Age and geographic variability of human papillomavirus high-risk genotype distribution in a large unvaccinated population and of vaccination impact on HPV prevalence

Update on Effects of the Prophylactic HPV Vaccines on HPV Type Prevalence and Cervical Pathology

Most national prophylactic HPV vaccination programs started in approximately 2008, with either the bivalent Cervarix HPV16/18 or quadrivalent Gardasil (HPV6/11/16/18) vaccines, which were then followed by introduction of the nonavalent Gardasil 9 (HPV6/11/16/18/ 31/33/45/52/58) vaccine from 2015. Since that time, these products have demonstrated their ability to prevent infection with vaccine-covered HPV types and subsequent development of HPV-related cervical and genital pathologies. The data indicate that vaccination of young girls prior to sexual debut is more effective than vaccination of older HPV+ve women. Although some studies have shown a decline in the prevalence of vaccine-covered HPV types, there are national and regional differences in overall vaccine efficacy. Furthermore, several recently published studies show an increase in the prevalence of non-vaccine-covered HPV types in vaccinated populations, which is indicative of HPV type-replacement. It is also notable that vaccine-related changes in HPV type prevalence spread between vaccinated and unvaccinated women at the same geographical location-presumably via sexual transmission. In conclusion, it is not yet clear what effect dissemination of vaccine-associated changes in HPV type prevalence will have on vaccine efficacy and cervical pathology, particularly in mixed populations of vaccinated and unvaccinated women. However, it is very clear these observations do underscore the need for long-term continuation of cervical screening combined with regular reassessment of testing practices.

Clinical and epidemiological features of high-risk human papillomavirus infection in patients with cervical intraepithelial lesions

OBJECTIVE

In this study, we analyzed the clinical and epidemiological features of high-risk human papillomavirus (HR-HPV) infection in patients with cervical intraepithelial lesions.

METHODS

Retrospective analysis was performed on the clinical data of 240 cases of histologically confirmed cervical squamous intraepithelial lesions to determine any correlation between HPV infection characteristics, age distribution, and cervical epithelial lesions.

RESULTS

Patients between the ages of 31 and 40 with cervical intraepithelial lesions were more likely to have high-grade squamous intraepithelial lesions (HSIL; 40.7%) than low-grade squamous intraepithelial lesions (LSIL; 31.3%) (P < 0.05). In patients with HSIL, HR-HPV16, HR-HPV33, and HR-HPV52 were the most common types of HPV infection, while in patients with LSIL, HR-HPV16, HR-HPV52, and HR-HPV58 were the most common types of HPV infection. The highest percentage of single infections occurred in the HSIL group (69.6%), followed by the LSIL group (68.8%). HSIL was present in a significant number of patients (28.6%) aged 30 years and above who tested positive for 12 HPV types but negative for TCT.

CONCLUSION

The prevalence of HSIL is greatest in younger patients. Patients with cervical epithelial lesions typically have a single infection of a high-risk HPV genotype-HR-HPV16, HR-HPV33, HR-HPV52, or HR-HPV58. Patients aged 30 years and above who test positive for one of 12 types of HPV but negative for TCT are at increased risk for developing HSIL. In order to detect cervical lesions early and begin treatment without delay, colposcopy should be performed regardless of whether or not a high-risk HPV infection is present.

Distribution of high-risk human papillomavirus in women with ASC-US or LSIL in Tunisian women: Place of HPV testing for women triage in Tunisia

The present study aimed to evaluate the distribution of oncogenic HPVs in Tunisian women diagnosed with ASC-US or LSIL in order to highlight the importance of HPV testing in the management of women with minor cytological lesions. The study involved 213 cervical samples from women aged from 18 to 82 years and diagnosed with ASC-US or LSIL. HPV detection and genotyping was performed by nested PCR followed by reverse Line Blotting. HPV DNA was identified in 161 cases (76.3%). Oncogenic HPV genotypes were detected in 53.1% of cases. The most frequent high-risk genotypes in this study were HPV16 (28.8%) followed by: HPV51 (9.6%), HPV18, HPV31 HPV56 (7.1%) and HPV45 (5.1%). Thus, 24 % of studied women were not infected by HPV and about 47% of infections are without oncogenic HPV. These results highlight the value of HPV testing in the decision algorithm of management of minor abnormalities lesions.

