Prevalence and type distribution of human papillomavirus in 5,000 British Columbia women--implications for vaccination

2023 Canadian Colposcopy Guideline: A Risk-Based Approach to Management and Surveillance of Cervical Dysplasia

This guideline provides evidence-based guidance on the risk-based management of cervical dysplasia in the colposcopy setting in the context of primary HPV-based screening and HPV testing in colposcopy. Colposcopy management of special populations is also discussed. The guideline was developed by a working group in collaboration with the Gynecologic Oncology Society of Canada (GOC), Society of Colposcopists of Canada (SCC) and the Canadian Partnership Against Cancer (CPAC). The literature informing these guidelines was obtained through a systematic review of the relevant literature via a multi-step search process led by information specialists. The literature was reviewed up to June 2021 with manual searches of relevant national guidelines and more recent publications. Quality of the evidence and strength of recommendations was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) framework. The intended users of this guideline include gynecologists, colposcopists, screening programs and healthcare facilities. Implementation of the recommendations is intended to promote equitable and standardized care for all people undergoing colposcopy in Canada. The risk-based approach aims to improve personalized care and reduce over-/under-treatment in colposcopy.

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.

Understanding the characteristics of multiple infections is critical in the era of HPV multivalent vaccines for the prevention of cervical carcinomas. Therefore, in this cross-sectional study, we aimed to investigate the pattern of multiple HPV infections and associated factors in 5,268 sexually active unvaccinated women (16–25 years old) who access the Brazilian public health care system. Cervical samples were collected by trained health professionals, and HPV detection was performed in a central laboratory by Linear Array. A total of 33.00% (95% CI 31.07–34.92) had multiple infections (60.43% of the HPV-positive sample). The number of HPV types in a multiple infection ranged from 2 to 14 different types. The viral types more frequently identified were HPV 16 and 52. All HPV types were detected more frequently in association with other types than alone. The incidence of multiple infections was 1.29 times higher in single than in married or cohabitating participants. Women who had two or more partners in the last year also had higher rates of multiple infections than those who had fewer than two sexual partners. In conclusion, a high prevalence of multiple infections prior to the national HPV immunization program was observed, especially with the increase in less safe behavior factors.

High-risk HPV prevalence among women undergoing cervical cancer screening: Findings a decade after HPV vaccine implementation in British Columbia, Canada

BACKGROUND

British Columbia (BC) introduced a publicly funded, school-based human papillomavirus (HPV) immunization program in 2008 with the quadrivalent vaccine. In 2010/2011, a baseline evaluation of HPV prevalence was conducted among women undergoing cervical cancer screening. After 10 years of publicly funded HPV vaccination, HPV-type prevalence was re-evaluated.

METHODS

From August 2017 to March 2018, 1107 physicians were invited to return cytobrushes used during routine Pap screening to the Cervical Cancer Screening Laboratory for HPV testing. Only age or year of birth was collected. Specimens were screened for high-risk HPV (hrHPV) and positive samples were genotyped. HPV type prevalence was compared for females 15-22 yrs (those eligible for the school-based vaccination) and 23+ yrs (ineligible for school-based vaccination) for the 2010/2011 and the 2017/2018 data.

RESULTS

There were 3309 valid samples received for testing; of these, 3107 were included in the analysis. The overall hrHPV prevalence was 12.2% (95% CI 11.3-13.3) in 2010/11, and 12.0% (95% CI 10.9-13.2) in 2017/18. For the 15-22 age group, the prevalence for any hrHPV was 26.8% (95% CI 23.1-30.8) in 2010/11 and 25.4% (95% CI 15.3-37.9) in 2017/18. For those aged 15-22, HPV16 prevalence in 2010/11 was 8.8% (95% CI 6.5-11.5) and in 2017/18 was 6.3% (95% CI 1.8-15.5), with corresponding figures for HPV18 3.7% (95% CI 2.3-5.7) and 0% (95% CI 0.0-5.7), respectively. For all hrHPV types, there were no statistically significant differences between the 2010/11 and 2017/18 periods.

CONCLUSIONS

This study illustrates the prevalence of hrHPV in BC over time in women undergoing cervical cancer screening, where an indication of a decline in HPV16/18 is seen in vaccine eligible women.

Cervical Intraepithelial Neoplasia Rates in British Columbia Women: A Population-Level Data Linkage Evaluation of the School-Based HPV Immunization Program

BACKGROUND

To understand real-world human papillomavirus (HPV) vaccine impact, continuous evaluation using population-based data is critical. We evaluated the early impact of the school-based HPV immunization program on cervical dysplasia in women in British Columbia, Canada.

METHODS

Data linkage was performed using records from provincial cervical screening and immunization registries. Precancerous outcomes were compared between unvaccinated and HPV-vaccinated women born 1994-2005. Incidence rate, relative rate (RR), and vaccine effectiveness (VE), using unadjusted and adjusted Poisson regression of cytology (HSIL) and histopathology (CIN2, CIN3, and CIN2+) outcomes, were compared across vaccination status groups.

