SARS-CoV-2 cellular and humoral responses in vaccine-naive individuals during the first two waves of COVID-19 infections in the southern region of The Netherlands: a cross-sectional population-based study

With the emergence of highly transmissible variants of concern, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) still poses a global threat of coronavirus disease 2019 (COVID-19) resurgence. Cellular responses to novel variants are more robustly maintained than humoral responses, and therefore, cellular responses are of interest in assessing immune protection against severe disease in the population. We aimed to assess cellular responses to SARS-CoV-2 at the population level. IFNγ (interferon γ) responses to wild-type SARS-CoV-2 were analyzed using an ELISpot assay in vaccine-naive individuals with different humoral responses: Ig (IgM and/or IgG) seronegative (n = 90) and seropositive (n = 181) with low (<300 U/mL) or high (≥300 U/mL) humoral responses to the spike receptor binding domain (anti-S-RBD). Among the seropositive participants, 71.3% (129/181) were IFNγ ELISpot positive, compared to 15.6% (14/90) among the seronegative participants. Common COVID-19 symptoms such as fever and ageusia were associated with IFNγ ELISpot positivity in seropositive participants, whereas no participant characteristics were associated with IFNγ ELISpot positivity in seronegative participants. Fever and/or dyspnea and anti-S-RBD levels were associated with higher IFNγ responses. Symptoms of more severe disease and higher anti-S-RBD responses were associated with higher IFNγ responses. A significant proportion (15.6%) of seronegative participants had a positive IFNγ ELISpot. Assessment of cellular responses may improve estimates of the immune response to SARS-CoV-2 in the general population.

IMPORTANCE

Data on adaptive cellular immunity are of interest to define immune protection against severe acute respiratory syndrome coronavirus 2 in a population, which is important for decision-making on booster-vaccination strategies. This study provides data on associations between participant characteristics and cellular immune responses in vaccine-naive individuals with different humoral responses.

Impact of post-COVID-19 condition on health status and activities of daily living: the PRIME post-COVID study

OBJECTIVE

To assess health and activities of daily living (ADL) in SARS-CoV-2-positive adults with and without post-COVID-19 condition (PCC) and compare this with negative tested individuals. Furthermore, different PCC case definitions were compared with SARS-CoV-2-negative individuals.

METHODS

All adults tested PCR positive for SARS-CoV-2 at the Public Health Service South Limburg (Netherlands) between June 2020 and November 2021 (n=41 780) and matched PCR negative individuals (2:1, on age, sex, year-quarter test, municipality; n=19 875) were invited by email. Health (five-level EuroQol five-dimension (EQ5D) index and EuroQol visual analogue scale (EQVAS)) and ADL impairment were assessed. PCC classification was done using the WHO case definition and five other common definitions.

RESULTS

In total, 8409 individuals (6381 SARS-CoV-2 positive; 53±15 years; 57% female; 9 (7-11) months since test) were included. 39.4% of positives had PCC by the WHO case definition (EQVAS: 71±20; EQ5D index: 0.800±0.191; ADL impairment: 30 (10-70)%) and perceived worse health and more ADL impairment than negatives, that is, difference of -8.50 points (95% CI -9.71 to -7.29; p<0.001) for EQVAS, which decreased by 1.49 points (95% CI 0.86 to 2.12; p<0.001) in individuals with PCC for each comorbidity present, and differences of -0.065 points (95% CI -0.074 to -0.056; p<0.001) for EQ5D index, and +16.72% (95% CI 15.01 to 18.43; p<0.001) for ADL impairment. Health and ADL impairment were similar in negatives and positives without PCC. Replacing the WHO case definition with other PCC definitions yielded comparable results.

CONCLUSIONS

Individuals with PCC have substantially worse health and more ADL impairment than negative controls, irrespective of the case definition. Authorities should inform the public about the associated burden of PCC and enable adequate support.

Anorectal Neisseria gonorrhoeae infections in women with and without reported anal sex and sex workers in sexual health centres in the Netherlands: a retrospective cohort study

BACKGROUND

Control of Neisseria gonorrhoeae infection (gonorrhoea) depends on effective testing strategies. Anorectal testing in women is often done on indication of anal sex; however, anorectal infections are seen with and without anal exposure, possibly caused by autoinoculation. This study aims to enhance understanding of anorectal infections in women, by identifying risk factors for anorectal diagnosis.

METHODS

In this retrospective cohort study we used national surveillance data from Dutch sexual health centres from Jan 1, 2016, to Dec 31, 2021. We included cisgender women having sex with men who were tested urogenitally and anorectally for gonorrhoea. Due to different testing policies, we identified three groups: women who had not reported recent anal sex (in the past 6 months), women who had reported recent anal sex, and sex workers. Extracted data for analyses included demographics, sexual behaviour, and diagnosis of a sexually transmitted infection (STI). Per group, multivariable models using Firth's penalised maximum likelihood logistic regression were constructed, identifying determinants of anorectal gonorrhoea among all women and among gonorrhoea-positive women only. Variables included in model construction were age, education level, migration background, number of partners, condom use, partner notification, STI symptoms, having a partner who has sex with men (MSM) or a migrant partner, previous STI test, anal sex, and chlamydia and gonorrhoea diagnoses per anatomical location.

FINDINGS

In total, 117 693 women were included: 43 757 women without reported recent anal sex, 51 728 women with reported recent anal sex, and 22 208 sex workers. In all three groups, around 2% of women were gonorrhoea positive, and 70% or more of women had an anorectal infection. The strongest determinant of anorectal gonorrhoea was a concurrent urogenital gonorrhoea diagnosis (adjusted odds ratios [aOR] 782 [95% CI 605-1018]) among women without reported recent anal sex (612 [490-768] among women with reported recent anal sex, and 464 [335-652] among sex workers). Among gonorrhoea-positive women, determinants of anorectal gonorrhoea were urogenital and anorectal chlamydia co-infection (aOR 2·03 [95% CI 1·38-3·02], for women without reported anal sex) and migration background (1·44 [1·02-2·06], for women with reported anal sex). Determinants among sex workers were condomless sex (2·43 [1·55-3·82]), anal sex (1·71 [1·10-2·66]), MSM or migrant partner (1·78 [1·13-2·79]), and urogenital and anorectal chlamydia co-infection (2·28 [1·11-5·14]).

INTERPRETATION

These findings support the possibility of an autoinoculation process from the urogenital to the anorectal location due to the very strong correlation between urogenital and anorectal gonorrhoea, and due to the similarity of results across all three groups. Current testing strategies could miss anorectal infections, which should be considered when developing gonorrhoea prevention and control guidelines.

FUNDING

None.

European policies for public health in border regions: no European mindset as yet

BACKGROUND

The sudden emergence of COVID-19 in 2020 demonstrated that Europe was not prepared for a public health crisis like this pandemic. In the European Union, matters of health have remained primarily under the jurisdiction of individual Member States. However, certain events, such as the Kohll-Decker ruling on free mobility of health services and the COVID-19 pandemic, compelled the EU to address health matters in border regions. This study examines how EU policies address public health in border regions. To that end, we have drawn from border studies, a field that provides insight into the fluidity and complexity of borders in everyday life. Besides that we used constructivist policy studies as a lens for the analysis of EU policy documents.

