Occurrence of cervical infection with multiple human papillomavirus types is associated with age and cytologic abnormalities

Epidemiologic characteristics of high-risk HPV and the correlation between multiple infections and cervical lesions

BACKGROUND

The aim of this study was to determine the prevalence of high-risk human papillomavirus (HR-HPV) and the correlation between multiple infections and cervical lesions.

METHODS

The current study involved population-based sample of 20,059 women who underwent cervical screening for 15 HR-HPV genotypes with ThinPrep cytologic test (TCT) results. The correlation between multiple HPV genotype infections and cervical lesions was also determined. The odds ratios (ORs) were calculated to assess co-infection patterns for each genotype with 15 other genotypes and the additive statistical interactions were evaluated.

RESULTS

There was a bimodal pattern among multiple HPV infections, with a peak in the younger group and a second peak in the elderly group. Indeed, most multiple HPV genotypes exhibited a bimodal pattern. The most common HPV type in patients with high-grade squamous intraepithelial lesions (HSILs) was HPV-16, followed by HPV-52, HPV-58, and HPV-33. The most frequent HPV type in patients with cervical cancer was HPV-16, followed by HPV-58 and HPV-33. Women with multiple infections were at a increased risk of low-grade squamous intraepithelial lesions [LSIL] (OR = 2.01; 95% CI 1.38-2.93) and HSIL (OR 2.28; 95% CI 1.36-3.81) when compared to women with single infections. patients with cervical cancer had the higher percentage of multiple HPV infections. Based on the data herein, we suggest that HPV-33 and HPV-58 may also be high-risk HPV types worthy of increased surveillance and follow-up.

CONCLUSION

Our findings suggested that the association between multiple HPV infections and HSIL and LSIL are stronger compared to single HPV infections. There may be some specific combinations that synergistically affected the risk of HSIL and LSIL.

Human Papillomavirus Intermittence and Risk Factors Associated With First Detections and Redetections in the Ludwig-McGill Cohort Study of Adult Women

BACKGROUND

We assessed the incidence and risk factors for first detection and redetection with the same human papillomavirus (HPV) genotype, and prevalence of cytological lesions during HPV redetections.

METHODS

The Ludwig-McGill cohort study followed women aged 18-60 years from São Paulo, Brazil in 1993-1997 for up to 10 years. Women provided cervical samples for cytology testing and HPV DNA testing at each visit. A redetection was defined as a recurring genotype-specific HPV positive result after 1 or more intervening negative visits. Predictors of genotype-specific redetection were assessed using adjusted hazard ratios (aHR) with Cox regression modeling.

RESULTS

In total, 2184 women contributed 2368 incident HPV genotype-specific first detections and 308 genotype-specific redetections over a median follow-up of 6.5 years. The cumulative incidence of redetection with the same genotype was 6.6% at 1 year and 14.8% at 5 years after the loss of positivity of the first detection. Neither age (aHR 0.90; 95% confidence interval [CI], .54-1.47 for ≥45 years vs < 25 years) nor new sexual partner acquisition (aHR 0.98; 95% CI, .70-1.35) were statistically associated with genotype-specific redetection. High-grade squamous intraepithelial lesion prevalence was similar during first HPV detections (2.9%) and redetection (3.2%).

CONCLUSIONS

Our findings suggest many HPV redetections were likely reactivations of latent recurring infections.

Behavioral factors associated with multiple-type HPV genital infections: data from a cross-sectional study in young women in Brazil

OBJECTIVES

To investigate the pattern of multiple human papillomavirus (HPV) infections and associated factors in young women who access the Brazilian public health care system to better understand the characteristics of multiple HPV infections, a critical issue in this era of multivalent vaccines.

METHODS

This was a cross-sectional, multicenter study with sexually active unvaccinated women (16-25 years old) from 119 primary Brazilian healthcare centers between September 2016 and November 2017. Cervical samples were collected by trained health professionals, and HPV detection was performed in a central laboratory by Linear Array.

RESULTS

Of the 5268 women, 33.00% (95% CI 31.07-34.92) had multiple infections. At least one type of high-risk HPV was present in 85.50% of all multiple infections. All HPV types were detected more frequently in association with other types than alone. Young individuals who were single or in a casual relationship and those who had more than one sexual partner in the past year were more likely to have multiple infections.

CONCLUSIONS

In this work, a high rate of multiple HPV infections among unvaccinated young adults tended to increase due to certain risk factors. Such data can provide insight for decision makers in the development of public policies regarding HPV prevention.

High-risk HPV genotypes in Zimbabwean women with cervical cancer: Comparative analyses between HIV-negative and HIV-positive women

BACKGROUND

High-risk human papillomavirus HPV (HR-HPV) modifies cervical cancer risk in people living with HIV, yet African populations are under-represented. We aimed to compare the frequency, multiplicity and consanguinity of HR-HPVs in HIV-negative and HIV-positive Zimbabwean women.

METHODS

This was a cross-sectional study consisting of women with histologically confirmed cervical cancer attending Parirenyatwa Group of Hospitals in Harare, Zimbabwe. Information on HIV status was also collected for comparative analysis. Genomic DNA was extracted from 258 formalin fixed paraffin embedded tumour tissue samples, and analysed for 14 HR-HPV genotypes. Data was analysed using Graphpad Prism and STATA.

RESULTS

Forty-five percent of the cohort was HIV-positive, with a median age of 51 (IQR = 42-62) years. HR-HPV positivity was detected in 96% of biospecimens analysed. HPV16 (48%), was the most prevalent genotype, followed by HPV35 (26%), HPV18 (25%), HPV58 (11%) and HPV33 (10%), irrespective of HIV status. One third of the cohort harboured a single HPV infection, and HPV16 (41%), HPV18 (21%) and HPV35 (21%) were the most prevalent. HIV status did not influence the prevalence and rate of multiple HPV infections (p>0.05). We reported significant (p<0.05) consanguinity of HPV16/18 (OR = 0.3; 95% CI = 0.1-0.9), HPV16/33 (OR = 0.3; 95% CI = 0.1-1.0), HPV16/35 (OR = 3.3; 95% CI = 2.0-6.0), HPV35/51 (OR = 6.0; 95%CI = 1.8-15.0); HPV39/51 (OR = 6.4; 95% CI = 1.8-15), HPV31/52 (OR = 6.2; 95% CI = 1.8-15), HPV39/56 (OR = 11 95% CI = 8-12), HPV59/68 (OR = 8.2; 95% CI = 5.3-12.4), HPV66/68 (OR = 7; 95% CI = 2.4-13.5), independent of age and HIV status.

CONCLUSION

We found that HIV does not influence the frequency, multiplicity and consanguinity of HR-HPV in cervical cancer. For the first time, we report high prevalence of HPV35 among women with confirmed cervical cancer in Zimbabwe, providing additional evidence of HPV diversity in sub-Saharan Africa. The data obtained here probes the need for larger prospective studies to further elucidate HPV diversity and possibility of selective pressure on genotypes.