Absolute Risk and Attributable Fraction of Type-Specific Human Papillomavirus in Cervical Cancer and Precancerous Lesions-A Population-Based Study of 6286 Women in Rural Areas of China

Background: To investigate the human papillomavirus (HPV) genotype distribution among the general population and assess the attribution of HPV genotypes targeted by vaccines to protect against cervical lesions theoretically. Methods: Cervical samples were collected from women aged 21 to 64 years old from Inner Mongolia and Shanxi Province in China who had not been vaccinated against HPV. HPV type-specific absolute risk (AR) to classified cervical lesions was calculated and then the attributable fraction (AF) was estimated, together with the combined contributions of the HPV types, targeted by four available HPV vaccines and five HPV vaccines in clinical trials in China to protect against cervical lesions. Results: A total of 6286 women with an average age of 44.1 years ± 8.41 (range: 21−64) participated in the study. The age distribution of 14 HR-HPV and HPV16/18 all showed a ‘U’ shape, which peaked in the ≤25 year-group and >55 year-group. The five most common genotypes were HPV16 (4.3%), HPV52 (4.1%), HPV58 (2.1%), HPV51 (2.1%), and HPV66 (1.7%). The prevalence of HPV types 6 and 11 infections was 1.1% and observed with n significant differences across age stratifications in China. AF to CIN2+ was predominated by HPV 16 with 56.2%, followed by HPV58 (12.0%), HPV52 (8.5%), HPV18 (4.3%), and HPV51 (2.9%). HPV52 and 58 in the prophylactic HPV vaccine would enhance the protection against CIN2+ by approximately 20%. Conclusions: Regarding multi-valent HPV vaccine development in China, the HPV types 16, 52, 58, and 18 should be given priority for their high prevalence at the population level, high AR, notable AF, and high relative risk to high-grade cervical lesions.

Distribution of human papillomavirus genotypes by severity of cervical lesions in HPV screened positive women from the ESTAMPA study in Latin America

The proportion of HPV16 and 18-associated cervical cancer (CC) appears rather constant worldwide (≥70%), but the relative importance of the other HR-HPV differs slightly by geographical region. Here, we studied the HPV genotype distribution of HPV positive Latin American (LA) women by histological grade, in a sub-cohort from the ESTAMPA study; we also explored the association of age-specific HPV genotypes in severe lesions. Cervical samples from 1,252 participants (854 ≤CIN1, 121 CIN2, 194 CIN3 and 83 CC) were genotyped by two PCRs-Reverse Blotting Hybridization strategies: i) Broad-Spectrum General Primers 5+/6+ and ii) PGMY9/11 PCRs. HPV16 was the most frequently found genotype in all histological grades, and increased with the severity of lesions from 14.5% in ≤ CIN1, 19.8% in CIN2, 51.5% in CIN3 to 65.1% in CC (p < 0.001). For the remaining HR-HPVs their frequency in CC did not increase when compared to less severe categories. The nonavalent vaccine HR-types ranked at the top in CC, the dominant ones being HPV16 and HPV45. HR-HPV single infection occurs, respectively, in 57.1% and 57.0% of ≤CIN1 and CIN2, increasing to 72.2% and 91.6% in CIN3 and CC (p<0.001). No association between age and HPV type was observed in CC, although the risk of HPV16 infection in CIN3 cases increased with age. Results confirm the relevance of HPV16 in the whole clinical spectrum, with a strong rise of its proportion in CIN3 and cancer. This information will be relevant in evaluating the impact of HPV vaccination, as a baseline against which to compare genotype changes in HPV type-specific distribution as vaccinated women participate in screening in LA region. Likewise, these data may help select the best HPV testing system for HPV-based efficient, affordable, and sustainable screening programmes.

