Human Papillomavirus type distribution in invasive cervical cancer in Uganda

Detection of human papillomavirus infection in oral cancers reported at dental facility: assessing the utility of FFPE tissues

Incidence of human papillomavirus (HPV)-associated oral cancers is on the rise. However, epidemiological data of this subset of cancers are limited. Dental hospital poses a unique advantage in detection of HPV-positive oral malignancies. We assessed the utility of formalin-fixed paraffin-embedded (FFPE) tissues, which are readily available, for evaluation of high-risk HPV infection in oral cancer. For protocol standardization, we used 20 prospectively collected paired FFPE and fresh tissues of histopathologically confirmed oral cancer cases reported in Oral Medicine department of a dental hospital for comparative study. Only short PCRs (~ 200 bp) of DNA isolated using a modified xylene-free method displayed a concordant HPV result. For HPV analysis, we used additional 30 retrospectively collected FFPE tissues. DNA isolated from these specimens showed an overall 23.4% (11/47) HPV positivity with detection of HPV18. Comparison of HPV positivity from dental hospital FFPE specimens with overall HPV positivity of freshly collected oral cancer specimens (n = 55) from three cancer care hospitals of the same region showed notable difference (12.7%; 7/55). Further, cancer hospital specimens showed HPV16 positivity and displayed a characteristic difference in reported sub-sites and patient spectrum. Overall, using a xylene-free FFPE DNA isolation method clubbed with short amplicon PCR, we showed detection of HPV-positive oral cancer in dental hospitals.

Cervical cancer risk perceptions, sexual risk behaviors and sexually transmitted infections among Bivalent Human Papillomavirus vaccinated and non-vaccinated young women in Uganda - 5 year follow up study

Background

Previous studies were conflicting regarding the associations between HPV vaccination, cervical cancer risk perceptions, high-risk sexual behaviors and STIs. This study compared the HPV-vaccinated and non-vaccinated young women in Uganda regarding cervical cancer risk perceptions, high-risk sexual behaviors, syphilis and HIV infections 5 years after vaccine implementation.

Methods

This was a population-based comparative cross-sectional survey conducted in Uganda. The 438 participants were sexually active young women aged 15–24 years and mean age was 18.6 (SD 1.4). The majority (53.0%) were HPV-vaccinated in 2008 without assessment of sexual activity prior to HPV vaccination. Upon verbal assessment of sexual activity at the time of follow-up, data were collected using a questionnaire and laboratory testing of blood samples for syphilis and HIV infections.

Results

There were no significant differences between the HPV-vaccinated and non-vaccinated groups regarding the prevalence of high-risk sexual behaviors, syphilis and HIV infections. Cervical cancer risk perceptions and age at sexual debut were nonetheless significantly lower among the vaccinated group compared to their non-vaccinated counterparts. However, HPV vaccination was not significantly associated to cervical cancer risk perceptions and early age at sexual debut in multivariate logistic regression analysis.

Conclusions

We found no associations between HPV vaccination, cervical cancer risk perceptions, high-risk sexual behaviors, syphilis and HIV infections among young women in Uganda 5 years after vaccine implementation. Young girls in the study population were found to be sexually active at a young age, affirming the importance of targeting girls of younger age for HPV vaccination.

Electronic supplementary material

The online version of this article (doi:10.1186/s12905-017-0394-y) contains supplementary material, which is available to authorized users.

Human Papillomavirus types distribution among women with cervical preneoplastic, lesions and cancer in Luanda, Angola

Introduction

Cervical cancer is the leading cause of cancer deaths among females in Angola and human papillomavirus (HPV) is the main risk factor for the development of pre-cancerous squamous intraepithelial lesions. The diversity and frequency of HPV types in Angola has yet to be reported.

Aim

To determine the frequency of HPV among women with squamous intraepithelial lesions from women in Luanda, Angola.

Methods

Study participants included women diagnosed with cytological abnormalities that voluntarily provided Pap smears (n = 64). Genomic DNA was extracted from the samples for use as templates in the PCR amplification of HPV sequences. PCR products were sequenced to determine HPV type.

Results

HPV DNA was detected in 71.9% (46/64) in the samples. A higher diversity of HPV types was found in the cytological lesions, such as ASCUS and LSIL (HPV16, 6, 18, 31, 58, 66, 70 and 82, in order of frequency) than that detected for HSIL and SSC (HPV16, 18, 6 and 33). The most prevalent HPV type were: HPV16, HPV6 and HPV18.

Conclusion

This is the first report on HPV type diversity and frequency in woman of Angola. The results suggest that large-scale studies across Africa would improve our understanding of interrelationship between HPV infections and cervical cancer. More directly, the identification of the HPV types most prevalent suggests that women in Angola would benefit from currently available HPV vaccines.