METHODS

A policy discourse analysis was conducted to explore how European policy addresses the development of a transnational, European public health in border regions. Key European policy documents published between 2002 and 2027 were analysed to understand how policies are constructed and problems are framed. The analysis was guided by research questions and the theoretical approach.

RESULTS

The analysis reveals that, while having limited competences in the field of health care, the EU is slowly developing a rationale and a knowledge base to increase its competences in health care. It also shows that in the field of public health, the EU argues for addressing health determinants and promoting healthy lifestyles, though it does not address health promotion in border regions. The EU's authority in public health in border regions revolves primarily around addressing physical, biological and chemical threats rather than social health problems.

CONCLUSION

Though the EU has carefully developed a transnational perspective on health care, the EU has not developed any authority with respect to transnational public health. Though public health and health promotion in border regions have been confronted with specific challenges, neither specific Member States nor the EU have a transnational collaborative perspective that does justice to the characteristics of border regions. When it comes to public health in border regions, there is no European mindset as yet.

One Health surveillance of colistin-resistant Enterobacterales in Belgium and the Netherlands between 2017 and 2019

BACKGROUND

Colistin serves as the last line of defense against multidrug resistant Gram-negative bacterial infections in both human and veterinary medicine. This study aimed to investigate the occurrence and spread of colistin-resistant Enterobacterales (ColR-E) using a One Health approach in Belgium and in the Netherlands.

METHODS

In a transnational research project, a total of 998 hospitalized patients, 1430 long-term care facility (LTCF) residents, 947 children attending day care centres, 1597 pigs and 1691 broilers were sampled for the presence of ColR-E in 2017 and 2018, followed by a second round twelve months later for hospitalized patients and animals. Colistin treatment incidence in livestock farms was used to determine the association between colistin use and resistance. Selective cultures and colistin minimum inhibitory concentrations (MIC) were employed to identify ColR-E. A combination of short-read and long-read sequencing was utilized to investigate the molecular characteristics of 562 colistin-resistant isolates. Core genome multi-locus sequence typing (cgMLST) was applied to examine potential transmission events.

RESULTS

The presence of ColR-E was observed in all One Health sectors. In Dutch hospitalized patients, ColR-E proportions (11.3 and 11.8% in both measurements) were higher than in Belgian patients (4.4 and 7.9% in both measurements), while the occurrence of ColR-E in Belgian LTCF residents (10.2%) and children in day care centres (17.6%) was higher than in their Dutch counterparts (5.6% and 12.8%, respectively). Colistin use in pig farms was associated with the occurrence of colistin resistance. The percentage of pigs carrying ColR-E was 21.8 and 23.3% in Belgium and 14.6% and 8.9% in the Netherlands during both measurements. The proportion of broilers carrying ColR-E in the Netherlands (5.3 and 1.5%) was higher compared to Belgium (1.5 and 0.7%) in both measurements. mcr-harboring E. coli were detected in 17.4% (31/178) of the screened pigs from 7 Belgian pig farms. Concurrently, four human-related Enterobacter spp. isolates harbored mcr-9.1 and mcr-10 genes. The majority of colistin-resistant isolates (419/473, 88.6% E. coli; 126/166, 75.9% Klebsiella spp.; 50/75, 66.7% Enterobacter spp.) were susceptible to the critically important antibiotics (extended-spectrum cephalosporins, fluoroquinolones, carbapenems and aminoglycosides). Chromosomal colistin resistance mutations have been identified in globally prevalent high-risk clonal lineages, including E. coli ST131 (n = 17) and ST1193 (n = 4). Clonally related isolates were detected in different patients, healthy individuals and livestock animals of the same site suggesting local transmission. Clonal clustering of E. coli ST10 and K. pneumoniae ST45 was identified in different sites from both countries suggesting that these clones have the potential to spread colistin resistance through the human population or were acquired by exposure to a common (food) source. In pig farms, the continuous circulation of related isolates was observed over time. Inter-host transmission between humans and livestock animals was not detected.

CONCLUSIONS

The findings of this study contribute to a broader understanding of ColR-E prevalence and the possible pathways of transmission, offering insights valuable to both academic research and public health policy development.

Differences in STI/HIV Burden and Sexual Health Care-Seeking Behavior Among First- and Second-Generation Migrant and Western-Born Male Sex Workers Who Have Sex With Men in the Netherlands: A Retrospective Cohort Study

BACKGROUND

Globally, migrant sex workers have a higher burden of sexually transmitted infections (STI)/human immunodeficiency virus (HIV). This large study aimed to assess demographics, STI/HIV burden, and sexual health care-seeking behavior of first-generation migrant and second-generation migrant male sex workers who have sex with men (MSW-MSM) versus Western-born MSW-MSM.

METHODS

Coded STI clinic consultations (n = 6970) from 3116 individual MSW-MSM attending any Dutch STI clinic between 2016 and 2021 were included. First-generation migrant: born outside of northern/central/southern/western Europe/North America/Oceania. Second-generation migrant: ≥1parent born outside of northern/central/southern/western Europe/North America/Oceania. Multivariable logistic regression analysis assessed associations between MSW-MSM groups and STI in first consultation in the data. A Cox proportional hazard regression compared the incidence of a first repeat consultation between migration groups, stratified by STI in first consultation. All analyses were adjusted for age and urbanity of STI clinic region.

RESULTS

First-generation migrant MSW-MSM (n = 1085) were mostly born in Latin America (50%), whereas second-generation migrant MSW-MSM (n = 368) mostly originated from North Africa (30.4%). The proportion of STI diagnoses differed (33.2%, 29.3%, 23.3%; P < 0.001) between the first-generation migrant, second-generation migrant, and Western-born MSW-MSM. First-generation migrant MSW-MSM versus Western-born had an adjusted odds ratio of 1.6 (95% confidence interval, 1.3-1.9) of STI diagnosis in the first consultation. First-generation migrant MSW-MSM versus Western-born had an adjusted hazard ratio of 1.5 (95% confidence interval, 1.3-1.8) of having a first repeat consultation at any time, when stratified for no STI in the first consultation.

CONCLUSIONS

The STI/HIV burden is high among all 3 MSW-MSM groups. First-generation migrants have higher odds of STI, but retention in care seems similar. Results highlight the importance of low-threshold STI testing and care for (migrant) MSW-MSM.

Cross-border differences in the prevalence and risk factors for carriage of antimicrobial resistance in children attending daycare centers: a point prevalence study in the Netherlands and Belgium

BACKGROUND

Day care centres (DCCs) are ideal settings for drug-resistant bacteria to emerge. Prevalence numbers of faecal carriage of antimicrobial resistant bacteria in these settings are rare. We aimed to determine the prevalence of faecal antimicrobial resistant bacteria carriage in children attending DCCs and to assess and identify infection risk factors within DCCs in The Netherlands and Belgium.