RESULTS

Women who received a complete series of vaccine on schedule between age 9 and 14 years had an adjusted RR = 0.42 (95% confidence interval [CI], 0.31-0.57) for CIN2+ over 7 years of follow-up compared to unvaccinated women, resulting in a VE of 57.9% (95% CI, 43.2%-69.0%). Adjusted RR for HSIL was 0.53 (95% CI, .43-.64), resulting in a VE of 47.1% (95% CI, 35.6%-56.7%).

CONCLUSION

Women vaccinated against HPV have a lower incidence of cervical dysplasia compared to unvaccinated women. Immunization between 9 and 14 years of age should be encouraged. Continued program evaluation is important for measuring long-term population impact.

Human papilloma and other DNA virus infections of the cervix: A population based comparative study among tribal and general population in India

Background

Despite being preventable, cervical cancer remains a major health concern among women. Persistent Human Papillomavirus (HPV) and other viral co-infections may influence cervical dysplasia. We determined and compared the prevalence and risk factors of cervical viral infections among the tribal and general population of southern coastal Karnataka, India.

Methods

A population-based cross-sectional survey was conducted among 1140 and 1100 women from tribal and general population, respectively. Cervical infections with HPV, Epstein-Barr Virus (EBV), Cytomegalovirus (CMV) and Herpes-Simplex Virus (HSV) were examined using polymerase chain reactions (PCR) and DNA sequencing.

Results

HPV prevalence was higher among tribal women (40.6%) than general population (14.3%) while the prevalence of EBV (55.1%) and CMV (49.4%) were lower among tribal women than general population (74.3% and 77.5%, respectively). HSV infection was observed in tribal women only (1.8%). Among HR-HPV strains, HPV-18 was predominant among tribal population (28.3%) while, HPV-16 was predominant among the general population (9.1%). Infections were associated with age, educational status, unemployment and personal hygiene of tribal women. Phylogenetic analysis revealed that HPV-16 variants of tribal participants were closely related to non-European sublineages indicating greater risk of HPV persistence and carcinogenesis.

Conclusion

The study provides a comparative estimate for DNA virus infections of the cervix among women from general as well as tribal population in this region and also reveals a different type-specific pattern of viral infection. Further research is required to delineate the role of specific interactions between multiple virus infections and their role in carcinogenesis.

The epidemiology of HIV and other sexually transmitted infections in African, Caribbean and Black men in Toronto, Canada

BACKGROUND

African, Caribbean, and Black (Black) men account for 16.5% of new HIV diagnoses among men in Ontario. There is substantial evidence that sexually transmitted infections (STIs) are associated with increased likelihood of HIV infection; however, little is known regarding the prevalence of HIV/STI co-infections among Black men in Toronto. Progress has been made in understanding factors contributing to racial/ethnic disparities in HIV between among men who have sex with men (MSM). In this study, we investigate within-racial group patterns of HIV/STI infection between Black MSM and Black men who only have sex with women (MSW).

METHODS

A cross-sectional descriptive epidemiological study was conducted with a non-probability sample of Black men recruited from Toronto, Ontario. Audio Computer Assisted Self-Interviews (ACASI) surveys were used to collect demographic and behavioral data. Biological specimens were collected to screen for HIV and other STIs. Chi-Square tests were used to compare the prevalence of (1) HIV and current STIs between MSM and MSW and (2) current STIs between people living with HIV and people not living with HIV. Logistic regression models were constructed to assess whether or not history of STIs were associated with current HIV infection.

RESULTS

The prevalence of HIV (9.2%), syphilis (7.2%), hepatitis B (2.7%), and high-risk anal HPV (8.4%) and penile HPV (21.3%) infections were high in Black men (N = 487) and were significantly increased in Black MSM compared with MSW; the prevalence of syphilis and high-risk HPV were also increased in men living with HIV. Men with a history of syphilis (OR = 6.48, 95% CI: 2.68,15.71), genital warts (OR = 4.32, 95% CI: 1.79,10.43) or genital ulcers (OR = 21.3, 95% CI: 1.89,239.51) had an increased odds of HIV infection.

CONCLUSIONS

The HIV/STI prevalence was high among this sample of Black men, although the study design may have led to oversampling of men living with HIV. The associations between STIs and current HIV infection highlight the need for integrated of HIV/STI screening and treatment programs for Black men. Public health strategies are also needed to reduce disproportionate HIV/STI burden among Black MSM-including improving HPV vaccine coverage.