Significantly Reduced Genoprevalence of Vaccine-Type HPV-16/18 Infections among Vaccinated Compared to Non-Vaccinated Young Women 5.5 Years after a Bivalent HPV-16/18 Vaccine (Cervarix®) Pilot Project in Uganda

The objective of this study was to determine the prevalence and some predictors for vaccine and non-vaccine types of HPV infections among bivalent HPV vaccinated and non-vaccinated young women in Uganda. This was a comparative cross sectional study 5.5 years after a bivalent HPV 16/18 vaccination (Cervarix®, GlaxoSmithKline, Belgium) pilot project in western Uganda. Cervical swabs were collected between July 2014-August 2014 and analyzed with a HPV genotyping test, CLART^® HPV2 assay (Genomica, Madrid Spain) which is based on PCR followed by microarray for determination of genotype. Blood samples were also tested for HIV and syphilis infections as well as CD4 and CD8 lymphocyte levels. The age range of the participants was 15–24 years and mean age was 18.6(SD 1.4). Vaccine-type HPV-16/18 strains were significantly less prevalent among vaccinated women compared to non-vaccinated women (0.5% vs 5.6%, p 0.006, OR 95% CI 0.08(0.01–0.64). At type-specific level, significant difference was observed for HPV16 only. Other STIs (HIV/syphilis) were important risk factors for HPV infections including both vaccine types and non-vaccine types. In addition, for non-vaccine HPV types, living in an urban area, having a low BMI, low CD4 count and having had a high number of life time sexual partners were also significant risk factors. Our data concurs with the existing literature from other parts of the world regarding the effectiveness of bivalent HPV-16/18 vaccine in reducing the prevalence of HPV infections particularly vaccine HPV- 16/18 strains among vaccinated women. This study reinforces the recommendation to vaccinate young girls before sexual debut and integrate other STI particularly HIV and syphilis interventions into HPV vaccination packages.

Acceptability of study procedures (self-collected introital swabs, blood draws and stool sample collection) by students 10-16 years for an HPV vaccine effectiveness study: a pilot study

Background

A cohort study was planned to evaluate vaccine immunogenicity and effect of malaria and helminth co-infections on the bivalent Human papilloma virus (HPV) vaccine. The study would involve self collected introital swabs, blood draws and stool sample collection. We therefore conducted a pilot study to assess the acceptability of these procedures among the students and their parents.

Results

A cross-sectional study among forty four students from two purposively selected primary schools of Western Uganda. Exit interviews and two focus group discussions (FGD) (for parents) were conducted. Acceptability was measured by willingness to undergo the procedures again, recommending the procedures to others as well as proportion of introital swabs positive for β globulin. FGD determined acceptability of the parents and explored opinions and perceptions that would influence their decisions. HPV-16/18 and β globulin deoxyribonucleic acid (DNA) were analysed using a polymerase chain reaction (PCR) kit. All the students (100 %) in the study were willing to provide a self- collected introital swab and a stool sample as well as recommending their friends while (86.3 %) were willing for blood draws. There were 40/44 (90.1 %) self collected introital swabs that had positive result for human β globulin though none of them was positive for HPV-16/18. In the FGD, it emerged that parents concerns were on the blood draws and introital swab collection which were addressed.

Conclusions

The study procedures were highly acceptable among this study population of students and their parents. Follow-up to assess HPV vaccine effectiveness and factors that may influence the vaccine in this age group is feasible.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-016-1984-8) contains supplementary material, which is available to authorized users.

Genotypic characterisation of human papillomavirus infections among persons living with HIV infection; a case-control study in Kumasi, Ghana

OBJECTIVES

The objective of this study is to describe the burden of human papillomavirus (HPV) infection among women living with HIV and non-infected women in Ghana.

METHODS

A case-control study was conducted involving 107 women living with HIV aged between 18 and 59 years (cases) and 100 non-HIV-infected apparently healthy women (controls) who were recruited from the Kumasi South Hospital, from July to December, 2014. Cervicovaginal swabs were taken from study participants to characterise 28 high- and low-risk HPV genotypes using a multiplex real-time PCR.

RESULTS

The overall mean age for the participants was 40.10 ± 9.76 years. The prevalence of high-risk (hr)-HPV genotypes was significantly higher among the cases than the controls (77.4% vs. 41.6%, P < 0.0001). Overall, HPV 58 and 54 were the most predominant high-risk (18.8%) and low-risk (15.0%) genotypes detected. The two most common hr-HPV genotype isolates were 58 (18.8%) and 35 (15.9%) with 58 being the most prevalent among age group 35-44 years compared with hr-HPV 16, 18, 35 and 45, found predominantly among 18-34 age group.

CONCLUSIONS

Significant variations exist in HPV genotypes among HIV-infected and uninfected women.