METHODS

A point-prevalence study was conducted in 28 Dutch (499 children) and 18 Belgian (448 children) DCCs. Stool samples were taken from the children's diapers and a questionnaire was filled in by their parents. Hygiene related to stool and toilet use, hygiene related to food, environmental contamination, hand hygiene and hygiene guidelines were assessed conform a standardized questionnaire by the infection prevention and control expert visiting the DCC. Multilevel logistical regression analyses were used to define which characteristics predicted the presence of extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E), carbapenemase-producing Enterobacterales (CPE), vancomycin-resistant enterococci (VRE), and ciprofloxacin-resistant Enterobacterales (CipR-E).

RESULTS

The ESBL-E prevalence was 16% (n = 71) in Belgium and 6% (n = 30) in the Netherlands. The CipR-E prevalence was 17% (n = 78) in Belgium and 8% (n = 38) in the Netherlands. Antimicrobial use (RR: 0.30; 95% CI: 0.33-0.48) and hospital admissions (RR: 0.37; 95% CI: 0.25-0.54) were lower in the Netherlands. Children travelling to Asia were at higher risk of being an ESBL-E carrier. Children using antimicrobials were at higher risk of being a CipR-E carrier. Cleaning the changing mat after each use was found as a protective factor for CipR-E carriage.

CONCLUSIONS

We established a significant difference in ESBL-E and CipR-E carriage and antimicrobial use and hospital admissions between the Netherlands and Belgium among children attending DCCs. The differences between both countries should be further studied to improve the policy on anti-microbial use and hospital admissions in children.

High proportions of post-exertional malaise and orthostatic intolerance in people living with post-COVID-19 condition: the PRIME post-COVID study

Background

Exercise-based treatments can worsen/exacerbate symptoms in people who were SARS-CoV-2 positive and living with post-COVID-19 condition (PL-PCC) and who have post-exertional malaise (PEM) or orthostatic intolerance (OI). Nevertheless, PEM and OI are not routinely assessed by clinicians. We estimated PEM and OI proportions in PL-PCC, as well as in people not living with PCC (PnL-PCC) and negatives (i.e., never reported a SARS-CoV-2 positive test), and identified associated factors.

Methods

Participants from the Prevalence, Risk factors, and Impact Evaluation (PRIME) post-COVID-19 condition study were included. PEM and OI were assessed using validated questionnaires. PCC was defined as feeling unrecovered after SARS-CoV-2 infection. Multivariable regression analyses to study PEM and OI were stratified for sex.

Results

Data from 3,783 participants were analyzed. In PL-PCC, the proportion of PEM was 48.1% and 41.2%, and the proportion of OI was 29.3% and 27.9% in women and men, respectively. Proportions were higher in PL-PCC than negatives, for PEM in women OR=4.38 [95%CI:3.01-6.38]; in men OR = 4.78 [95%CI:3.13-7.29]; for OI in women 3.06 [95%CI:1.97-4.76]; in men 2.71 [95%CI:1.75-4.21]. Associated factors were age ≤ 60 years, ≥1 comorbidities, and living alone.

Conclusion

High proportions of PEM and OI are observed in PL-PCC. Standard screening for PEM and OI is recommended in PL-PCC to promote appropriate therapies.

Using a theoretical framework of Intervention Mapping to inform public health communication messages designed to increase vaccination uptake; the example of mpox in the Netherlands

INTRODUCTION

During an infectious disease outbreak, primary preventive pre-exposure vaccination (PPV) could substantially increase the potential for its control, if uptake is sufficiently high. An important tool to increase PPV uptake, are communication strategies, with tailored messages targeted to modify determinants for PPV uptake. Here, we take the example of the 2022 mpox multicountry outbreak, as we inform the development of communication strategies by applying a theoretical framework for selecting effective communication strategies.

METHODS

The theoretical framework Intervention Mapping (IM) was applied during the outbreak to inform communications [program]. Steps included: 1. Creating a logic model of the problem [not accepting PPV] by reviewing available literature, conducting an online survey among people at risk of mpox exposure, and consulting community-members, healthcare-and communication professionals; 2. Creating a matrix of change [from lower to higher PPV acceptance]; and 3. Selecting theory-based methods and practical applications for communication messages to achieve the intended behaviour change (getting vaccinated).

RESULTS

The program objective was to promote PPV uptake in people at risk of mpox exposure. Important changeable determinants identified included perceived risk and severity of mpox, importance to protect against mpox [attitude], experienced effectiveness of vaccination and side-effects [response efficacy], and social norm. Theory-based communication methods for optimizing these determinants include provision of facts [increasing knowledge], personalized risk and scenario-based risk information [addressing risk perception/severity], elaboration, arguments [stimulating a positive attitude], gain framing [increasing perceived response efficacy], guided practice [increasing skills/self-efficacy in overcoming barriers] and social norm approach [demonstrating positive norm]. Other key important factors include that communication delivery is uniform (across channels), clear, accessible, and with stigma-free messaging, and that is well-timed and repeated.

CONCLUSION

IM provided a valuable tool in selecting communication methods to promote mpox vaccination uptake. These methods can be used to (more quickly) produce and implement a communication program in the context of possible future, vaccine-preventable, infectious disease outbreaks.

Maternal pertussis vaccination behavior: Psychosocial, attitudinal and organizational factors

BACKGROUND

In December 2019, the maternal pertussis vaccination (MPV) became part of the Dutch National Immunization Program. This study aims to study MPV behavior and associated psychosocial, attitudinal and organizational factors of pertussis vaccination behavior during pregnancy in the Netherlands.

METHODS

We conducted a cross-sectional survey among pregnant women and recent mothers, up to six months post-partum. The primary outcome measure of this study was MPV behavior. Associations between psychosocial, attitudinal and organizational factors and MPV behavior were assessed using univariate and multivariate binary logistic regression analysis.

RESULTS

In total 1348 participants filled out the questionnaire, including 1282 (95.1%) MPV acceptors and 66 (4.9%) MPV refusers. The most important factors associated with MPV behavior were: attitude (aOR: 10.19; 95%CI: 4.30-24.16), outcome expectations (aOR: 8.94; 95%CI: 3.60-22.21), omission bias (aOR: 0.11; 95%CI: 0.02-0.59) and physical accessibility (aOR: 7.44; 95%CI: 3.37-16.46).

CONCLUSION

Pregnant women make their decision about the MPV primarily based on attitudinal and psychosocial factors, such as outcome expectations and attitude. A combination and variation of different messages, about the advantages (effectiveness) and disadvantages (side effects) of maternal vaccination, can be used in reaching pregnant women with a positive and negative attitude about the MPV. In addition, strategies to increase MPV uptake should not only focus on providing information, but also decrease experienced practical barriers, such as poor physical accessibility, in people that are intended to receive the MPV but are not getting vaccinated.

