Leading causes of death and high mortality rates in an HIV endemic setting (Kisumu county, Kenya, 2019).

BACKGROUND: In resource-limited settings, underlying causes of death (UCOD) often are not ascertained systematically, leading to unreliable mortality statistics. We reviewed medical charts to establish UCOD for decedents at two high volume mortuaries in Kisumu County, Kenya, and compared ascertained UCOD to those notified to the civil registry. METHODS: Medical experts trained in COD certification examined medical charts and ascertained causes of death for 456 decedents admitted to the mortuaries from April 16 through July 12, 2019. Decedents with unknown HIV status or who had tested HIV-negative >90 days before the date of death were tested for HIV. We calculated annualized all-cause and cause-specific mortality rates grouped according to global burden of disease (GBD) categories and separately for deaths due to HIV/AIDS and expressed estimated deaths per 100,000 population. We compared notified to ascertained UCOD using Cohen's Kappa (κ) and assessed for the independence of proportions using Pearson's chi-squared test. FINDINGS: The four leading UCOD were HIV/AIDS (102/442 [23.1%]), hypertensive disease (41/442 [9.3%]), other cardiovascular diseases (23/442 [5.2%]), and cancer (20/442 [4.5%]). The all-cause mortality rate was 1,086/100,000 population. The highest cause-specific mortality was in GBD category II (noncommunicable diseases; 516/100,000), followed by GBD I (communicable, perinatal, maternal, and nutritional; 513/100,000), and III (injuries; 56/100,000). The HIV/AIDS mortality rate was 251/100,000 population. The proportion of deaths due to GBD II causes was higher among females (51.9%) than male decedents (42.1%; p = 0.039). Conversely, more men/boys (8.6%) than women/girls (2.1%) died of GBD III causes (p = 0.002). Most of the records with available recorded and ascertained UCOD (n = 236), 167 (70.8%) had incorrectly recorded UCOD, and agreement between notified and ascertained UCOD was poor (29.2%; κ = 0.26). CONCLUSIONS: Mortality from infectious diseases, especially HIV/AIDS, is high in Kisumu County, but there is a shift toward higher mortality from noncommunicable diseases, possibly reflecting an epidemiologic transition and improving HIV outcomes. The epidemiologic transition suggests the need for increased focus on controlling noncommunicable conditions despite the high communicable disease burden. The weak agreement between notified and ascertained UCOD could lead to substantial inaccuracies in mortality statistics, which wholly depend on death notifications.

Population Impact of Girls-Only Human Papillomavirus 16/18 Vaccination in The Netherlands: Cross-Protective and Second-Order Herd Effects.

BACKGROUND: Human papillomavirus (HPV) vaccination programs achieve substantial population-level impact, with effects extending beyond protection of vaccinated individuals. We assessed trends in HPV prevalence up to 8 years postvaccination among men and women in the Netherlands, where bivalent HPV vaccination, targeting HPV types 16/18, has been offered to (pre)adolescent girls since 2009 with moderate vaccination coverage. METHODS: We used data from the PASSYON study, a survey initiated in 2009 (prevaccination) and repeated biennially among 16- to 24-year-old visitors of sexual health centers. We studied genital HPV positivity from 2009 to 2017 among women, heterosexual men, and unvaccinated women using Poisson generalized estimating equation models, adjusted for individual- and population-level confounders. Trends were studied for 25 HPV types detected by the SPF10-LiPA25 platform. RESULTS: A total of 6354 women (64.7% self-reported unvaccinated) and 2414 heterosexual men were included. Percentual declines in vaccine types HPV-16/18 were observed for all women (12.6% per year [95% confidence interval {CI}, 10.6-14.5]), heterosexual men (13.0% per year [95% CI, 8.3-17.5]), and unvaccinated women (5.4% per year [95% CI, 2.9-7.8]). We observed significant declines in HPV-31 (all women and heterosexual men), HPV-45 (all women), and in all high-risk HPV types pooled (all women and heterosexual men). Significant increases were observed for HPV-56 (all women) and HPV-52 (unvaccinated women). CONCLUSIONS: Our results provide evidence for first-order herd effects among heterosexual men against HPV-16/18 and cross-protective types. Additionally, we show second-order herd effects against vaccine types among unvaccinated women. These results are promising regarding population-level and clinical impact of girls-only bivalent HPV vaccination in a country with moderate vaccine uptake.