Cervical cancer screening in low-resource settings: A cost-effectiveness framework for valuing tradeoffs between test performance and program coverage

As cervical cancer screening programs are implemented in low-resource settings, protocols are needed to maximize health benefits under operational constraints. Our objective was to develop a framework for examining health and economic tradeoffs between screening test sensitivity, population coverage and follow-up of screen-positive women, to help decision makers identify where program investments yield the greatest value. As an illustrative example, we used an individual-based Monte Carlo simulation model of the natural history of human papillomavirus (HPV) and cervical cancer calibrated to epidemiologic data from Uganda. We assumed once in a lifetime screening at age 35 with two-visit HPV DNA testing or one-visit visual inspection with acetic acid (VIA). We assessed the health and economic tradeoffs that arise between (i) test sensitivity and screening coverage; (ii) test sensitivity and loss to follow-up (LTFU) of screen-positive women; and (iii) test sensitivity, screening coverage and LTFU simultaneously. The decline in health benefits associated with sacrificing HPV DNA test sensitivity by 20% (e.g., shifting from provider- to self-collection of specimens) could be offset by gains in coverage if coverage increased by at least 20%. When LTFU was 10%, two-visit HPV DNA testing with 80-90% sensitivity was more effective and more cost-effective than one-visit VIA with 40% sensitivity and yielded greater health benefits than VIA even as VIA sensitivity increased to 60% and HPV test sensitivity declined to 70%. As LTFU increased, two-visit HPV DNA testing became more costly and less effective than one-visit VIA. Setting-specific data on achievable test sensitivity, coverage, follow-up rates and programmatic costs are needed to guide decision making for cervical cancer screening.

Human papillomavirus genotypes distribution by cervical cytologic status among women attending the General Hospital of Loandjili, Pointe-Noire, Southwest Congo (Brazzaville)

HPV infection is associated with cervical cancer, one of the major public health problems in developing countries. In the Republic of Congo, despite of the high age-standardized incidence rate estimated at 25.2 per 100,000 women, molecular epidemiology data on HPV infections are very limited. We investigated HPV genotypes distribution in cervical smears among patients attending the General Hospital of Loandjili, Southwest Congo. A cross-sectional hospital-based study was conducted on 321 women. Liquid-based cytology samples were collected for cytological diagnosis and HPV detection. Nested-PCR was performed using MY09/MY11 and GP5+/GP6+ primers with genotyping by direct sequencing. Type-specific PCR for HPV-6, -11, -16, -18, -31 and -33 was also used to assess multiple infections. Out of 321 women examined, 189 (58.8%) had normal cytology, 16 (5.0%) had ASCUS and 116 (36.1%) had cytological abnormalities. HPV-DNA was detected in 22 (11.6%), 6 (37.5%), and 104 (89.6%) normal cytology, ASCUS and cytological abnormalities respectively. HPV16 was the most prevalent genotype regardless of cytological status followed by HPV70 in women without lesions and HPV33 among those with lesions. HR-HPV prevalence varied significantly according to the cervical cytology (P = 0.000). Among women without lesions, two peaks of HPV infections were observed in age group less than 30 years (60.0%) and in age group 50-59 years (7.1%). Age, age of first sex, multiple sexual partners and pregnancies were the risk factors for HPV infection in women without lesions. Our findings could be used as evidence data base for future epidemiological monitoring in this region.

Prevalence of human papillomavirus genotypes among African women with normal cervical cytology and neoplasia: a systematic review and meta-analysis

BACKGROUND

Several meta-analyses confirmed the five most prevalent human papillomavirus (HPV) strains in women with and without cervical neoplastic diseases are HPV16, 18, 31, 52, and 58. HPV16/18 are the predominant oncogenic genotypes, causing approximately 70% of global cervical cancer cases. The vast majority of the women studied in previous analyses were from Europe, North America, Asia, and most recently Latin America and the Caribbean. Despite the high burden of cervical cancer morbidity and mortality in Africa, a robust meta-analysis of HPV genotype prevalence and distribution in African women is lacking.

METHODS AND FINDINGS

We systematically searched 14 major databases from inception to August 2013 without language restriction, following the Meta-Analysis of Observational Studies in Epidemiology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Seventy-one studies from 23 African countries were identified after screening 1162 citations and data abstracted and study quality appraised from 195 articles. HPV type-specific prevalence and distribution was estimated from 17,273 cases of women with normal cervical cytology; 1019 women with atypical squamous cells of undetermined significance (ASCUS); 1444 women with low-grade squamous intraepithelial lesion (LSIL); 1571 women with high-grade squamous intraepithelial lesion (HSIL); and 4,067 cases of invasive cervical carcinoma (ICC). Overall prevalence of HPV16/18 were 4.4% and 2.8% of women with normal cytology, 12.0% and 4.4% with ASCUS, 14.5% and 10.0% with LSIL, 31.2% and 13.9% with HSIL, and 49.7% and 18.0% with ICC, respectively. Study limitations include the lack of adequate data from Middle and Northern African regions, and variations in the HPV type-specific sensitivity of different genotyping protocols.

CONCLUSIONS

To our knowledge, this study is the most comprehensive assessment of the overall prevalence and distribution of HPV genotypes in African women with and without different cervical neoplasias. We have established that HPV16/18 account for 67.7% of ICC cases among African women. Based on our findings, we highly recommend the administration of existing prophylactic vaccines to younger women not infected with HPV16/18 and an increase in HPV screening efforts for high-risk genotypes to prevent cervical cancer.

REVIEW REGISTRATION

International Prospective Register of Systematic Reviews CRD42013006558.