Prevalence of cervicovaginal human papillomavirus infection and genotypes in the pre-vaccine era in China: A nationwide population-based study

OBJECTIVE

The HPV vaccine has been licensed in mainland China since 2017. This study aimed to assess the epidemiological characteristics of HPV genotypes in the pre-vaccine era in China.

METHODS

We conducted a multicentric population-based study nested in the largest health clinic chain in China. Between January 1, 2017 and December 31, 2017, 427,401women aged 20 years or older with polymerase chain reaction-based HPV genotyping tests were included in the study. The cervicovaginal infection of 14 high-risk HPV genotypes and 9 low-risk genotypes was assessed using adjusted prevalence, multivariable logistic regression, cluster analysis, and heatmap.

RESULTS

HPV prevalence was 15.0% (95% confidence interval [CI]: 14.1-15.9%) in China, with high- and low-risk genotypes being 12.1% (95%CI: 11.4-12.7%) and 5.2% (95%CI: 4.8-5.7%), respectively. The prevalence of HPV genotypes corresponding to bivalent, quadrivalent, and nonavalent vaccines were 2.1%, 2.4%, and 8.3%, respectively, whereas the prevalence of non-vaccine high-risk genotypes was 5.7%. The most common high-risk genotypes were HPV-52 (3.5%), HPV-58 (2.1%), and HPV-16 (1.6%), and the prevalence of HPV-18 (0.6%), HPV-6 (0.1%), and HPV-11 (0.2%) were relatively low. Infection with HPV genotypes differed significantly across age groups and geographic locations.

CONCLUSION

HPV prevalence was high in the pre-vaccine era in China, and a population-based HPV vaccination strategy is needed in the future.

Chlamydia trachomatis and Human Papillomavirus Infection in Women From Southern Hunan Province in China: A Large Observational Study

Chlamydia trachomatis and human papillomavirus (HPV) are the most common pathogens of sexually transmitted infections (STIs), which can increase the risk of cervical cancer and infertility. The purpose of this study was to evaluate the prevalence, genotype and risk factors of C. trachomatis and/or HPV infection in women attending the annual physical examination, assistant reproductive treatment and visiting the gynecology clinics from Southern Hunan province in China. Cervical-swab samples were collected from 5006 participants. We found that the overall prevalence of C. trachomatis, HPV infection and C. trachomatis/HPV coinfection was 4.7% (236/5006), 15.5% (778/5006) and 1.2% (59/5006), while the prevalence of asymptomatic infection of that was 3.8% (38/1006), 10.8% (109/1006) and 0.6% (6/1006), respectively. Furthermore, 25.0% (59/236) of C. trachomatis infection and 7.6% (59/778) of HPV infection were attributable to C. trachomatis and HPV coinfection. C. trachomatis and HPV infection were more often observed in young women of less than 25 years (10.4% and 21.3%, respectively) and in the outpatients from gynecology clinics (5.2% and 18.0%, respectively). Of note, a higher prevalence of C. trachomatis infection was observed in HPV-positive women (7.6%) than HPV- negative ones (4.2%), and vice versa. The top three C. trachomatis genotypes were E (1.4%), F (1.1%) and J (0.8%), and the counterparts of HPV genotypes were HPV52 (4.2%), HPV16 (2.3%) and HPV58 (2.2%), respectively. Among the 151 outpatients with colposcopy data, HPV infection was associated with severe cervical lesions with OR of 15.86 (95% CI 3.14–80.0, P < 0.001) while C. trachomatis infection was more likely associated with a low grade colposcopy impression (OR = 3.25, 95% CI: 1.22–8.65, P = 0.018). Our data highlight the high prevalence of asymptomatic C. trachomatis and HPV infection, particularly among women of <25 years. The two pathogens may serve as mutual risk factors to increase the risk of infections and cervical lesions. Widespread implementation of HPV and C. trachomatis screening programs, especially for young women, would be an effective strategy to relieve the burden of sexually transmitted infections.

Performance of HPV16/18 in Triage of Cytological Atypical Squamous Cells of Undetermined Significance

CONTEXT

Human papillomavirus (HPV) testing is widely used in cervical cancer screening in women; however, its efficiency in triaging women with atypical squamous cells of undetermined significance (ASC-US) needs to be validated.