Partial Protective Effect of Bivalent Human Papillomavirus 16/18 Vaccination Against Anogenital Warts in a Large Cohort of Dutch Primary Care Patients.

BACKGROUND: There is ongoing debate about the possible protective effect of the bivalent human papillomavirus (2vHPV) vaccine, targeting oncogenic types HPV-16/18, against anogenital warts (AGWs), commonly attributed to HPV-6/11. We performed a retrospective registry-based open cohort study to assess the effect of 2vHPV vaccination on AGWs. METHODS: We linked general practice (ie, primary care) data from women born between 1993 and 2002, who had been eligible for HPV vaccination in the Netherlands, to the Dutch national immunization registry on an individual level. Women were followed until their first AGW diagnosis or end of follow-up. Adjusted incidence rate ratios (aIRRs) were estimated using Poisson regression with vaccination status as a time-dependent exposure. RESULTS: We linked data of 96 468 women with a total of 328 019 years observation time and 613 AGW diagnoses (incidence: 1.87/1000 person-years). At the end of follow-up, 61% were 2vHPV vaccinated (≥ 1 dose) of whom 91% were fully vaccinated. The AGW incidence was lower among those with ≥ 1 dose vs 0 doses (aIRR, 0.75 [95% confidence interval {CI}, .64-.88]). The effect of vaccination was stronger after full vaccination (aIRR, 0.72 [95% CI, .61-.86]) and for women who were offered vaccination at 12-13 years of age (aIRR, 0.69 [95% CI, .51-.93]) vs those at 13-16 years of age (aIRR, 0.77 [95% CI, .64-.93]). CONCLUSIONS: This is the largest population-based study so far to examine the effect of 2vHPV vaccination on AGWs, with reliable individual information on AGW diagnoses and vaccination status. The results indicate that 2vHPV vaccination partially protects against AGWs, especially when administered in early adolescence.

Hepatitis B prevention: Can we learn from the response to HIV/AIDS?

Mirjam Kretzschmar and Marianne van der Sande discuss the accompanying research study by Anna McNaughton and colleagues on strategies to reduce the burden of hepatitis B in African countries.

HPV infections among young MSM visiting sexual health centers in the Netherlands: Opportunities for targeted HPV vaccination.

INTRODUCTION: In 2009, girls-only HPV16/18 vaccination was introduced in the Netherlands which has achieved 46-61% uptake. Heterosexual men have benefitted from herd protection, but it is unknown whether men who have sex with men (MSM) also benefit from herd effects of the girls-only HPV16/18 vaccination program. Because MSM bear a high HPV-related disease burden, countries might consider targeted vaccination for MSM. To study possible herd effects and prior HPV exposure at a potential moment of vaccination, we assessed trends in the HPV prevalence and proportions (sero)negative for the various vaccine types among young MSM visiting sexual health centers (SHCs). METHODS: We used data from MSM included in PASSYON study years 2009-2017. In this biennial cross-sectional study among visitors of SHCs aged 16-24 years, MSM provided a penile and anal swab for HPV DNA testing (including vaccine types HPV6/11/16/18/31/33/45/52/58) and blood for HPV antibody testing (HPV16/18/31/33/45/52/58). RESULTS: In total 575 MSM were included, with a median of 22 years of age and 15 lifetime sex partners and 3.5% HIV positive. Trends in penile or anal HPV prevalence during 2009-2017 were statistically non-significant for all vaccine types. Of the 455 MSM with a penile and anal swab, 360 (79%), 283 (62%) and 242 (53%) were HPV DNA negative at both anatomical sites for HPV16/18, HPV6/11/16/18 and HPV6/11/16/18/31/33/45/52/58 respectively. Among MSM who were HPV16/18 and HPV16/18/31/33/45/52/58 DNA negative and were tested for serology (n = 335 and 279 respectively), 82% and 71% were also seronegative for the respective types. DISCUSSION: There were no significant declines in the HPV prevalence among MSM up to eight years after introduction of girls-only HPV16/18 vaccination, indicating that MSM are unlikely to benefit largely from herd effects from girls-only vaccination. Most MSM were vaccine-type DNA negative and seronegative, suggesting that vaccination of young MSM visiting SHCs could still be beneficial.