Correlation between human papillomavirus infection and histopathological diagnosis of women in Northeast Brazil

Cervical carcinoma is the fourth leading cause of death among women worldwide. Epidemiological studies claim that human papillomavirus (HPV) infection is a necessary condition for cervical cancer development. Knowledge of the geographic distribution of HPV is important in guiding the introduction of prophylactic vaccines. This study analyzed the prevalence of HPV infection in cervical samples obtained from women with abnormal cervical histopathological diagnosis in Northeast Brazil. The study included an analysis of 211 women whose diagnosis was confirmed for cervical intraepithelial neoplasia type 1 (CIN-1), cervical intraepithelial neoplasia type 2 (CIN-2), cervical intraepithelial neoplasia type 3 (CIN-3), and cancer. The identification of the HPV genotypes was based on the polymerase chain reaction-restriction fragment length polymorphism technique. A total of 42.7% of the samples showed a single HPV infection, while 57.3% showed multiple infections. The most common genotypes detected were HPV-16, HPV-18, and HPV-31. HPV-16, HPV-31, HPV-35, and HPV-18 were the most common types in CIN-1 with a single infection. HPV-16 and HPV-18 were the most often found in CIN-2 with a single infection. HPV-16, HPV-18, and HPV-31 were the most detected in CIN-3 with a single infection. HPV-16 and HPV-31 were the most frequent in cancer with a single infection. Multiple infection with HPV-16 shows a 2.7 times greater risk of CIN-3 (P = .04). Multiple infections for HPV with HPV-16 and excluding the HPV18/31 types, were associated with CIN-3 (P = .01). The results allowed the detection and genotyping of HPV types circulating in the population studied. These findings must be taken into account when devising vaccination strategies against HPV.

Patterns of incident genital human papillomavirus infection in women: A literature review and meta-analysis

Human papillomavirus (HPV) infection acquisition is a necessary step in the development of cervical cancer. No study has systematically quantified the rate of newly acquired HPV infections from the published literature and determined its relationship with age. We performed a systematic review and meta-analysis to describe incident HPV infections in women. Medline® and Thomson Reuters Web of Science via PubMed® databases were searched. A total of 46 of 5136 studies met inclusion criteria and contributed results. We conducted a meta-regression analysis of 13 studies, which reported incidence rate estimates on over 13 high-risk HPV types, to provide pooled stratum-specific incidence rates and rate ratios for key population and study characteristics among 8488 women. Studies with mean age < 30 years had relatively higher HPV incidence rates compared to studies with mean age ≥30 years: relative risk = 3.12; 95% CI: 1.41–6.93. HPV-16 was most frequently detected, followed by HPV-18: relative risk = 0.47; 95% CI: 0.33–0.67, and by HPV-58: relative risk = 0.45; 95% CI: 0.27–0.74. Younger age is a key predictor of genital HPV incidence in women. These data on the relative distribution of incident HPV infections will provide a baseline comparison for monitoring of changes in HPV incidence following the implementation of population-level HPV vaccination.

Atypical Squamous Cells of Undetermined Significance: Analysis of Microbiology, Cytological Criteria and Clinical Conduct

Aims

To differentiate between two types of atypical squamous cells of undetermined significance (ASCUS): probably neoplastic (PN) or probably reactive (PR), and, in accordance with the recommendations on screening protocols of the Emilia-Romagna Region (PSRER), Italy, to define the best management to follow and the prognosis. Furthermore, the associations between ASCUS and infectious agents and human papillomavirus (HPV) were evaluated.

Methods

Fifty-eight ASCUS smears were reviewed and sorted; if a diagnosis of ASCUS was confirmed, the smear was classified as PR or PN, and the PSRER group was identified. Then, colposcopy was performed with checks for infectious agents (culture evaluation with cytological or clinical criteria) and HPV (hybrid capture).

Results

The ASCUS frequency was 3.96%. Of the 58 cases, 33 (56.9%) were diagnosed as ASCUS on review, of which 15 cases were PN and 18 were PR, while 23 (39.7%) smears were normal and 2 (3.4%) showed cervical intraepithelial neoplasia (CIN). There was a higher frequency of bacterial vaginosis (BV) and HPV in ASCUS PR patients compared with normal cytology, and a higher frequency of CIN in ASCUS PN patients compared with normal controls (P <0.05). By grouping ASCUS 1 and 3, we observed a higher frequency of CIN and of high-grade colposcopy findings compared with ASCUS 2 and 4 (P <0.05). From the 23 cases not found to be ASCUS, 18 (87.5%) had normal cytology and colposcopy results on the first follow-up.

Conclusions

Classification of ASCUS as either PN or PR helps in clinical conduct and prognosis, because a higher frequency of CIN is found in ASCUS PN. ASCUS subdivisions, based on PSRER and colposcopy, may facilitate the clinical conduct because ASCUS 1 and 3 with high-grade colposcopic findings proved to be related to the presence of CIN. We propose that initial ASCUS cytology be reviewed, and if it is confirmed, colposcopy should be performed. For those cases found to be normal on review of the cytology results, it is suggested that a cytological check-up be carried out every 6 months.

Multiple high-risk HPV genotypes are grouped by type and are associated with viral load and risk factors

Investigating whether high-risk human papillomavirus (HR-HPV) types tend to become grouped in a particular way and whether factors are associated with such grouping is important for measuring the real impact of vaccination. In total, 219 women proving positive for HPV as detected by real-time PCR were included in the study. Each sample was analysed for detecting and quantifying six viral types and the hydroxymethylbilane synthase gene. Multiple correspondence analysis led to determining grouping patterns for six HR-HPV types and simultaneous association with multiple variables and whether viral load was related to the coexistence of other viral types. Two grouping profiles were identified: the first included HPV-16 and HPV-45 and the second profile was represented by HPV-31, HPV-33 and HPV-58. Variables such as origin, contraceptive method, births and pregnancies, educational level, healthcare affiliation regime, atypical squamous cells of undetermined significance and viral load were associated with these grouping profiles. Different socio-demographic characteristics were found when coinfection occurred by phylogenetically related HPV types and when coinfection was due to non-related types. Biological characteristics, the number of viral copies, temporality regarding acquiring infection and competition between viral types could influence the configuration of grouping patterns. Characteristics related to women and HPV, influence such interactions between coexisting HPV types reflecting the importance of their evaluation.

Epidemiologic Evaluation of Human Papillomavirus Type Competition and the Potential for Type Replacement Post-Vaccination

Background

Millions of women have been vaccinated with one of two first-generation human papillomavirus (HPV) vaccines. Both vaccines remain in use and target two oncogenic types (HPVs 16 and 18); however, if these types naturally compete with others that are not targeted, type replacement may occur following reductions in the circulating prevalence of targeted types. To explore the potential for type replacement, we evaluated natural HPV type competition in unvaccinated females.

Methods

Valid HPV DNA typing information was available from five epidemiological studies conducted in Canada and Brazil (n = 14,685; enrollment across studies took place between1993 and 2010), which used similar consensus-primer PCR assays, capable of detecting up to 40 HPV types. A total of 38,088 cervicovaginal specimens were available for inclusion in our analyses evaluating HPV type-type interactions involving vaccine-targeted types (6, 11, 16, and 18), and infection with each of the other HPV types.