OBJECTIVE

To evaluate the performance of HPV16/18 in the triage of women with ASC-US.

METHODS

Women presenting for routine cervical cancer screening had cervical specimens collected, with which both liquid-based cytology (LBC) and hrHPVs were examined; those with ASC-US cytology underwent colposcopy. HPV16/18 and 12 other types were tested with domestic hybridization capture and chemiluminescence signal amplification (DH3). Performance characteristics of HPV test (sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) for identification of cervical intraepithelium neoplasma (CIN) grade 2 or worse (CIN2+), and CIN grade 3 or worse (CIN3+)) were determined using standard statistical tests.

RESULTS

317 women with ASC-US were eligible for the study. HrHPV prevalence was 15.77% (50/317); HPV16/18 prevalence was 3.61% (20/317). Sensitivity and specificity of HPV16/18 for detection of CIN 2+ were 64.71% and 97% and 64.29% and 96.37% for detection of CIN 3+, respectively. The positive predictive values (PPVs) and negative predictive values (NPVs) of HPV16/18 were 55.00% and 97.98% for CIN2+ and 45.00% and 98.32% for CIN3+, respectively.

CONCLUSION

HPV16/18 can be considered as an effective method to triage women with ASC-US as its good clinical performance.

TRIAL REGISTRATION

This trial is registered with Henan Cancer Hospital Medical Ethics Committee on July 5, 2016 (http://www.anti-cancer.com.cn), with registry no.: 2016037.

Age-Related Changes in the Fraction of Cervical Intraepithelial Neoplasia Grade 3 Related to HPV Genotypes Included in the Nonavalent Vaccine

Objective

The prevalence of some human papillomavirus (HPV) genotypes has been shown to change with age. So, also the distribution of HPV genotypes included in the nonavalent vaccine may not be the same at all ages, and this could mean that vaccine protection against cervical cancer may be affected by age. The present study aimed to evaluate whether there are age-related changes in the fraction of high-grade cervical intraepithelial neoplasia (CIN) attributable to HPV genotypes included in the nonavalent vaccine.

Methods

Two hundred four consecutive women undergoing conization with a histological diagnosis of CIN3 were retrospectively analyzed. All included women had a preconization HPV genotyping (HPV Sign® Genotyping Test). The women were divided into three groups according to age: <35, 35–44, and ≥45 years of age. Based on HPV genotypes detected in cervical lesions, the age-related changes in the expected vaccine protection were evaluated by the Cochran–Armitage test for trend.

Results

The fraction of CIN3 attributable to HPV genotypes included in the nonavalent vaccine showed a significant negative trend with increasing age, with potential vaccine protection of 82% after the age of 45 (p=0.006). The rate of HPV-16 and HPV-33, included in the vaccine, showed a negative trend with age (p=0.047 and p=0.044, respectively). Among HPV genotypes not covered by the vaccine, the rate of non-high-risk HPVs (genotypes: 53-54-70-73-82-85-87) showed a significant positive trend with increasing age (p=0.018).

Conclusions

Although the fraction of CIN3 attributable to genotypes included in the nonavalent HPV vaccine was high even after age 45, older women appeared to be more at risk of high-grade CIN related to HPV genotypes not included in the vaccine. Interestingly, older women showed a higher rate of precancerous cervical lesions associated with non-high-risk HPV. The present findings seem to raise the question about the management of cervical pathology at a later age in a future postvaccination era.

Sexual behavior and infection with cervical human papillomavirus types 16 and 18

Objective

This study assessed whether sexual behavior, including engaging in early sexual intercourse and having had multiple sexual partners, can predict the risk of infection with cervical human papillomavirus (HPV) types 16 and 18.

Methods

Records were reviewed of women who underwent cervical cancer screening and were found to be infected with high-risk HPV. The genotypes of high-risk HPV were categorized as HPV 16, HPV 18, and other than 16 or 18. Early sexual intercourse was defined as first sexual intercourse at the age of 19 years or younger. Multiple sexual partners was defined as having more than three lifetime sexual partners. Associations between sexual behavior and HPV 16/18 infection were presented as odds ratios (ORs) and 95% confidence intervals (CIs).