Bivalent Vaccine Effectiveness Against Anal Human Papillomavirus Positivity Among Female Sexually Transmitted Infection Clinic Visitors in the Netherlands.

Human papillomavirus (HPV) vaccines are indicated for anal cancer prevention, but evidence for vaccine effectiveness (VE) against anal HPV infections among women is limited. We estimated the VE (≥1 dose) against anal HPV positivity of the bivalent vaccine, whose target types HPV-16/18 are associated with approximately 90% of HPV-related anal cancers. Among 548 female STI clinic visitors 16-24 years old who provided an anal swab sample as part of a repeated cross-sectional survey, VE against HPV-16/18 was 89.9% (95% confidence interval, 63.0%-97.2%). Type-specific VE correlated well with VE against cervicovaginal HPV (Spearman ρ = 0.76), suggesting comparable effectiveness of HPV-16/18 vaccination against genital and anal infections.

Cervical determinants of anal HPV infection and high-grade anal lesions in women: a collaborative pooled analysis.

BACKGROUND: Cervical cancer screening might contribute to the prevention of anal cancer in women. We aimed to investigate if routine cervical cancer screening results-namely high-risk human papillomavirus (HPV) infection and cytohistopathology-predict anal HPV16 infection, anal high-grade squamous intraepithelial lesions (HSIL) and, hence, anal cancer. METHODS: We did a systematic review of MEDLINE, Embase, and the Cochrane library for studies of cervical determinants of anal HPV and HSIL published up to Aug 31, 2018. We centrally reanalysed individual-level data from 13 427 women with paired cervical and anal samples from 36 studies. We compared anal high-risk HPV prevalence by HIV status, cervical high-risk HPV, cervical cytohistopathology, age, and their combinations, using prevalence ratios (PR) and 95% CIs. Among 3255 women with anal cytohistopathology results, PRs were similarly calculated for all anal HSIL and HPV16-positive anal HSIL. FINDINGS: Cervical and anal HPV infections were highly correlated. In HIV-negative women, anal HPV16 prevalence was 41% (447/1097) in cervical HPV16-positive versus 2% (214/8663) in cervical HPV16-negative women (PR 16·5, 95% CI 14·2-19·2, p<0·0001); these values were 46% (125/273) versus 11% (272/2588) in HIV-positive women (4·4, 3·7-5·3, p<0·0001). Anal HPV16 was also associated with cervical cytohistopathology, with a prevalence of 44% [101/228] for cervical cancer in HIV-negative women (PR vs normal cytology 14·1, 11·1-17·9, p<0·0001). Anal HSIL was associated with cervical high-risk HPV, both in HIV-negative women (from 2% [11/527] in cervical high-risk HPV-negative women up to 24% [33/138] in cervical HPV16-positive women; PR 12·9, 95% CI 6·7-24·8, p<0·0001) and HIV-positive women (from 8% [84/1094] to 17% [31/186]; 2·3, 1·6-3·4, p<0·0001). Anal HSIL was also associated with cervical cytohistopathology, both in HIV-negative women (from 1% [5/498] in normal cytology up to 22% [59/273] in cervical HSIL; PR 23·1, 9·4-57·0, p<0·0001) and HIV-positive women (from 7% [105/1421] to 25% [25/101]; 3·6, 2·5-5·3, p<0·0001). Prevalence of HPV16-positive anal HSIL was 23-25% in cervical HPV16-positive women older than 45 years (5/20 in HIV-negative women, 12/52 in HIV-positive women). INTERPRETATION: HPV-based cervical cancer screening programmes might help to stratify anal cancer risk, irrespective of HIV status. For targeted secondary anal cancer prevention in high-risk groups, HIV-negative women with cervical HPV16, especially those older than 45 years, have a similar anal cancer risk profile to that of HIV-positive women. FUNDING: International Agency for Research on Cancer.