Comparison of five protocols to extract DNA from paraffin-embedded tissues for the detection of human papillomavirus

Formalin-fixed paraffin-embedded (FFPE) tissues are a valuable source of DNA with which to perform large retrospective studies on the epidemiology of HPV infection. Five different DNA extraction protocols were carried out to evaluate the DNA obtained from FFPE samples with polymerase chain reaction (PCR) using two primer sets to amplify a constitutive human gene, β-globin, and two primer sets to detect the L1 and E6 HPV genes. From the five DNA extraction protocols evaluated, the best results were obtained with protocol A, corresponding to a crude extract from the sample. With the procedures described herein, we were able to amplify DNA extracted from archival paraffin blocks stored for six years. However, the amplification products were more efficiently obtained with primers that amplified shorter fragments. This result indicates that a major factor limiting the extraction process in these samples is DNA fragmentation, a factor that will naturally vary between the different specimens evaluated. Also, depending upon the extraction method, PCR amplification of a human gene does not necessarily guarantee the successful extraction of viral DNA. In conclusion, different DNA and HPV detection methods can significantly influence the results. Therefore, the DNA extraction methods and primers used for DNA amplification in fixed tissues need to be chosen carefully, depending on the specific requirements of the study being carried out.

Update on prevention and screening of cervical cancer

Cervical cancer is the third most common cause of cancer in women in the world. During the past few decades tremendous strides have been made toward decreasing the incidence and mortality of cervical cancer with the implementation of various prevention and screening strategies. The causative agent linked to cervical cancer development and its precursors is the human papillomavirus (HPV). Prevention and screening measures for cervical cancer are paramount because the ability to identify and treat the illness at its premature stage often disrupts the process of neoplasia. Cervical carcinogenesis can be the result of infections from multiple high-risk HPV types that act synergistically. This imposes a level of complexity to identifying and vaccinating against the actual causative agent. Additionally, most HPV infections spontaneously clear. Therefore, screening strategies should optimally weigh the benefits and risks of screening to avoid the discovery and needless treatment of transient HPV infections. This article provides an update of the preventative and screening methods for cervical cancer, mainly HPV vaccination, screening with Pap smear cytology, and HPV testing. It also provides a discussion of the newest United States 2012 guidelines for cervical cancer screening, which changed the age to begin and end screening and lengthened the screening intervals.

The burden of human papillomavirus infections and related diseases in sub-saharan Africa

Despite the scarcity of high quality cancer registries and lack of reliable mortality data, it is clear that human papillomavirus (HPV)-associated diseases, particularly cervical cancer, are major causes of morbidity and mortality in sub-Saharan Africa (SSA). Cervical cancer incidence rates in SSA are the highest in the world and the disease is the most common cause of cancer death among women in the region. The high incidence of cervical cancer is a consequence of the inability of most countries to either initiate or sustain cervical cancer prevention services. In addition, it appears that the prevalence of HPV in women with normal cytology is higher than in more developed areas of the world, at an average of 24%. There is, however, significant regional variation in SSA, with the highest incidence of HPV infection and cervical cancer found in Eastern and Western Africa. It is expected that, due to aging and growth of the population, but also to lack of access to appropriate prevention services and the concomitant human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) epidemic, cervical cancer incidence and mortality rates in SSA will rise over the next 20 years. HPV16 and 18 are the most common genotypes in cervical cancer in SSA, although other carcinogenic HPV types, such as HPV45 and 35, are also relatively more frequent compared with other world regions. Data on other HPV-related anogenital cancers including those of the vulva, vagina, anus, and penis, are limited. Genital warts are common and associated with HPV types 6 and 11. HIV infection increases incidence and prevalence of all HPV-associated diseases. Sociocultural determinants of HPV-related disease, as well as the impact of forces that result in social destabilization, demand further study. Strategies to reduce the excessive burden of HPV-related diseases in SSA include age-appropriate prophylactic HPV vaccination, cervical cancer prevention services for women of the reproductive ages, and control of HIV/AIDS. This article forms part of a regional report entitled "Comprehensive Control of HPV Infections and Related Diseases in the Sub-Saharan Africa Region" Vaccine Volume 31, Supplement 5, 2013. Updates of the progress in the field are presented in a separate monograph entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.

The association between HIV infection, antiretroviral therapy and cervical squamous intraepithelial lesions in South Western Nigerian women

Introduction

Findings from studies that evaluated the effect of antiretroviral drug use on the development of cervical squamous intraepithelial lesion differed in their conclusions. This study investigated the association between HIV infection, antiretroviral drug use and cervical squamous intraepithelial lesion in a high HIV and cervical cancer burden setting- Nigeria.

Methods

A cross sectional study among 1140 women of known HIV status enrolled in a randomised study to determine the test characteristics of visual inspection in detecting cytology diagnosed squamous intraepithelial lesion. Multivariate analysis was used to determine the association between HIV infection, antiretroviral drug use and the twin outcome variables of cervical squamous intraepithelial lesion (SIL) and High grade squamous intraepithelial lesion (HSIL) while controlling for confounders.