Results

Of the 349 women included in the study, 72 (20.6%) and 30 (8.6%) were infected by HPV 16 and 18, respectively. Eighty-two women (26.0%) reported having engaged in early sexual intercourse, and 33 (10.4%) reported having had multiple sexual partners. After adjustment for age, parity, and smoking habits, we found that women who had engaged in early sexual intercourse tended to have a higher risk of HPV 16 (OR 1.74; 95% CI 0.93-3.29), and those who had had multiple sexual partners were found to be at a significantly higher risk for HPV 18 (OR 4.58; 95% CI 1.44-14.58).

Conclusion

Sexual behavior was associated with an increased risk of HPV 16/18 infection. Engaging in early sexual intercourse increased the risk of HPV 16 infection, and having had multiple sexual partners increased that of HPV 18.

Age-specific HPV type distribution in high-grade cervical disease in screened and unvaccinated women

BACKGROUND AND AIM

Age-specific type-distribution of high-risk human papillomavirus (hrHPV) in cervical precancerous lesions is subject to change in the HPV vaccination era. Knowing the pre-vaccination type-distribution helps to anticipate changes induced by mass vaccination and optimize screening.

METHODS

We recruited 1279 women referred to colposcopy for abnormal cytology into a population-based study on HPV type distribution in diagnostic cervical samples (ISRCTN10933736). The HPV genotyping findings were grouped as: HPV16/18+, other hrHPV+ (HPV31/33/35/39/45/51/52/56/58/59/66/68), non-vaccine targeted hrHPV+ (HPV35/39/51/56/59/66/68), low-risk HPV, and HPV negative. We estimated the HPV group-specific prevalence rates according to diagnostic histopathological findings in the age groups of <30 (n = 339), 30-44.9 (n = 614), and ≥45 (n = 326).

RESULTS

Altogether 503 cases with high grade squamous intraepithelial lesion or worse (HSIL+) were diagnosed. More than half, 285 (56.7%) of HSIL+ cases were associated with HPV16/18: 64.3% (101/157) in women <30 years (reference group), 58.4% (157/269) in women 30-44.9 years (risk ratio (RR) 0.91, 95% confidence interval (95% CI) 0.78-1.06), and 35.1% (27/77) in women ≥45 years of age (RR 0.55, 95% CI 0.39-0.75). Conversely, other hrHPV's were associated with 191 (38.0%) of HSIL+: 31.9% (50/157) in women <30, 36.8% (99/269) in women 30-44.9 years, 54.6% (42/77) and in women ≥45 (RR 1.71, 95% CI 1.26-2.33). The proportion of non-vaccine targeted hrHPV and HPV negative HSIL+ increased with advancing age.

CONCLUSIONS

Pre-vaccination HPV type distribution in HSIL+ was distinctly polarised by age with HPV16/18 attributed disease being markedly more prevalent in women aged <30. In the older women the other hrHPV types, however, dominated suggesting a need for more age-dependent screening strategies.

Impacts of human papillomavirus vaccination for different populations: A modeling study

International variations in the prevalence of HPV infection derive from differences in sexual behaviors, which are also a key factor of the basic reproductive number (R0 ) of HPV infection in different populations. R0 affects the strength of herd protection and hence the impact of a vaccination program. Similar vaccination programs may therefore generate different levels of impact depending upon the population's pre-vaccination HPV prevalence. We used IARC's transmission model to estimate (i) the overall effectiveness of vaccination versus no vaccination in women aged 15-34 years measured as percent prevalence reduction (%PR) of HPV16 and (ii) the corresponding herd protection in populations with gender-equal or traditional sexual behavior and with different levels of sexual activity, corresponding to pre-vaccination HPV16 prevalence from 1 to 8% as observed worldwide. Between populations with different levels of gender-equal sexual activity, the highest difference in %PR under girls-only vaccination is observed at 40% coverage (91%PR vs. 48%PR for 1% and 8% pre-vaccination prevalence, respectively). HPV16 elimination is obtained with 55 and 97% coverage, respectively. To achieve desirable levels of HPV16 prevalence after vaccination, different levels of coverage are required in populations with different levels of pre-vaccination HPV16 prevalence, for example, in populations with gender-equal sexual behavior a decrease to 1/1000 HPV16 from pre-vaccination prevalence of 1 and 8% would require coverages of 37 and 96%, respectively. In traditional populations, corresponding coverages would need to be 28 and 93%, respectively. In conclusion, pre-vaccination HPV prevalence strongly influences herd immunity and helps predict the overall effectiveness of HPV vaccination.

