Characterizing the temporal dynamics of human papillomavirus DNA detectability using short-interval sampling

Cervical cancer: Challenges and prevention strategies: A narrative review

Background and Aims

Human papillomavirus (HPV) infections that continue to exist are the main cause of cervical cancer (CC), two-thirds of CC occurrences worldwide are caused by HPV 16 and HPV 18, and 99.7% of CC tumors are linked to oncogenic HPV infection. To identify challenges of CC and its prevention and treatment modalities.

Methods

This review examined the epidemiology, predisposing factors, genetic factors, clinical assessment methods, current treatment options, and prevention approaches for CC. We had perform a narrative data synthesis rather than a pooled analysis. A thorough literature search in pertinent databases related to CC was done with the inclusion of data that were published in the English language.

Results

Early detection of CC is of utmost importance to detect precancerous lesions at an early stage. Therefore, all responsible agencies concerned with health should make all women aware of the benefits of CC screening and educate the general public. HPV vaccination coverage is very low in resource-limited settings.

Conclusion

To achieve the goal of eliminating CC as a public health problem in 2030, the World Health Organization will pay special attention to increasing HPV vaccination coverage throughout the world. To further improve HPV vaccine acceptability among parents and their children, safety-related aspects of the HPV vaccine should be further investigated through post-marketing surveillance and multicentre randomized clinical trials.

"Easy women get it": pre-existing stigma associated with HPV and cervical cancer in a low-resource setting prior to implementation of an HPV screen-and-treat program

BACKGROUND

Cervical cancer is preventable with vaccination and early detection and treatment programs. However, for these programs to work as intended, stigma related to HPV and cervical cancer must be understood and addressed. We explored pre-existing stigma associated with HPV and cervical cancer in the public healthcare system and community of a low-resource setting prior to implementation of an HPV screen-and-treat program.

METHODS

This study conducted thematic analysis of data collected during implementation of a novel HPV screen-and-treat system for cervical cancer early detection and treatment in Iquitos, Peru. We included 35 semi-structured interviews (19 health professionals, 16 women with cervical precancer or cancer), eight focus groups (70 community women), one workshop (14 health professionals), 210 counseling observations (with 20 nurse-midwives), and a document review. We used the Socio-Ecological Model to organize the analysis.

RESULTS

We identified three main themes: 1. the implication that women are to blame for their HPV infection through characterizations of being easy or promiscuous, 2. the implication that men are to blame for women's HPV infections through being considered careless or unfaithful, 3. HPV is shameful, embarrassing, and something that should be hidden from others. Consequently, in some cases, women refrained from getting screened for HPV. These themes were seen at the individual level among women, relationship level among women, men, and family members, community level among healthcare staff, and societal level within components of cervical cancer guidelines and male chauvinism.

CONCLUSIONS

Cervical cancer early detection and treatment programs in limited resource settings must address stigma entrenched throughout the entire healthcare system and community in order to sustainably and successfully implement and scale-up new programs. Interventions to tackle this stigma can incorporate messages about HPV infections and latency to lessen the focus on the influence of sexual behavior on HPV acquisition, and instead, promote screening and treatment as paramount preventative measures.

"Easy women get it": Pre-existing stigma associated with HPV and cervical cancer in a low-resource setting prior to implementation of an HPV screen-and-treat program

Background

Cervical cancer is preventable with vaccination and early detection and treatment programs. However, in order for these programs to work as intended, stigma related to HPV and cervical cancer must be understood and addressed. We explored pre-existing stigma associated with HPV and cervical cancer in the public healthcare system of a low-resource setting prior to implementation of an HPV screen-and-treat program.

Methods

This study conducted thematic analysis of data collected during implementation of a novel HPV screen-and-treat system for cervical cancer early detection and treatment in Iquitos, Peru. We included 35 semi-structured interviews (19 health professionals, 16 women with cervical precancer or cancer), eight focus groups (70 community women), one workshop (14 health professionals), 210 counseling observations (with 20 nurse-midwives), and a document review. We used the Socio-Ecological Model to organize the analysis.

Results

We identified three main themes: 1. the implication that women are to blame for their HPV infection through characterizations of being easy or promiscuous, 2. the implication that men are to blame for women's HPV infections through being considered careless or unfaithful, 3. HPV is shameful, embarrassing, and something that should be hidden from others. Consequently, in some cases, women refrained from getting screened for HPV. These themes were seen at the individual level among women, relationship level among women, men, and family members, community level among healthcare staff, and societal level within components of cervical cancer guidelines and male chauvinism.

Conclusions

Cervical cancer early detection and treatment programs in limited resource settings must address stigma entrenched throughout the entire healthcare system in order to sustainably and successfully implement and scale-up new programs. Interventions to tackle this stigma can incorporate messages about HPV infections and latency to lessen the focus on the influence of sexual behavior on HPV acquisition, and instead, promote screening and treatment as paramount preventative measures.

