Hepatitis B vaccination of men who have sex with men in the Netherlands: should we vaccinate more men, younger men or high-risk men?

Contribution of sexual health services to hepatitis B detection and control (Netherlands, 2008-2016)

OBJECTIVES

Case finding is one of the priority actions to reduce the disease burden of chronic hepatitis B (CHB). We estimated the contribution of CHB case finding at sexual health centres (SHCs) to the total national number of newly diagnosed CHB cases in the Netherlands and determined the characteristics of CHB cases detected at SHCs.

METHODS

This observational study used surveillance data from all outpatient SHCs in the Netherlands (SOAP database) and the number of CHB from national notification data (Osiris) from 2008 to 2016. The proportion of CHB notifications (hepatitis B surface antigen positive serology) detected at SHCs was calculated. SHC consultations without hepatitis B virus (HBV) testing (n=669 308), with acute hepatitis B diagnosis (n=73), with HBV vaccination only (n=182) or an inconclusive hepatitis B diagnosis (n=24) were excluded. Univariable and multivariable logistic regression analyses were performed, stratified by gender and sexual preference, to analyse patient characteristics associated with CHB.

RESULTS

During the study period, 12 149 CHB cases were notified. 405 646 SHC consultations were included in the analysis and 1452 CHB cases (0.4%) were detected at SHCs. The proportion of CHB cases detected at SHCs in relation to the national notified number ranged between 12.4% (200 of 1613) in 2008 and 10.8% (106 of 980) in 2016. 87% of CHB cases were among first-generation migrants (FGMs) originating from high endemic countries for sexually transmitted infections or men who have sex with men (MSM). In multivariable analysis, an older age category, migration background and being a commercial sex worker (CSW) were associated with CHB in all stratified analyses.

CONCLUSIONS

The contribution of SHCs is relevant to case finding of CHB in the Netherlands. SHCs should therefore be considered as an important health setting to screen for HBV in high-risk groups, especially among MSM, CSW and FGM, to achieve a reduction in the HBV-related disease burden.

Ending risk-group HBV vaccination for MSM after the introduction of universal infant HBV vaccination: A mathematical modelling study

BACKGROUND

Risk-group HBV vaccination for men who have sex with men (MSM) was introduced in the Netherlands in 2002, followed by universal infant vaccination in 2011, that will enable termination of risk-group vaccination over time. The introduction of pre-exposure prophylaxis (PrEP) for HIV prevention might result in increased HBV testing and vaccination against HBV. The aim of this study was to investigate the impact of the transition from risk-group to universal HBV vaccination, accounting for improvements in HBV testing and treatment, as well as the introduction of PrEP.

METHODS

We developed a mathematical model for HBV transmission among MSM. Universal vaccination was modelled by assigning some MSM (5-15% in 2028 increasing to 80-90% in 2033 and thereafter) to be vaccinated when they become sexually active. We investigated different scenarios assuming 0.5% extra vaccination rate and 0.5% extra testing rate due to PrEP consultations; and 5% of HIV-negative MSM on PrEP, that will reduce the probability of HBV acquisition by 88%.

RESULTS

Universal vaccination resulted in a reduction of 24% (interquartile range; 22-25%) of the total number of HBV infections among MSM estimated to occur from 2020 to 2070. With universal vaccination, terminating risk-group vaccination in 2030 or 2040 resulted in 30% or 10% more HBV infections over 2020-2070, respectively, compared to continuation of risk-group vaccination until 2070. With PrEP and continued risk-group vaccination, the total number of HBV infections over 2020-2070 was reduced by 13%.

CONCLUSIONS

Universal HBV vaccination can lead to a major reduction in HBV incidence among MSM in the future. The reduction becomes smaller when ending risk-group HBV vaccination, but larger by PrEP use for HIV prevention. Efforts to keep high levels of HBV vaccination, testing, and treatment have to be continued in the coming decades in order to eliminate HBV as a health threat for MSM.

Infection Pressure in Men Who Have Sex With Men and Their Suitability to Donate Blood

BACKGROUND

Deferral of men who have sex with men (MSM) from blood donation is highly debated. We therefore investigated their suitability to donate blood.

METHODS

We compared the antibody prevalence of 10 sexually and transfusion-transmissible infections (TTIs) among 583 MSM and 583 age-matched repeat male blood donors. MSM were classified as low risk (lr) or medium-to-high risk (hr) based on self-reported sexual behavior and as qualified or unqualified using Dutch donor deferral criteria. Infection pressure (IP) was defined as the number of antibody-reactive infections, with class A infections (human immunodeficiency virus-1/2, hepatitis B virus, hepatitis C virus, human T-cell lymphotropic virus-1/2, syphilis) given double weight compared to class B infections (cytomegalovirus, herpes simplex virus-1/2, human herpesvirus 8, hepatitis E virus, parvovirus B19).