Sexual (Risk) Behavior and Risk-Reduction Strategies of Home-Based Male Sex Workers Who Have Sex with Men (MSW-MSM) in The Netherlands: A Qualitative Study

An understanding of sexual (risk) behavior is necessary to successfully develop prevention and care strategies for the sexually transmitted infections (STI) high-risk group of male sex workers who have sex with men (MSW-MSM). However, limited scientific knowledge is available on sexual (risk) behavior of (home-based) MSW-MSM. This study aimed to gain an understanding of sexual (risk) behavior, factors influencing sexual (risk) behavior, and applied risk-reduction strategies of home-based MSW-MSM. For this qualitative study, semi-structured individual interviews were conducted with 20 home-based MSW-MSM in the Netherlands. The interviews' recordings were transcribed verbatim and thematically analyzed with Atlas.ti 8. Condom use was reported to be high during anal sex, but low during oral sex and mostly determined by STI risk perception, trust in clients, and sexual pleasure. Many experienced condom failure, while few knew what to do after condom failure and were aware of post-exposure prophylaxis (PEP). Many MSW-MSM had chemsex in the past 6 months in order to loosen up and enhance sexual pleasure. Some were not vaccinated against hepatitis B virus (HBV), mainly due to the lack of information and awareness of HBV vaccination and low risk perception of HBV. The results of this study can be used to tailor future STI/HIV risk-reduction strategies for home-based MSW-MSM and to increase awareness and uptake of available STI/HIV prevention strategies such as P(r)EP and HBV vaccination.

Prevalence of Long-term Symptoms Varies When Using Different Post-COVID-19 Definitions in Positively and Negatively Tested Adults: The PRIME Post-COVID Study

Background

Long-term symptoms after a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (ie, post-coronavirus disease 2019 [COVID-19] condition or long COVID) constitute a substantial public health problem. Yet, the prevalence remains currently unclear as different case definitions are used, and negatively tested controls are lacking. We aimed to estimate post-COVID-19 condition prevalence using 6 definitions.

Methods

The Prevalence, Risk factors, and Impact Evaluation (PRIME) post-COVID-19 condition study is a population-based sample of COVID-19-tested adults. In 2021, 61 655 adults were invited to complete an online questionnaire, including 44 symptoms plus a severity score (0-10) per symptom. Prevalence was calculated in both positively and negatively tested adults, stratified by time since their COVID-19 test (3-5, 6-11, or ≥12 months ago).

Results

In positive individuals (n = 7405, 75.6%), the prevalence of long-term symptoms was between 26.9% and 64.1% using the 6 definitions, while in negative individuals (n = 2392, 24.4%), the prevalence varied between 11.4% and 32.5%. The prevalence of long-term symptoms potentially attributable to COVID-19 ranged from 17.9% to 26.3%.

Conclusions

There is a (substantial) variation in prevalence estimates when using different post-COVID-19 condition definitions, as is current practice; there is limited overlap between definitions, indicating that the essential post-COVID-19 condition criteria are still unclear. Including negatives is important to determine long-term symptoms attributable to COVID-19.

Trial registration

ClinicalTrials.gov Identifier: NCT05128695.

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.

Differences in non-positive intention to accept the COVID-19 booster vaccine between three countries in the cross-border region Meuse-Rhine Euroregion: The Netherlands, Belgium, and Germany

COVID-19 booster vaccination has shown to add to the protection against infection with SARS-CoV2 and subsequent severe disease. This longitudinal cross-border study aimed to identify factors associated with COVID-19 booster vaccine intentions in an initially vaccinated adult population living in the Meuse-Rhine Euroregion (EMR; including the Netherlands, Belgium, and Germany) and differences between countries. Data collection took place in autumn of 2021 and consisted of online questionnaires sent to a random sample of the population based on governmental registries. Data from 3,319 fully and partially vaccinated adults were used to examine determinants of non-positive intention for a booster vaccination (i.e., uncertain or do not want), using multivariable logistic regression analyses weighted by age group, sex, and country. Compared to German residents, Dutch residents (OR = 2.4) and Belgian residents (OR = 1.4) were more likely to be uncertain or not want to receive a booster vaccine in September-October 2021. Factors independently associated with non-positive intention were female sex (OR = 1.6), absence of comorbidities (OR = 1.3), time since last vaccination less than 3 months ago for those fully vaccinated (OR = 1.6), being partially vaccinated (OR = 3.6), a negative experience with communication of COVID-19 measures (OR = 2.2), and regarding measures as ineffective (OR = 1.1). Results indicate that booster vaccine intentions differ between countries in the cross border Meuse-Rhine Euroregion. Non-positive intention for the booster vaccine is prevalent in all three countries of the EMR, but to a different extent, as shown in this study. Cross-border collaboration and sharing information and knowledge about vaccination strategies could play a role in limiting the impact of COVID-19.

Refining Timely Diagnosis of Early Syphilis by Using Treponema pallidum PCR or IgM Immunoblotting Next to Conventional Serology for Syphilis

Treponema pallidum subsp. pallidum is a fastidious spirochete and the etiologic agent of syphilis, a sexually transmitted infection (STI). Syphilis diagnoses and disease staging are based on clinical findings and serologic testing. Moreover, according to most international guidelines, PCR analysis of swab samples from genital ulcers is included in the screening algorithm where possible. It has been suggested that PCR might be omitted from the screening algorithm due to low added value. As an alternative to PCR, IgM serology might be used. In this study, we wanted to establish the added value of PCR and IgM serology for diagnosing primary syphilis. Added value was defined as finding more cases of syphilis, preventing overtreatment, or limiting the extent of partner notification to more recent partners. We found that both PCR and IgM immunoblotting could aid the timely diagnosis of early syphilis in ~24% to 27% of patients. PCR has the greatest sensitivity and can be applied to cases with an ulcer with suspected reinfection or primary infection. In the absence of lesions, the IgM immunoblot could be used. However, the IgM immunoblot has better performance in cases with suspected primary infection than in reinfections. The target population, testing algorithm, time pressures, and costs should determine whether either test provides sufficient value to be implemented in clinical practice.

Newly diagnosed HIV and use of HIV-PrEP among non-western born MSM attending STI clinics in the Netherlands: a large retrospective cohort study

Introduction

The World Health Organization recommends HIV-PrEP for all people at risk for HIV infection, which includes men who have sex with men (MSM). Substantial part of new HIV diagnoses in the Netherlands are in non-western born MSM. This study evaluated new HIV diagnoses and reported PrEP use among non-western born MSM and compared it to western-born MSM. To inform public health efforts in the context of equitable PrEP access, we further assessed sociodemographic factors related to higher HIV risk and lower PrEP use among non-western born MSM.

Methods

Surveillance data of consultations among MSM in all Dutch STI-clinics (2016-2021) were analyzed. STI-clinics provide PrEP via the national pilot-program since August 2019. In non-western born MSM (born in Eastern-Europe/Latin-America/Asia/Africa/Dutch-Antilles/Suriname), sociodemographic factors were evaluated for association with HIV (by multivariable generalized estimating equations) and reported PrEP use in the past 3 months (by multivariable logistic regression; restricted to an at-risk for HIV person-level data-subset from August 2019).

Results

New HIV infections were diagnosed among 1.1% (493/44,394) of non-western born MSM-consultations (vs. 0.4% among western-born MSM, 742/210,450). Low education (aOR: 2.2, 95%CI: 1.7-2.7, vs. high education) and age under 25 years (aOR: 1.4, 95%CI: 1.1-1.8, vs. age above 35 years) were associated with new HIV diagnoses. PrEP use in the past 3 months was 40.7% in non-western born MSM (1,711/4,207; 34.9% among western-born MSM, 6,089/17,458). PrEP use was lower among non-western born MSM aged under 25 years (aOR: 0.3, 95%CI: 0.2-0.4), living in less urban areas (aOR: 0.7, 95%CI: 0.6-0.8), and having low education level (aOR: 0.6, 95%CI: 0.5-0.7).