Evidence of latent HPV infection in older Danish women with a previous history of cervical dysplasia

INTRODUCTION

Understanding whether human papillomavirus (HPV) may establish latency in the uterine cervix is important. A better understanding of HPV natural history is useful for clinical counseling of women attending screening and to accurately inform health prevention strategies such as screening and HPV vaccination. We evaluated the extent of latent HPV infections in older women with a history of abnormal cytology.

MATERIAL AND METHODS

We conducted a cross-sectional study in Aarhus, Denmark, from March 2013 through April 2015. Women were enrolled if they underwent cervical amputation or total hysterectomy because of benign disease. Prior to surgery, women completed a questionnaire and a cervical smear was collected for HPV testing and morphological assessment. For evaluation of latency (i.e., no evidence of active HPV infection, but HPV detected in the tissue), we selected women with a history of abnormal cervical cytology or histology, as these women were considered at increased risk of harboring a latent infection. Cervical tissue underwent extensive HPV testing using the SPF10-DEIA-LipA25 assay.

RESULTS

Of 103 women enrolled, 26 were included in this analysis. Median age was 55 years (interquartile range [IQR] 52-65), and most women were postmenopausal and parous. The median number of sexual partners over the lifetime was six (IQR 3-10), and 85% reported no recent new sexual partner. Five women (19.2%) had evidence of active infection at the time of surgery, and 19 underwent latency evaluation. Of these, a latent infection was detected in 11 (57.9%), with HPV16 being the most prevalent type (50%). Nearly 80% (n = 14) of the 18 women with a history of previous low-grade or high-grade cytology with no treatment had an active or latent HPV infection, with latent infections predominating. HPV was detected in two of the six women with a history of high-grade cytology and subsequent excisional treatment, both as latent infections.

CONCLUSIONS

HPV can be detected in cervical tissue specimens without any evidence of an active HPV infection, indicative of a latent, immunologically controlled infection. Modeling studies should consider including a latent state in their model when estimating the appropriate age to stop screening and when evaluating the impact of HPV vaccination.

Possible Reactivation of Latent Anal Human Papillomavirus Associated with Markers of Immune Dysfunction in Gay and Bisexual Men

BACKGROUND

It is unknown whether reactivation of human papillomavirus (HPV) after latency occurs in the anus. We measured incidence and predictors of incident anal HPV in sexually inactive gay and bisexual men (GBM) as a surrogate of HPV reactivation.

METHODS

The Study of the Prevention of Anal Cancer collected data on sexual behavior, anal cytology, HPV DNA, histology and HPV serology. HPV incidence during periods when zero sexual partners were reported in the last six months at both the current and previous annual visit ("no sexual activity") was analyzed by Cox regression using the Wei-Lin-Weissfeld method to determine univariable predictors.

RESULTS

Of 617 men enrolled, 525 had results for ≥2 visits, of whom 58 (11%) had ≥ one period of "no sexual activity". During sexually inactive periods, there were 29 incident high risk HPV infections in 20 men, which occurred more commonly in older men (Ptrend = 0.010), HIV-positive men (HR = 3.12; 95% CI, 0.91-16.65), longer duration of HIV (Ptrend = 0.028), history of AIDS defining illness (P = 0.010), lower current (P = 0.010) and nadir CD4 count (P = 0.014). For 18 of 29 infections with available results, 12 men remained type-specific HRHPV L1 seronegative. None were consistently seropositive. A new diagnosis of HSIL occurred in only two men, caused by an HPV type other than the incident type.

CONCLUSIONS

Our findings suggest that in sexually inactive GBM, anal HRHPV incidence is relatively common, and is associated with increasing age and immune dysfunction, a pattern consistent with HPV reactivation.

IMPACT

Reactivation of anal HPV may occur.

HPV and the Risk of HIV Acquisition in Women

The risk of HIV acquisition is low on a per-contact basis but increased by transmission co-factors such as other sexually transmitted infections (STIs). Human papillomavirus (HPV) is a prevalent STI that most individuals will acquire HPV in their lifetime. Current HPV vaccines can prevent newly acquired infections, but are largely ineffective against established HPV, complicating worldwide eradication efforts. In addition to being the causative agent of cervical cancer, accumulating evidence suggests that HPV infection and/or accompanying cervical inflammation increase the risk of HIV infection in men and women. The fact that immunological features observed during HPV infection overlap with cellular and molecular pathways known to enhance HIV susceptibility underscore the potential interplay between these two viral infections that fuel their mutual spread. Here we review current insights into how HPV infection and the generation of anti-HPV immunity contribute to higher HIV transmission rates, and the impact of HPV on mucosal inflammation, immune cell trafficking, and epithelial barrier function.