Results

Across the studies, the average age of participants ranged from 21.0 to 43.7 years. HPV16 was the most common type (prevalence range: 1.0% to 13.8%), and in general HPV types were more likely to be detected as part of a multiple infection than as single infections. In our analyses focusing on each of the vaccine-targeted HPV types separately, many significant positive associations were observed (particularly involving HPV16); however, we did not observe any statistically significant negative associations.

Conclusions

Our findings suggest that natural HPV type competition does not exist, and that type replacement is unlikely to occur in vaccinated populations.

Infections with multiple high-risk HPV types are associated with high-grade and persistent low-grade intraepithelial lesions of the cervix

BACKGROUND

Infections with multiple human papillomavirus (HPV) types (mHPV) in Papanicolaou tests have been reported but the histologic correlation and clinical meaning remains debatable.

METHODS

The authors prospectively tested 37 HPV types using the Linear Array HPV Genotyping Test and correlated the results to cytology and histology findings in 260 women evaluated from June 2009 to October 2011 and followed for up to 60 months.

RESULTS

HPV was detected in 148 of 235 samples (63%) and high-risk HPV was detected in 132 samples (56%). mHPV infection was found to be twice as common as single HPV (sHPV) infection and was detected more frequently in low-grade squamous intraepithelial lesion (LSIL) (48 of 83 samples [58%]) and high-grade squamous intraepithelial lesion or invasive carcinoma (HSIL + (26 of 47 samples [55%]) compared with other categories (P<.001). Of 34 LSIL/cervical intraepithelial neoplasia 1 (CIN1) index cases, 13 of 21 patients with mHPV (61.9%) persisted on CIN1, whereas no histologic abnormality was detected during follow-up in all 12 patients with sHPV infection (high risk or low risk) (P<.001). Eighteen of 20 patients with HSIL/cervical intraepithelial neoplasia 2 (CIN2) (90%) and high-risk mHPV persisted on HSIL+/CIN2 + whereas 6 of 11 patients with sHPV infection did not demonstrate HSIL+/CIN2 + on follow-up (54.5%) (P = .066). Approximately 40% of women with HSIL were infected by high-risk HPV types other than types 16 or 18.

CONCLUSIONS

High-risk mHPV infection identified patients with persistent LSIL/CIN1 and may to help identify patients at higher risk of disease progression to HSIL+/CIN2+. Longer follow-up will clarify the role of mHPV testing in patient care. Cancer Cytopathol 2017;125:138-143. © 2016 American Cancer Society.

Cervical Infection With Vaccine-Associated Human Papillomavirus (HPV) Genotypes as a Predictor of Acquisition and Clearance of Other HPV Infections

BACKGROUND

Recent birth cohorts vaccinated against human papillomavirus (HPV) may be protected against up to 4 genotypes (HPV-6, -11, -16, and -18). If natural competition exists between these and other HPV types, then the prevalence of other types may increase after vaccination.

METHODS

Cohort information from 3 studies was used to compare acquisition and clearance of 30 different HPV types (individually and grouped by species), according to infection status with vaccine-targeted types at baseline and the time of the index infection, respectively. Hazard ratios (HRs) were adjusted for predictors of multiple-type infection.

RESULTS

Among 3200 females across all studies, 857 were infected with HPV at baseline, and 994 acquired new infections during follow-up. Females infected with HPV-16 were at higher risk of acquiring other α-9 HPV types (HR, 1.9; 95% confidence interval [CI], 1.2-3.0) but at similar risk of clearing existing α-9 HPV infections (HR, 0.9; 95% CI, .7-1.3). Females infected with vaccine-targeted types were generally at higher risk of acquiring additional types (HRs, > 1.0) and at equal risk of clearing existing infections. Accounting for multiple comparisons, none of the HRs of < 1.0 or >1.0 were statistically significant in our analyses of acquisition or clearance.

CONCLUSIONS

Vaccine-targeted HPV types do not appear to compete with other types, suggesting that HPV type replacement is unlikely to occur.

Detection of Human Papillomavirus Infections at the Single-Cell Level

OBJECTIVE

To explore the possibility of single-cell analysis of human papillomavirus (HPV) infection.

METHODS

Two hundred and twenty cells were isolated by laser capture microdissection from formalin-fixed and paraffin-embedded cervical tissue blocks from 8 women who had HPV DNA detected in their cervical swab samples. The number of type-specific HPV copies in individual cells was measured by quantitative polymerase chain reaction with and without a prior reverse transcription. The cells were assayed and counted for more than once if the corresponding swab sample was positive for ≥2 HPV types.

RESULTS

Infection with HPV16, HPV39, HPV51, HPV52, HPV58, HPV59 and HPV73 was detected in 12 (5.5%) of 220, 3 (9.4%) of 32, 3 (5.8%) of 52, 11 (22.9%) of 48, 9 (18.8%) of 48, 3 (9.4%) of 32 and none of 20 cells, respectively. The numbers of HPV genome copies varied widely from cell to cell. The coexistence of multiple HPV types was detected in 6 (31.6%) of 19 positive cells from 1 of the 6 women who had 2 or 3 HPV types detected in their swab samples.

CONCLUSION

Given the heterogeneity of HPV status in individual cells, further clarification of HPV infection at the single-cell level may refine our understanding of HPV-related carcinogenesis.

The association of HPV genotype with the regression, persistence or progression of low-grade squamous intraepithelial lesions

BACKGROUND

Human papillomavirus (HPV) is a highly prevalent sexually transmitted virus causing cytological alterations that precede cervical cancer. Approximately 130 genotypes have been sequenced. Low-grade squamous intraepithelial lesions (LSIL) are the most frequent cytological alteration and have an uncertain behavior.

OBJECTIVES

To analyze the frequency of HPV types in LSIL and their association with the regression, persistence or progression of these lesions.

METHODS

A cohort study of forty patients with LSIL cytology was conducted from December 2007 to March 2011. The follow-up lasted two years and included cytology and colposcopy. HPV detection was performed using PCR, and genotyping was performed using PCR-specific and RFLP techniques.

RESULTS

DNA-HPV was detected in 87% (35/40) of the cases, with oncogenic HPV accounting for 76%; type 16 in 32% (11/35) and type 18 in 20%. LSIL regression, persistence and progression rates at the end of the study were 60%, 23% and 17%, respectively. There was 50% regression in lesions in the high oncogenic risk group (types 16 and 18).

CONCLUSION

HPV 16 was the most frequent genotype found in LSIL. The persistence and progression of the LSIL were related to the persistence of oncogenic HPV. The longer the follow-up time, the lower the LSIL persistence rate and the higher its regression rate; the progression rate remained stable. In addition to the presence of oncogenic HPV, other factors are necessary for the progression of LSIL.

Lineages of oncogenic human papillomavirus types other than type 16 and 18 and risk for cervical intraepithelial neoplasia

BACKGROUND

Data on clinical outcomes of infection with variants of oncogenic human papillomavirus (HPV) types other than HPV16 and HPV18 are rare. We investigated intratypic variations in non-HPV16/18 oncogenic types and their corresponding relationships with cervical intraepithelial neoplasia grades 2-3 (CIN2/3).