Human papilloma virus genotyping for the cross-sectional and longitudinal probability of developing cervical intraepithelial neoplasia grade 2 or more

Human papilloma virus (HPV) testing is more sensitive but less specific than cytology. We evaluated stand-alone genotyping as a possible triage method. During a multicentre randomised controlled trial comparing HPV testing to conventional cytology, HPV-positive women were referred to colposcopy and followed up if no high-grade lesion was detected. HPV-positive samples were genotyped by GP5+/GP6+ primed polymerase chain reaction followed by reverse line blot. Genotypes were hierarchically ordered by positive predictive value (PPV) for CIN grade 2 or more (CIN2+), and grouped by cluster analysis into three groups (A, B and C in decreasing order). Receiver operating characteristic curves were computed. Among 2,255 HPV-positive women with genotyping, 239 CIN2+ (including 113 CIN3+) were detected at baseline or during a 3-year follow-up. HPV33 had the highest PPV with CIN2+ and CIN3+ as the endpoint and when considering lesions detected at baseline or also during follow-up. HPV16 and HPV35 were the second and third, respectively. Cross-sectional sensitivity for CIN2+ at baseline was 67.3% (95% CI 59.7-74.2), 91.8% (95% CI 86.6-95.5) and 94.7% (95% CI 90.2-97.6), respectively, when considering as "positive" any of the HPV types in group A (33, 16 and 35), A or B (31, 52, 18, 59 and 58) and A or B or C (39, 51, 56, 45 and 68). The corresponding cross-sectional PPVs for CIN2+ were 15.8% 95% (CI 13.2-18.7), 12.0% (95% CI 10.3-13.9) and 9.6% (95% CI 8.2-11.1), respectively. HPV33, 16 and 35 confer a high probability of CIN2+ but this rapidly decreases when adding other genotypes.

Epidemiology of cervical human papillomavirus (HPV) infection and squamous intraepithelial lesions (SIL) among a cohort of HIV-infected and uninfected Ghanaian women

Background

There is limited data in Ghana on the epidemiology of HPV and cervical neoplasia and their associations with HIV. This study aimed to compare among HIV-1 seropositive and HIV-seronegative Ghanaian women: (1) the prevalence, genotype distribution and risk factors associated with cervical HPV infection; and (2) the prevalence and risk factors associated with abnormal cervical cytology.

Methods

A comparative frequency-matched study was conducted in a systematic sample of women aged ≥18 years attending HIV and general outpatient clinics in Cape Coast Teaching Hospital, Ghana. Participants were interviewed and cervical samples collected for HPV genotyping (Seegene Anyplex-II HPV28) and cytological testing.

Results

Overall, 333 women were recruited, 163 HIV-1 seropositive and 170 HIV-seronegative women of mean age 43.8 years (SD ±9.4)) and 44.3 years (SD ±12.8), respectively. The prevalence of 14 high-risk (hr) HPV genotypes was higher among HIV-1 seropositive women (65.6% vs. 30.2%, P < 0.0001), as was proportion with multiple hr.-HPV infections (60.6% vs. 21.3%, P < 0.0001). HPV35 was the most prevalent hr.-HPV genotype in both groups (11.9% and 5.3%). The main factors associated with hr.-HPV infection were age for HIV-positive women and circumcision status of main sexual partner for both HIV-negative and positive women.