Incidence and clearance of oral and cervicogenital HPV infection: longitudinal analysis of the MHOC cohort study

OBJECTIVES

The Michigan HPV and Oropharyngeal Cancer study aimed to evaluate patterns of oral and cervicogenital human papillomavirus (HPV) infection prevalence, incidence, and clearance as well as their relationship to sexual behaviours.

DESIGN

Cohort SETTING: General public in and around Ann Arbor, Michigan.

PARTICIPANTS

394 college-age and older-adult participants of both sexes provided oral samples, and 325 completed at least 2 visits. 130 who provided a cervicogenital samples, and 127 completed at least 2 visits.

OUTCOMES

Incidence and clearance rates as well as HRs for oral and cervicogenital HPV.

RESULTS

Oral HPV infections were transient, with only 16% of genotypes persisting to the next visit. The mean time to clearance of a genotype was 46 days (95% CI 37 to 58). In contrast, cervicogenital infections were more persistent, with 56% of genotypes persisting to the next visit. The mean time to clearance of a genotype was 87 days (95% CI 74 to 102). HPV vaccination was associated with reduced incidence of cervicogenital HPV infection (HR 0.63; 95% CI 0.47 to 0.83) but not oral HPV infection. Incidence of oral HPV infection was associated with 2+ recent deep kissing partners (HR 2.00; 95% CI 1.13 to 3.56). Incidence of both oral (HR: 1.70; 95% CI 1.08 to 2.68) and cervicogenital (HR 2.46; 95% CI 1.69 to 3.59) was associated with 2+ recent sexual partners.

CONCLUSIONS

Detection of oral HPV was highly transient, but incidence was associated with recent deep kissing and sexual partners. Detection of cervicogenital HPV was more persistent, and incidence was positively associated with recent sexual partners and negatively associated with HPV vaccination.

HPV vaccination among seropositive, DNA negative cohorts: a systematic review & meta-analysis

Objective

Vaccine efficacy among previously exposed, but currently uninfected women, i.e., those who have serological evidence of a prior human papillomavirus (HPV) infection without corresponding detectable HPV DNA, remains incompletely defined. This meta-analysis assessed the serotype-specific efficacy of prophylactic HPV vaccination against HPV16/18 persistent infection (PI) and cervical intraepithelial neoplasia (CIN) among seropositive, DNA negative (SPDN) women enrolled to randomized controlled trials (RCTs) of HPV L1-based vaccines.

Methods

Searches were conducted on 08/16/20 on MEDLINE, Embase, Scopus and CENTRAL. RCTs of L1-based prophylactic bivalent or quadrivalent HPV vaccines, reporting serotype-specific clinical efficacy endpoints in the HPV16/18 seropositive, DNA-negative populations were included. Relative risks (RRs) of 6-month PI (6mPI), 12-month PI (12mPI), CIN1+ and CIN2+ were pooled using a random-effects model.

Results

A total of 1,727 citations were reviewed. 8 studies, with a total of 9,569 SPDN participants, met all eligibility criteria. The RR of 6mPI (RR=0.22; 95% confidence interval [CI]=0.08–0.61; p=0.018), 12mPI (RR=0.20; 95% CI=0.05–0.80; p=0.035), CIN1+ (RR=0.13; 95% CI=0.05–0.30; p=0.003) and CIN2+ (RR=0.15; 95% CI=0.04–0.59; p=0.022) was significantly reduced in the vaccinated compared to the unvaccinated group.

Conclusion

Our findings suggest high serotype-specific efficacy for HPV vaccination among cohorts of women with evidence of prior HPV16/18 infections, including 87% efficacy (95% CI=70%–95%; p=0.003) against HPV16/18 cervical dysplasia. HPV vaccination is highly effective among uninfected women, regardless of prior exposure history.

Trial Registration

PROSPERO Identifier: CRD42020206888

Comparison between Urine and Cervical High-Risk HPV Tests for Japanese Women with ASC-US

Most uterine cervical cancers are caused by the persistent infection of the high-risk human papillomavirus (hrHPV). Thus, the hrHPV-DNA test, which examines specimens from the cervix, is the standard screening method as well as cytology in western countries. Urine sampling for the hrHPV-DNA test would be easier and help improving screening rates. This study prospectively investigated the concordance between urine and cervical hrHPV tests for patients with atypical squamous cells of undetermined significance (ASC-US) in cervical cytology. We recruited 338 women with the cytologic diagnosis of ASC-US and performed hrHPV-DNA tests to both samples from the uterine cervix and first void urine, using the Cobas 4800 system. In all hrHPV genotypes, the simple concordance rate was 90.8% (307/338) and the Kappa statistic value was 0.765, which shows substantial concordance. The positive concordance rate was 70.5% (74/105), which was the rate excluding women who had negative results in both tests. When limited to types 16 and 18, the simple concordance rate was 98.8% (334/338), and the Kappa statistical value was calculated to be 0.840, which showed almost perfect concordance. The positive concordance rate resulted in 81.8% (18/22). We conclude that the urine hrHPV-DNA test could substitute the cervical test in women with ASC-US.