Results

Prevalence of cervical squamous intraepithelial lesion was 8.5%, with a higher prevalence of 14.3% in HIV positive compared to 3.3% in HIV negative women (aOR: 5.4; 95% CI: 2.9–8.8). Not using antiretroviral drugs was found to be associated with an increased risk of SIL (aOR: 2.1; 95% CI: 1.4–3.5) and HSIL (aOR: 2.6; 95% CI: 1.1–6.4). Participants who had a CD4 cell count <200 cells/mm³, were also found to be at increased risk for SIL (aOR: 1.9; 95% CI: 1.1–5.9) and HSIL (aOR: 5.7; 95% CI: 1.1–7.2).

Conclusion

HIV infection and severe immunosuppression were found to be associated with increased risk of cervical squamous intraepithelial lesion but not viral load. For the first time, in the West African sub-region with specific HIV type and strains, we established the protective effect of antiretroviral drug use against the development of SIL. Integration of cervical cancer screening programme into HIV services and early initiation of antiretroviral drug in HIV positive women especially those with severe immune-suppression could therefore prove to be useful in preventing and controlling cervical cancer development in HIV positive women.

Prospective evaluation of E6/E7 mRNA detection by the NucliSENS Easy Q HPV assay in a stepwise protocol

The objective of the study was to evaluate prospectively the added value of E6/E7 mRNA detection in a stepwise protocol. A total of 1,422 samples were collected over a period of 17 months. The samples were referred for human papillomavirus (HPV) genotyping if they showed cytological evidence of atypical squamous cells of undetermined significance, low- or high-grade squamous intraepithelial lesion. If one or more of HPV types 16, 18, 31, 33, or 45 were present, mRNA was analyzed by the NucliSENS EasyQ HPV assay. The genotypical distribution of high-risk HPV was very heterogeneous; HPV 16, 18, 31, 33, and 45 represented 20.2%, 3.4%, 10.8%, 3.4%, and 3.8% of HPV-positive samples, respectively. Follow-up data were available for 35 patients. Although over the half (51.4%) of follow-up samples showing HPV DNA/mRNA consensus evolved to cervical intraepithelial neoplastic lesions, 25.7% showed no progression to neoplasia despite mRNA positivity. However, the major concern was the group (14.3%) that showed progression to cervical intraepithelial neoplasia despite mRNA negativity: all but one of these cases had a high-risk HPV genotype other than the five included in the NucliSENS EasyQ HPV assay. Markedly, 66.7% of the discordant samples between colposcopy and histology that underestimated the degree of cervical dysplasia were found in this group. Close monitoring of high-risk HPV DNA-positive/mRNA-negative cases remains necessary, which leads to questions about the added value of the evaluated protocol.

Are the currently existing anti-human papillomavirus vaccines appropriate for the developing world?

Cervical cancer prevention is expected to be achieved by vaccination of girls 2-3 years before sexual debut, and cervical smear cytology follow-up. The existing human papillomavirus (HPV) vaccines target the low-risk 6 and 11, and the high-risk 16 and 18 subtypes, the most common agents of ano-genital pre-invasive and invasive lesions. We conducted the review by searching PubMed using the terms "HPV," "HPV subtypes," "developing world," and "HPV-vaccine" to retrieve articles published between 2000 and 2011. We focused on studies that were relevant to the developing world. The proposed vaccination policy is currently unachievable in the developing world because of the cost of the vaccine, the lack of adequate cytology and follow-up infrastructures. Moreover, the subtypes of HPV involved in cervical pathology, their associations, and natural history (clearance and persistence rates) differ from the industrialized world. Therefore, the current bivalent and quadrivalent anti-HPV vaccines are unlikely to achieve their target in the developing world. It follows from published data that there is an obligation of the pharmaceutical industry and of the public-health policy makers not to embark on mass vaccination campaigns without thorough information and investigation of the local relevance.

Potential benefits of second-generation human papillomavirus vaccines

Background

Current prophylactic vaccines against human papillomavirus (HPV) target two oncogenic types (16 and 18) that contribute to 70% of cervical cancer cases worldwide. Our objective was to quantify the range of additional benefits conferred by second-generation HPV prophylactic vaccines that are expected to expand protection to five additional oncogenic types (31, 33, 45, 52 and 58).

Methods

A microsimulation model of HPV and cervical cancer calibrated to epidemiological data from two countries (Kenya and Uganda) was used to estimate reductions in lifetime risk of cervical cancer from the second-generation HPV vaccines. We explored the independent and joint impact of uncertain factors (i.e., distribution of HPV types, co-infection with multiple HPV types, and unidentifiable HPV types in cancer) and vaccine properties (i.e., cross-protection against non-targeted HPV types), compared against currently-available vaccines.

Results

Assuming complete uptake of the second-generation vaccine, reductions in lifetime cancer risk were 86.3% in Kenya and 91.8% in Uganda, representing an absolute increase in cervical cancer reduction of 26.1% in Kenya and 17.9% in Uganda, compared with complete uptake of current vaccines. The range of added benefits was 19.6% to 29.1% in Kenya and 14.0% to 19.5% in Uganda, depending on assumptions of cancers attributable to multiple HPV infections and unidentifiable HPV types. These effects were blunted in both countries when assuming vaccine cross-protection with both the current and second-generation vaccines.

