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.

Evaluation of a Web-Based Culturally Sensitive Educational Video to Facilitate Informed Cervical Cancer Screening Decisions Among Turkish- and Moroccan-Dutch Women Aged 30 to 60 Years: Randomized Intervention Study

Background

In the Netherlands, since 1996, a national cervical cancer (CC) screening program has been implemented for women aged 30 to 60 years. Regional screening organizations send an invitation letter and information brochure in Dutch to the home addresses of targeted women every 5 years. Although this screening is free of charge, Turkish- and Moroccan-Dutch women, especially, show low screening participation and limited informed decision-making (IDM). As Turkish- and Moroccan-Dutch women indicated their need for information on the practical, emotional, cultural, and religious aspects of CC screening, we developed a culturally sensitive educational video (CSEV) as an addition to the current information brochure.

Objective

In this study, we aimed to evaluate the added effect of the CSEV on IDM regarding CC screening participation among Turkish and Moroccan women aged 30 to 60 years in the Netherlands through a randomized intervention study.

Methods

Initial respondents were recruited via several social media platforms and invited to complete a web-based questionnaire. Following respondent-driven sampling, respondents were asked to recruit a number of peers from their social networks to complete the same questionnaire. Respondents were randomly assigned to the control (current information brochure) or intervention condition (brochure and CSEV). We measured respondents’ knowledge and attitude regarding CC screening and their intention to participate in the next CC screening round before and after the control or intervention condition. We evaluated the added effect of the CSEV (above the brochure) on their knowledge, attitude, intention, and IDM using intention-to-treat analyses.

Results

The final sample (n=1564) included 686 (43.86%) Turkish and 878 (56.14%) Moroccan-Dutch women. Of this sample, 50.7% (793/1564) were randomized to the control group (350/793, 44.1% Turkish and 443/793, 55.9% Moroccan) and 49.3% (771/1564) to the intervention group (336/771, 43.6% Turkish and 435/771, 56.4% Moroccan). Among the Turkish-Dutch women, 33.1% (116/350) of the control respondents and 40.5% (136/336) of the intervention respondents consulted the brochure (not statistically significant). Among Moroccan-Dutch women, these percentages were 28.2% (125/443) and 37.9% (165/435), respectively (P=.003). Of all intervention respondents, 96.1% (323/336; Turkish) and 84.4% (367/435; Moroccan) consulted the CSEV. The CSEV resulted in more positive screening attitudes among Moroccan-Dutch women than the brochure (323/435, 74.3% vs 303/443, 68.4%; P=.07). Women, who had never participated in CC screening before, showed significantly more often a positive attitude toward CC screening compared with the control group (P=.01).

Conclusions

Our short and easily implementable CSEV resulted in more positive screening attitudes, especially in Moroccan-Dutch women. As the CSEV was also watched far more often than the current brochure was read, this intervention can contribute to better reach and more informed CC screening decisions among Turkish- and Moroccan-Dutch women.

Trial Registration

International Clinical Trial Registry Platform NL8453; https://tinyurl.com/2dvbjxvc

Effects of Dutch livestock production on human health and the environment

Observed multiple adverse effects of livestock production have led to increasing calls for more sustainable livestock production. Quantitative analysis of adverse effects, which can guide public debate and policy development in this area, is limited and generally scattered across environmental, human health, and other science domains. The aim of this study was to bring together and, where possible, quantify and aggregate the effects of national-scale livestock production on 17 impact categories, ranging from impacts of particulate matter, emerging infectious diseases and odor annoyance to airborne nitrogen deposition on terrestrial nature areas and greenhouse gas emissions. Effects were estimated and scaled to total Dutch livestock production, with system boundaries including feed production, manure management and transport, but excluding slaughtering, retail and consumption. Effects were expressed using eight indicators that directly express Impact in the sense of the Drivers-Pressures-State-Impact-Response framework, while the remaining 14 express Pressures or States. Results show that livestock production may contribute both positively and negatively to human health with a human disease burden (expressed in disability-adjusted life years) of up to 4% for three different health effects: those related to particulate matter, zoonoses, and occupational accidents. The contribution to environmental impact ranges from 2% for consumptive water use in the Netherlands to 95% for phosphorus transfer to soils, and extends beyond Dutch borders. While some aggregation across impact categories was possible, notably for burden of disease estimates, further aggregation of disparate indicators would require normative value judgement. Despite difficulty of aggregation, the assessment shows that impacts receive a different contribution of different animal sectors. While some of our results are country-specific, the overall approach is generic and can be adapted and tuned according to specific contexts and information needs in other regions, to allow informed decision making across a broad range of impact categories.