Screening for cervical cancer: Choices & dilemmas

Cervical cancer is the fourth most common cancer in women in the world. To eliminate cervical cancer by 2030, the World Health Organization has given the target of 70 per cent coverage of twice lifetime screening. A multitude of screening methods are available, including cytology, human papillomavirus (HPV) DNA testing and visual inspection tests. Precision tests, including molecular and protein biomarkers such as DNA methylation, p16 immunostaining, and HPV mRNA testing help to enhance specificity of the screening. Worldwide HPV DNA testing with or without cytology is used as a screening method of choice, while in resource-poor settings, visual inspection tests are recommended. The major hurdle is a uniform and systematic implementation with a recall method in the population. Besides, controversies still exist regarding strategies to manage HPV-positive women and developing guidelines to screen the vaccinated population.

Importance of Lifetime Sexual History on the Prevalence of Genital Human Papillomavirus (HPV) Among Unvaccinated Adults in the National Health and Nutrition Examination Surveys: Implications for Adult HPV Vaccination

BACKGROUND

Although the United States Food and Drug Administration recently approved the human papillomavirus (HPV) vaccine for individuals aged 27-45 years, the Centers for Disease Control and Prevention did not change its guidelines for routine HPV vaccination. Since recommendations for adult vaccination emphasize shared clinical decision-making based on risk of new infections, we examined the relationship between HPV prevalence and sexual behavior.

METHODS

This study was conducted among 5093 HPV-unvaccinated, sexually experienced adults aged 18-59 years in the National Health and Nutrition Examination Surveys (2013-2016). For each sex and age group, adjusted prevalences of 9-valent vaccine-specific, high-risk, and any HPV infection were estimated by number of lifetime sexual partners (LTSPs) using logistic regression. An analysis restricted to persons who did not have a new sexual partner in the past year (ie, removing those at highest risk of newly acquired HPV) was also conducted.

RESULTS

In each age group, genital HPV prevalence was higher among persons with >5 LTSPs compared with 1-5 LTSPs in both males and females. There were only slight reductions in HPV prevalence after removing participants who reported a new sexual partner in the past year. For example, among females aged 27-45 years with >5 LTSPs, the adjusted prevalence of 9-valent vaccine-type HPV infection was 13.4% (95% confidence interval [CI], 9.9%-17.0%) in the full population compared to 12.1% (95% CI, 8.8%-15.4%) among those with no new sexual partners.

CONCLUSIONS

Prevalent HPV infection was primarily reflective of cumulative exposures over time (higher LTSPs). New exposures had limited impact, emphasizing the need to consider sexual history in the decision-making process for adult HPV vaccination.

Screening for the prevention and early detection of cervical cancer: protocol for systematic reviews to inform Canadian recommendations

PURPOSE

To inform recommendations by the Canadian Task Force on Preventive Health Care on screening in primary care for the prevention and early detection of cervical cancer by systematically reviewing evidence of (a) effectiveness; (b) test accuracy; (c) individuals' values and preferences; and (d) strategies aimed at improving screening rates.

METHODS

De novo reviews will be conducted to evaluate effectiveness and to assess values and preferences. For test accuracy and strategies to improve screening rates, we will integrate studies from existing systematic reviews with search updates to the present. Two Cochrane reviews will provide evidence of adverse pregnancy outcomes from the conservative management of cervical intraepithelial neoplasia. We will search Medline, Embase, and Cochrane Central (except for individuals' values and preferences, where Medline, Scopus, and EconLit will be searched) via peer-reviewed search strategies and the reference lists of included studies and reviews. We will search ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. Two reviewers will screen potentially eligible studies and agree on those to include. Data will be extracted by one reviewer with verification by another. Two reviewers will independently assess risk of bias and reach consensus. Where possible and suitable, we will pool studies via meta-analysis. We will compare accuracy data per outcome and per comparison using the Rutter and Gatsonis hierarchical summary receiver operating characteristic model and report relative sensitivities and specificities. Findings on values and preferences will be synthesized using a narrative synthesis approach and thematic analysis, depending on study designs. Two reviewers will appraise the certainty of evidence for all outcomes using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and come to consensus.

DISCUSSION

The publication of guidance on screening in primary care for the prevention and early detection of cervical cancer by the Task Force in 2013 focused on cytology. Since 2013, new studies using human papillomavirus tests for cervical screening have been published that will improve our understanding of screening in primary care settings. This review will inform updated recommendations based on currently available studies and address key evidence gaps noted in our previous review.