Relation between Chlamydia trachomatis infection and pelvic inflammatory disease, ectopic pregnancy and tubal factor infertility in a Dutch cohort of women previously tested for chlamydia in a chlamydia screening trial.

OBJECTIVES: A better understanding of Chlamydia trachomatis infection (chlamydia)-related sequelae can provide a framework for effective chlamydia control strategies. The objective of this study was to estimate risks and risk factors of pelvic inflammatory disease (PID), ectopic pregnancy and tubal factor infertility (TFI) with a follow-up time of up until 8 years in women previously tested for chlamydia in the Chlamydia Screening Implementation study (CSI) and participating in the Netherlands Chlamydia Cohort Study (NECCST). METHODS: Women who participated in the CSI 2008-2011 (n=13 498) were invited in 2015-2016 for NECCST. Chlamydia positive was defined as a positive CSI-PCR test, positive chlamydia serology and/or self-reported infection (time dependent). Data on PID, ectopic pregnancy and TFI were collected by self-completed questionnaires. Incidence rates and HRs were compared between chlamydia-positive and chlamydia-negative women corrected for confounders. RESULTS: Of 5704 women included, 29.5% (95% CI 28.3 to 30.7) were chlamydia positive. The incidence rate of PID was 1.8 per 1000 person-years (py) (1.6 to 2.2) overall, 4.4 per 1000 py (3.3 to 5.7) among chlamydia positives compared with 1.4 per 1000 py (1.1 to 1.7) for chlamydia negatives. For TFI, this was 0.4 per 1000 py (0.3 to 0.5) overall, 1.3 per 1000 py (0.8 to 2.1) and 0.2 per 1000 py (0.1 to 0.4) among chlamydia positives and negatives, respectively. And for ectopic pregnancy, this was 0.6 per 1000 py (0.5 to 0.8) overall, 0.8 per 1000 py (0.4 to 1.5) and 0.6 per 1000 py (0.4 to 0.8) for chlamydia negatives. Among chlamydia-positive women, the strongest risk factor for PID was symptomatic versus asymptomatic infection (adjusted HR 2.88, 1.4 to 4.5) and for TFI age <20 versus >24 years at first infection (HR 4.35, 1.1 to 16.8). CONCLUSION: We found a considerably higher risk for PID and TFI in chlamydia-positive women, but the incidence for ectopic pregnancy was comparable between chlamydia-positive and chlamydia-negative women. Overall, the incidence rates of sequelae remained low. TRIAL REGISTRATION: NTR-5597.

Changes in (risk) behavior and HPV knowledge among Dutch girls eligible for HPV vaccination: an observational cohort study.

BACKGROUND: Implementation of human papillomavirus (HPV) vaccination raised concerns that vaccination could lead to riskier sexual behavior. This study explored how possible differences in sexual behavior and HPV knowledge developed over time between HPV-vaccinated and unvaccinated girls. METHODS: A random sample of 19,939 girls (16-17 year olds) eligible for the catch-up HPV vaccination campaign in the Netherlands was invited for a longitudinal study with questionnaires every 6 months over a two-year follow-up period. Possible differences over time between vaccinated and unvaccinated participants were studied using generalized equations estimation (GEE). RESULTS: A total of 2989 girls participated in round one, of which 1574 participated (52.7%) in the final 5th round. Vaccinated girls were more likely to live in more urban areas (OR 1.28, 95%CI 1.10-1.47) and to use alcohol (OR 1.46, 95%CI 1.24-1.70) and contraceptives (OR 1.69, 95%CI 1.45-1.97). Vaccinated and unvaccinated girls showed comparable knowledge on HPV, HPV vaccination, and transmission. Vaccinated girls were more likely to be sexually active (OR 1.19, 95%CI 1.02-1.39), and this difference increased over time (OR for interaction 1.06, 95%CI 1.00-1.12). However, they had a slightly lower number of lifetime sexual partners (mean difference - 0.20, 95%CI -0.41-0.00). Vaccinated girls were less likely to use a condom with a steady partner (aOR 0.71, 95%CI 0.56-0.89). However, the difference between vaccinated and unvaccinated girls with regard to condom use with casual or steady partner(s) did not significantly change over time. CONCLUSION: Overall, we did not find indications that vaccination influenced sexual behavior in girls during 2 years of follow-up. The few differences found may be related to existing disparities in the socio-demographic characteristics of the young population pointing to the importance and improvement of education with regard to safe sex practices. Our findings do not suggest that vaccination status is associated with changes in sexual risk behavior and thus it is unlikely that this might influence the effectiveness of the vaccination program.