Conclusion

Our study confirmed that non-western born MSM are an important key population in HIV prevention. Access to HIV prevention, including HIV-PrEP, should be further optimized to all non-western born MSM at risk for HIV, and specifically to those who are younger, live in less urban areas, and have a low education level.

Social networks and health behaviors during the COVID-19 pandemic: a qualitative study among older adults in the Netherlands

Aim

Social networks, all social relationships that people have, may influence people's health behavior and well-being, which was evaluated in this qualitative study in older adults. Furthermore, we evaluated people's needs for strengthening social networks.

Subject and methods

For this qualitative study, semi-structured interviews were conducted between May and July 2021 among 24 adults aged 60 years and older.

Results

Respondents provided information on social network structure (number and types of relations) and function (social support). They received informational support from friends, emotional support from their partner/spouse, and all types of support (including practical support) from family. Respondents stated that their health behavior was mainly influenced by a partner/spouse. Family and friends were mostly for socializing. To strengthen networks, in-person bilateral or small group interactions were preferred.

Conclusion

Family and friends were important social supporters and positively influenced health behaviors. This study emphasizes the importance of social networks in health promotion.

SARS-CoV-2 transmission dynamics in bars, restaurants, and nightclubs

Background

In an attempt to control the spread of SARS-CoV-2, many governments decided to close public venues including bars, restaurants, and nightclubs during the pandemic, making it difficult to study how transmission occurs in these environments. In this study, we were able to gain insight into the transmission dynamics of SARS-CoV-2 in 16 venues in the city of Maastricht using a combination of epidemiological and whole-genome sequencing (WGS) data during a period of 2 weeks in 2021, when bars, restaurants, and nightclubs were temporarily reopened in the Netherlands. This led to a subsequent rise of SARS-CoV-2 cases in the community following the reopening.

Methods

WGS was performed on samples from 154/348 of selected cases and combined with epidemiological investigation (e.g., contact tracing and linking cases to specific venues) to identify SARS-CoV-2 transmission clusters. In addition, genomic surveillance data were used to investigate spillover of outbreak-associated genotypes into the community.

Results

Clustering was observed in 129/136 (95%) successfully genotyped samples. We established that most cases were linked to venues with dancing facilities and that specific genotypes of the Delta variant were more frequently spread within and from these venues compared to venues without dancing facilities. In addition, we show indications of spillover of certain genotypes from the bar and restaurant industry into the community, with the number of hospital admissions increasing in the weeks following peak cases in the community.

Conclusion

Lifting restrictions on bar and restaurant industry venues with a corona entree ticket in a largely unvaccinated population led to a surge in COVID-19 cases and promoted the spread of new (sub)variants. Nightclubs were identified as potential super-spreading locations.

COVID-19 pandemic response in the Meuse-Rhine Euroregion: methods, participation and recommendations of a longitudinal cross-border study

BACKGROUND

Comparative data collection in transborder areas can contribute to informed decision making processes when dealing with borderless health threats such as pandemics, and thus help minimize the negative health effects for its citizens. To examine the pandemic response over time and the impact of infectious disease control in a cross-border setting, a prospective longitudinal study was conducted in the border area between Germany, Belgium and the Netherlands. In the spring of 2021, a random sample of 26,925 adult citizens selected from governmental registries was invited to collect a blood sample at home for SARS-CoV-2 antibody testing and to fill in an online questionnaire on attitudes and behaviour towards infection prevention measures, cross-border mobility, social network and support, COVID-19 self-reported infection(s) and symptoms, vaccination, general self-reported health and socio-demographics. In autumn 2021, participants were invited for a follow-up round. An online tool was developed to coordinate fieldwork procedures, real-time monitoring of participation and consultation of antibody test results. Furthermore, a helpdesk in all three languages for participants' support was set up.

RESULTS

In the first round, 6,006 citizens in the Meuse-Rhine Euroregion participated. 15.3% of the invited citizens on the Belgian side of the border participated. In the Netherlands and Germany this was respectively 27% and 23.7%. In the follow-up round 4,286 (71.4%) citizens participated for the second time. The participation rate was highest in the age group 50-69 years and lowest in > 80 in all sub regions of the Meuse-Rhine Euroregion. More women participated than men. Overall, more blood samples were returned than completed questionnaires. In total, 3,344 citizens in the Meuse-Rhine Euroregion completed all components of participation in both rounds.

CONCLUSIONS

The collection of comparative data can help better assess the pandemic response and the impact of infectious disease control in a cross-border area. Recommendations for a longitudinal cross-border study include a centralized online environment, mapping out potential challenges related to national regulations in the preparation phase and organizing regional coordination centres to create more familiarity and trust towards the involved organisations.

Alcohol and drug use during sex and its association with sexually transmitted infections: a retrospective cohort study among young people aged under 25 years visiting Dutch STI clinics

INTRODUCTION

Alcohol use and drug use are common behaviours among young people. STI positivity is higher in young people than in people aged above 25 years. While there is an increasing amount of knowledge about drug use during sex among men who have sex with men (MSM), data on this behaviour among young women and heterosexual men are scarce. Therefore, this study aims to assess the proportion and characteristics of women and heterosexual men aged under 25 years reporting alcohol and/or drug use during sex and its association with STI positivity.

METHODS

Surveillance data of heterosexual individuals younger than 25 years visiting two Dutch STI clinics between 2016 and 2019 were assessed (n=11 714). We used multivariable logistic regression analyses to assess associations between alcohol and drug use during sex and STI positivity (Chlamydia trachomatis and/or Neisseria gonorrhoeae diagnosis), adjusting for sociodemographic characteristics (sex, age, ethnicity, educational level, socioeconomic status and urbanisation) and sexual behaviour (condom use, number of sex partners).

RESULTS

Alcohol use during sex was reported by 45.3% (5311/11 714; 49.5% in men vs 43.2% in women, p<0.001) and drug use during sex by 22.0% (2580/11 714; 30.7% in men vs 17.6% in women, p<0.001). The most reported drugs were cannabis (17.9%), ecstasy (XTC)/methylenedioxymethamphetamine (MDMA) (6.9%) and cocaine (4.7%). The use of at least one of the following drugs (XTC/MDMA, cocaine, speed, ketamine, gamma-hydroxybutyrate (GHB)/gamma-butyrolactone (GBL), heroin, crystal meth and/or designer drugs) was significantly associated with STI positivity after adjustment for sociodemographic characteristics (adjusted OR (aOR): 1.3, 95% CI 1.1 to 1.4), but this association did not remain significant after adjustment for sexual behaviour (aOR: 1.12, 95% CI 0.94 to 1.34). Significant associations between drug use during sex and inconsistent condom (aOR: 2.5, 95% CI 1.9 to 3.2) use and having four or more sex partners (aOR: 3.2, 95% CI 2.8 to 3.6) in the past 6 months were assessed.