Discriminating high-risk cervical Human Papilloma Virus infections with urinary biomarkers via non-targeted GC-MS-based metabolomics

Genital human papillomavirus (HPV) is the world’s most commonly diagnosed sexually transmitted infection, and high-risk HPV types are strongly linked to cervical dysplasia and carcinoma. Puerto Ricans are among the US citizens with higher HPV prevalence and lower screening rates and access to treatment. This bleak statistic was as a motivation to detect biomarkers for early diagnosis of HPV in this population. We collected both urine and cervical swabs from 43 patients attending San Juan Clinics. Cervical swabs were used for genomic DNA extractions and HPV genotyping with the HPV SPF10-LiPA25 kit, and gas chromatography-mass spectrometry (GC-MS) was employed on the urine-derived products for metabolomics analyses. We aimed at discriminating between patients with different HPV categories: HPV negative (HPV-), HPV positive with simultaneous low and high-risk infections (HPV+B) and HPV positive exclusively high-risk (HPV+H). We found that the metabolome of HPV+B is closer to HPV- than to HPV+H supporting evidence that suggests HPV co-infections may be antagonistic due to viral interference leading to a lower propensity for cervical cancer development. In contrast, metabolites of patients with HPV+H were significantly different from those that were HPV-. We identified three urinary metabolites 5-Oxoprolinate, Erythronic acid and N-Acetylaspartic acid that discriminate HPV+H cases from negative controls. These metabolites are known to be involved in a variety of biochemical processes related to energy and metabolism and may likely be biomarkers for HPV high-risk cervical infection. However, further validation should follow using a larger patient cohort and diverse populations to confirm our finding.

Prevalence and distribution of human papillomavirus genotypes among women with high-grade squamous intraepithelial lesion and invasive cervical cancer in Ganzhou, China

BACKGROUND

Human papillomavirus (HPV) infection can lead to the development of cervical cancer. This study assessed the genotype distribution of HPV of high-grade squamous intraepithelial lesion (HSIL) and invasive cervical cancer (ICC) in Ganzhou population.

METHODS

A total of 935 females who got HPV testing from January 2016 to July 2018 in the maternal and child health hospital of Ganzhou were enrolled in the study, including 806 HSIL and 129 ICC. HPV detection and genotyping were tested by HPV Geno-Array test kit.

RESULTS

The overall HPV-positive rate was 74.0% in Ganzhou. Among the HSIL and ICC patients, the positive rates of HPV detection were 75.6% and 64.3%. Among the HSIL individuals, the most prevalent hr-HPV genotype was HPV 16. And the 4 common subtypes in decreasing order were HPV 52, 58, 33, and 18. Of the ICC patients, the most frequently hr-HPV subtype was HPV 16 followed by 18, 52, 58, and 59. Among the squamous cell carcinoma (SCC) patients, for hr-HPV genotypes, HPV 16, 18, 52, 58, and 59 were five most common subtypes. In patients with adenocarcinoma (ADC), the most common hr-HPV genotype was HPV 18, followed by HPV 16, 52, 56, 68, 73. And, we found U-shaped and S-shaped curves in the HPV distribution of different age groups.

CONCLUSION

The prevalence and distribution of HPV genotypes in Ganzhou differed from other regions of China and Western countries. These results can serve as valuable reference for HPV vaccination programs for Ganzhou women.

Investigating Canadian parents' HPV vaccine knowledge, attitudes and behaviour: a study protocol for a longitudinal national online survey

INTRODUCTION

Human papillomavirus (HPV), a sexually transmitted infection, can cause anogenital warts and a number of cancers. To prevent morbidity and mortality, three vaccines have been licensed and are recommended by Canada's National Advisory Committee on Immunisation (for girls since 2007 and boys since 2012). Nevertheless, HPV vaccine coverage in Canada remains suboptimal in many regions. This study will be the first to concurrently examine the correlates of HPV vaccine decision-making in parents of school-aged girls and boys and evaluate changes in parental knowledge, attitudes and behaviours over time.

METHODS AND ANALYSIS

Using a national, online survey utilising theoretically driven constructs and validated measures, this study will identify HPV vaccine coverage rates and correlates of vaccine decision-making in Canada at two time points (August-September 2016 and June-July 2017). 4606 participants will be recruited to participate in an online survey through a market research and polling firm using email invitations. Data cleaning methods will identify inattentive or unmotivated participants.

ETHICS AND DISSEMINATION

The study received research ethics board approval from the Research Review Office, Integrated Health and Social Services University Network for West-Central Montreal (CODIM-FLP-16-219). The study will adopt a multimodal approach to disseminate the study's findings to researchers, clinicians, cancer and immunisation organisations and the public in Canada and internationally.