RESULTS

Donors had a lower median IP than qualified lr-MSM and qualified hr-MSM (2 [interquartile range {IQR}, 1-2] vs 3 [IQR, 2-4]; P < .001). Low IP was found in 76% of donors, 39% of qualified lr-MSM, and 27% of qualified hr-MSM. The prevalence of class A infections did not differ between donors and qualified lr-MSM but was significantly higher in qualified hr-MSM and unqualified MSM. Recently acquired class A infections were detected in hr-MSM only. Compared to blood donors, human herpesviruses were more prevalent in all MSM groups (P < .001).

CONCLUSIONS

IP correlates with self-reported risk behavior among MSM. Although lr-MSM might form a low threat for blood safety with regard to class A infections, the high seroprevalence of human herpesviruses in lr-MSM warrants further investigation.

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.

Factors associated with self-reported hepatitis B virus vaccination status among men who have sex with men in the Netherlands

Background Reducing the number of new acute hepatitis B virus (HBV) infections to zero by 2022 is an important goal in the Netherlands. Free HBV vaccination is available for population groups at higher risk of infection, including men who have sex with men (MSM). Identifying correlates of HBV vaccination among MSM can guide the development of health promotion interventions to increase coverage of HBV vaccination.

METHODS

We assessed factors associated with the HBV vaccination status of 4270 MSM in the Netherlands. Data were collected through the 2018 online Men & Sexuality survey.

RESULTS

Multinomial regression analysis showed that lower education level, having never tested for HIV, not recently diagnosed with a sexually transmissible infection, recently having had sex abroad and unknown HBV testing status were associated with higher odds of being unvaccinated as opposed to fully vaccinated. Living in Amsterdam and testing HBV negative were associated with lower odds of being unvaccinated as opposed to fully vaccinated. Age (25-39 years vs younger ages), living in Amsterdam and using pre-exposure prophylaxis decreased the odds to be partly vaccinated as opposed to fully vaccinated; having a migration background increased these odds.

CONCLUSIONS

HBV vaccination rates among MSM will not reduce HBV transmission to zero. HBV promotion should focus on MSM outside of Amsterdam who are likely less connected with sexual health services and may be at lower (perceived) risk. The factors identified related to HBV vaccination status provide guidance for health promotion interventions to increase uptake and vaccination completion among MSM.

Potential effectiveness of prophylactic HPV immunization for men who have sex with men in the Netherlands: A multi-model approach

BACKGROUND

Men who have sex with men (MSM) are at high risk for anal cancer, primarily related to human papillomavirus genotype 16 (HPV16) infections. At 8.5 per 100,000 per year, the incidence rate of anal cancer among MSM is similar to that of cervical cancer among adult women in the Netherlands. However, MSM are not included in most HPV vaccination programs. We explored the potential effectiveness of prophylactic immunization in reducing anogenital HPV16 transmission among MSM in the Netherlands.

METHODS AND FINDINGS

We developed a range of mathematical models for penile-anal HPV16 transmission, varying in sexual contact structure and natural history of infection, to provide robust and plausible predictions about the effectiveness of targeted vaccination. Models were informed by an observational cohort study among MSM in Amsterdam, 2010-2013. Parameters on sexual behavior and HPV16 infections were obtained by fitting the models to data from 461 HIV-negative study participants, considered representative of the local MSM population. We assumed 85% efficacy of vaccination against future HPV16 infections as reported for HIV-negative MSM, and age-specific uptake rates similar to those for hepatitis B vaccination among MSM in the Netherlands. Targeted vaccination was contrasted with vaccination of 12-year-old boys at 40% uptake in base-case scenarios, and we also considered the effectiveness of a combined strategy. Offering vaccine to MSM without age restrictions resulted in a model-averaged 27.3% reduction (90% prediction interval [PI] 11.9%-37.5%) in prevalence of anal HPV16 infections, assuming similar uptake among MSM as achieved for hepatitis B vaccination. The predicted reduction improved to 46.1% (90% PI 21.8%-62.4%) if uptake rates among MSM were doubled. The reductions in HPV16 infection prevalence were mostly achieved within 30 years of a targeted immunization campaign, during which they exceeded those induced by vaccinating 40% of preadolescent boys, if started simultaneously. The reduction in anal HPV16 prevalence amounted to 74.8% (90% PI 59.8%-93.0%) under a combined vaccination strategy. HPV16 prevalence reductions mostly exceeded vaccine coverage projections among MSM, illustrating the efficiency of prophylactic immunization even when the HPV vaccine is given after sexual debut. Mode of protection was identified as the key limitation to potential effectiveness of targeted vaccination, as the projected reductions were strongly reduced if we assumed no protection against future infections in recipients with prevalent infection or infection-derived immunity at the time of immunization. Unverified limitations of our study include the sparsity of data to inform the models, the omission of oral sex in transmission to the penile or anal site, and the restriction that our modeling results apply primarily to HIV-negative MSM.