DISCUSSION

Alcohol and drug use during sex was highly prevalent among young women and heterosexual men visiting the STI clinic and drug use during sex was associated with an increased risk for STI, probably mediated by sexual behaviour. This indicates that a holistic health promotion strategy, addressing STI prevention and alcohol and drug use-related harm reduction, is important in this group. STI clinics should address this behaviour not only among MSM, but also among young women and heterosexual men.

Trends in antibiotic prescribing in Dutch general practice and determinants of nonprudent antibiotic prescriptions

BACKGROUND

Antibiotic resistance is mainly driven by (incorrect) use of antibiotics. Most antibiotics are prescribed in family medicine. Therefore, regularly monitoring of antibiotic prescriptions and evaluation of their (non-) prudent use in primary care is warranted.

OBJECTIVES

The aim of this study was to determine time trends in antibiotic prescriptions by Dutch family physicians (FPs) and to identify determinants of nonprudent antibiotic prescriptions by Dutch FPs.

METHODS

Retrospective study among 27 Dutch general practices from the Research Network Family Medicine Maastricht, from 2015 to 2019.

RESULTS

In total 801,767 patient years were analysed. Antibiotic prescriptions mainly increased in patients aged 65+ while prescriptions mainly decreased in patients below 65 years. Nonprudent antibiotic prescriptions decreased from 2015 to 2019 with the highest percentage of decline found in skin infections (66.9% [2015] to 53.9% [2019]). Overall, higher likelihood of nonprudent antibiotic prescriptions was found among men (odds ratio [OR] 4.11, 95% confidence interval [CI]: 3.91-4.33), patients aged 80+ (OR 1.44, 95% CI: 1.03-2.01; reference category ≤17 years), patients with comedication (OR 1.24, 95% CI: 1.17-1.31), and patients in urban general practices (OR 1.47, 95% CI: 1.38-1.56).

CONCLUSIONS

Antibiotic prescriptions increased over time in the elderly aged categories. Although an overall decrease in nonprudent antibiotic prescriptions was established from 2015 to 2019, percentages of nonprudent prescriptions remained high for skin infections and respiratory tract infections. Additionally, men, elderly aged patients (80+), patients with comedication and patients in urban general practices were more likely to receive nonprudent antibiotic prescriptions. Our results will help FPs to prioritize optimalization of antibiotic prescriptions in family medicine.

Mpox vaccination willingness, determinants, and communication needs in gay, bisexual, and other men who have sex with men, in the context of limited vaccine availability in the Netherlands (Dutch Mpox-survey)

Introduction

In the 2022 multicountry mpox (formerly named monkeypox) outbreak, several countries offered primary preventive vaccination (PPV) to people at higher risk for infection. We study vaccine acceptance and its determinants, to target and tailor public health (communication-) strategies in the context of limited vaccine supply in the Netherlands.

Methods

Online survey in a convenience sample of gay, bisexual and other men who have sex with men, including transgender persons (22/07-05/09/2022, the Netherlands). We assessed determinants for being (un)willing to accept vaccination. We used multivariable multinominal regression and logistic regression analyses, calculating adjusted odds ratios (aOR) and 95 percent confidence-intervals. An open question asked for campaigning and procedural recommendations.

Results

Of respondents, 81.5% (n = 1,512/1,856) were willing to accept vaccination; this was 85.2% (799/938) in vaccination-eligible people and 77.7% (713/918) in those non-eligible. Determinants for non-acceptance included: urbanization (rural: aOR:2.2;1.2-3.7; low-urban: aOR:2.4;1.4-3.9; vs. high-urban), not knowing mpox-vaccinated persons (aOR:2.4;1.6-3.4), and lack of connection to gay/queer-community (aOR:2.0;1.5-2.7). Beliefs associated with acceptance were: perception of higher risk/severity of mpox, higher protection motivation, positive outcome expectations post vaccination, and perceived positive social norms regarding vaccination. Respondents recommended better accessible communication, delivered regularly and stigma-free, with facts on mpox, vaccination and procedures, and other preventive options. Also, they recommended, "vaccine provision also at non-clinic settings, discrete/anonymous options, self-registration" to be vaccinated and other inclusive vaccine-offers (e.g., also accessible to people not in existing patient-registries).

Conclusion

In the public health response to the mpox outbreak, key is a broad and equitable access to information, and to low-threshold vaccination options for those at highest risk. Communication should be uniform and transparent and tailored to beliefs, and include other preventive options. Mpox vaccine willingness was high. Public health efforts may be strengthened in less urbanized areas and reach out to those who lack relevant (community) social network influences.

A systematic review of barriers and facilitators for hepatitis B and C screening among migrants in the EU/EEA region

Introduction

Hepatitis B and C are a threat to public health. Screening of high-risk groups, such as migrants from high-endemic areas, enables early identification and treatment initiation. This systematic review identified barriers and facilitators for hepatitis B and C screening among migrants in the European Union/European Economic Area (EU/EEA).

Methods

Following PRISMA guidelines, databases PubMed, Embase via Ovid, and Cochrane were searched for English articles published between 1 July 2015 and 24 February 2022. Articles were included, not restricted to a specific study design, if they elaborated on HBV or HCV screening in migrant populations from countries outside Western Europe, North America, and Oceania, and residing in EU/EEA countries. Excluded were studies with solely an epidemiological or microbiological focus, including only general populations or non-migrant subgroups, or conducted outside the EU/EEA, without qualitative, quantitative, or mixed methods. Data appraisal, extraction, and quality assessment were conducted and assessed by two reviewers. Barriers and facilitators were categorized into seven levels based on multiple theoretical frameworks and included factors related to guidelines, the individual health professional, the migrant and community, interaction, the organization and economics, the political and legal level, and innovations.

Results

The search strategy yielded 2,115 unique articles of which 68 were included. Major identified barriers and facilitators to the success of screening related to the migrant (knowledge and awareness) and community level (culture, religion, support) and the organizational and economic level (capacity, resources, coordinated structures). Given possible language barriers, language support and migrant sensitivity are indispensable for facilitating interaction. Rapid point-of-care-testing is a promising strategy to lower screening barriers.

Discussion

The inclusion of multiple study designs provided extensive insight into barriers, strategies to lower these barriers, and facilitators to maximize the success of screening. A great variety of factors were revealed on multiple levels, therefore there is no one-size-fits-all approach for screening, and initiatives should be adopted for the targeted group(s), including tailoring to cultural and religious beliefs. We provide a checklist of facilitators and barriers to inform adapted interventions to allow for optimal screening impact.

Design and recruitment of a large-scale cohort study on prevalence, risk factors and impact evaluation of post-COVID-19 condition and its wider long-term social, mental, and physical health impact: The PRIME post-COVID study

Background

Persistent symptoms, described as long COVID or post-COVID-19 condition, pose a potential public health problem. Here, the design and recruitment of the PRIME post-COVID study is described. PRIME post-COVID is a large-scale population-based observational study that aims to improve understanding of the occurrence, risk factors, social, physical, mental, emotional, and socioeconomic impact of post-COVID-19 condition.