Diagnostic performance of serological assays for anti-HBs testing: Results from a quality assessment program

BACKGROUND

Post-vaccination testing after hepatitis B vaccination is indispensable to evaluate long-term immunological protection. Using a threshold level of antibodies against hepatitis B surface antigen (anti-HBs) to define serological protection, implies reproducible and valid measurements of different diagnostic assays.

OBJECTIVES

In this study we assess the performance of currently used anti-HBs assays.

STUDY DESIGN

In 2013, 45 laboratories participated in an external quality assessment program using pooled anti-HBs serum samples around the cutoff values 10IU/l and 100IU/l. Laboratories used either Axsym (Abbott Laboratories), Architect (Abbott Laboratories), Access (Beckman-Coulter), ADVIA Centaur anti-HBs2 (Siemens Healthcare Diagnostics), Elecsys, Modular or Cobas (Roche Diagnostics) or Vidas Total Quick (Biomerieux) for anti-HBs titre quantification. We analysed covariance using mixed-model repeated measures. To assess sensitivity/specificity and agreement, a true positive or true negative result was defined as an anti-HBs titre respectively above or below the cutoff value by ≥4 of 6 assays.

RESULTS

Different anti-HBs assays were associated with statistically significant (P<0.05) differences in anti-HBs titres in all dilutions. Sensitivity and specificity ranged respectively from 64%-100% and 95%-100%. Agreement between assays around an anti-HBs titre cutoff value of 10IU/l ranged from 93%-100% and was 44% for a cutoff value of 100IU/l.

CONCLUSIONS

Around a cutoff value of 10IU/l use of the Access assay may result in false-negative results. Concerning the cutoff value of 100IU/l, a sample being classified below or above this cutoff relied heavily on the specific assay used, with both the Architect and the Access resulting in false-negative results.

Increase in Ticks and Lyme Borreliosis, Yet Research into Its Prevention on the Wane

There is increased concern about the upward incidence of Lyme Borreliosis (LB) in Europe, the United States, Asia, and Northern Africa. However, effective measures to control tick populations or vaccines for LB are not yet available. Therefore, behavioral measures including avoidance of areas inhabited by ticks, performing routine body checks, using protective clothing, and the application of tick repellents are of great importance. Unfortunately, acceptance and uptake of many of these preventive behaviors are currently low. Hence, effective health education and public health communication aimed at promoting the uptake of preventive behaviors regarding tick bites and LB are urgently needed. In 2012, Mowbray recommended to conduct more research aimed at improving evidence-based insights regarding the promotion of preventive behaviors among the general public when exposed to the risk of LB. We fully agree with Mowbray and repeated her systematic review in May 2015 covering the period 1995-May 2015. Unfortunately, our review yielded exactly the same studies as already included in the review by Mowbray. Therefore, we again sound the alarm bell, just as Mowbray did a few years ago. As long as there are no effective measures for controlling tick populations and there is no vaccine available, we rely solely on health education and communication efforts to prevent tick bites and LB. We call on researchers and funders to prioritize research in the field of public health interventions for tick bites and LB because, in the words of Benjamin Franklin, "an ounce of prevention is worth a pound of cure."

Quantifying reporting timeliness to improve outbreak control

The extent to which reporting delays should be reduced to gain substantial improvement in outbreak control is unclear. We developed a model to quantitatively assess reporting timeliness. Using reporting speed data for 6 infectious diseases in the notification system in the Netherlands, we calculated the proportion of infections produced by index and secondary cases until the index case is reported. We assumed interventions that immediately stop transmission. Reporting delays render useful only those interventions that stop transmission from index and secondary cases. We found that current reporting delays are adequate for hepatitis A and B control. However, reporting delays should be reduced by a few days to improve measles and mumps control, by at least 10 days to improve shigellosis control, and by at least 5 weeks to substantially improve pertussis control. Our method provides quantitative insight into the required reporting delay reductions needed to achieve outbreak control and other transmission prevention goals.