Cervical HPV type-specific pre-vaccination prevalence and age distribution in Croatia

The main etiological factor of precancerous lesion and invasive cervical cancer are oncogenic human papillomaviruses types (HPVs). The objective of this study was to establish the distribution of the most common HPVs in different cervical lesions and cancer prior to the implementation of organized population-based cervical screening and HPV vaccination in Croatia. In this study, 4,432 cervical specimens, collected through a 16-year period, were tested for the presence of HPV-DNA by polymerase chain reaction (PCR) with three sets of broad-spectrum primers and type-specific primers for most common low-risk (LR) types (HPV-6, 11) and the most common high-risk (HR) types (HPV-16, 18, 31, 33, 45, 52, 58). Additional 35 archival formalin-fixed, paraffin embedded tissue of cervical cancer specimens were analyzed using LiPA25 assay. The highest age-specific HPV-prevalence was in the group 18-24 years, which decreased continuously with age (P<0.0001) regardless of the cytological diagnosis. The prevalence of HR-HPV types significantly increased (P<0.0001) with the severity of cervical lesions. HPV-16 was the most common type found with a prevalence (with or without another HPV-type) of 6.9% in normal cytology, 15.5% in atypical squamous cells of undetermined significance, 14.4% in low-grade squamous intraepithelial lesions, 33.3% in high-grade squamous intraepithelial lesions, and 60.9% in cervical cancer specimens (P<0.0001). This study provides comprehensive and extensive data on the distribution of the most common HPV types among Croatian women, which will enable to predict and to monitor the impact of HPV-vaccination and to design effective screening strategies in Croatia.

Human Papillomavirus Genotype Distribution among Cervical Cancer Patients prior to Brazilian National HPV Immunization Program

To evaluate the impact of HPV immunization and possible changes in virus type-specific prevalence associated with cervical cancer, it is important to obtain baseline information based on socioeconomic, educational, and environmental characteristics in human populations. We describe these characteristics and the type-specific HPV distribution in 1,183 women diagnosed with cervical cancer in two Brazilian healthcare institutions located at the Southeastern (Rio de Janeiro/RJ) and the Amazonian (Belém/PA) regions. Large differences were observed between women in these regions regarding economic, educational, and reproductive characteristics. The eight most frequent HPV types found in tumor samples were the following: 16, 18, 31, 33, 35, 45, 52, and 58. Some HPV types classified as unknown or low risk were found in tumor samples with single infections, HPV 83 in RJ and HPV 11, 61, and 69 in PA. The proportion of squamous cervical cancer was lower in RJ than in PA (76.3% versus 87.3%, p < 0.001). Adenocarcinoma was more frequent in RJ than in PA (13.5% versus 6.9%, p < 0.001). The frequency of HPV 16 in PA was higher in younger women (p < 0.05). The success of a cervical cancer control program should consider HPV types, local health system organization, and sociodemographic diversity of Brazilian regions.

Bias Due to Correlation Between Times-at-Risk for Infection in Epidemiologic Studies Measuring Biological Interactions Between Sexually Transmitted Infections: A Case Study Using Human Papillomavirus Type Interactions

The clustering of human papillomavirus (HPV) infections in some individuals is often interpreted as the result of common risk factors rather than biological interactions between different types of HPV. The intraindividual correlation between times-at-risk for all HPV infections is not generally considered in the analysis of epidemiologic studies. We used a deterministic transmission model to simulate cross-sectional and prospective epidemiologic studies measuring associations between 2 HPV types. When we assumed no interactions, the model predicted that studies would estimate odds ratios and incidence rate ratios greater than 1 between HPV types even after complete adjustment for sexual behavior. We demonstrated that this residual association is due to correlation between the times-at-risk for different HPV types, where individuals become concurrently at risk for all of their partners' HPV types when they enter a partnership and are not at risk when they are single. This correlation can be controlled in prospective studies by restricting analyses to susceptible individuals with an infected sexual partner. The bias in the measured associations was largest in low-sexual-activity populations, cross-sectional studies, and studies which evaluated infection with a first HPV type as the exposure. These results suggest that current epidemiologic evidence does not preclude the existence of competitive biological interactions between HPV types.

Variability of high risk HPV genotypes among HIV infected women in Mwanza, Tanzania- the need for evaluation of current vaccine effectiveness in developing countries

Background

High risk (HR) human papilloma Virus (HPV) genotypes have been associated with cervical cancer. In Tanzania there is a limited data on the epidemiology of HPV and genotypes distribution among HIV infected women. Here we document varieties of HPV genotypes associated with cervical squamous intraepithelial lesions (SIL) among HIV- infected women at Bugando Medical Centre, Mwanza-Tanzania.

Methods

A cross sectional hospital based study involving HIV infected women was conducted between August and October, 2014. Exfoliated cells from ectocervix and endocervix were collected using cytobrush. HPV genotypes were detected using polymerase chain reaction (PCR) followed by sequencing using specific primers targeting broad range of HPV types. Cytology was done to establish squamous intraepithelial lesions. Log binomial regression analysis was done to establish risk ratios (RR) associated with HPV infection using STATA version 11.