Association of Thiamine Intake with Human Papillomavirus (HPV) Infection in American Women: A Secondary Data Analysis Based on the National Health and Nutrition Examination Survey from 2003 to 2016

Background

Studies have shown that thiamine intake is associated with cervical cancer, but the relationship between thiamine and HPV infection remains unclear. In the present study, we used the National Health and Nutrition Examination Survey (NHANES) database to investigate whether HPV infection was associated with thiamine intake.

Material/Methods

A total of 13 471 women ages 18–59 years were selected from the NHANES database from 2003 to 2016. Using thiamine intake as the independent variable, HPV infection as the dependent variable, and sociodemographic data and other data as the covariates, we analyzed the relationship between thiamine and HPV infection by conducting a weighted logistic regression model in a cross-sectional research design.

Results

The two-piecewise linear model indicated the inflection point of thiamine intake was 2.07 mg. On the left side of the inflection point, the difference in the thiamine intake of log2 conversion was related to the difference of 0.82 in HPV infection, which means that the increase of every 1 unit increase in thiamine intake is associated with the decrease of the HPV infection by 18%. On the right side of the inflection point, we did not observe a correlation between HPV infection and thiamine intake.

Conclusions

Thiamine intake is negatively correlated with HPV infection. Intake of an appropriate amount of thiamine can prevent HPV infection. The best preventive effect can be achieved when the intake is about 2 mg, and excessive intake will not increase the preventive effect.

Rates of New Human Papillomavirus Detection and Loss of Detection in Middle-aged Women by Recent and Past Sexual Behavior

BACKGROUND

Understanding the source of newly detected human papillomavirus (HPV) in middle-aged women is important to inform preventive strategies, such as screening and HPV vaccination.

METHODS

We conducted a prospective cohort study in Baltimore, Maryland. Women aged 35-60 years underwent HPV testing and completed health and sexual behavior questionnaires every 6 months over a 2-year period. New detection/loss of detection rates were calculated and adjusted hazard ratios were used to identify risk factors for new detection.

RESULTS

The new and loss of detection analyses included 731 women, and 104 positive for high-risk HPV. The rate of new high-risk HPV detection was 5.0 per 1000 woman-months. Reporting a new sex partner was associated with higher detection rates (adjusted hazard ratio, 8.1; 95% confidence interval, 3.5-18.6), but accounted only for 19.4% of all new detections. Among monogamous and sexually abstinent women, new detection was higher in women reporting ≥5 lifetime sexual partners than in those reporting <5 (adjusted hazard ratio, 2.2; 95% confidence interval, 1.2-4.2).

CONCLUSION

Although women remain at risk of HPV acquisition from new sex partners as they age, our results suggest that most new detections in middle-aged women reflect recurrence of previously acquired HPV.

The Host-Microbe Interplay in Human Papillomavirus-Induced Carcinogenesis

Every year nearly half a million new cases of cervix cancer are diagnosed worldwide, making this malignancy the fourth commonest cancer in women. In 2018, more than 270,000 women died of cervix cancer globally with 85% of them being from developing countries. The majority of these cancers are caused by the infection with carcinogenic strains of human papillomavirus (HPV), which is also causally implicated in the development of other malignancies, including cancer of the anus, penis cancer and head and neck cancer. HPV is by far the most common sexually transmitted infection worldwide, however, most infected people do not develop cancer and do not even have a persistent infection. The development of highly effective HPV vaccines against most common high-risk HPV strains is a great medical achievement of the 21st century that could prevent up to 90% of cervix cancers. In this article, we review the current understanding of the balanced virus-host interaction that can lead to either virus elimination or the establishment of persistent infection and ultimately malignant transformation. We also highlight the influence of certain factors inherent to the host, including the immune status, genetic variants and the coexistence of other microbe infections and microbiome composition in the dynamic of HPV infection induced carcinogenesis.

Vaginal dysbiosis and the risk of human papillomavirus and cervical cancer: systematic review and meta-analysis

OBJECTIVE

The vaginal microbiota proposedly influence the association between human papillomavirus and cervical cancer. Our aim was to assess whether vaginal dysbiosis affects human papilloma virus acquisition, persistence, and progression to related cervical premalignancy.

DATA SORUCES

MEDLINE, Embase, CINAHL, Cochrane Library, and Web of Science (inception until June 2018) were used for this study. The study protocol was registered at PROSPERO (CRD42016035620).

STUDY ELIGIBILITY CRITERIA

This systematic review included all observational studies reporting on incident human papilloma virus, persistent human papilloma virus, and/or related cervical disease in women with or without vaginal dysbiosis prior to outcome assessment.

STUDY APPRAISAL AND SYNTHESIS METHODS

We used random-effects models for meta-analyses and report pooled relative risks with 95% confidence intervals. The risk for incident and/or persistent human papilloma virus or related cervical disease based on longitudinal results was determined.