Efficacy, effectiveness and safety of vaccination against human papillomavirus in males: a systematic review.

BACKGROUND: Human papillomavirus (HPV) vaccination is safe and effective in preventing cervical cancer in females. As HPV infections can also induce cancers of the anus, penis and oral cavity, male vaccination is also advocated, but systematic reviews on efficacy and safety in males are lacking. METHODS: We performed a systematic review on the efficacy, effectiveness and safety of HPV vaccination in males of any age. MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and ClinicalTrials.gov were searched from inception to April 2017. RESULTS: We identified 5196 articles and seven studies (four randomized controlled trials (RCTs), three non-randomized studies) were included, comprising a total of 5294 participants. Vaccine efficacy against at least 6-month persisting anogenital HPV 16 infections was 46.9% (95% confidence interval (CI) 28.6-60.8%), whereas efficacy against persisting oral infections was 88% (2-98%). A vaccine efficacy of 61.9% (21.4-82.8%) and 46.8% (- 20 to -77.9%) was observed against anal intraepithelial neoplasia grade 2 and grade 3 lesions, respectively. No meaningful estimates were available on vaccine efficacy or effectiveness against penile intraepithelial neoplasia grade 2 or 3, and no data were identified for anal, penile or head and neck squamous cell cancer. In participants who were HPV-seronegative and PCR-negative at enrolment, efficacy against all outcomes was higher as compared to seropositive and/or PCR-positive individuals. Risk of bias was low in three RCTs and high in one, while the three non-randomized studies were at serious to critical risk of bias. Grading of Recommendations Assessment, Development and Evaluation evidence quality was moderate to low for most outcomes. CONCLUSIONS: HPV vaccination in males is moderately effective against persistent anogenital HPV infection and high-grade anal intraepithelial lesions in studies where the population consists mainly of HPV-infected males. Vaccine effectiveness was high in study groups comprising HPV-naïve males. This supports a recommendation for vaccination of boys before the onset of sexual activity with the goal of establishing optimal vaccine-induced protection. Mathematical modelling studies will still be needed to assess the effects of adding males to existing HPV vaccination programs in females. TRIAL REGISTRATION: Prospective Register for Systematic Reviews (PROSPERO) registration CRD42016038965 .

Detection of Incident Anal High-Risk Human Papillomavirus DNA in Men Who Have Sex With Men: Incidence or Reactivation?

Background: We aimed to assess whether sexual exposure may explain all incident anal human papillomavirus (HPV) detections among men who have sex with men (MSM). Methods: A longitudinal study among MSM was conducted between 2010 and 2013 with visits every 6 months and up to 24 months of follow-up. Risk-factor questionnaires, blood samples, and anal and penile self-swabs were collected at each visit. Self-swabs were used for detection and genotyping of HPV by the broad spectrum L1 based SPF10 PCR DNA/enzyme immunoassay LiPA25 system. Serum samples were tested for high-risk HPV (hrHPV) antibodies. Incident anal HPV detection rates among sexually non-, low, and highly exposed MSM were compared. Factors associated with incident anal hrHPV detection were assessed using multivariable Cox regression. Results: Seven hundred fourteen men (median age, 40 years; 39% human immunodeficiency virus [HIV] infected) were included in the analysis. Incident anal detections of all hrHPV types were observed among both sexually nonexposed and exposed MSM. In multivariable analyses, being highly sexually exposed, being HIV infected, and having a penile HPV infection were positively associated with incident anal HPV detection; those reporting more sex partners had a nonsignificantly increased risk of HPV detection. Conclusions: Incident anal hrHPV detection is common among recently nonexposed MSM, suggesting that a reactivated latent HPV infection instead of an incident infection may underlie incident HPV detection.