Results

A total of 255 HIV infected women with mean age 39.2 ± 9.1 years were enrolled in the study. HPV DNA was detected in 138/255 (54.1 %, 95 % CI: 47-60) of HIV infected women. Twenty six genotypes were detected in various combinations; of these 17(65.3 %) were of HR genotypes. HR genotypes were detected in 124(48.6 %) of HIV infected women. Common HR genotypes detected were HPV-52(26), HPV-58(21), HPV-35(20) and HPV-16(14). The risk of being HPV positive was significantly higher among women with CD4 counts <100 (RR: 1.20, 95 % CI: 1.05-1.35, P = 0.006) and women with SIL (RR: 1.37, 95 % CI: 1.11-1.68, P = 0.005)

Conclusion

Significant proportion of HIV infected women with low CD4 counts have various grades of cervical SIL associated with varieties of uncommon HR genotypes. There is a need to evaluate the effectiveness of the current vaccine in preventing cervical cancer in developing countries where HIV is endemic.

Update on the new 9-valent vaccine for human papillomavirus prevention

OBJECTIVE

To provide family physicians with information on the efficacy, safety, public health effects, and cost-effectiveness of the 9-valent human papillomavirus (HPV) vaccine.

QUALITY OF EVIDENCE

Relevant publications in PubMed up to May 2015 were reviewed and analyzed. Most evidence cited is level I (randomized controlled trials and meta-analyses) or level II (cross-sectional, case-control, and epidemiologic studies). Government reports and recommendations are also referenced.

MAIN MESSAGE

The 9-valent HPV vaccine, which protects against HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58, is safe and effective and will further reduce the incidence of HPV infection, as well as HPV-related cancers. It can also indirectly protect unvaccinated individuals through herd immunity. With an effective vaccination program, most cervical cancers can be prevented. Analyses show that the cost-effectiveness of the 9-valent HPV vaccine in female patients is comparable to the original quadrivalent HPV vaccine (which protects against HPV types 6, 11, 16, and 18) currently in use. However, the usefulness of vaccinating male patients with the 9-valent HPV vaccine needs further investigation.

CONCLUSION

The 9-valent HPV vaccine offers more protection against HPV than the quadrivalent HPV vaccine does and is as safe. Analysis of cost-effectiveness favours its use, at least in adolescent girls. Therefore, physicians should recommend the 9-valent HPV vaccine to patients instead of the quadrivalent HPV vaccine.

The DNA load of six high-risk human papillomavirus types and its association with cervical lesions

Background

Analysing human papillomavirus (HPV) viral load is important in determining the risk of developing cervical cancer (CC); most knowledge to date regarding HPV viral load and cervical lesions has been related to HPV-16. This study evaluated the association between the viral load of the six most prevalent high-risk viral types in Colombia and cervical intraepithelial neoplasia (CIN) frequency.

Methods

114 women without CIN and 59 women having CIN confirmed by colposcopy, all of them positive by conventional PCR for HPV infection in the initial screening, were included in the study. Samples were tested for six high-risk HPV types to determine viral copy number by real-time PCR. Crude and adjusted odds ratios (OR_a) were estimated for evaluating the association between each viral type’s DNA load and the risk of cervical lesions occurring.

Results

The highest viral loads were identified for HPV-33 in CIN patients and for HPV-31 in patients without lesions (9.33 HPV copies, 2.95 interquartile range (IQR); 9.41 HPV copies, 2.58 IQR). Lesions were more frequent in HPV-16 patients having a low viral load (3.53 OR_a, 1.16–10.74 95%CI) compared to those having high HPV-16 load (2.62 OR_a, 1.08–6.35 95%CI). High viral load in HPV-31 patients was associated with lower CIN frequency (0.34 OR_a, 0.15–0.78 95%CI).

Conclusions

An association between HPV DNA load and CIN frequency was seen to be type-specific and may have depended on the duration of infection. This analysis has provided information for understanding the effect of HPV DNA load on cervical lesion development.

Type-specific human papillomavirus infections and Pap test findings in Inuit and non-Inuit women in Nunavut, Canada

Objective

To determine the prevalence and distribution of type-specific human papillomavirus (HPV) infections and their association with cytological outcomes in women living in the Canadian territory of Nunavut.

Methods

Surveillance of type-specific HPV infection was conducted. Cervical specimens of all Inuit, First Nations and non-Aboriginal women in Nunavut who presented for a Pap test in any clinical setting between January 2008 and March 2009 were tested for HPV infection. The association between high-grade cervical lesions and HPV type was also examined.

Results

HPV results were available for 4,043 individual women (13 to 77 years). Of those with known ethnicity (N=4,033), 89.2% were Inuit, 0.4% were First Nations and 10.4% were non-Aboriginal. First Nations women were included in all analyses except those making comparisons by ethnicity, due to the small number of individuals in this group. Overall, 29.9% of women were found to be infected with HPV (any type) and 19.9% with any high-risk HPV (type 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58 or 59). Most often, women were infected with HPV 16 (6.4%) followed by HPV 31 (3.1%). There were no statistically significant differences between Inuit and non-Aboriginal (reference group) women 20 years of age and older regarding the prevalence of any HPV (odds ratios (OR): 1.19, 95% confidence intervals (CI): 0.92-1.54), high-risk HPV (OR: 1.06, 95% CI: 0.78-1.44) or HPV 16 and 18 (OR: 0.81, 95% CI: 0.51-1.27). HPV 31 was the only type that was significantly more frequent among Inuit than non-Aboriginal women (OR: 3.95, 95% CI: 1.24-12.54). There was no difference in the overall occurrence of cervical abnormalities between non-Aboriginal and Inuit women (p-value = 0.17). HPV 16 was strongly associated with cervical dysplasia, being present in 50.9% of specimens with a high-grade lesion.