RESULTS

Of 1645 unique articles, 15 mainly prospective cohort studies were included, published between 2003 and 2017, including a total of 101,049 women. Vaginal dysbiosis was associated with an increased risk of incident human papilloma virus (overall relative risk, 1.33, 1.18-1.50, I² = 0%; among young women relative risk, 1.43, 1.10-1.85, I² = 0%), human papilloma virus persistence (overall relative risk, 1.14, 1.01-1.28, I² = 44.2%; for oncogenic types relative risk, 1.18, 1.01-1.38, I² = 0%), and high-grade lesions and cancer (relative risk, 2.01, 1.40-3.01, I² = 0%), but women with lesions/cancer were compared with those without, regardless of their oncogenic human papilloma virus status. Overall, comparable results were found in the molecular vaginal microbiota studies.

CONCLUSION

This study supports a causal link between vaginal dysbiosis and cervical cancer along the oncogenic human papillomavirus acquisition, persistence, and cervicovaginal dysplasia development pathway.

Whole tissue cervical mapping of HPV infection: Molecular evidence for focal latent HPV infection in humans

In this study, we aimed to provide molecular evidence of HPV latency in humans and discuss potential challenges of conducting studies on latency. We analyzed the entire cervix of two women who underwent hysterectomy unrelated to cervical abnormality. The cervices were sectioned into 242 and 186 sets respectively, and each set was tested separately for HPV using the SPF10-PCR-DEIA-LiPA25 system. To identify whether there was any evidence of transforming or productive infection, we used the biomarkers E4 and P16^INK4a to stain slides immediately adjacent to HPV-positive sections. HPV was detected in both cervices. In patient 1, 1/242 sets was positive for HPV31. In patient 2, 13/186 sets were positive for HPV18 and 1/186 was positive for HPV53. The infection was very focal in both patients, and there was no sign of a transforming or productive infection, as evaluated by the markers E4 and P16^INK4a. Had we only analyzed one set from each block, the probability of detecting the infection would have been 32.3% and 2%, respectively.Our findings support the idea that HPV may be able to establish latency in the human cervix; however, the risk associated with a latent HPV infection remains unclear.

Comparison between professional sampling and self-sampling for HPV-based cervical cancer screening among postmenopausal women

OBJECTIVE

To investigate whether self-sampling is as reliable as professional sampling for HPV testing and genotype detection among postmenopausal women.

METHODS

In the present prospective cross-sectional study, women in Örebro County, Sweden, who had high-risk HPV (hrHPV) and normal cytology results in exit screening tests conducted in between January 1, 2012, and December 31, 2014, were invited to follow-up screenings between February 24, 2015 and May 15, 2015, that included professional sampling and self-sampling. HPV genotypes were identified by a DNA-based assay that could detect 35 HPV genotypes. Findings between the different sampling methods were compared.

RESULTS

Of 143 women who participated, 119 returned a self-sample. Completely concordant results were observed in 67 of these samples when both hrHPV and low-risk HPV genotypes were analyzed. Overall, 99 (83.2%) women had the same clinically relevant finding from both sampling methods. Twenty women had discordant hrHPV results (hrHPV detected in 10 self-samples vs 10 professionally collected samples; Cohen κ 0.66, 95% confidence interval 0.53-0.80). There was no significant difference between the two sampling methods for clinically significant infections (P>0.99) or extended genotyping (P=0.827).

CONCLUSION

Postmenopausal women could be offered self-sampling devices to increase screening-program coverage while maintaining test quality.

Why Human Papillomavirus Acute Infections Matter

Most infections by human papillomaviruses (HPVs) are `acute', that is non-persistent. Yet, for HPVs, as for many other oncoviruses, there is a striking gap between our detailed understanding of chronic infections and our limited data on the early stages of infection. Here we argue that studying HPV acute infections is necessary and timely. Focusing on early interactions will help explain why certain infections are cleared while others become chronic or latent. From a molecular perspective, descriptions of immune effectors and pro-inflammatory pathways during the initial stages of infections have the potential to lead to novel treatments or to improved handling algorithms. From a dynamical perspective, adopting concepts from spatial ecology, such as meta-populations or meta-communities, can help explain why HPV acute infections sometimes last for years. Furthermore, cervical cancer screening and vaccines impose novel iatrogenic pressures on HPVs, implying that anticipating any viral evolutionary response remains essential. Finally, hints at the associations between HPV acute infections and fertility deserve further investigation given their high, worldwide prevalence. Overall, understanding asymptomatic and benign infections may be instrumental in reducing HPV virulence.