METHODS

Study subjects were women who were positive for one or more of 11 non-HPV16/18 oncogenic types. Subjects were followed every six months for two years for detection of HPV and cervical lesions. Variant lineages were defined by sequencing the 3' part of the long control region and the entire E6/E7 region of HPV genome. Lineage-associated risk of CIN2/3 was assessed using logistic regression with generalized estimating equations.

RESULTS

A total of 4591 type-specific HPV infections among 2667 women were included in the analysis. The increase in risk of CIN2/3 was statistically significant for women with HPV31 A or B compared with C variants, HPV33 A1 compared with B variants, HPV45 A3 or B2 compared with B1 variants, HPV56 B compared with A2 variants, and HPV58 A1 or A3 compared with C variants. For these five types, the adjusted odds ratio associated with CIN2/3 was 2.0 (95% confidence interval [CI] = 1.5 to 2.6) for infections with single-type high-risk (HR) variants, 1.7 (95% CI = 1.0 to 2.7) for infections with two or more types but only one HR variant, and 5.3 (95% CI = 3.1 to 8.4) for infections with HR variants of two or more types as compared with those with single-type non-HR variants. The likelihood of CIN2/3 was similar for women with HPV16 infection and for those with HPV58 A1 variant infection.

CONCLUSIONS

These findings suggest that for a given HPV type, intratypic nucleotide changes may alter phenotypic traits that affect the probability of neoplasia.

Multiple-type human papillomavirus (HPV) infections: a cross-sectional analysis of the prevalence of specific types in 309,000 women referred for HPV testing at the time of cervical cytology

OBJECTIVES

To determine the frequency of multiple-type cervical human papillomavirus (HPV) infections, and whether any types are involved in multiple-type infections more or less frequently than might be expected if these infections occur randomly.

METHODS

In this retrospective analysis of type-specific HPV testing, results from women 18 to 65 years old with samples collected between July 2007 and May 2011 were considered.Multivariate logistic regression analysis was used to model the presence of each of the 24 most prevalent HPV types, adjusting for one other HPV type, age, laboratory region, and age-by-region interactions.

RESULTS

Human papillomavirus infection was present in 74,543 (24.1%) of 309,471 women and 65,492 (21.1%) were positive for one of the top 24 most prevalent HPV types. The most common HPV type was type 16, occurring in 4.1% of the entire sample. A total of 14,181 women were positive for 2 or more HPV types (4.6% of entire sample and 19.0% of HPV-positive sample). Two-way HPV type comparisons were analyzed. Types 52, 53, 81, and 83 were more likely to occur in multiple infections with other types; and types 16, 58, and 66 were less likely to occur in multiple infections with other types. Human papillomavirus types 72 and 81 have the strongest positive relationship (odds ratio, 5.2; 95% confidence interval, 3.6-7.4). Human papillomavirus types 33 and 66 have the strongest negative relationship (odds ratio, 0.4; 95% confidence interval, 0.2-0.6).

CONCLUSIONS

In this population, multiple-type HPV infections were present in 4.6% of all women. Our findings suggest that there may be both competitive and cooperative interactions between HPV types.

Revising ecological assumptions about Human papillomavirus interactions and type replacement

The controversy over whether vaccine-targeted HPV types will be replaced by other oncogenic, non-vaccine-targeted types remains unresolved. This is in part because little is known about the ecology of HPV types. Patient data has been interpreted to suggest independence or facilitative interactions between types and therefore replacement is believed to be unlikely. With a novel mathematical model, we investigated which HPV type interactions and their immune responses gave qualitatively similar patterns frequently observed in patients. To assess the possibility of type replacement, vaccination was added to see if non-vaccine-targeted types increased their 'niche'. Our model predicts that independence and facilitation are not necessary for the coexistence of types inside hosts, especially given the patchy nature of HPV infection. In fact, independence and facilitation inadequately represented co-infected patients. We found that some form of competition is likely in natural co-infections. Hence, non-vaccine-targeted types that are not cross-reactive with the vaccine could spread to more patches and can increase their viral load in vaccinated hosts. The degree to which this happens will depend on replication and patch colonization rates. Our results suggest that independence between types could be a fallacy, and so without conclusively untangling HPV within-host ecology, type replacement remains theoretically viable. More ecological thinking is needed in future studies.

Genotype-specific prevalence and distribution of human papillomavirus genotypes in underserved Latino women with abnormal Papanicolaou tests

INTRODUCTION

Knowledge about the prevalence and distribution of human papillomavirus (HPV) genotypes in cervical premalignant and malignant lesions is crucial to guide development of clinical management strategies and prophylactic vaccines. The aim of this study was to determine HPV genotype-specific prevalence and distribution in an underserved cohort of Latino women.

MATERIALS AND METHODS

From December 2009 to April 2011, 808 SurePath cervicovaginal specimens were collected from women who were referred from charity clinics for abnormal Papanicolaou tests. The patients' average age was 36.5 years (range 19-85 years). The specimens were tested for HPV genotypes by DNA microarray and sequencing assays.

RESULTS

The HPV infection rate was extremely high (93% for any HPV and 64% for high-risk [HR]-HPV), with frequent multiple-strain infection (39%). Younger age (<30 years) was associated with frequent HR-HPV infection, multiple strain infections, and cytologic abnormalities. When compared with previous reports, HPV 16 remained the most common genotype (44.6%) in women with high-grade squamous intraepithelial lesion; however, a significant increase in HPV 31 (17.9%) and 45 (10.7%) and a decrease in HPV 35, 52, 33, and 66 were observed.

CONCLUSIONS

The HPV genotype-specific prevalence and distribution pattern in this cohort of underserved Latino women differed significantly from previously published data in the United States. Understanding the potentially changing trends in HPV distribution pattern will help guide the development of appropriate preventive and therapeutic strategies for both underserved and general populations.

Randomization modeling to ascertain clustering patterns of human papillomavirus types detected in cervicovaginal samples in the United States

Detection of multiple human papillomavirus (HPV) types in the genital tract is common. Associations among HPV types may impact HPV vaccination modeling and type replacement. The objectives were to determine the distribution of concurrent HPV type infections in cervicovaginal samples and examine type-specific associations. We analyzed HPV genotyping results from 32,245 cervicovaginal specimens collected from women aged 11 to 83 years in the United States from 2001 through 2011. Statistical power was enhanced by combining 6 separate studies. Expected concurrent infection frequencies from a series of permutation models, each with increasing fidelity to the real data, were compared with the observed data. Statistics were computed based on the distributional properties of the randomized data. Concurrent detection occurred more than expected with 0 or ≥3 HPV types and less than expected with 1 and 2 types. Some women bear a disproportionate burden of the HPV type prevalence. Type associations were observed that exceeded multiple hypothesis corrected significance. Multiple HPV types were detected more frequently than expected by chance and associations among particular HPV types were detected. However vaccine-targeted types were not specifically affected, supporting the expectation that current bivalent/quadrivalent HPV vaccination will not result in type replacement with other high-risk types.