CONCLUSIONS

Our findings suggest that targeted vaccination may generate considerable reductions in anogenital HPV16 infections among MSM, and has the potential to accelerate anal cancer prevention, especially when combined with sex-neutral vaccination in preadolescence.

Predictors of hepatitis B vaccination completion among people who use drugs participating in a national program of targeted vaccination

BACKGROUND

Targeted vaccination strategies are necessary to prevent people who use drugs (PWUD) becoming infected with hepatitis B virus (HBV). The aims of this study were to provide an overview of the activities for PWUD in a decentralised vaccination program in the Netherlands and to explore the determinants associated with completing a standard hepatitis B vaccination series.

METHODS

We used data for behavioural risk groups from the register of the national vaccination program. The data concerned PWUD who were immunised against hepatitis B in the Netherlands between 2002 and 2011. A standard series of three vaccinations (at 0, 1, and 6 months) was offered at inclusion and was continued if serological markers for past or chronic HBV infection were absent. Completion of a vaccination series (at least three vaccinations, irrespective of timing) was a dependent variable in our logistic regression analysis.

RESULTS

The program reached 18,054 PWUD. Of the 15,746 participants eligible for vaccination (i.e. they were neither carriers of hepatitis B nor immune to hepatitis B), 9089 (58%) completed a series of three hepatitis B vaccinations. Factors associated with a higher completion rate of a vaccination series (p < 0.01) were: starting vaccination in the earlier years of the program, older age of PWUD, intravenous drug use, vaccine administration by addiction care centres, and flexibility in location of vaccine delivery.

CONCLUSION

Despite using a standard HBV vaccination schedule and no financial incentives, vaccination completion among PWUD was relatively high. Our results suggest that flexibility of vaccination location and administration of vaccines by healthcare workers with sustainable contact with PWUD could improve vaccination programs for this risk group.

Impact of Heterogeneity in Sexual Behavior on Effectiveness in Reducing HIV Transmission with Test-and-Treat Strategy

The WHO’s early-release guideline for antiretroviral treatment (ART) of HIV infection based on a recent trial conducted in 34 countries recommends starting treatment immediately upon an HIV diagnosis. Therefore, the test-and-treat strategy may become more widely used in an effort to scale up HIV treatment and curb further transmission. Here we examine behavioural determinants of HIV transmission and how heterogeneity in sexual behaviour influences the outcomes of this strategy. Using a deterministic model, we perform a systematic investigation into the effects of various mixing patterns in a population of men who have sex with men (MSM), stratified by partner change rates, on the elimination threshold and endemic HIV prevalence. We find that both the level of overdispersion in the distribution of the number of sexual partners and mixing between population subgroups have a large influence on endemic prevalence before introduction of ART and on possible long term effectiveness of ART. Increasing heterogeneity in risk behavior may lead to lower endemic prevalence levels, but requires higher coverage levels of ART for elimination. Elimination is only feasible for populations with a rather low degree of assortativeness of mixing and requires treatment coverage of almost 80% if rates of testing and treatment uptake by all population subgroups are equal. In this case, for fully assortative mixing and 80% coverage endemic prevalence is reduced by 57%. In the presence of heterogeneity in ART uptake, elimination is easier to achieve when the subpopulation with highest risk behavior is tested and treated more often than the rest of the population, and vice versa when it is less. The developed framework can be used to extract information on behavioral heterogeneity from existing data which is otherwise hard to determine from population surveys.

HIV is endemic in populations of MSM in Western countries. As ART reduces transmission risk, increased testing and treatment rates are expected to lower HIV incidence. However, concerns are that in MSM populations changing risk behavior may counteract the impact of ART on transmission. Using a mathematical model, we investigated how heterogeneity in sexual behavior influences the possible effects of a test-and-treat strategy on HIV prevalence and in particular the prospects of eliminating HIV from these populations. We demonstrated that behavioral heterogeneity plays an important role in determining the impact of ART on reducing HIV transmission. Knowledge of behavioral heterogeneity is key in setting intervention goals in populations of MSM.