Methods

An observational open cohort study was set up, with retrospective and prospective assessments on various health-conditions and health-factors (medical, demographic, social, and behavioral) based on a public health COVID-19 test and by self-report (using online questionnaires in Dutch language). Invited for participation were, as recorded in a public health registry, adults (18 years and older) who were tested for COVID-19 and had a valid Polymerase Chain Reaction (PCR) positive or negative test result, and email address. In November 2021, 61,655 individuals were invited by email to participate, these included all eligible adults who tested PCR positive between 1 June 2020 and 1 November 2021, and a sample of adults who tested negative (2:1), comparable in distribution of age, sex, municipality of residence and year-quarter of testing. New recruitment periods are planned as well. Participants are followed over time by regular follow-up measurements. Data are analyzed using the appropriate data-analyses methods.

Discussion

The PRIME post-COVID study will provide insights into various health-related aspects of post-COVID-19 condition in the context of various stages of the COVID-19 pandemic. Results will inform practical guidance for society, clinical and public health practice for the prevention and care for long-term impact of COVID-19.

Trial registration ClinicalTrialsgov identifier

NCT05128695.

Evaluation of symptomatology and viral load among residents and healthcare staff in long-term care facilities: A coronavirus disease 2019 retrospective case-cohort study

Objectives

We evaluated COVID-19 symptoms, case fatality rate (CFR), and viral load among all Long-Term Care Facility (LTCF) residents and staff in South Limburg, the Netherlands (February 2020-June 2020, wildtype SARS-CoV-2 Wuhan strain).

Methods

Patient information was gathered via regular channels used to notify the public health services. Ct-values were obtained from the Maastricht University Medical Centre laboratory. Logistic regression analyses were performed to assess associations between COVID-19, symptoms, CFR, and viral load.

Results

Of 1,457 staff and 1,540 residents, 35.1% and 45.2% tested positive for COVID-19. Symptoms associated with COVID-19 for female staff were fever, cough, muscle ache and loss of taste and smell. Associated symptoms for men were cough, and loss of taste and smell. Associated symptoms for residents were subfebrility, fatigue, and fever for male residents only. LTCF residents had a higher mean viral load compared to staff. Male residents had a higher CFR (35.8%) compared to women (22.5%). Female residents with Ct-values 31 or less had increased odds of mortality.

Conclusions

Subfebrility and fatigue seem to be associated with COVID-19 in LTCF residents. Therefore, physicians should also consider testing residents who (only) show aspecific symptoms whenever available resources prohibit testing of all residents. Viral load was higher in residents compared to staff, and higher in male residents compared to female residents. All COVID-19 positive male residents, as well as female residents with a medium to high viral load (Ct-values 31 or lower) should be monitored closely, as these groups have an overall increased risk of mortality.

Increased transmissibility of SARS-CoV-2 alpha variant (B.1.1.7) in children: three large primary school outbreaks revealed by whole genome sequencing in the Netherlands

Background

Variant of concern (VOC) SARS-CoV-2 alpha variant (B.1.1.7) was the dominant strain in the Netherlands between March 2021–June 2021. We describe three primary school outbreaks due to the alpha variant using whole genome sequencing with evidence of large-scale transmission among children, teachers and their household contacts.

Method

All outbreaks described were investigated by the South Limburg Public Health Service, the Netherlands. A case was defined as an individual with a real-time polymerase chain reaction test or antigen test positive for SARS-CoV-2. Whole genome sequencing was performed on random samples from at least one child and one teacher of each affected class.

Results

Peak attack rates in classes were 53%, 33% and 39%, respectively. Specific genotypes were identified for each school across a majority of affected classes. Attack rates were high among staff members, likely to promote staff-to-children transmission. Cases in some classes were limited to children, indicating child-to-child transmission. At 39%, the secondary attack rate (SAR) in household contacts of infected children was remarkably high, similar to SAR in household contacts of staff members (42%). SAR of household contacts of asymptomatic children was only 9%.

Conclusion

Our findings suggest increased transmissibility of the alpha variant in children compared to preceding non-VOC variants, consistent with a substantial rise in the incidence of cases observed in primary schools and children aged 5–12 since the alpha variant became dominant in March 2021. Lack of mandatory masking, insufficient ventilation and lack of physical distancing also probably contributed to the school outbreaks. The rise of the delta variant (B.1.617.2) since July 2021 which is estimated to be 55% more transmissible than the alpha variant, provides additional urgency to adequate infection prevention in school settings.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07623-9.

Infections with the SARS-CoV-2 Delta variant exhibit fourfold increased viral loads in the upper airways compared to Alpha or non-variants of concern

There has been a growing body of evidence that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant (B.1.617.2) shows enhanced transmissibility and increased viral loads compared to other variants. A recent study has even suggested that respiratory samples from people infected with the Delta variant can harbor up to 1000 times higher viral loads compared to samples with variants that are more closely related to the original Wuhan strain, although the sample size of this study (n = 125) was very limited. Here, we have compared the viral load in 16,185 samples that were obtained in periods during which non-VOC, the Alpha (B.1.1.7) or Delta variant (B.1.617.2) were dominant as evidenced by genomic surveillance. We found that the Delta variant contained about fourfold higher viral loads across all age groups compared to the non-VOC or Alpha variants, which is significantly lower than reported earlier. Interestingly, the increased viral load for the Delta variant seemed to be age-dependent, regardless of sex, as the viral load was about 14-fold higher for Delta compared to the non-VOC or Alpha variant in age group 0–20 years and fourfold higher in age group 21–40 years, while there was no difference in viral load between variants in age groups 41–60 and 61+ years, most likely as a consequence of a higher degree of vaccination in the older age groups.

Intention to use and acceptability of home-based sexual health care among men who have sex with men who previously attended clinic-based sexual health care

The COVID-19 pandemic has temporarily disrupted access to clinic-based sexual health care for men who have sex with men (MSM) in the Netherlands. The importance of home-based sexual health care has been underpinned as an extension of clinic-based care. This paper aims to assess intention to use, and acceptability of home-based sexual health care among MSM who previously attended clinic-based sexual health care. In November 2020, 424 MSM who had attended an STI clinic pre-pandemic were invited to participate in an online survey; 154 MSM completed the survey (response 36%). Intention to use self-sampling STI/HIV tests was assessed (median; scale 0–100) and compared across sociodemographic and sexual behavior characteristics by Kruskal-Wallis H tests. Descriptive analyses provided insights in acceptability of home-based sexual health care. Of participants (median age 47), 60.4% (93/154) tested for STI/HIV in the past 6 months, most of them attended a clinic. The median score on intention to use self-sampling tests was 86.5 (SD = 33.4) and did not differ by sociodemographic or sexual behavioral characteristics (all p-values > 0.1). Participants were positive toward online sexual health counseling (median attitude = 75.0, SD = 29.6) and their main preferred topics were PrEP use and STI/HIV testing. MSM who attended clinic-based care expressed intention to use self-sampling tests and a positive attitude toward online sexual health counseling. Home-based sexual health care elements are not currently integrated within Dutch clinic-based sexual health care and should be considered an addition for continued provision of care and extended reach of MSM.