Prevalence, genotype profile and risk factors for multiple human papillomavirus cervical infection in unimmunized female adolescents in Goiânia, Brazil: a community-based study

Background

The epidemiology of infection with multiple human papillomavirus (HPV) types in female adolescents is poorly understood. The purpose of this study was to explore the epidemiology of infection with multiple HPV types in adolescents and its association with demographic, behavioral and biological variables, as well as with cytological abnormalities.

Methods

This community-based study included 432 sexually active females between 15 and 19 years of age. Genotyping for 30 HPV types was performed using a reverse blot strip assay/restriction fragment length polymorphism. Unconditional multivariate logistic regression was performed to identify factors significantly associated with HPV infection. The association between HPV infection and cytological abnormalities was calculated using a prevalence ratio.

Results

The most common HPV types detected were 16, 51, 31, 52 and 18. Of the 121 HPV-positive women, 54 (44.6%) were infected with multiple HPV types. Having more than one lifetime sexual partner was associated with infection with any HPV infection, single HPV infection, and infection with multiple HPV types. The presence of cytological abnormalities was associated with infection with multiple HPV types.

Conclusions

Co-infecting HPV genotypes occur in a high proportion of sexually active adolescents. Socio-demographic or sexual behavior factors associated with single HPV infection were similar to those associated with multiple HPV types. The higher risk of cytological abnormalities conferred by infection with multiple HPV types suggests a potential role of co-infection in the natural history of HPV infection.

Epidemiologic approaches to evaluating the potential for human papillomavirus type replacement postvaccination

Currently, 2 vaccines exist that prevent infection by the genotypes of human papillomavirus (HPV) responsible for approximately 70% of cervical cancer cases worldwide. Although vaccination is expected to reduce the prevalence of these HPV types, there is concern about the effect this could have on the distribution of other oncogenic types. According to basic ecological principles, if competition exists between ≥2 different HPV types for niche occupation during natural infection, elimination of 1 type may lead to an increase in other type(s). Here, we discuss this issue of "type replacement" and present different epidemiologic approaches for evaluation of HPV type competition. Briefly, these approaches involve: 1) calculation of the expected frequency of coinfection under independence between HPV types for comparison with observed frequency; 2) construction of hierarchical logistic regression models for each vaccine-targeted type; and 3) construction of Kaplan-Meier curves and Cox models to evaluate sequential acquisition and clearance of HPV types according to baseline HPV status. We also discuss a related issue concerning diagnostic artifacts arising when multiple HPV types are present in specific samples (due to the inability of broad-spectrum assays to detect certain types present in lower concentrations). This may result in an apparent increase in previously undetected types postvaccination.

Human papillomavirus infection and spontaneous abortion: a case-control study performed in Mexico

OBJECTIVE

To investigate if HPV cervical infection is associated with spontaneous abortion in a Mexican population.

STUDY DESIGN

Case control study including 281 women from two Social Security Hospitals in Merida, Mexico. Cases were women with spontaneous abortion attending for curettage, and controls were pregnant women at term who attended for delivery. HPV molecular detection and typing of HPV 16, 18, 58 and 6/11 was performed on cervical samples, and TORCH serology IgM tests (against T. gondii, CMV, HSV) were performed on cases. Data were analyzed using Chi square, odds ratio and linear regression tests.

RESULTS

HPV global prevalence was 19.8% (24.4% in cases and 15.2% in controls). HPV types 16 and 58 were the most frequently detected in both groups. Multiple HPV types concurrent infection were found in 31.4% of typified samples. Amongst cases 27.3% of HPV positive women reported at least one previous pregnancy loss; compared to 17.43% amongst HPV negative women. Nevertheless, HPV was not significantly associated with spontaneous or to repetitive abortion. Cases were 60.2% positive to any TORCH agent, although it was not significantly associated to referred miscarriage history. Spontaneous abortion was associated to a previous pregnancy loss and to women's age older than 35 years old. HPV infection was significantly associated to alcohol intake before pregnancy and to multiple sexual partners.

CONCLUSION

HPV cervical infection was not associated with spontaneous abortion. HPV in spontaneous abortion and other adverse pregnancy outcomes merits further study.

High-risk human papillomavirus genotype detection by electrochemical DNA chip method

High-risk human papillomavirus (HPV) genotypes are the major cause of cervical cancer. Hence, HPV genotype detection is a helpful preventive measure to combat cervical cancer. Recently, several HPV detection methods have been developed, each with different sensitivities and specificities. The objective of this study was to compare HPV high risk genotype detection by an electrochemical DNA chip system, a line probe assay (INNO- LiPA) and sequencing of the L1, E1 regions. A total of 361 cervical smears with different cytological findings were subjected to polymerase chain reaction-sequencing and electrochemical DNA chip assessment. Multiple infections were found in 21.9% (79/361) of the specimens, most prevalently in 20-29-year olds while the highest prevalence of HPV infection was found in the 30-39-year age group. The most prevalent genotype was HPV 16 at 28.2% (138/489) followed by HPV 52 at 9.6% (47/489), with the other types occurring at less than 9.0%. The electrochemical DNA chip results were compared with INNO-LiPA and sequencing (E1 and L1 regions) based on random selection of 273 specimens. The results obtained by the three methods were in agreement except for three cases. Direct sequencing detected only one predominant genotype including low risk HPV genotypes. INNO-LiPA identified multiple infections with various specific genotypes including some unclassified-risk genotypes. The electrochemical DNA chip was highly accurate, suitable for detection of single and multiple infections, allowed rapid detection, was less time-consuming and was easier to perform when compared with the other methods. It is concluded that for clinical and epidemiological studies, all genotyping methods are perfectly suitable and provide comparable results.

Incidence and cost of anal, penile, vaginal and vulvar cancer in Denmark

Background

Besides being a causative agent for genital warts and cervical cancer, human papillomavirus (HPV) contributes to 40-85% of cases of anal, penile, vaginal and vulvar cancer and precancerous lesions. HPV types 16 & 18 in particular contribute to 74-93% of these cases. Overall the number of new cases of these four cancers may be relatively high implying notable health care cost to society. The aim of this study was to estimate the incidence and the health care sector costs of anal, penile, vaginal and vulvar cancer.

Methods

New anogenital cancer patients were identified from the Danish National Cancer Register using ICD-10 diagnosis codes. Resource use in the health care sector was estimated for the year prior to diagnosis, and for the first, second and third years after diagnosis. Hospital resource use was defined in terms of registered hospital contacts, using DRG (Diagnosis Related Groups) and DAGS (Danish Outpatient Groups System) charges as cost estimates for inpatient and outpatient contacts, respectively. Health care consumption by cancer patients diagnosed in 2004–2007 was compared with that by an age- and sex-matched cohort without cancer. Hospital costs attributable to four anogenital cancers were estimated using regression analysis.

Results

The annual incidence of anal cancer in Denmark is 1.9 per 100,000 persons. The corresponding incidence rates for penile, vaginal and vulvar cancer are 1.7, 0.9 and 3.6 per 100,000 males/females, respectively. The total number of new cases of these four cancers in Denmark is about 270 per year. In comparison, the total number of new cases cervical cancer is around 390 per year. The total cost of anogenital cancer to the hospital sector was estimated to be 7.6 million Euros per year. Costs associated with anal and vulvar cancer constituted the majority of the costs.