Abnormal cervical cytology prevalence was higher among HIV-1 seropositive women (any SIL: 14.1% vs. 1.2%, P < 0.0001; low-grade SIL [LSIL]: 4.9% vs. 0.6%, P = 0.02; high-grade SIL: 1.8% vs. 0%, P = 0.07). Among HIV-1 seropositive women, number of pregnancies and CD4+ cell count were associated with LSIL+ cytology. There was strong association between LSIL+ abnormalities and HPV35 (aOR = 4.7, 95%CI: 1.3–17.7, P = 0.02).

Conclusions

HIV-1 infected women bear significant burden of HPV infection and related disease. Prevention and screening programmes should be specifically deployed for this population in Ghana.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3682-x) contains supplementary material, which is available to authorized users.

Different Challenges in Eliminating HPV16 Compared to Other Types: A Modeling Study

Background

Human papillomavirus (HPV) vaccination is still not reaching many high-risk populations. HPV16/18 vaccines offer cross-protection against other types, for example, HPV45. Both direct vaccine efficacy and indirect herd protection contribute to vaccination effectiveness.

Methods

We used a dynamic transmission model, calibrated to cervical screening data from Italy, to estimate vaccination effectiveness against HPV16 and HPV45 infection, assuming for HPV45 either 95% or lower cross-protection.

Results

Basic reproductive number was smaller (2.1 vs 4.0) and hence vaccine effectiveness and herd protection stronger for HPV45 than for HPV16. The largest difference in the reduction of infection prevalence in women <35 years old was found at 70% coverage in girls-only vaccination programs (99% vs 83% for total protection for HPV45 and HPV16, respectively, mainly owing to stronger herd protection, ie, 37% vs 16%). In gender-neutral vaccination, the largest difference was at 40% coverage (herd protection, 54% vs 28% for HPV16 and HPV45, respectively). With ≥80% coverage, even 50% cross-protection would reduce HPV45 by ≥94%.

Conclusions

The characteristics of individual high-risk HPV types strongly influence herd protection and determine the level of coverage and cross-protection required to reduce or eliminate the infection through HPV vaccination. HPV16 infection and related cancers are the most difficult to eliminate.

Prevalence of Primary HPV in Djibouti: Feasibility of Screening for Early Diagnosis of Squamous Intraepithelial Lesions

OBJECTIVE

In many African Sub-Saharan countries, human papilloma virus (HPV) prevalence data are not available. The current study estimated the prevalence of HPV virus in the female population of Djibouti.

METHODS

Approximately 1000 asymptomatic women 16 to 64 years old were enrolled from 3 of the main health structures of Djibouti in 2014 and 2015; 998 cervical samples were tested for HPV-DNA of high risk types, 499 during the first year, and 499 during the second. Positive samples were typed with an HPV genotyping kit.

RESULTS

The women were an average age of 38.8 years (SD, 10.2); 54 women tested positive for HPV (prevalence rate, 5.4% [95% confidence interval, 4.0-6.8]). The highest prevalence was observed among the women younger than 35 years. HPV66 was the most prevalent (15.4% of the infections), followed by HPV31 and HPV52 (10.8% both) and HPV16 (9.2%). All 54 women who tested HPV-positive underwent a Pap test, which was positive in 8 cases (14.8%): 2 high-grade squamous intraepithelial lesion (HSIL) and 6 low-grade (LSIL).

CONCLUSIONS

The HPV prevalence shows a curve by age similar to that of other African countries. The proportion of HPV16 is among the lowest ever seen in similar studies. The findings suggest to Djibouti the choice of a strategy of screening that includes forms of cytological triage, thus limiting recourse to colposcopy.