Conclusion

Second-generation HPV vaccines that protect against additional oncogenic HPV types have the potential to improve cervical cancer prevention. Co-infection with multiple HPV infections and unidentifiable HPV types can influence vaccine effectiveness, but the magnitude of effect may be moderated by vaccine cross-protective effects. These benefits must be weighed against the cost of the vaccines in future analyses.

Human papillomavirus distribution in invasive cervical carcinoma in sub-Saharan Africa: could HIV explain the differences?

OBJECTIVES

To describe human papillomavirus (HPV) distribution in invasive cervical carcinoma (ICC) from Mali and Senegal and to compare type-specific relative contribution among sub-Saharan African (SSA) countries.

METHODS

A multicentric study was conducted to collect paraffin-embedded blocks of ICC. Polymerase chain reaction, DNA enzyme immunoassay and line probe assay were performed for HPV detection and genotyping. Data from SSA (Mozambique, Nigeria and Uganda) and 35 other countries were compared.

RESULTS

One hundred and sixty-four ICC cases from Mali and Senegal were tested from which 138 were positive (adjusted prevalence = 86.8%; 95% CI = 79.7-91.7%). HPV16 and HPV18 accounted for 57.2% of infections and HPV45 for 16.7%. In SSA countries, HPV16 was less frequent than in the rest of the world (49.4%vs. 62.6%; P < 0.0001) but HPV18 and HPV45 were two times more frequent (19.3%vs. 9.4%; P < 0.0001 and 10.3%vs. 5.6%; P < 0.0001, respectively). There was an ecological correlation between HIV prevalence and the increase of HPV18 and the decrease of HPV45 in ICC in SSA (P = 0.037 for both).

CONCLUSION

HPV16/18/45 accounted for two-thirds of the HPV types found in invasive cervical cancer in Mali and Senegal. Our results suggest that HIV may play a role in the underlying HPV18 and HPV45 contribution to cervical cancer, but further studies are needed to confirm this correlation.

Risk of seropositivity to multiple oncogenic human papillomavirus types among human immunodeficiency virus-positive and -negative Ugandan women

To understand the prospects for human papillomavirus (HPV) mass vaccination in the setting of a developing country, we studied the co-occurrence of seropositivity to multiple high-risk (hr) HPV types among HIV-positive and HIV-negative Ugandan women. Our seroepidemiological study was conducted among 2053 women attending antenatal clinics. Sera were analysed for antibodies to eight hrHPV types of the α-7 (18/45) and α-9 (16/31/33/35/52/58) species of HPV by using a multiplex serology assay. Our results show that seropositivity for greater than one hrHPV type was as common (18 %) as for a single type (18 %). HIV-positive women had higher HPV16, HPV18 and HPV45 seroprevalences than HIV-negative women. In multivariate logistic regression analysis, age (>30 years) and level of education (secondary school and above) reduced the risk, whereas parity (>5) and HIV-positivity increased the risk for multiple hrHPV seropositivity. However, in stepwise logistic regression analyses, HIV-status remained the only independent, stand-alone risk factor [odds ratio (OR) 1.7, 95 % confidence interval (CI) 1.0–2.8). On the other hand, the risk of HPV16 or HPV18 seropositive women, as compared to HPV16 or HPV18 seronegative women, for being seropositive to other hrHPV types was not significantly different when they were grouped by HIV-status (ORHPV16/HIV+ 12, 95 % CI 4.5–32 versus ORHPV16/HIV− 22, 95 % CI 15–31 and ORHPV18/HIV+ 58, 95 % CI 14–242 versus ORHPV18/HIV− 45, 95 % CI 31–65). In conclusion, seropositivity to HPV16, HPV18 and to non-vaccine hrHPV types is common in Ugandan women, suggesting that there is little natural cross-protective immunity between the types. HIV-positivity was an independent, stand-alone, albeit moderate risk factor for multiple hrHPV seropositivity. HPV mass vaccination may be the most appropriate method in the fight against cervical cancer in the Ugandan population.

Epidemiology of HPV genotypes in Uganda and the role of the current preventive vaccines: A systematic review

BACKGROUND

Limited data are available on the distribution of human papillomavirus (HPV) genotypes in the general population and in invasive cervical cancer (ICC) in Uganda. Yet, with the advent of preventive HPV vaccines that target HPV 16 and 18 responsible for causing about 70% of ICC cases in the world, such information is crucial to predict how vaccination and HPV-based screening will influence prevention of ICC.

METHODS

To review the distribution of HPV infection and prevalent genotypes, electronic databases (e.g. PubMed/MEDLINE and HINARI) were searched for peer reviewed English articles on HPV infection up to November 30, 2010. Eligible studies were selected according to the following criteria: DNA-confirmed cervical or male genital HPV prevalence and genotypes, HPV incidence estimates and HPV seroprevalence among participants.