Speed versus coverage trade off in targeted interventions during an outbreak

Which case-based intervention measures should be applied during an epidemic outbreak depends on how timely they can be applied and how effective they are. During the course of each individual's infection, the earlier control measures are applied on him/her the more effectively further disease spread can be prevented. However, quick implementation can lead to loss of efficacy or coverage, e.g., when individuals are targeted based on rapid but poorly sensitive diagnostic tests in place of slower but accurate PCR tests. To analyse this trade off between speed and coverage we used stochastic models considering how the individual reproduction density is modified by interventions. We took as example the case-based intervention strategy employed in the Netherlands during the beginning of the H1N1 pandemic. Suspected cases were isolated and samples were collected for PCR diagnosis. In case of positive diagnosis, antiviral drugs were provided to contacts as post-exposure prophylaxis. At the time there were also rapid influenza diagnostic tests (RIDTs) available which provided results within an hour after sample collection compared to a median of 2.7 days for PCR tests, but they were less sensitive. We studied how interventions based on RIDTs with various sensitivities affect the outbreak size and how these compare to PCR diagnosis based interventions. Using an intervention based on a bedside RIDT with 60% detection ratio or a laboratory RIDT with 70% detection ratio is as effective as the most effective PCR-diagnosis based intervention. Relative performances of interventions are not dependent on the basic reproduction number R0 but only on distributions of individual reproduction density and of delay periods. The individual reproduction density combines R0 and infection time distribution, both crucial in determining the impact of case-based interventions during epidemic outbreaks.

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

OBJECTIVES

The selective vaccination programme against hepatitis B virus (HBV) was introduced in the Netherlands in 2002 targeting high-risk groups, including men who have sex with men (MSM). Despite the high average age of vaccination in MSM, the number of notifications of acute HBV recently declined. We investigate whether this can be attributed to the selective vaccination programme. We examine how vaccination strategies could be improved and the impact of universal infant vaccination introduced in 2011.

METHODS

We use a mathematical model for HBV transmission among MSM. The incidence of HBV was calculated from the model and from notification data of acute HBV.

RESULTS

A decline was observed in the incidence of HBV since 2006, as calculated from the model; this decline was smaller than that observed in data if all MSM were equally likely to be vaccinated. Assuming that high-risk MSM were more likely to be vaccinated than low-risk MSM resulted in a steeper decline in modelled incidence and better agreement with observed incidence. Vaccinating MSM at a younger age or doubling the vaccination rate would increase the impact of selective vaccination, but is less effective than vaccinating high-risk MSM.

CONCLUSIONS

Selective HBV vaccination of MSM in the Netherlands has had a substantial impact in reducing HBV incidence. The reduction suggests that vaccination rates among high-risk MSM were higher than those among low-risk MSM. Countries that have not yet reached 35-year cohorts with universal childhood vaccination should actively implement or continue selective high-risk MSM vaccination.

Determinants of HPV vaccination intentions among Dutch girls and their mothers: a cross-sectional study

BACKGROUND

The Dutch government recently added universal Human Papilloma Virus (HPV) vaccination for 12-year-old girls to the existing national immunization program. The participation rate for the initial catch-up campaign for girls aged 13 to 16 years in 2009 was lower (47%) than expected (70%). To inform future HPV information campaigns, this paper examines the social and psychological determinants of the HPV vaccination intentions of girls aged 13 to 16 years and their mothers who were targeted by the Dutch catch-up campaign of 2009.

METHODS

A random sample of girls and their mothers was chosen from the Dutch vaccination register and received a letter inviting them to participate (n = 5,998 mothers and daughters). In addition, a random sample was recruited via an online panel by a marketing research company (n = 650 mothers; n = 350 daughters). Both groups were asked to complete a web-based questionnaire with questions on social demographic characteristics, social-psychological factors and HPV vaccination intention. Backward linear regression analyses were conducted to examine which social-psychological factors were most dominantly associated with vaccination intention.