Conclusion

HPV is a significant public health issue in the territory of Nunavut. The findings presented in this article are similar to those in other studies among Inuit women, with prevalence of HPV being higher than in studies conducted among non-Inuit women in other regions of Canada. These results provide a baseline of HPV prevalence that precedes the introduction of the Nunavut HPV Immunization Program in 2010 and will allow for future evaluation. The high prevalence of HPV infection among women living in Nunavut can be reduced through immunization and associated high-grade cervical abnormalities mitigated by regular cervical screening.

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.

Self-reported barriers and facilitators to preventive human papillomavirus vaccination among adolescent girls and young women: a systematic review

OBJECTIVE

Widespread uptake of preventive human papillomavirus vaccination among target groups is an important public health goal. To evaluate barriers and facilitators to human papillomavirus vaccination, we conducted a systematic review of self-reported views of adolescent girls and young women.

METHODS

Twenty-two studies including 8079 females aged 9-26 years in North America, published between 2008 and 2011 (representing studies conducted post-vaccine availability), were included. Two reviewers performed all levels of screening and data abstraction in duplicate. We collated findings pertaining to vaccination barriers and facilitators, study characteristics, and study quality.

RESULTS

Participants were mainly unvaccinated (70%) and sexually active. Twenty-one barriers to vaccination were identified. Cost was the most frequently reported barrier, followed by feelings that vaccination was unnecessary, and concerns regarding vaccine safety and side effects. Facilitators included perceived benefit of vaccination, health care provider recommendations, and social norms. Few studies specifically sought to isolate the views of adolescents, though not being sexually active was the most commonly reported barrier among this group.

CONCLUSION

Understanding factors which arbitrate in vaccination decisions among key target groups can improve the success of health promotion interventions. Additional studies of superior methodological quality are needed to produce reliable data to inform health promotion strategies.

The epidemiology of sexually transmitted co-infections in HIV-positive and HIV-negative African-Caribbean women in Toronto

BACKGROUND

HIV disproportionately affects African-Caribbean women in Canada but the frequency and distribution of sexually transmitted infections in this community have not been previously studied.

METHODS

We recruited women based on HIV status through a Toronto community health centre. Participants completed a socio-behavioural questionnaire using Audio Computer Assisted Self-Interview (ACASI) and provided blood for syphilis, HIV, hepatitis B and C, herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), and human cytomegalovirus (CMV) serology, urine for chlamydia and gonorrhea molecular testing and vaginal secretions for bacterial vaginosis (BV) and human papillomavirus (HPV). Differences in prevalence were assessed for statistical significance using chi-square.

RESULTS

We recruited 126 HIV-positive and 291 HIV-negative women, with a median age of 40 and 31 years, respectively (p < 0.001). Active HBV infection and lifetime exposure to HBV infection were more common in HIV-positive women (4.8% vs. 0.34%, p = 0.004; and 47.6% vs. 21.2%, p < 0.0001), as was a self-reported history of HBV vaccination (66.1% vs. 44.0%, p = 0.0001). Classical STIs were rare in both groups; BV prevalence was low and did not vary by HIV status. HSV-2 infection was markedly more frequent in HIV-positive (86.3%) than HIV-negative (46.6%) women (p < 0.0001). Vaginal HPV infection was also more common in HIV-positive than in HIV-negative women (50.8% vs. 22.6%, p < 0.0001) as was infection with high-risk oncogenic HPV types (48.4% vs. 17.3%, p < 0.0001).

CONCLUSIONS

Classical STIs were infrequent in this clinic-based population of African-Caribbean women in Toronto. However, HSV-2 prevalence was higher than that reported in previous studies in the general Canadian population and was strongly associated with HIV infection, as was infection with hepatitis B and HPV.

Self-collected versus clinician-collected sampling for sexually transmitted infections: a systematic review and meta-analysis protocol

BACKGROUND

Three meta-analyses and one systematic review have been conducted on the question of whether self-collected specimens are as accurate as clinician-collected specimens for STI screening. However, these reviews predate 2007 and did not analyze rectal or pharyngeal collection sites. Currently, there is no consensus on which sampling method is the most effective for the diagnosis of genital chlamydia (CT), gonorrhea (GC) or human papillomavirus (HPV) infection. Our meta-analysis aims to be comprehensive in that it will examine the evidence of whether self-collected vaginal, urine, pharyngeal and rectal specimens provide as accurate a clinical diagnosis as clinician-collected samples (reference standard).