Factors associated with hepatitis B vaccination among men who have sex with men: a systematic review of published research

This systematic review identified and synthesised evidence from published research regarding personal and environmental factors associated with hepatitis B virus (HBV) vaccination uptake among gay men and other men who have sex with men (MSM) in low prevalence, high-income countries. A systematic literature search identified 18 eligible papers that addressed factors potentially associated with HBV vaccination uptake among MSM, of which 16 reported research conducted in the US. Studies assessed possible associations between HBV vaccination among MSM and socio-demographic characteristics, behavioural and social-cognitive factors and indicators of health service access. Converging evidence was found for associations between HBV vaccination and younger age, gay self-identification, and not using alcohol and drugs; evidence suggests a lack of association between HBV vaccination and ethnicity. There was converging evidence for associations between HBV vaccination and social-cognitive factors, in particular knowledge, perceived vulnerability and perceived severity regarding HBV infection, and perceived barriers to HBV vaccination. Evidence further supported associations between HBV vaccination and indicators of health service access. While research regarding factors associated with HBV vaccination among MSM remains limited, the identified correlates of HBV vaccination among MSM provide important guidance for the development of health promotion interventions to effectively increase coverage of HBV vaccination among MSM.

Ongoing transmission of hepatitis B virus in rural parts of the Netherlands, 2009-2013

Background

Reported acute hepatitis B incidence in the Netherlands reached its nadir in 2013. However, regional signals about increased number of hepatitis B cases raised the question how hepatitis B incidence was distributed over the country. In this study, regional differences in hepatitis B epidemiology were investigated using epidemiological and molecular data.

Methods

Acute hepatitis B virus (HBV) infections, reported between 2009–2013, were included. If serum was available, a fragment of S and C gene of the HBV was amplified and sequenced. Regional differences in incidence were studied by geographical mapping of cases and cluster analysis. Regional differences in transmission were studied by constructing regional maximum parsimony trees based on the C gene to assess genetic clustering of cases.

Results

Between 2009 and 2013, 881 cases were notified, of which respectively 431 and 400 cases had serum available for S and C gene sequencing. Geographical mapping of notified cases revealed that incidences in rural border areas of the Netherlands were highest. Cluster analysis identified two significant clusters (p<0.000) in the South-western and North-eastern regions. Genetic cluster analysis showed that rural border areas had relatively large clusters of cases with indistinguishable sequences, while other regions showed more single introductions.

Conclusion

This study showed that regional differences in HBV epidemiology were present in the Netherlands. Rural border regions showed higher incidences and more ongoing transmission, mainly among MSM, than the more urban inland areas. Therefore, preventive measures should be enhanced in these regions.

Hepatitis B virus: Where do we stand and what is the next step for eradication?

Hepatitis B (HB) virus (HBV) infection, which causes liver cirrhosis and hepatocellular carcinoma, is endemic worldwide. Hepatitis B vaccines became commercially available in the 1980s. The World Health Organization recommended the integration of the HB vaccine into the national immunisation programs in all countries. HBV prevention strategies are classified into three groups: (1) universal vaccination alone; (2) universal vaccination with screening of pregnant women plus HB immune globulin (HBIG) at birth; and (3) selective vaccination with screening of pregnant women plus HBIG at birth. Most low-income countries have adopted universal vaccine programs without screening of pregnant women. However, HB vaccines are not widely used in low-income countries. The Global Alliance for Vaccine and Immunization was launched in 2000, and by 2012, the global coverage of a three-dose HB vaccine had increased to 79%. The next challenges are to further increase the coverage rate, close the gap between recommendations and routine practices, approach high-risk individuals, screen and treat chronically infected individuals, and prevent breakthrough infections. To eradicate HBV infections, strenuous efforts are required to overcome socioeconomic barriers to the HB vaccine; this task is expected to take several decades to complete.

Targeted vaccination programme successful in reducing acute hepatitis B in men having sex with men in Amsterdam, the Netherlands

BACKGROUND & AIMS

In the Netherlands, transmission of hepatitis B virus occurs mainly within behavioural high-risk groups, such as in men who have sex with men. Therefore, a vaccination programme has targeted these high-risk groups. This study evaluates the impact of the vaccination programme targeting Amsterdam's large population of men who have sex with men from 1998 through 2011.

METHODS

We used Amsterdam data from the national database of the vaccination programme for high-risk groups (January 1, 1998 to December 31, 2011). Programme and vaccination coverage were estimated with population statistics. Incidence of acute hepatitis B was analyzed with notification data from the Amsterdam Public Health Service (1992-2011). Mathematical modelling accounting for vaccination data and trends in sexual risk behaviour was used to explore the impact of the programme.

RESULTS

At the end of 2011, programme coverage was estimated at 41% and vaccination coverage from 30% to 38%. Most participants (67%) were recruited from the outpatient department for sexually transmitted infections and outreach locations such as saunas and gay bars. Incidence of acute hepatitis B dropped sharply after 2005. The mathematical model in which those who engage most in high-risk sex are vaccinated, best explained the decline in incidence.

CONCLUSIONS

Transmission of hepatitis B virus among Amsterdam's men who have sex with men has decreased, despite ongoing high-risk sexual behaviour. Vaccination programmes targeting men who have sex with men do not require full coverage; they may be effective when those who engage most in high-risk sex are reached.