalence peaked below age 25 or 35, and declined with age in Italy, the Netherlands, Spain, Argentina, Korea and in Lampang, Thailand and Ho Chi Minh, Vietnam. This was not the case in Songkla, Thailand nor Hanoi, Vietnam, where HPV prevalence was low in all age groups. In Chile, Colombia and Mexico, a second peak of HPV prevalence was detected among older women. In the poorest study areas in Asia (Shanxi, China and Dindigul, India), and in Nigeria, HPV prevalence was high across all age groups. The substantial differences observed in age-specific curves of HPV prevalence between populations may have a variety of explanations. These differences, however, underline that great caution should be used in inferring the natural history of HPV from age-specific prevalences.

Human papillomavirus: the burden of infection

Vaccines for preventing human papillomavirus (HPV) infection are far along in clinical development and testing, and hold great promise for reducing HPV infections and HPV-associated disease. HPV is the most common sexually transmitted infection in the United States, affecting an estimated 75% of the U.S. population. HPV infection is highly prevalent in sexually active adolescents and young adults. Sexual activity is the most important risk factor for infection, with 64% to 82% of sexually active adolescent girls testing positive for HPV. Clinical manifestations of HPV infection include genital warts, cervical intraepithelial neoplasia (CIN), and invasive cervical cancer, all of which cause significant morbidity and, in the case of cervical cancer, mortality. The majority of HPV-associated disease is caused by 4 HPV types: HPV 6 and 11 are responsible for low-grade genital lesions and more than 90% of genital warts, and HPV 16 and 18 both account for approximately 70% of all high-grade CIN or dysplasia and invasive cervical cancer. Although current screening methods have proven effective in reducing cervical cancer incidence and associated mortality, more than 10,000 women are diagnosed annually and 4000 U.S. women die from the disease each year.

Reproductive Factors, Oral Contraceptive Use, and Human Papillomavirus Infection: Pooled Analysis of the IARC HPV Prevalence Surveys

High parity, early age at first full-term pregnancy (FTP), and long-term oral contraceptive (OC) use increase cervical cancer risk, but it is unclear whether these variables are also associated with increased risk of acquisition and persistence of human papillomavirus (HPV) infection, the main cause of cervical cancer. Information on reproductive and menstrual characteristics and OC use were collected from 14 areas worldwide, among population-based, age-stratified random samples of women aged 15 years or older. HPV testing was done using PCR-based enzyme immunoassay. Unconditional logistic regression was used to estimate the odds ratios (OR) of being HPV-positive according to reproductive and menstrual factors and corresponding 95% confidence intervals (CI). When more than two groups were compared, floating CIs (FCI) were estimated. A total of 15,145 women (mean age, 40.9 years) were analyzed. Women with >or=5 FTPs (OR, 0.90; 95% FCI, 0.76-1.06) showed a similar risk of being HPV-positive compared with women with only one FTP (OR, 1.00; 95% FCI, 0.86-1.16). However, nulliparous women showed an OR of 1.40 (95% CI, 1.16-1.69) compared with parous women. Early age at first FTP was not significantly related to HPV positivity. HPV positivity was similar for women who reported >or=10 years of use of OCs (OR, 1.16; 95% FCI, 0.85-1.58) and never users of OCs (OR, 1.00; 95% FCI, 0.90-1.12). Our study suggests, therefore, that high parity, early age at first FTP, and long-term OC use are not associated with HPV prevalence, but rather these factors might be involved in the transition from HPV infection to neoplastic cervical lesions.

Relationships of Human Papillomavirus Type, Qualitative Viral Load, and Age with Cytologic Abnormality

Persistent cervical infections with carcinogenic human papillomaviruses (HPV) cause virtually all cervical cancer. Cytologic abnormalities are the manifestations of HPV infections used to identify women at risk. To compare the potential of the full range of anogenital HPV genotypes to induce cytopathic effects, we examined the influences of HPV type, viral load, and age on cytopathology among 1,222 women having a single HPV type at enrollment into a 10,000-woman population-based study in Costa Rica. Cervical specimens were tested for approximately 40 HPV types by MY09/MY11 L1 primer PCR and type-specific dot blot hybridization. Types were organized by phylogenetic species and cancer risk. PCR signal strength served as a qualitative surrogate for viral load. Overall, 24.8% [95% confidence interval (95% CI), 22.4-27.3] of single prevalent HPV infections had concurrent abnormalities (atypical squamous cells or worse) ranging from 0.0% to 80.0% based on HPV type. Noncarcinogenic alpha3/alpha15 types, although highly prevalent, uncommonly caused cytologic abnormalities (13.1%; 95% CI, 9.8-17.0). In contrast, one quarter to nearly one half of infections with a single major carcinogenic species type (alpha9/alpha11/alpha7/alpha5/alpha6) produced abnormalities. Greater abnormalities were observed with increasing qualitative viral load of carcinogenic types; fewer abnormalities were observed among older women (>54 years). A high percentage (46.2%) of detected abnormalities in women infected with HPV16 or related alpha9 types were high grade or worse, consistent with strong carcinogenicity, compared with 10.7% in women infected with alpha7 types, including HPV18, a major cause of adenocarcinoma. The lack of evident severe abnormalities associated with HPV18 and related HPV types might have implications for screening for poorly detected glandular and alpha7-related lesions.