Conclusions

Anogenital cancer incurs considerable costs to the Danish hospital sector. It is expected that the current HPV vaccination program will markedly reduce this burden.

Human papillomavirus genotype distribution and risk factors for infection in women from a small municipality in north east Brazil

In order to assess the prevalence of human papillomavirus (HPV) infection, the HPV genotypes and factors associated with infection, we conducted a population-based survey in a small municipality in north east Brazil among women aged between 12 and 49 years. A questionnaire regarding socioeconomic variables, reproductive life and sexual behaviour was used, and women were examined gynaecologically, followed by collection of vaginal lavage with saline solution for HPV DNA determination. HPV DNA was detected by the Digene® SHARP SignalTM-System, and further genotyped by INNO-LiPA Genotyping System®. Of 579 women, HPV infection was present in 68 (prevalence: 11.7%; 95% CI: 9.3–14.7). The most common HPV types were 16, 31 and 74, each accounting for 14.7% of infections. Of all HPV-positive women, 35.3% showed multiple HPV genotypes. Variables independently associated with HPV infection were: ≥3 partners in life (adjusted OR [aOR]: 3.06; 95% CI: 1.68–5.60) and the use of oral contraception in the last 12 months (aOR: 2.39; 95% CI: 1.33–4.30). Previous participation in a cervical cancer screening programme was protective (aOR: 0.28; 95% CI: 0.13–0.60). HPV infection is common among women from rural Brazil, and HPV genotypes identified indicate that immunization could be an important preventive measure in this population.

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.

Distribution of human papillomavirus among women with abnormal cervical cytology in Kuwait

This study investigates the distribution of human papillomavirus (HPV) in women with abnormal cervical cytology in Kuwait. Two hundred and ninety-eight (298) abnormal ThinPreps were taken from women seeking routine gynecological care and screened for HPV DNA by real-time PCR. HPV genotyping was determined by PCR-based sequencing. HPV DNA was detected in 152 women (51%), and 29 different HPV genotypes were detected, comprising 16 high-risk (HR) (16, 18, 31, 33, 35, 39, 45, 51, 53, 56, 58, 59, 66, 68, 73, 97), nine low-risk (LR) (6, 11, 54, 61, 74, 81, 90, 102, 106), and four intermediate-risk (IR) (62, 67, 84, 87). HPV16 had the highest prevalence (24.3%), followed by HPV11 (13.8%), HPV66 (11.2%), HPV33 (9.9%), HPV53 (9.2%), HPV81 (9.2%), HPV56 (7.9%) and HPV18 (6.6%). HPV prevalence was 86, 67, and 89% in women with invasive cervical carcinoma (ICC), high-grade squamous intraepithelial lesion (HSIL) and low-grade squamous intraepithelial lesion (LSIL), respectively. As for age distribution, 69% of all HPVs were found in women aged 20-29 years, and the HPV incidence rate deceased with increasing age. The proportion of single infections decreased as the severity of the cytological diagnosis increased, while the proportion of multiple infections increased. This study is the first of its type in Kuwait and one of few in the Middle East. The findings are consistent with the hypothesis that HPV infection is the primary cause of cervical neoplasia. They support HPV vaccine research to prevent cervical cancer and efforts to develop HPV DNA diagnostic tests.

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 infection with multiple types: pattern of coinfection and risk of cervical disease

OBJECTIVE

We investigated coinfection patterns for 25 human papillomavirus (HPV) types and assessed the risk conferred by multiple HPV types toward cervical disease.

METHODS

Sexually active women (n=5,871) in the NCI-sponsored Costa Rica HPV Vaccine Trial's prevaccination enrollment visit were analyzed. Genotyping for 25 HPVs was performed using SPF(10)/LiPA(25). We calculated odds ratios (ORs) to assess coinfection patterns for each genotype with 24 other genotypes. These ORs were pooled and compared with pair-specific ORs to identify genotype combinations that deviated from the pooled OR. We compared risk of CIN2+/HSIL+between multiple and single infections and assessed additive statistical interactions.

RESULTS

Of the 2478 HPV-positive women, 1070 (43.2%) were infected with multiple types. Multiple infections occurred significantly more frequently than predicted by chance. However, this affinity to be involved in a coinfection (pooled OR for 300 type-type combinations=2.2; 95% confidence interval [CI]=2.1-2.4) was not different across HPV type-type combinations. Compared with single infections, coinfection with multiple α9 species was associated with significantly increased risk of CIN2+(OR=2.2; 95% CI=1.1-4.6) and HSIL+(OR=1.6; 95% CI=1.1-2.4). However, disease risk was similar to the sum of estimated risk from individual types, with little evidence for synergistic interactions.

CONCLUSIONS

Coinfecting HPV genotypes occur at random and lead to cervical disease independently.

Natural history of multiple human papillomavirus infections in female adolescents with prolonged follow-up

PURPOSE

The aim of the study was to better characterize the natural history of human papillomavirus (HPV) infections in female adolescents.

METHODS

Female adolescents were enrolled in a longitudinal study. Self-vaginal samples were obtained every 3 months and tested for HPV. No participants received HPV vaccination. The findings for 40 female adolescents with the longest follow-up are reported in this study.

RESULTS

Average age at the time of enrollment was 15.2 years (range: 14-17; SD: .97). Mean duration of follow-up was 6.7 years (range: 4.4-9.2; SD: 1.2). In all, 32 participants (80%) reported being involved in sexual activity before their enrollment in the study; all reported being involved in sexual activity before enrollment; all reported being involved in sexual activity during follow-up. Baseline and cumulative prevalence of HPV among participants was 55% and 100%, respectively. During the study, each participant tested positive for a mean of 14 HPV types. Cumulatively, HPV 16 was detected in 29 of 40 participants (72.5%). Mean duration of high- and low-risk infections was 655.9 (median: 433) and 524.1 days (median: 334), respectively.

CONCLUSION

With prolonged follow-up, HPV infections with multiple types were found in all participants. Most had infection with HPV-16 or HPV-18, the oncogenic types represented in current vaccines, as well as infection with other oncogenic types. These data reinforce the importance of vaccine and non-vaccine strategies for prevention of HPV infections.

Cervical HPV infection in Brazil: systematic review

OBJECTIVE

To assess the prevalence of human papillomavirus (HPV) infection in women in Brazil.

METHODS

A systematic literature review was conducted with an active search in PubMed and Virtual Health Library databases using the terms "human papillomavirus," "HPV," "prevalence," and "Brazil". Of 155 articles retrieved, 82 were selected after reading their title and abstract. After a thorough examination, 14 articles were included in the study.

RESULTS

The 14 articles selected were published between 1989 and 2008 and comprised studies from four Brazilian macroregions (Southeast - 43%; South - 21.4%; Northeast - 21.4%; and North - 7.1%). Nine were cross-sectional studies. Eight articles used polymerase chain reaction and seven used hybrid capture for HPV detection. The study samples ranged from 49 to 2,329 women. The overall prevalence of HPV cervical infection was between 13.7% and 54.3%; and women with cytologically normal results had 10% to 24.5% prevalence of HPV cervical infection. Four articles described the most common HPV types.