Natural History of HPV Infection across the Lifespan: Role of Viral Latency

Large-scale epidemiologic studies have been invaluable for elaboration of the causal relationship between persistent detection of genital human papillomavirus (HPV) infection and the development of invasive cervical cancer. However, these studies provide limited data to adequately inform models of the individual-level natural history of HPV infection over the course of a lifetime, and particularly ignore the biological distinction between HPV-negative tests and lack of infection (i.e., the possibility of latent, undetectable HPV infection). Using data from more recent epidemiological studies, this review proposes an alternative model of the natural history of genital HPV across the life span. We argue that a more complete elucidation of the age-specific probabilities of the alternative transitions is highly relevant with the expanded use of HPV testing in cervical cancer screening. With routine HPV testing in cervical cancer screening, women commonly transition in and out of HPV detectability, raising concerns for the patient and the provider regarding the source of the positive test result, its prognosis, and effective strategies to prevent future recurrence. Alternative study designs and analytic frameworks are proposed to better understand the frequency and determinants of these transition pathways.

Mechanistic mathematical models: An underused platform for HPV research

Health economic modeling has become an invaluable methodology for the design and evaluation of clinical and public health interventions against the human papillomavirus (HPV) and associated diseases. At the same time, relatively little attention has been paid to a different yet complementary class of models, namely that of mechanistic mathematical models. The primary focus of mechanistic mathematical models is to better understand the intricate biologic mechanisms and dynamics of disease. Inspired by a long and successful history of mechanistic modeling in other biomedical fields, we highlight several areas of HPV research where mechanistic models have the potential to advance the field. We argue that by building quantitative bridges between biologic mechanism and population level data, mechanistic mathematical models provide a unique platform to enable collaborations between experimentalists who collect data at different physical scales of the HPV infection process. Through such collaborations, mechanistic mathematical models can accelerate and enhance the investigation of HPV and related diseases.

The vaginal microbiota, human papillomavirus infection and cervical intraepithelial neoplasia: what do we know and where are we going next?

The vaginal microbiota plays a significant role in health and disease of the female reproductive tract. Next-generation sequencing techniques based upon the analysis of bacterial 16S rRNA genes permit in-depth study of vaginal microbial community structure to a level of detail not possible with standard culture-based microbiological techniques. The human papillomavirus (HPV) causes both cervical intraepithelial neoplasia (CIN) and cervical cancer. Although the virus is highly prevalent, only a small number of women have a persistent HPV infection and subsequently develop clinically significant disease. There is emerging evidence which leads us to conclude that increased diversity of vaginal microbiota combined with reduced relative abundance of Lactobacillus spp. is involved in HPV acquisition and persistence and the development of cervical precancer and cancer. In this review, we summarise the current literature and discuss potential mechanisms for the involvement of vaginal microbiota in the evolution of CIN and cervical cancer. The concept of manipulation of vaginal bacterial communities using pre- and probiotics is also discussed as an exciting prospect for the field of cervical pathology.

Tracking vaginal, anal and oral infection in a mouse papillomavirus infection model

Noninvasive and practical techniques to longitudinally track viral infection are sought after in clinical practice. We report a proof-of-principle study to monitor the viral DNA copy number using a newly established mouse papillomavirus (MmuPV1) mucosal infection model. We hypothesized that viral presence could be identified and quantified by collecting lavage samples from cervicovaginal, anal and oral sites. Nude mice infected at these sites with infectious MmuPV1 were tracked for up to 23 weeks starting at 6 weeks post-infection. Viral DNA copy number was determined by SYBR Green Q-PCR analysis. In addition, we tracked viral DNA load through three complete oestrous cycles to pinpoint whether there was a correlation between the DNA load and the four stages of the oestrous cycle. Our results showed that high viral DNA copy number was reproducibly detected from both anal and cervicovaginal lavage samples. The infection and disease progression were further confirmed by histology, cytology, in situ hybridization, immunohistochemistry and transmission electron microscopy. Interestingly, the viral copy number fluctuated over the oestrous cycle, with the highest level at the oestrus stage, implying that multiple sampling might be necessary to provide a reliable diagnosis. Virus DNA was detected in oral lavage samples at a later time after infection. Lower viral DNA load was found in oral samples when compared with those in anal and vaginal tracts. To our knowledge, our study is the first in vivo study to sequentially monitor papillomavirus infection from mucosal anal, oral and vaginal tracts in a preclinical model.

Role of the microbiome in non-gastrointestinal cancers

“The forgotten organ”, the human microbiome, comprises a community of microorganisms that colonizes various sites of the human body. Through coevolution of bacteria, archaea and fungi with the human host over thousands of years, a complex host-microbiome relationship emerged in which many functions, including metabolism and immune responses, became codependent. This coupling becomes evident when disruption in the microbiome composition, termed dysbiosis, is mirrored by the development of pathologies in the host. Among the most serious consequences of dysbiosis, is the development of cancer. As many as 20% of total cancers worldwide are caused by a microbial agent. To date, a vast majority of microbiome-cancer studies focus solely on the microbiome of the large intestine and the development of gastrointestinal cancers. Here, we will review the available evidence implicating microbiome involvement in the development and progression of non-gastrointestinal cancers, while distinguishing between viral and bacterial drivers of cancer, as well as “local” and “systemic”, “cancer-stimulating” and “cancer-suppressing” effects of the microbiome. Developing a system-wide approach to cancer-microbiome studies will be crucial in understanding how microbiome influences carcinogenesis, and may enable to employ microbiome-targeting approaches as part of cancer treatment.