Anal HPV 16 and 18 viral load: A comparison between HIV-negative and -positive MSM and association with persistence.

Does anal HPV viral load explain the difference in anal HPV persistence between HIV-negative and -positive men who have sex with men (MSM)? MSM ≥18 years were recruited in Amsterdam, the Netherlands, in 2010-2011. Anal self-swabs were collected every 6 months and genotyped (SPF10 -PCR-DEIA-LIPA25 -system). HPV16 and HPV18 load was determined with a type specific quantitative (q)PCR, and compared between HIV-negative and -positive men using ranksum test. Persistence was defined as ≥3 positive samples for the same HPV-type. Determinants of persistent HPV16/18 infection and its association with HPV16/18 load were assessed with logistic regression. Of 777 recruited MSM, 54 and 22 HIV negative men were HPV16 and HPV18 positive at baseline, and 64 and 39 HIV-positive MSM. The geometric mean titer (GMT) of HPV16 was 19.6 (95%CI 10.1-38.0) and of HPV18 8.6 (95%CI 2.7-27.5) DNA copies/human cell. HPV16 and HPV18 load did not differ significantly between HIV-negative and -positive MSM (P = 0.7; P = 0.8, respectively). In multivariable analyses HPV16 load was an independent determinant of HPV16 persistence (OR 1.8, 95%CI 1.3-2.4). No difference in anal HPV viral load was found between HIV-positive and HIV-negative MSM. HPV 16/18 viral load is an independent determinant of type-specific persistence.

Bivalent Vaccine Effectiveness Against Type-Specific HPV Positivity: Evidence for Cross-Protection Against Oncogenic Types Among Dutch STI Clinic Visitors.

Background: Observational postmarketing studies are important to assess vaccine effectiveness (VE). We estimated VE from the bivalent human papillomavirus (HPV) vaccine against HPV positivity of vaccine and nonvaccine types in a high-risk population. Methods: We included all vaccine-eligible women from the PASSYON study, a biennial cross-sectional survey in Dutch sexually transmitted infection clinics. Vaginal swabs were analyzed using a polymerase chain reaction-based assay (SPF10-LiPA25) able to detect the 12 high-risk HPV (hrHPV) types 16/18/31/33/35/39/45/51/52/56/58/59. We compared hrHPV positivity between self-reported vaccinated (≥1 dose) and unvaccinated women, and estimated VE by a logistic mixed model. Results: We included 1087 women of which 53% were hrHPV positive and 60% reported to be vaccinated. The adjusted pooled VE against HPV-16/18 was 89.9% (81.7%-94.4%). Moreover, we calculated significant VE against nonvaccine types HPV-45 (91%), HPV-35 (57%), HPV-31 (50%), and HPV-52 (37%). Among women who were offered vaccination 5/6 years ago, we estimated similar VE against HPV-16/18 (92%) and all hrHPV types (35%) compared to women who were offered vaccination <5 years ago (83% and 33%, respectively). Conclusion: We demonstrated high VE of the bivalent vaccine against HPV-16/18 and cross-protection against HPV-45/35/31/52. Protection against HPV-16/18 was sustained up to 6 years postvaccination.

No evidence for cross-protection of the HPV-16/18 vaccine against HPV-6/11 positivity in female STI clinic visitors.