HPV genotypes distribution in Chlamydia trachomatis co-infection in a large cohort of women from north-east Italy

Human papillomavirus (HPV) and Chlamydia trachomatis are pathogens with oncogenic potential associated with persistent infections. Epidemiological data on C. trachomatis infection status, C. trachomatis/HPV co-infection and the relationship between HPV genotypes in Italian women are only preliminary. The aim of the present study was to characterize the relationship between HPV genotypes and C. trachomatis in an extending cohort of asymptomatic immunocompetent women from an area of north-east Italy. A retrospective study was conducted using Luminex technology on cervical swabs from asymptomatic immunocompetent women, comprising 921 attending the prevention centre for the Cervical Cancer Program and 6214 who had been referred to the Sexually Transmitted Infections Center, with clinical indications of HPV and C. trachomatis infections. A quantitative real-time PCR was performed to assess chronic C. trachomatis infection by heat-shock protein 60 (Hsp60) gene expression. The overall prevalence of the investigated pathogens was 39 % (359/921) for HPV and 4 % (251/6214) for C. trachomatis. The Hsp60 gene was detected in 57 % of the women infected with C. trachomatis. HPV co-infection was present in 58 % of C. trachomatis-infected women. A high prevalence of co-infection was found in women with chronic C. trachomatis infection (68 %, P = 0.0002), especially in women ≤ 25 years (72 %) where HPV multiple infections were found in 78 % (P = 0.022). HPV genotype distribution showed that uncommon low-risk genotypes were associated with C. trachomatis. These results indicate a high frequency of co-detection of multiple HPV genotypes in chronically infected young women and suggest that the expression of the C. trachomatis Hsp60 gene may favour HPV infection.

Cervical pathology in high-risk human papillomavirus- positive, cytologically normal women

This study was undertaken to evaluate the prevalence of significant cervical pathology among women who are high-risk human papillomavirus (HR-HPV)-positive/cytology negative, the most common combination of positive co-tests. The records of 244 women HR-HPV-positive/cytology-negative who had undergone colposcopy at Srinagarind Hospital, Khon Kaen University during January 2010 and April 2014 were reviewed. Mean age was 46.4 years. Of these 224 women, 75 were positive for HPV types 16/18 (33.5%) and 123 were positive for non-16/18 types (54.9%). HR-HPV was not genotyped in the remaining 26 women (11.6%). Prevalence of significant lesions for the entire cohort was 2.4%, and 2.6% and 3.3%, respectively, for those with HPV 16/18 and other oncogenic HPV types. One woman with HPV 16/18 (1.3%) had invasive cervical cancer. Multiparous women were more likely to be infected with HPV 16/18 compared to nulliparous women (36.3% versus 17.6%, respectively). In conclusion, the prevalence of significant cervical lesion among our study population was 2.4%. Multiparous women were more likely to be infected with HPV 16/18 compared to nulliparous women.

High prevalence of hpv multiple genotypes in women with persistent chlamydia trachomatis infection

BACKGROUND

Chlamydia trachomatis interaction with HR-HPV types has highlighted a central role in cervical cancer development. The aim of this study was to investigate HPV prevalence and genotypes distribution in women at risk for C. trachomatis infection and negative for intraepithelial lesion or malignancy.

METHODS

1071 cervical swabs were tested for C. trachomatis by Real Time PCR and genotyping by ompA gene sequencing. Additionally, a quantitative Real time-PCR was performed to assess the expression of the C. trachomatis Hsp60-encoding gene (Ct604 portion), linked to a persistent status of infection. HPV infection and genotypes was investigated in C. trachomatis positive women using Luminex technology.

RESULTS

C. trachomatis infection was detected in 53 out of 1071 (4.5%) samples, of which the 53% resulted positive for Hsp60 gene expression. The overall prevalence of HPV infection in C. trachomatis positive samples was of 60.4% (32/53): in 37.5% of samples was present a single genotype, while multiple genotypes infections were found in the 62.5% of them. Among women with a C. trachomatis chronic infection, 68% were HPV co-infected and the 79% showed multiple genotypes. Should be noted that levels of C. trachomatis Hsp60 expression in HPV co-infected women were significantly lower compared to women infected only with C. trachomatis. The C. trachomatis serotype F was found in the majority of samples, independently of HPV infection.

CONCLUSIONS

A high prevalence of HPV multiple infections have been found in young women affected with a C. trachomatis chronic infection. These observations suggested that the expression of CHSP60-1, interfering with both apoptotic and cellular senescence pathways, may promote a favourable local microenvironment for HPV infection.