INCLUSION AND EXCLUSION CRITERIA

Eligible studies include both randomized and non-randomized controlled trials, pre- and post-test designs, and controlled observational studies.

SEARCH STRATEGY

The databases that will be searched include the Cochrane Database of Systematic Reviews, Web of Science, Database of Abstracts of Reviews of Effects (DARE), EMBASE and PubMed/Medline.

DATA COLLECTION AND ANALYSIS

Data will be abstracted independently by two reviewers using a standardized pre-tested data abstraction form. Heterogeneity will be assessed using the Q2 test. Sensitivity and specificity estimates with 95% confidence intervals as well as negative and positive likelihood ratios will be pooled and weighted using random effects meta-analysis, if appropriate. A hierarchical summary receiver operating characteristics curve for self-collected specimens will be generated.

DISCUSSION

This synthesis involves a meta-analysis of self-collected samples (urine, vaginal, pharyngeal and rectal swabs) versus clinician-collected samples for the diagnosis of CT, GC and HPV, the most prevalent STIs. Our systematic review will allow patients, clinicians and researchers to determine the diagnostic accuracy of specimens collected by patients compared to those collected by clinicians in the detection of chlamydia, gonorrhea and HPV.

The prevalence of human papillomavirus and its impact on cervical dysplasia in Northern Canada

Introduction

Certain types of the Human Papillomavirus (HPV) are sexually transmitted and highly associated with development of cervical dysplasia and cervical cancer but the distribution of HPV infection in the North, particularly amongst First Nations, Metis, and Inuit peoples, is little known. The purposes of the study are to identify the prevalence of type-specific HPV infections and the association of different HPV types with cervical dysplasia among women in Northern Canada.

Methods

This was a cross-sectional study with attendants of the routine or scheduled Pap testing program in the Northwest Territories (NWT), Nunavut, Labrador and Yukon, Canada. Approximately half of each sample was used for Pap test and the remaining was used for HPV genotyping using a Luminex-based method. Pap test results, HPV types, and demographic information were linked for analyses.

Results

Results from 14,598 specimens showed that HPV infection was approximately 50% higher among the Aboriginal than the non-Aboriginal population (27.6% vs. 18.5%). Although the most common HPV type detected was HPV 16 across region, the prevalence of other high risk HPV types was different. The age-specific HPV prevalence among Aboriginal showed a ‘U’ shape which contrasted to non-Aboriginal. The association of HPV infection with cervical dysplasia was similar in both Aboriginal and non-Aboriginal populations.

Conclusions

The HPV prevalence was higher in Northern Canada than in other Areas in Canada. The prevalence showed a higher rate of other high risk HPV infections but no difference of HPV 16/18 infections among Aboriginal in comparison with non-Aboriginal women. This study provides baseline information on HPV prevalence that may assist in surveillance and evaluation systems to track and assess HPV vaccine programs.

Type-specific prevalence of human papillomavirus in women screened for cervical cancer in Labrador, Canada

Background

A higher incidence of cervical cancer and human papillomavirus (HPV) infection has been reported in northern Canada and in First Nation, Métis and Inuit women, with some evidence to suggest that the HPV type distribution in these populations may be different from the rest of Canada.

Objective

The objective of this study was to measure the HPV type prevalence in Labrador women to determine if significant differences in HPV types could reduce the effectiveness of HPV vaccination.

Design

The prevalence of HPV types was determined in 1,370 women presenting for routine pap screening in Labrador between February and November 2010. Cervical cytology and HPV genotyping were performed on the same liquid-based cytology specimens.

Results

The overall prevalence of HPV was 21.4%; cytological abnormalities were found in 8.8% of the participants. HPV 16 and 18 were the most common high-risk HPV types. These two types were found in 52.4% of high-grade lesions. The prevalence in HPV infections was comparable across the Labrador regions.

Conclusions

The present results support the potential effectiveness of the HPV immunization program in Labrador.

Type-specific prevalence of Human Papillomavirus infection among women in the Northwest Territories, Canada

BACKGROUND

Certain types of Human Papillomavirus (HPV) are highly associated with cervical cancer and precursor lesions (dysplasia), but the distribution of HPVs in Northern Canada is largely unknown. This study determined the prevalences of HPV infection due to different virus types and the association of different virus types with cervical dysplasia in the Northwest Territories (NWT).

METHODS

Between April 2008 and March 2009, women who underwent routine Pap testing in the NWT were included in the study. An in-house Luminex assay detected type-specific HPV infections. The HPV prevalence rates and population attributable risk fractions were calculated.

RESULTS

In 5725 bio-samples, the overall HPV prevalence was 24.2%, and of the HPV-positive samples, 76.6% harbored high-risk types, 35.2% harbored multi-type infections, and 21.6% harbored HPV16 or 18 infections. The HPV prevalence was approximately 50% higher among Aboriginal than non-Aboriginal women. The age-specific HPV prevalence exhibited a U-shape distribution in the Aboriginal group. The prevalence of HPV16 or 18 infections found in high-grade lesions was 34.1%. Among this study population, 89.5% of the cases with cervical dysplasia were attributable to HPV infection, with 27.1% attributable to HPV16/18.