RESULTS

Data from 952 mothers (14%) and 642 daughters (10%) were available for the intended analyses. The contribution of social demographic variables to the explained variance of HPV vaccination intention was small but significant for mothers (ΔR² = .01; p = .007), but not significant for daughters (ΔR² = .02; p = .17) after controlling for HPV vaccination uptake and the sample. In addition, social-psychological determinants largely contributed to the explained variance of HPV vaccination intention of mothers (ΔR² = .35; p < .001) and daughters (ΔR² = .34; p < .001). Attitudes, beliefs, subjective norms and habit strength were significantly associated with participants' HPV vaccination intentions.

CONCLUSIONS

Because of the large contribution of social-psychological variables to the explained variance of HPV vaccination intentions among the mothers and daughters, future communication strategies targeting HPV vaccination uptake should address attitudes, beliefs, subjective norms and habit strength. There is a need for longitudinal research to confirm the causality of the association between these determinants and HPV vaccination behavior indicated by this study.

Effectiveness and timing of vaccination during school measles outbreak

Implementing a vaccination campaign during an outbreak can effectively reduce the outbreak size.

[Reasons for having oneself vaccinated against HPV: implications for the future provision of information]

OBJECTIVE

To examine which factors determined the participation in HPV vaccination programme in 2009 and 2010.

DESIGN

Retrospective cross-sectional study.

METHOD

Random samples of Dutch girls who had been invited for the HPV vaccination programme in 2009 and 2010, as well as their mothers, were drawn from an Internet panel. Data were gathered by means of a web-based questionnaire.

RESULTS

The questionnaire was filled out by 243 girls and 511 mothers from cohort 2009, and by 225 girls and 250 mothers from cohort 2010. In both cohorts, the following factors were related to HPV vaccination: perceived susceptibility for cervical cancer, general opinion about the vaccine, anticipated feelings of regret about the decision made, specific beliefs (e.g. about the protective effects of the vaccine), trust in responsible authorities, perceived opinion of others about the vaccination and their HPV vaccination participation, the degree to which vaccination is taken for granted and the extent to which the decision to have oneself vaccinated is unambiguously perceived. In both cohorts, these factors explained a large and significant part of the variation in HPV vaccination; namely, 89% and 81% of the girls and 94% and 82% of the mothers from the cohorts in 2009 and 2010, respectively.

CONCLUSION

This study provides insight into the reasons behind the disappointing participation in the HPV vaccination programme. In order to increase HPV vaccination uptake, future communication should provide balanced information about facts and opinions, and advantages and disadvantages of the vaccination. There should also be room for uncertainty in the choice whether or not to have oneself vaccinated.

Acute hepatitis B in a healthcare worker: a case report of genuine vaccination failure

BACKGROUND

Individuals who reach the antibody threshold level of 10IU/l against the surface protein of the hepatitis B virus (HBV) after completion of a series of hepatitis B vaccination are considered to be long-term protected against a clinically manifest HBV infection.

CASE REPORT

Here we describe an acute hepatitis B infection in a patient who received five hepatitis B vaccinations. Although his initial response to vaccination was moderate, he finally reached an excellent hepatitis B surface antibody level (anti-HBs) titres of more than 1000 IU/l in response to a booster vaccination with a recombinant DNA vaccine. Nevertheless, he developed full-blown acute hepatitis due to an HBV infection 14years after this booster vaccination. A DNA analysis of the surface protein encoding region followed by phylogenetic analysis showed that our patient was infected with a normal HBV strain that is circulating among men who have sex with men. To our knowledge, this is the first report of a genuine hepatitis B vaccination failure in someone who acquired a high anti-HBs level in response to a recombinant DNA hepatitis B vaccine.

CONCLUSION

Healthcare workers whose response to the initial hepatitis B vaccination is moderate might be vulnerable to hepatitis B virus infection.