RESULTS

Twenty studies were included in the review. Among HIV negative adult women, the prevalence of HR-HPV infections ranged from 10.2% -40.0% compared to 37.0% -100.0% among HIV positive women. Among HIV positive young women aged below 25 years, the prevalence of HR-HPV genotypes ranged from 41.6% -75.0% compared to 23.7% -67.1% among HIV negative women. Multiple infections with non vaccine HR-HPV genotypes were frequent in both HIV positive and HIV negative women. The main risk factors for prevalent HPV infections were age, lifetime number of sexual partners and HIV infection. Incident infections with HR-HPV genotypes were more frequent among adult HIV positive than HIV negative women estimated at 17.3 and 7.0 per 100 person-years, respectively. Similarly, incident HR-HPV among young women aged below 25 years were more frequent among HIV positive (40.0 per 100 person-years) than HIV negative women (20.3 per 100 person-years) women. The main risk factor for incident infection was HIV infection. HPV 16 and 18 were the most common genotypes in ICC with HPV 16/18 contributing up to 73.5% of cases with single infections.Among uncircumcised adult HIV positive males, HR-HPV prevalence ranged from 55.3% -76.6% compared to 38.6% -47.6% in HIV negative males. Incident and multiple HR-HPV infections were frequent in HIV positive males. Being uncircumcised was the main risk factor for both prevalent and incident HPV infection.

CONCLUSION

Infections with HR-HPV genotypes were very common particularly among HIV positive individuals and young women irrespective of HIV status. Given the high prevalence of HIV infection, HPV-associated conditions represent a major public health burden in Uganda. However, although the most common HPV genotypes in ICC cases in Uganda were those targeted by current preventive vaccines, there were a large number of individuals infected with other HR-HPV genotypes. Technology allowing, these other HR-HPV types should be considered in the development of the next generation of vaccines.

Human papillomavirus prevalence and cytopathology correlation in young Ugandan women using a low-cost liquid-based Pap preparation

Screening for HPV-driven cervical dysplasia and neoplasia is a significant public health concern in the developing world. The purpose of this study was to use a manual, low-cost liquid-based Pap preparation to determine HPV prevalence in HIV-positive and HIV-negative young women in Kampala, Uganda and to correlate cervical cytopathology with HPV-DNA genotype. About 196 post-partum women aged 18-30 years underwent rapid HIV testing and pelvic examination. Liquid-based cervical cytology samples were processed using a low-cost manual technique. A DNA collection device was used to collect specimens for HPV genotyping. HIV and HPV prevalence was 18 and 64%, respectively. Overall, 49% of women were infected with a high-risk HPV genotype. The most common high-risk HPV genotypes were 16 (8.2%), 33 (7.7%), 35 (6.6%), 45 (5.1%), and 58 (5.1%). The prevalence of HPV 18 was 3.6%. HIV-positive women had an HPV prevalence of 86% compared to 59% in HIV-negative women (P = 0.003). The prevalence of HPV 16/18 did not differ by HIV status. HIV-positive women were infected with a significantly greater number of HPV genotypes compared to HIV-negative women. By multivariate analysis, the main risk factor for HPV infection was coinfection with HIV. HIV-positive women were four times more likely to have abnormal cytology than HIV-negative women (43% vs. 11.6%, P < 0.001). These data highlight that HIV infection is a strong risk factor for HPV infection and resultant abnormal cervical cytology. Notably, the manual low-cost liquid-based Pap preparation is practical in this setting and offers an alternate method for local studies of HPV vaccine efficacy.

Comparison of human papillomavirus detection between freshly frozen tissue and paraffin embedded tissue of invasive cervical cancer

Background

Human Papillomavirus (HPV) detection results comparing paraffin embedded cervical tissue and other cervical specimens have been done with varying degrees of agreement. However, studies comparing freshly frozen specimens and paraffin embedded specimens of invasive cervical carcinomas are lacking. The aim of the study was to compare HPV detection using SPF₁₀ broad-spectrum primers PCR followed by DEIA and genotyping by LiPA₂₅ (version 1) between freshly frozen cervical tissue samples and paraffin embedded blocks of cervical tissue from the same patient. There were 171 pairs of paraffin embedded and freshly frozen samples analyzed from cervical carcinoma cases from Kampala, Uganda.

Results

88.9% (95% CI: 83.2%-93.2%) of paraffin embedded samples were HPV positive compared with 90.1% (95% CI: 84.6%-94.1%) of freshly frozen samples, giving an overall agreement in HPV detection between fresh tissue and paraffin embedded tissue at 86.0% (95% CI: 79.8%-90.8%). Although the proportion of HPV positive cases in freshly frozen tissue was higher than those in paraffin blocks, the difference was not statistically significant (p > 0.05). In both types of tissues, single HPV infections were predominant, with HPV16 accounting for 47% of positive cases. Comparison in the overall agreement, taking into accounts not only positivity in general, but also HPV types, showed a 65% agreement (complete agreement of 59.7%, partial agreement of 5.3%) and complete disagreement of 35.0%. HPV detection in squamous cell carcinomas (SCC) and adenocarcinomas (ADC) was similar in fresh tissue or paraffin blocks (p ≥ 0.05).

p16 immunostaining in samples that had at least one HPV negative results showed that 24 out of 25 cases had an over-expressed pattern.