CONCLUSIONS

The cytology techniques available use different classifications leading to different HPV prevalence estimates. However, considering the studies individually according to the detection technique used, the HPV prevalence has increased. HPV16 was the most prevalent type among women, regardless of the cytology result. The concentration of studies in the Southeast region, especially in metropolitan regions, evidences that further investigations are needed to improve information coverage of Brazilian women.

Prevalence of human papillomavirus genotypes in cytologic abnormalities from unvaccinated women living in north-western Spain

Cervical cancer and its precursors low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL) are associated with infection by human papillomavirus (HPV), in particular HPV 16 and 18. The distribution of the HPV genotype varies with the severity of cervical disease, age and the geographic location of the patients. We report the results of a population study carried out in a region of north-western (NW) Spain aimed at determining the prevalence of single and multiple infections by 35 types of HPV using low-density microarrays for 113 cases with negative for intraepithelial lesions or malignancies; 588 with atypical squamous cells of undetermined significance (ASCUS)/LSIL; 183 with HSIL; and seven cases of squamous cell carcinomas. Of the 891 patients analysed, 50.2% had single infections and 49.8% had multiple HPV infections. In women aged below 30 years, there was a predominance of multiple infections (p = 0.027). ASCUS/LSIL was associated with multiple and HSIL with single infections (p = 0.025). We observed significant increases in the percentage of infections due to a high-risk (HR) type of HPV when the severity of the cytological lesion increased (p = 0.001). No relationship was found between greater aggressiveness in the cytological diagnosis and a higher number of HPV types involved in multiple infections. The five most frequent genotypes were HPV 16 (26.3%), 53 (18.2%), 51 (17.3%), 6 (14.8%) and 66 (13.1%). The prevalence of HPV 16, 33 and 58 increased significantly from ACUS/LSIL to HSIL and the prevalence of HPV 51, 53 and 66 decreased. HPV 16 was the only genotype that showed a significant increase in prevalence when the severity of the cytological disease increased in single infections (p = 0.0001). The implementation of bivalent prophylactic vaccination could potentially lead to prevention in 32% of the population included in the study - in at least a quarter of patients with ACUS/LSIL (26.7%), and in half of HSIL (50.2%).

Prevalence of human papillomavirus genotypes in northern Taiwanese women

The prevalence of Human Papillomavirus (HPV) in the general population of northern Taiwan is described. A total of 343 consecutive cervical swabs from women visiting the medical center for routine gynecologic care were included. Cervical cell cytology was examined by the Papanicolaou (Pap) test, and a PCR-based hybridization gene chip analysis was used to identify HPV genotypes. The HPV prevalence in the overall population was 32.4%. When divided into two groups according to cytology, 20.9% of women with normal cytology were HPV positive while 75.3% of women with abnormal cytology were HPV positive. Among positive samples, 68.5% were single type infections while 31.5% harbored multiple HPV types. A total of 32 types of HPV were identified; the leading five were HPV16 (5.8%), HPV58 (5.3%), HPV53 (4.1%), HPV52 (3.8%), and HPV18 (2.3%). Our results constitute baseline data and may provide important implications for future prophylactic programs. The relatively high prevalence of HPV 58, 53, and 52 among northern Taiwanese women has important implications for vaccine development.

Monitoring of human papillomavirus vaccination

Persistent infection with oncogenic human papillomavirus (HPV) is a necessary causal factor in the development of cervical cancer. Moreover, HPV, predominately type 16 and to a lesser degree type 18, is linked causally to varying proportions of other anogenital cancers (vulva, vagina, penis, anus) as well as cancers elsewhere in the body (oropharynx, larynx, conjunctiva). HPV types 6 and 11 cause most of genital warts and recurrent respiratory papillomatosis. Effective prophylactic vaccines have been developed. In this review, we address briefly the immunological aspects of HPV infection and the results of HPV vaccination trials. Internationally standardized monitoring and evaluation of prophylactic HPV vaccination programmes will be essential for arriving at the most cost-effective strategies for cancer control.

Acquisition of high-risk human papillomavirus infection in a population-based cohort of Danish women

BACKGROUND

Human papillomavirus (HPV) is the cause of cervical cancer. To better understand the natural history of HPV, we assessed the incidence of type-specific HPV infection and examined risk factors for acquisition of high-risk (HR) HPV infection in Danish women.

METHODS

A population-based prospective cohort study of women aged 20 to 29 years was conducted. Participants were interviewed and underwent 2 gynaecological examinations 2 years apart. Women for whom Hybrid Capture 2 results were available at both visits were included in the analysis (n = 7454).

RESULTS

A HR HPV infection was acquired by 12.8% of the women during follow-up. The incidence decreased with increasing age. The commonest types were HPV16, HPV31, and HPV52. HPV66, HPV58, and HPV53 were mainly acquired with other HR types. Multiple HR types were acquired in 50% of the women who became HPV-positive during follow-up. In initially HPV-negative women age, number of sexual partners, and oral contraceptive use were the main risk factors for acquisition, particularly of multiple HR HPV types.

CONCLUSIONS

HPV infections were commonly acquired. We confirmed the sexually transmitted nature of the infection. Our findings show that both the level of potential exposure and other behavioral factors increase the risk for HR HPV acquisition.

[HPV immunization for the prevention of cervical cancer]

CONTEXT

Human Papillomaviruses (HPV) infect epithelial cells of the skin and mucosae. Mucosal high-risk HPV types (mainly HPV 16 and 18) are involved in the development of cervical cancer, one of the most common cancers in young women. HPV infection is usually asymptomatic and clears spontaneously, but 10 - 15 % of high-risk HPV infections are persistent and increase the risk of precancerous and cancerous lesions of the cervix. Two HPV vaccines have been licensed to provide protection against cervical cancer.

OBJECTIVES

To report the different aspects of HPV infection in order to improve the understanding of the particular problems of HPV vaccination and to review the most recent findings related to HPV vaccines, particularly regarding the protective efficacy of vaccines and the roles of adjuvants and immune response in protection.

METHODS

Articles were selected from the PubMed database (National Library of Medicine- National Institute of Health) with the following Keywords "HPV", "Prevention", "HPV vaccines", "Immune response", "Antibody". Abstracts of oral presentations from international meetings were also selected for the more recent findings. a critical analysis of the majority of papers published was undertaken and relevant information summarized.

RESULTS

Virus-like particle production by expressing the major protein of the HPV capsid was carried out in the early 90's, leading to the recent development of two HPV vaccines. These vaccines are now licensed in many countries and have been demonstrated to be highly immunogenic. In subjects that are non-infected at the time of vaccination, HPV vaccines are highly effective in preventing persistent HPV 16 - 18 infections (90 %) and precursors lesions of cervical cancer associated with these two HPV types (close to 100 %). Clinical trials have also confirmed that HPV vaccines are well tolerated by recipients.

CONCLUSIONS

The present paper is a detailed review published in French on HPV vaccines, their efficacy in the prevention of HPV infections and unresolved questions regarding the use of HPV vaccines. This report also includes biological and immunological information to improve the understanding of HPV vaccination.