OBJECTIVES: Data from a vaccine trial and from post-vaccine surveillance in the United Kingdom have suggested that the bivalent HPV-16/18 vaccine offers cross-protection against HPV-6/11 and protection against anogenital warts (AGW). We studied the effect of the bivalent vaccine on genital HPV-6/11 positivity and AGW in the Netherlands. METHODS: We included all vaccine-eligible women from the PASSYON study, a biennial cross-sectional study among 16- to 24-year-old sexually transmitted infection (STI) clinic attendants. Vaginal self-swabs were analyzed for type specific HPV and AGW were diagnosed at the STI-clinic. Prevalence of HPV-6 and/or HPV-11 and AGW were compared between self-reported vaccinated and unvaccinated women by log-binomial regression analysis, adjusted for demographics and risk behavior. RESULTS: Of the 1198 women included, 56% reported to be vaccinated at least once. Relative to unvaccinated women, the adjusted prevalence ratio (PR) for HPV-6/11 was 1.03 (95% confidence interval [CI] 0.74-1.43) for women vaccinated at least once. The crude PR for AGW was 0.67 (95% CI 0.22-2.07) for women vaccinated at least once. Adjustment did not change these results. CONCLUSIONS: We observed no cross-protective effect of the bivalent vaccine on genital HPV-6/11 positivity and a non-significant partially protective effect on AGW.

Genetic Diversity in the Major Capsid L1 Protein of HPV-16 and HPV-18 in the Netherlands.

OBJECTIVES: Intratypic molecular variants of human papillomavirus (HPV) type-16 and -18 exist. In the Netherlands, a bivalent vaccine, composed of recombinant L1 proteins from HPV-16 and -18, is used to prevent cervical cancer since 2009. Long-term vaccination could lead to changes in HPV-16 and -18 virus population, thereby hampering vaccination strategies. We determined the genetic diversity of the L1 gene in HPV-16 and -18 viral strains circulating in the Netherlands at the start of vaccination in order to understand the baseline genetic diversity in the Dutch population. METHODS: DNA sequences of the L1 gene were determined in HPV-16 (n = 241) and HPV-18 (n = 108) positive anogenital samples collected in 2009 and 2011 among Dutch 16- to 24-year old female and male attendees of the sexually transmitted infection (STI) clinics. Phylogenetic analysis was performed and sequences were compared to reference sequences HPV-16 (AF536179) and HPV-18 (X05015) using BioNumerics 7.1. RESULTS: For HPV-16, ninety-five single nucleotide polymorphism (SNPs) were identified, twenty-seven (28%) were non-synonymous variations. For HPV-18, seventy-one SNPs were identified, twenty-nine (41%) were non-synonymous. The majority of the non-silent variations were located in sequences encoding alpha helix, beta sheet or surface loops, in particular in the immunodominant FG loop, and may influence the protein secondary structure and immune recognition. CONCLUSIONS: This study provides unique pre-vaccination/baseline data on the genetic L1 diversity of HPV-16 and -18 viruses circulating in the Netherlands among adolescents and young adults.

Correction: Genetic Diversity in the Major Capsid L1 Protein of HPV-16 and HPV-18 in the Netherlands.

[This corrects the article DOI: 10.1371/journal.pone.0152782.].

The effect of HIV infection on anal and penile human papillomavirus incidence and clearance: a cohort study among MSM.

OBJECTIVES: A large portion of anogenital cancers is caused by high-risk human papillomavirus (hrHPV) infections, which are especially common in HIV-infected men. We aimed to compare the incidence and clearance of anal and penile hrHPV infection between HIV-infected and HIV-negative MSM. DESIGN: Analyses of longitudinal data from a prospective cohort study. METHODS: MSM aged 18 years or older were recruited in Amsterdam, the Netherlands, and followed-up semi-annually for 24 months. At each visit, participants completed risk-factor questionnaires. Anal and penile self-samples were tested for HPV DNA using the SPF10-PCR DEIA/LiPA25 system. Effects on incidence and clearance rates were quantified via Poisson regression, using generalized estimating equations to correct for multiple hrHPV types. RESULTS: Seven hundred and fifty MSM with a median age of 40 years (interquartile 35-48) were included in the analyses, of whom 302 (40%) were HIV-infected. The incidence rates of hrHPV were significantly higher in HIV-infected compared with HIV-negative MSM [adjusted incidence rate ratio (aIRR) 1.6; 95% confidence interval (CI) 1.3-2.1 for anal and aIRR 1.4; 95%CI 1.0-2.1 for penile infection]. The clearance rate of hrHPV was significantly lower for anal [adjusted clearance rate ratio (aCRR) 0.7; 95%CI 0.6-0.9], but not for penile infection (aCRR 1.3; 95%CI 1.0-1.7). HrHPV incidence or clearance did not differ significantly by nadir CD4 cell count. CONCLUSION: Increased anal and penile hrHPV incidence rates and decreased anal hrHPV clearance rates were found in HIV-infected compared with HIV-negative MSM, after adjusting for sexual behavior. Our findings suggest an independent effect of HIV infection on anal hrHPV infections.