Human papillomavirus DNA in urine samples of women with or without cervical cancer and their male partners compared with simultaneously collected cervical/penile smear or biopsy specimens

Infection of specific types of high-risk human papillomaviruses (HPVs) causes cervical cancer in women. Conventional test for genital HPV infection requires collection of scraped cervical cells or biopsy specimens, which involves invasive procedures. Utility of non-invasive urine sampling for detection of HPV in women and their male sexual partners is controversial. The validation of this urine-based HPV DNA test is of immense value not only in screening large population and children but also for HPV vaccine monitoring in adolescents. We examined the frequency of high risk HPV types 16 and 18 in simultaneously collected urine samples and cervical scrapes or biopsy specimens from women with cervical cancer and their single lifetime male sexual partners in order to validate the utility of urine sampling as a reliable non-invasive method for detection of genital HPV infection. Thirty women with invasive cervical cancer and their husbands along with 30 age-matched normal healthy women including their husbands were recruited for the study. Cervical biopsies/scrapes from women subjects and penile scrapes from their husbands and urine samples from all of them were collected before taking biopsy or scrapes. HPV-L1 consensus primer as well as high-risk HPV (HPV 16 and 18) type-specific oligo-primers were used for PCR detection of HPV DNA. The total frequency of HPV in women with cervical cancer was found to be 83% (25/30) while it was only 67% (20/30) in their male partners but there was virtually no difference in results between urine and scrape or tissue biopsy either in women or their male partners. Although healthy women and their husbands showed similar frequency of HPV infection both in urine and scrape samples, there was a significant difference (p=0.05) in the prevalence of high risk HPV type 16 in women with cervical cancer (70%) and their male partners (30%). Similar was the trend between control women and their male partners. The results also showed a very high prevalence of HPV type 16 among Indian women with cervical cancer while its frequency was significantly low in their single lifetime male partners. The case by case matching of HPV positivity and negativity between urine and cervical/penile scrapes or biopsies obtained from women and their male partners demonstrated that the non-invasive urine sampling can be reliably used for screening genital HPV infection in both men and women.

The epidemiology of genital human papillomavirus infection

Clinical and subclinical human papillomavirus (HPV) infections are the most common sexually transmitted infections in the world, and most sexually-active individuals are likely to be exposed to HPV infection during their lifetimes. More than 40 genotypes of HPV infect the epithelial lining of the anogenital tract and other mucosal areas of the body; of these, 13-18 types are considered to be high-oncogenic risk HPV types (HR-HPV). Persistent infection with HR-HPVs is now unequivocally established as a necessary cause of cervical cancer and is likely to be responsible for a substantial proportion of other anogenital neoplasms and upper aero-digestive tract cancers. Low oncogenic risk HPV types (LR-HPV) are also responsible for considerable morbidity as the cause of genital warts. Youth and certain sexual characteristics are key risk factors for HPV acquisition and persistence of HPV infection, but other mediating factors include smoking, oral contraceptive (OC) use, other STIs (e.g. chlamydia, herpes simplex virus), chronic inflammation, immunosuppressive conditions including HIV infection, parity, dietary factors, and polymorphisms in the human leukocyte antigen system. Not surprisingly, these factors are also established or candidate cofactors identified in epidemiologic studies of cervical cancer. HPV transmissibility and molecular events in HPV-induced carcinogenesis have been the focus of recent multidisciplinary epidemiologic studies. This shift in research focus coincides with a shift in cancer prevention techniques towards immunization with HPV vaccines and HPV testing of precancerous lesions.

Frequency of antibodies against E4 and E7 from human papillomavirus type 16 in Mexican soldiers

The high prevalence of HPV in men's genitalia and the low frequency of virus-associated lesions gave rise to questions on the influence of infection-site on the HPV antibody profile. In a cross-sectional study, HPV infection in penis and urethra, and serum antibodies against HPV-16 E4 and E7 proteins were evaluated in 288 Mexican soldiers. The results showed that HPV prevalence was 31% (51% in penis, 11% in urethra and 38% in both sites), while 47% were multiple infections. Overall, seroprevalence was 13% for anti-E4 antibodies and 6% for anti-E7. However, the highest prevalence of anti-E4 antibodies was observed in men with HPV infection in urethra (30%), while for E7 antibodies, the highest prevalence (10%) was found in men who tested positive for HPV in penis. The prevalence of IgG and IgA anti-E4 was related to HPV-16 urethral infection, while detection of HPV-16 in penis was related to IgG anti-E7 prevalence. In conclusion, the high-risk sexual behavior observed in this population might be responsible for high HPV prevalence and multiple infections. However, the seroprevalence of E4 and E7 was similar to that observed in healthy Mexican women. These results suggest that the humoral immune response against HPV infection in men differs, depending on the site of infection.