Genotype distribution of human papillomavirus (HPV) and co-infections in cervical cytologic specimens from two outpatient gynecological clinics in a region of southeast Spain

Background

Human Papillomavirus (HPV) genotype distribution and co-infection occurrence was studied in cervical cytologic specimens from Murcia Region, (southeast Spain), to obtain information regarding the possible effect of the ongoing vaccination campaign against HPV16 and HPV18.

Methods

A total of 458 cytologic specimens were obtained from two outpatient gynecological clinics. These included 288 normal benign (N/B) specimens, 56 atypical squamous cell of undetermined significance (ASC-US), 75 low-grade squamous intraepithelial lesions (LSIL) and 39 high-grade squamous intraepithelial lesions (HSIL). HPV genotyping was performed using PCR and tube array hybridization.

Results

The most frequent genotype found was HPV16 (14.9% in N/B; 17.9% in ASC-US; 29.3% in LSIL and 33.3% HSIL). Distribution of other genotypes was heavily dependent on the cytologic diagnoses. Co-infections were found in 15.3% of N/B, 10.7% of ASC-US, 48% of LSIL and 25.6% of HSIL cases (significantly different at p < 0.001). Strikingly, in N/B diagnoses, genotypes from A5 species were found as coinfecting in all cases. Genotypes from A7 or A9 species appeared in co-infections in 56.5% and 54% respectively whereas genotypes from A6 species appeared in 25.1% of cases.

Conclusion

HPV vaccination might prevent 34.6% and 35.8% of LSIL and HSIL, respectively. Co-infection rate is dependent on both cytologic diagnosis and HPV genotype. Moreover, genotypes belonging to A5, A7 and A9 species are more often found as co-infections than genotype pertaining to A6 species. This suggests that phylogenetically related genotypes might have in common similar grades of dependency for cervical epithelium colonization.

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

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

Multiple-type human papillomavirus infection in male anogenital sites: prevalence and associated factors

Human papillomavirus (HPV) causes cervical cancer and is strongly associated with other anogenital cancers. Multiple-type HPV infection has been associated with lengthier infection and precancerous lesions. Little is known about multiple-type HPV prevalence and associated factors in men. We examined the prevalence of and risk factors for multiple-type HPV in primarily asymptomatic men. Detection of 37 HPV types in male anogenital epithelium and semen was completed in 463 men in two U.S. cities. The proportions of men with multiple HPV of any type and with multiple oncogenic or nononcogenic types were calculated. Factors associated with multiple HPV were evaluated using multinomial logistic regression. Overall, 22.9% of men had multiple-HPV, 8.6% of men had multiple oncogenic types, and 13.4% had multiple nononcogenic types. Greater proportions of samples at the shaft, glans/corona, and scrotum had multiple HPV types (18.7%, 12.8%, and 7.3%, respectively) than did other anogenital sites (all < or =2.8%). Factors independently associated with multiple-type HPV were Hispanic ethnicity [adjusted odds ratio (AOR), 2.45; 95% confidence interval (95% CI), 1.05-5.67], concurrent detection of genital warts (AOR, 10.40; 95% CI, 1.12-96.6), smoking > or =10 cigarettes/d (AOR, 3.00; 95% CI, 1.07-8.43), greater lifetime number of female sexual partners (AOR, 13.73 for > or =21 versus 1-5; 95% CI, 5.34-35.3), and condom use less than half the time (AOR, 2.03; 95% CI, 1.07-3.84). Detection of multiple HPV types in this study of primarily asymptomatic men was common, particularly at external genital sites. Lifetime number of female sex partners, condom use, and smoking were modifiable factors associated with multiple HPV.

High-risk and multiple human papillomavirus (HPV) infections in cancer-free Jamaican women

Background

Vaccines, that target human papillomavirus (HPV) high risk genotypes 16 and 18, have recently been developed. This study was aimed at determining genotypes commonly found in high-risk and multiple-HPV infections in Jamaican women. Two hundred and fifty three (253) women were enrolled in the study. Of these, 120 pregnant women, aged 15–44 years, were recruited from the Ante Natal Clinic at the University Hospital of the West Indies and 116 non-pregnant, aged 19–83, from a family practice in Western Jamaica. Cervical cell samples were collected from the women and HPV DNA was detected using Polymerase Chain Reaction and Reverse Line Hybridization. HPV genotypes were assessed in 236 women. Data were collected from January 2003 to October 2006.

Results

HPV DNA was detected in 87.7% (207/236) and of these 80.2% were positive for high-risk types. The most common high-risk HPV types were: HPV 45 (21.7%), HPV 58 (18.8%), HPV 16 (18.4%), HPV 35 (15.0%), HPV 18 (14.5%), HPV 52 (12.0%) and HPV 51(11.1%). Other high-risk types were present in frequencies of 1.4% – 7.2%.

Multivariate regression analyses showed that bacterial vaginosis predicted the presence of multiple infections (OR 3.51; CI, 1.26–9.82) and that alcohol use (OR 0.31; CI, 0.15–0.85) and age at first sexual encounter (12–15 years: OR 3.56; CI, 1.41–9.12; 16–19 years, OR 3.53, CI, 1.22–10.23) were significantly associated with high risk infections. Cervical cytology was normal in the majority of women despite the presence of high-risk and multiple infections.

Conclusion

HPV genotype distribution in this group of Jamaican women differs from the patterns found in Europe, North America and some parts of Asia. It may be necessary therefore to consider development of other vaccines which target genotypes found in our and similar populations. HPV genotyping as well as Pap smears should be considered.

Identification of vaccine human papillomavirus genotypes in squamous intraepithelial lesions (CIN2-3)

OBJECTIVE

To identify the prevalence of human papillomavirus vaccine genotypes and non-vaccine genotypes implicated in the appearance of cervical intraepithelial neoplasia (CIN2-3).

METHODS

Prospective study of 519 women with abnormal cytology. All the women underwent a second Papanicolaou test, cervicovaginal sampling for type-specific HPV detection and colposcopy, and women with abnormal colposcopy results were referred to biopsy. Pearson's chi-square test was used for statistical analysis.

RESULTS

HPV was detected in 340 patients (65.5%), and in 125 (24%) more than one HPV genotype was present. We selected 206 patients with CIN2 or CIN3 confirmed by biopsy. In 88 (42.7%) of these patients, HPV types 16 and 18 were detected, but only 58 (28.2%) without co-infection by other high-risk or probable high-risk HPV types. In 115 (55.8%) women diagnosed with CIN2 or CIN3 high-risk or probable high-risk HPV types other than 16 or 18 were found. High-risk and/or probable high-risk HPV genotypes not included in the vaccine were isolated in this study more frequently than 16 or 18, and this difference was statistically significant (p=0.047). Of the 206 women diagnosed with CIN2 or CIN3, 19 tested negative for HPV and 14 tested positive for low-risk HPV types.

CONCLUSION

Only 28.2% of women with CIN2 or CIN3 confirmed by biopsy were infected exclusively by HPV type 16 or 18, a finding that places in doubt the degree of protection afforded by HPV vaccination.