Incidence and persistence of carcinogenic genital human papillomavirus infections in young women with or without Chlamydia trachomatis co-infection.

We assessed whether infection with chlamydia increases the incidence of carcinogenic human papillomavirus (HPV) infections and if HPV persistence is affected by chlamydia co-infection. For 1982 women (16-29 years-old) participating in two consecutive rounds of a chlamydia screening implementation trial, swabs were polymerase chain reaction tested to detect chlamydia and 14 carcinogenic HPV genotypes. HPV type-specific incidence and persistence rates were stratified for chlamydia positivity at follow-up. Associations were assessed by multilevel logistic regression analyses with correction for sexual risk factors. HPV type-specific incidence ranged from 1.4% to 8.9% and persistence from 22.7% to 59.4% after a median follow-up of 11 months (interquartile range: 11-12). Differences in 1-year HPV persistence rates between chlamydia -infected and noninfected women were less distinct than differences in HPV incidence rates (pooled adjusted odds ratios of 1.17 [95% CI: 0.69-1.96] and 1.84 [95% CI: 1.36-2.47], respectively). The effect of chlamydia co-infection on HPV-infection risk did not significantly differ by HPV genotype. In conclusion, infection with chlamydia increases the risk of infection by carcinogenic HPV types and may enhance persistence of some HPV types. Although these findings could reflect residual confounding through unobserved risk factors, our results do give reason to explore more fully the association between chlamydia and HPV type-specific acquisition and persistence.

Association of HIV Infection With Anal and Penile Low-Risk Human Papillomavirus Infections Among Men Who Have Sex With Men in Amsterdam: The HIV & HPV in MSM Study.

BACKGROUND: This study among men who have sex with men (MSM) aimed to (1) assess prevalence of anogenital low-risk human papillomavirus (lrHPV) infections, (2) evaluate associations with HIV infection, and (3) investigate lrHPV concordance. METHODS: In 2010 to 2011, MSM 18 years or older were recruited in Amsterdam, the Netherlands, and provided anal and penile self-swabs (HIV & HPV in MSM study). Using the HPV SPF10-PCR/DEIA/LiPA25 system, the presence of lrHPV types 6, 11, 34, 40, 42, 43, 44, 53, 54, 66, 68/73, 70, and 74 could be detected. Logistic regression with generalized estimating equations was used to assess the independent effect of HIV on lrHPV infections. The model was repeated for lrHPV subcategories (nononcogenic and weakly oncogenic infections separately). Concordance was defined as detection of the same lrHPV type in both self-swabs of one individual. RESULTS: A total of 778 MSM were included, of whom 317 (41%) were HIV positive (median CD4 count at enrollment, 530 cells/mm). Prevalence of anal lrHPV was 45% (95% confidence interval [CI], 41%-50%) in HIV-negative MSM and 69% (95% CI, 64%-74%) in HIV-positive MSM. Prevalence of penile lrHPV was 20% (95% CI, 16%-24%) and 37% (95% CI, 31%-42%), respectively. In multivariable analysis, HIV infection was independently associated with anal (adjusted odds ratio [aOR], 1.9; 95% CI, 1.5-2.3) and penile lrHPV (aOR, 2.0; 95% CI, 1.4-2.7). Nononcogenic and weakly oncogenic lrHPV subcategories showed a similar pattern of association. Anal lrHPV infections were strongly associated with the presence of a type-concordant penile infection (aOR, 5.8; 95% CI, 4.4-7.5) and vice versa (aOR, 5.7; 95% CI, 4.4-7.5). CONCLUSIONS: Anal and penile infections with lrHPV are common in MSM. HIV infection was an independent determinant for lrHPV infections.