Prevalent high-risk HPV infection and vaginal microbiota in Nigerian women

In this study, we evaluated the association between high-risk human papillomavirus (hrHPV) and the vaginal microbiome. Participants were recruited in Nigeria between April and August 2012. Vaginal bacterial composition was characterized by deep sequencing of barcoded 16S rRNA gene fragments (V4) on Illumina MiSeq and HPV was identified using the Roche Linear Array® HPV genotyping test. We used exact logistic regression models to evaluate the association between community state types (CSTs) of vaginal microbiota and hrHPV infection, weighted UniFrac distances to compare the vaginal microbiota of individuals with prevalent hrHPV to those without prevalent hrHPV infection, and the Linear Discriminant Analysis effect size (LEfSe) algorithm to characterize bacteria associated with prevalent hrHPV infection. We observed four CSTs: CST IV-B with a low relative abundance of Lactobacillus spp. in 50% of participants; CST III (dominated by L. iners) in 39·2%; CST I (dominated by L. crispatus) in 7·9%; and CST VI (dominated by proteobacteria) in 2·9% of participants. LEfSe analysis suggested an association between prevalent hrHPV infection and a decreased abundance of Lactobacillus sp. with increased abundance of anaerobes particularly of the genera Prevotella and Leptotrichia in HIV-negative women (P < 0·05). These results are hypothesis generating and further studies are required.

HPV clearance and the neglected role of stochasticity

Clearance of anogenital and oropharyngeal HPV infections is attributed primarily to a successful adaptive immune response. To date, little attention has been paid to the potential role of stochastic cell dynamics in the time it takes to clear an HPV infection. In this study, we combine mechanistic mathematical models at the cellular level with epidemiological data at the population level to disentangle the respective roles of immune capacity and cell dynamics in the clearing mechanism. Our results suggest that chance—in form of the stochastic dynamics of basal stem cells—plays a critical role in the elimination of HPV-infected cell clones. In particular, we find that in immunocompetent adolescents with cervical HPV infections, the immune response may contribute less than 20% to virus clearance—the rest is taken care of by the stochastic proliferation dynamics in the basal layer. In HIV-negative individuals, the contribution of the immune response may be negligible.

Worldwide, 5% of all cancers are associated with the sexually transmitted human papillomavirus (HPV). The most common cancer types attributed to HPV are cervical and anal cancers, but HPV-related head and neck cancers are on the rise, too. Even though the lifetime risk of infection with HPV is as high as 80%, most infections clear spontaneously within 1–2 years, and only a small fraction progress to cancer. In order to identify who is at risk for HPV-related cancer, a better understanding of the underlying biology is of great importance. While it is generally accepted that the immune system plays a key role in HPV clearance, we investigate here a mechanism which could be equally important: the stochastic division dynamics of stem cells in the infected tissues. Combining mechanistic mathematical models at the cell-level with population-level data, we disentangle the contributions from immune system and cellular dynamics in the clearance process. We find that cellular stochasticity may play an even more important role than the immune system. Our findings shed new light onto open questions in HPV immunobiology, and may influence the way we vaccinate and screen individuals at risk of HPV-related cancers.

Interplay between the temporal dynamics of the vaginal microbiota and human papillomavirus detection

BACKGROUND

We sought to describe the temporal relationship between vaginal microbiota and human papillomavirus (HPV) detection.

METHODS

Thirty-two reproductive-age women self-collected midvaginal swabs twice weekly for 16 weeks (937 samples). Vaginal bacterial communities were characterized by pyrosequencing of barcoded 16S rRNA genes and clustered into 6 community state types (CSTs). Each swab was tested for 37 HPV types. The effects of CSTs on the rate of transition between HPV-negative and HPV-positive states were assessed using continuous-time Markov models.

RESULTS

Participants had an average of 29 samples, with HPV point prevalence between 58%-77%. CST was associated with changes in HPV status (P<.001). Lactobacillus gasseri-dominated CSTs had the fastest HPV remission rate, and a low Lactobacillus community with high proportions of the genera Atopobium (CST IV-B) had the slowest rate compared to L. crispatus-dominated CSTs (adjusted transition rate ratio [aTRR], 4.43, 95% confidence interval [CI], 1.11-17.7; aTRR, 0.33, 95% CI, .12-1.19, respectively). The rate ratio of incident HPV for low Lactobacillus CST IV-A was 1.86 (95% CI, .52-6.74).

CONCLUSIONS

Vaginal microbiota dominated by L. gasseri was associated with increased clearance of detectable HPV. Frequent longitudinal sampling is necessary for evaluation of the association between HPV detection and dynamic microbiota.