Conclusions

HPV DNA detection was lower among ADC as compared to SCC. However, such differences were minimized when additional p16 testing was added, suggesting that the technical issues may largely explain the HPV negative cases.

The usefulness of immunohistochemistry in tissue microarrays of Human Papillomavirus negative adenocarcinoma of the uterine cervix

Background

The origin of adenocarcinomas presenting on the cervix uteri may be doubtful, i.e. whether it is of cervical or endometrial origin, due to the overlapping morphological features. In HPV negative samples, further tests may be needed to ascertain the nature of the tumours. We aimed to explore the use of immunohistochemistry profiles in tissue microarrays in archived samples of adenocarcinoma (ADC) of the cervix from Uganda that tested negative for HPV DNA.

Findings

Five commercially available antibodies were tested in tissue array sections immunostained utilizing the avidin-biotin (AB) technique. In 26 ADC samples, HPV was detected in 13, p16 in 15 (8 in HPV positive and 7 in HPV negative), CEA in 12, vimentin in 6, ER in 0, and PR in 2. Among the 13/25 HPV negative ADC samples, five were positive for CEA suggesting endocervical origin, and three were vimentin positive (one had a mucinous endocervical histological pattern and two were ADC, not otherwise specified, most likely of endometrial origin).

Conclusions

The immunoprofiles of ADC with the antibodies studied are rather nonspecific. By using immunohistochemistry in 13 HPV negative ADC, endocervical tumour origin was suspected in five CEA positive cases while two out of three vimentin positive samples were probably of endometrial origin, suggesting that CEA and vimentin may be valuable in distinguishing HPV negative cervical adenocarcinomas from endometrial adenocarcinomas.

Association of HIV infection with distribution and viral load of HPV types in Kenya: a survey with 820 female sex workers

BACKGROUND

Human papillomavirus (HPV) and HIV are each responsible for a considerable burden of disease. Interactions between these infections pose substantial public health challenges, especially where HIV prevalence is high and HPV vaccine coverage low.

METHODS

Between July 2005 and January 2006, a cross-sectional community-based survey in Mombasa, Kenya, enrolled female sex workers using snowball sampling. After interview and a gynaecological examination, blood and cervical cytology samples were taken. Quantitative real-time PCR detected HPV types and viral load measures. Prevalence of high-risk HPV was compared between HIV-infected and -uninfected women, and in women with abnormal cervical cytology, measured using conventional Pap smears.

RESULTS

Median age of the 820 participants was 28 years (inter-quartile range [IQR] = 24-36 years). One third of women were HIV infected (283/803; 35.2%) and these women were y more likely to have abnormal cervical cytology than HIV-negative women (27%, 73/269, versus 8%, 42/503; P < 0.001). Of HIV-infected women, 73.3% had high-risk HPV (200/273) and 35.5% had HPV 16 and/or 18 (97/273). Corresponding figures for HIV-negative women were 45.5% (229/503) and 15.7% (79/503). After adjusting for age, number of children and condom use, high-risk HPV was 3.6 fold more common in HIV-infected women (95%CI = 2.6-5.1). Prevalence of all 15 of the high-risk HPV types measured was higher among HIV-infected women, between 1.4 and 5.5 fold. Median total HPV viral load was 881 copies/cell in HIV-infected women (IQR = 33-12,110 copies/cell) and 48 copies/cell in HIV-uninfected women (IQR = 6-756 copies/cell; P < 0.001). HPV 16 and/or HPV 18 were identified in 42.7% of LSIL (32/75) and 42.3% of HSIL (11/26) lesions (P = 0.98). High-risk HPV types other than 16 and 18 were common in LSIL (74.7%; 56/75) and HSIL (84.6%; 22/26); even higher among HIV-infected women.

CONCLUSIONS

HIV-infected sex workers had almost four-fold higher prevalence of high-risk HPV, raised viral load and more precancerous lesions. HPV 16 and HPV 18, preventable with current vaccines, were associated with cervical disease, though other high-risk types were commoner. HIV-infected sex workers likely contribute disproportionately to HPV transmission dynamics in the general population. Current efforts to prevent HIV and HPV are inadequate. New interventions are required and improved implementation of existing strategies.

Cervical cancer: the sub-Saharan African perspective

Cervical cancer is the second most common cancer in women worldwide and the leading cause of cancer deaths in developing countries. While incidence and mortality rates of cervical cancer have fallen significantly in developed countries, 83% of all new cases that occur annually and 85% of all deaths from the disease occur in developing countries. Cervical cancer is the most common cancer among women in sub-Saharan Africa. The incidence is on the increase in some countries. Knowledge and awareness of this disease on the continent are very poor and mortality still very high. Facilities for the prevention and treatment of cervical cancer are still very inadequate in many countries in the region. Governments in sub-Saharan Africa must recognise cervical cancer as a major public health concern and allocate appropriate resources for its prevention and treatment, and for research. Indeed, cervical cancer in this region must be accorded the same priority as HIV, malaria, tuberculosis and childhood immunisations.