CONCLUSION

The high prevalence of high-risk HPV in this population, particularly in the Aboriginal group, will require further studies to identify specific predictors of infection.

Canadian oncogenic human papillomavirus cervical infection prevalence: systematic review and meta-analysis

BACKGROUND

Oncogenic human papillomavirus (HPV) infection prevalence is required to determine optimal vaccination strategies. We systematically reviewed the prevalence of oncogenic cervical HPV infection among Canadian females prior to immunization.

METHODS

We included studies reporting DNA-confirmed oncogenic HPV prevalence estimates among Canadian females identified through searching electronic databases (e.g., MEDLINE) and public health websites. Two independent reviewers screened literature results, abstracted data and appraised study quality. Prevalence estimates were meta-analyzed among routine screening populations, HPV-positive, and by cytology/histology results.

RESULTS

Thirty studies plus 21 companion reports were included after screening 837 citations and 120 full-text articles. Many of the studies did not address non-response bias (74%) or use a representative sampling strategy (53%). Age-specific prevalence was highest among females aged < 20 years and slowly declined with increasing age. Across all populations, the highest prevalence estimates from the meta-analyses were observed for HPV types 16 (routine screening populations, 8 studies: 8.6% [95% confidence interval 6.5-10.7%]; HPV-infected, 9 studies: 43.5% [28.7-58.2%]; confirmed cervical cancer, 3 studies: 48.8% [34.0-63.6%]) and 18 (routine screening populations, 8 studies: 3.3% [1.5-5.1%]; HPV-infected, 9 studies: 13.6% [6.1-21.1%], confirmed cervical cancer, 4 studies: 17.1% [6.4-27.9%].

CONCLUSION

Our results support vaccinating females < 20 years of age, along with targeted vaccination of some groups (e.g., under-screened populations). The highest prevalence occurred among HPV types 16 and 18, contributing a combined cervical cancer prevalence of 65.9%. Further cancer protection is expected from cross-protection of non-vaccine HPV types. Poor study quality and heterogeneity suggests that high-quality studies are needed.

Human Papillomavirus in Brazilian women with and without cervical lesions

Background

Human Papillomavirus (HPV) high-risk (HR) types are the causal factor for cervical cancer and premalignant dysplasia. Data on frequency of HPV types provide a basis to design and evaluate HPV prevention programs. Taking into account the heterogeneity of HPV types across and within populations this study aims to access the HPV frequency in Brazilian women.

Results

We identified 24 different types of HPV, including a Betapapillomavirus and a likely new type, previously reported, from 132 women positive for the virus analysed by Hybrid Capture II assay. These women were infected by a single or multiple HPV types and 142 HPV strains were identified. HR types were found in 75% of women and HPV types 16, 18, 45, 58, and 66 had the highest frequency. Significant differences in frequency of HR HPV types were found for presence of cervical lesions, and for different HPV species and women age.

Conclusions

Compared with previous studies in Brazil, our data indicated differences in frequency and HPV type diversity, a significant association of other HR-types but HPV16 and 18 and cervical lesions, and a trend for distinct distribution of HPV types by age.

A randomized controlled trial of Human Papillomavirus (HPV) testing for cervical cancer screening: trial design and preliminary results (HPV FOCAL Trial)

BACKGROUND

In the HPV FOCAL trial, we will establish the efficacy of hr-HPV DNA testing as a stand-alone screening test followed by liquid based cytology (LBC) triage of hr-HPV-positive women compared to LBC followed by hr-HPV triage with > or = CIN3 as the outcome.

METHODS/DESIGN

HPV-FOCAL is a randomized, controlled, three-armed study over a four year period conducted in British Columbia. It will recruit 33,000 women aged 25-65 through the province's population based cervical cancer screening program. Control arm: LBC at entry and two years, and combined LBC and hr-HPV at four years among those with initial negative results and hr-HPV triage of ASCUS cases; Two Year Safety Check arm: hr-HPV at entry and LBC at two years in those with initial negative results with LBC triage of hr-HPV positives; Four Year Intervention Arm: hr-HPV at entry and combined hr-HPV and LBC at four years among those with initial negative results with LBC triage of hr-HPV positive cases

DISCUSSION

To date, 6150 participants have a completed sample and epidemiologic questionnaire. Of the 2019 women enrolled in the control arm, 1908 (94.5%) were cytology negative. Women aged 25-29 had the highest rates of HSIL (1.4%). In the safety arm 92.2% of women were hr-HPV negative, with the highest rate of hr-HPV positivity found in 25-29 year old women (23.5%). Similar results were obtained in the intervention arm HPV FOCAL is the first randomized trial in North America to examine hr-HPV testing as the primary screen for cervical cancer within a population-based cervical cancer screening program.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number Register, ISRCTN79347302.