Infectieziektebestrijding: jonge beroepsgroep in een robuuste organisatie

Maatregelen om verspreiding van infectieziekten tegen te gaan worden door alle kuddedieren genomen (zoals afzondering), en zullen dus ook zeker door onze prehistorische voorouders zijn genomen. Infectieziektebestrijding is derhalve een van de oudste medische kundes, maar de bestrijders bij de GGD’en zijn als beroepsgroep nog maar kort geleden begonnen. Sinds de Wcpv (1990) dicteert dat iedere gemeente een GGD in stand moest houden en daarin onder meer deskundigheid ten behoeve van infectieziektebestrijding onder moet brengen zijn de ontwikkelingen snel gegaan. De disciplines, sociaal geneeskundigen en sociaal verpleegkundigen, hebben zich inhoudelijk snel in de breedte en in de diepte ontwikkeld. Deze ontwikkelingen gaan nog steeds door: inhoudelijke verdieping is noodzakelijk om steeds nieuwe problemen aan te kunnen en om aansluiting bij klinische en laboratoriumontwikkelingen te behouden, maar ook om te kunnen blijven voldoen aan de steeds hoger wordende maatschappelijke eisen ten aanzien van de bestrijding, én aan de eisen die we zelf stellen: op rationele wijze werken met evidence-based richtlijnen.

Social-cognitive determinants of vaccination behavior against hepatitis B: an assessment among men who have sex with men

BACKGROUND

Many individuals who are at risk for infection with the hepatitis B virus (HBV), including men who have sex with men (MSM), are not vaccinated. This study assessed social-cognitive determinants of obtaining vaccination against HBV.

METHODS

A targeted survey was conducted among 432 MSM by means of a written questionnaire that contained assessments of social-cognitive determinants of vaccination behavior derived from the Health Belief Model (HBM) and the Theory of Planned Behavior. Vaccination behavior was anonymously linked to questionnaire data for which informed consent was obtained.

RESULTS

Of the 290 men eligible for vaccination, 248 (86%) had obtained vaccination. Multivariate logistic regression analysis showed that these men were younger, more often were in a steady relationship, and had fewer sex partners. In addition, significant effects were also found for central factors proposed by the Health Belief Model. Notably, men who obtained vaccination against HBV perceived more personal threat from HBV. None of the Theory of Planned Behavior variables were related to obtaining vaccination.

CONCLUSIONS

Findings suggest that health education interventions that address perceived susceptibility and severity are likely to contribute to increased uptake of HBV vaccination among MSM. Influencing perceived susceptibility in particular is important, more so than increasing perceived severity by scare tactics.

Rubella outbreak in an unvaccinated religious community in the Netherlands spreads to Canada

There are indications that the rubella outbreak that started in September 2004 among members of a religious community in the Netherlands has spread to Canada

Large ongoing rubella outbreak in religious community in the Netherlands since September 2004

As of 25 February 2005, 128 serologically confirmed cases of rubella were notified in the Netherlands (since 1 September 2004). This is a large increase compared with the annual average of five cases

Transmission of H7N7 avian influenza A virus to human beings during a large outbreak in commercial poultry farms in the Netherlands

BACKGROUND

An outbreak of highly pathogenic avian influenza A virus subtype H7N7 started at the end of February, 2003, in commercial poultry farms in the Netherlands. Although the risk of transmission of these viruses to humans was initially thought to be low, an outbreak investigation was launched to assess the extent of transmission of influenza A virus subtype H7N7 from chickens to humans.

METHODS

All workers in poultry farms, poultry farmers, and their families were asked to report signs of conjunctivitis or influenza-like illness. People with complaints were tested for influenza virus type A subtype H7 (A/H7) infection and completed a health questionnaire about type of symptoms, duration of illness, and possible exposures to infected poultry.

FINDINGS

453 people had health complaints--349 reported conjunctivitis, 90 had influenza-like illness, and 67 had other complaints. We detected A/H7 in conjunctival samples from 78 (26.4%) people with conjunctivitis only, in five (9.4%) with influenza-like illness and conjunctivitis, in two (5.4%) with influenza-like illness only, and in four (6%) who reported other symptoms. Most positive samples had been collected within 5 days of symptom onset. A/H7 infection was confirmed in three contacts (of 83 tested), one of whom developed influenza-like illness. Six people had influenza A/H3N2 infection. After 19 people had been diagnosed with the infection, all workers received mandatory influenza virus vaccination and prophylactic treatment with oseltamivir. More than half (56%) of A/H7 infections reported here arose before the vaccination and treatment programme.

INTERPRETATION

We noted an unexpectedly high number of transmissions of avian influenza A virus subtype H7N7 to people directly involved in handling infected poultry, and we noted evidence for person-to-person transmission. Our data emphasise the importance of adequate surveillance, outbreak preparedness, and pandemic planning.