Human papillomavirus infection in Shanxi Province, People's Republic of China: a population-based study

To investigate the prevalence of, and risk factors for, cervical infection with human papillomavirus (HPV) in the rural province of Shanxi, People's Republic of China, which has relatively high cervical cancer mortality rates, we interviewed and obtained cervical cell samples from 662 women aged 15–59 years. A total of 24 different HPV types were identified using a GP5+/6+-based PCR assay able to detect 44 different HPV types. Human papillomavirus prevalence was 14.8% overall and 9.6% among women without cervical abnormalities (14.2 and 8.9%, respectively, age standardised to the world standard population). Multiple-type infections accounted for 30.6% of all infections. By far the most commonly found type was HPV16 (5.7% of all women and 38.8% of HPV-positive women), followed by HPV 58, 52, 33 and 18. Unlike most previous studies published, HPV prevalence was lower among women younger than 35 years (8.7%) than those older than 35 years (17.8%). High-risk HPV types predominated in all age groups. Although low-risk HPV types were rare in young women, they became more common with increasing age. 92.3% of women with cervical intraepithelial neoplasia grade 3 were infected with high-risk HPV types, but none with low-risk types only. No significant difference in HPV positivity was observed by educational level, sexual habits, reproductive history or use of contraceptive methods in this rural low-income Chinese population.

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.

High prevalence of genital human papillomavirus type 52 and 58 infection in women attending gynecologic practitioners in South Taiwan

BACKGROUND

We attempted to determine the prevalence of genital human papillomavirus (HPV) infection in women attending gynecologic practitioners in South Taiwan.

METHODS

The population included 4383 women aged 16-78 seeking HPV testing at primary gynecologic practitioners regardless of their cervical cytology results. HPV DNA was identified from cervical swabs using semi-nested polymerase chain reaction with MY11, MY09/HMB01, and MY11/bioGP6+ primers. Genotyping for high-risk HPV (HR-HPV) was done separately by a HR-HPV chip, which contained 13 type-specific oligonucleotides on a nylon membrane.

RESULTS

The overall HPV prevalence was 19.3% (849/4383), 11.1% (488/4383) were confirmed as HR-HPV positive. Among the women with HR-HPV infection, HPV-16 was the most prevalent type (22.1%; 108/488), followed by HPV-52 (21.3%; 104/488), and HPV-58 (19.9%; 97/488). Multiple infections were detected in 73 women (15.0%; 73/488). For women with age 30 or younger, the overall HPV and HR-HPV prevalence were 32.0% and 20.7%, respectively, which were significantly higher than those of women age older than 30 (17.2% and 9.5%, P < 0.001). More multiple infections (22.1% vs. 12.4%) were also found in women with age 30 or younger (P = 0.021). However, the relative contribution of types to the overall HR-HPV positive among different age groups remains the same.

CONCLUSIONS

Our results showed an HPV prevalence that is similar compared with worldwide levels. HPV prevalence and multiple infections rate were decreasing across the age groups. Unlike most previous studies, the relative high prevalence of HPV 52 and 58 among South Taiwan women has important implications in vaccine prophylaxis.

Human papillomavirus in men: comparison of different genital sites

OBJECTIVE

To elucidate which anatomical sites need to be sampled to detect human papillomavirus (HPV) infection in the lower male genital tract.

METHOD

In an HPV survey of Mexican soldiers (median age 24 years; range 16-50 years), a cell sample from 2 cm deep into the distal urethra (group 1; n = 168 men), or 0.5 cm deep into the meatus urethralis (group 2; n = 414 men) was collected, along with a sample from the external genitalia. The different samples were tested for 27 HPV types using a polymerase chain reaction based strip assay.

RESULTS

HPV DNA was detected more frequently in external genitalia samples (46.4%) than in the urethra (20.8%) or meatus samples (12.1%). Lack of samples from the urethra or meatus would have led to 5.1% and 1.5% false HPV negative results, respectively. The most frequently detected high risk HPV types (HPV 59, 52, 51, and 16) were similar in different sites, whereas low risk types were found rarely in urethra samples.

CONCLUSIONS

The addition of cell samples from the meatus to those from external genitalia contributed negligibly to the evaluation of the prevalence of HPV in men. HPV detection was slightly improved by the addition of urethra samples, but the gain may not justify the discomfort of the procedure in large epidemiological studies.

Cervical human papillomavirus screening among older women

Rates of acquisition and clearance of cervical human papillomavirus (HPV) during a 3-year period in women 51 years of age were compared with rates in younger women to provide data on cervical screening for women >50 years of age. Paired, cytologically negative, archived cervical smears taken 3 years apart from 710 women in Nottingham, United Kingdom, were retrieved and tested for HPV infection with polymerase chain reaction (PCR) with GP5+/6+ primers. Seventy-one (21.3%) of 333 women 51 years of age who were HPV negative at baseline were positive 3 years later. This percentage was higher than the corresponding acquisition rates among women 21 (15.2%), 31 (14.1%), and 41 (13.3%) years of age, although these differences were not significant. This retrospective study shows that HPV-negative women >50 years of age can acquire HPV and, therefore, require cervical screening.