Sexual risk and STI testing behaviour among Dutch female and male self-employed sex workers; a cross-sectional study using an Internet based survey

Background

Sex workers are men, women or transgender people who have sex in exchange for money or goods. Self-employed sex workers solicit clients independently from a third-party. Self-employed sex workers are at risk of acquiring sexually transmitted infections (STIs) through their work.

We performed a cross-sectional study, using an Internet survey conducted in 2019–2020 aiming to establish sexual risk behaviour and STI testing behaviour among female and male self-employed sex workers.

Results

A total of 76 female self-employed sex workers (FSW) and 79 male self-employed sex workers (MSW) completed the survey. Both FSW and MSW more often had sex with partners of the opposite sex during work (65.8% FSW, 61.6% MSW) and in their private life (63.3% FSW; 64.5% MSW). During vaginal sex 35.7% of FSW and 29.6% of MSW did not always use a condom. Inconsistent condom use was observed in 35.7% of FSW and 29.6% of MSW during vaginal sex, 46.2% of FSW and 35.7% of MSW did not always use a condom during receptive anal sex. The majority of both FSW and MSW tested for STIs in the past year (67.1% FSW; 67.7% MSW) and 67.5% were aware of the possibility of low-threshold testing at an STI clinic. In the past year, 11.6% of FSW and 8.1% of MSW had an STI.

Conclusion

The reported STI positivity rate among self-employed sex workers was not very high. However, STI prevention efforts remain important considering the low compliance with condom use during sex work. Moreover, not testing for STIs in the past year was substantial with one-third of both FSW and MSW and one-third of both FSW and MSW being unaware of the possibility of low-threshold testing at an STI clinic, warranting efforts to increase testing uptake in this population.

Psychosocial and organizational barriers and facilitators of meningococcal vaccination (MenACWY) acceptance among adolescents and parents during the Covid-19 pandemic: a cross-sectional survey

BACKGROUND

This study aimed to identify differences and similarities among adolescents and parents in various psychosocial factors influencing meningococcal ACWY (MenACWY) vaccination acceptance. Besides, the impact of the Covid-19 pandemic was assessed as well as resulting organizational adjustments.

METHODS

We conducted a cross-sectional survey among adolescents that attended the appointment for the MenACWY vaccination in South Limburg between May and June 2020, and their parents. Independent t-tests and χ² test were performed to explore differences in psychosocial and organisational factors between adolescents and parents.

RESULTS

In total, 592 adolescents (20%) and 1197 parents (38%) filled out the questionnaire. Adolescents scored lower on anticipated negative affect towards MenACWY vaccination refusal [t (985.688) = - 9.32; ρ < 0.001], moral norm towards MenACWY vaccination acceptance [t (942.079) = - 10.38; ρ < 0.001] and knowledge about the MenACWY vaccination and meningococcal disease [t (1059.710) = - 11.24; ρ < 0.001]. Both adolescents and parents reported a social norm favouring accepting childhood vaccinations, but adolescent scored higher [t (1122.846) = 23.10; ρ < 0.001]. The Covid-19 pandemic did barely influence the decision to accept the MenACWY vaccination. Only 6% of the participants indicated that Covid-19 influenced their decision. In addition, the individual vaccination appointment was rated very positive. Most adolescents (71.5%) and parents (80.6%) prefer future vaccinations to be offered individually rather than having mass vaccinations sessions.

CONCLUSIONS

This study provides an indication of which psychosocial and organisational factors should be addressed in future MenACWY vaccination campaigns. Individual vaccination appointments for adolescents should be considered, taking the costs and logistical barriers into account.

Exposure factors associated with SARS-CoV-2 seroprevalence during the first eight months of the COVID-19 pandemic in the Netherlands: A cross-sectional study

Background

The availability of valid Severe Acute Respiratory Syndrome Coronvirus-2 (SARS-CoV-2) serological tests overcome the problem of underestimated cumulative Coronavirus Disease 2019 (COVID-19) cases during the first months of the pandemic in The Netherlands. The possibility to reliably determine the number of truly infected persons, enabled us to study initial drivers for exposure risk in the absence of routine testing. Numerous activities or circumstances can accelerate virus spread, here defined as exposure factors. Hence, we aimed to evaluate a wide variety of demographic, behavioural and social exposure factors associated with seropositivity during the first eight months of the pandemic in Limburg, The Netherlands.

Methods

SARS-CoV-2 point-seroprevalence was determined cross-sectionally to indicate previous infection in a convenience sample of minimal 10,000 inhabitants of the study province. All adult (18+ years) inhabitants of the study province were eligible to register themselves for participation. Once the initial 10,000 registrations were reached, a reserve list was kept to ensure sufficient participants. Possible exposure factors were mapped by means of an extensive questionnaire. Associated exposure factors were determined using univariable and multivariable logistic regression models.

Results

Seropositivity was established in 19.5% (n = 1,948) of the 10,001 participants (on average 49 years old (SD = 15; range 18–90 years), majority women (n = 5,829; 58.3%). Exposure factors associated with seropositivity included current education, working in healthcare and not working from home, and being a member of three or four associations or clubs. Specifically for February-March 2020, visiting an après-ski bar during winter sports in Austria, travelling to Spain, celebrating carnival, and participating in a singing activity or ball sport were associated with seropositivity.

Conclusions

Our results confirm that relevant COVID-19 exposure factors generally reflected circumstances where social distancing was impossible, and the number and duration of contacts was high, in particular for indoor activities.

Routine universal testing versus selective or incidental testing for oropharyngeal Chlamydia trachomatis in women in the Netherlands: a retrospective cohort study

BACKGROUND

Pharyngeal Chlamydia trachomatis in women might contribute to autoinoculation and transmission to sexual partners. Data for effectiveness of different testing practices for pharyngeal C trachomatis are scarce. We therefore aimed to assess the prevalence of pharyngeal C trachomatis, determinants, and effectiveness of different testing practices in women.

METHODS

We did a retrospective cohort study, in which surveillance data for all women visiting sexually transmitted infection clinics in all regions in the Netherlands between Jan 1, 2008, and Dec 31, 2017, were used. We collected consultation-level data and individual-level data from 2016 onwards for sociodemographic characteristics, sexual behaviour in the past 6 months, self-reported symptoms, and STI diagnoses. The primary outcome was the positivity rate of pharyngeal C trachomatis infection compared between routine universal testing (>85% tested pharyngeally per clinic year), selective testing (5-85% tested pharyngeally per clinic year), and incidental testing (<5% pharyngeally tested per clinic year). We calculated the number of missed infections by extrapolating the positivity rate assessed by routine universal testing to all selectively tested women. We used multivariable generalised estimating equations logistic regression analyses to assess independent risk factors for pharyngeal C trachomatis and used the assessed risk factors as testing indicators for comparing alternative testing scenarios.

FINDINGS

Between Jan 1, 2008, and Dec 31, 2017, a total of 550 615 consultations with at least one C trachomatis test was recorded, of which 541 945 (98·4%) consultations (including repeat visits) were included in this analysis. Pharyngeal C trachomatis positivity was lower in the routine universal testing group than in the selective testing group (1081 [2·4%; 95% CI 2·2-2·5] of 45 774 vs 3473 [2·9%; 2·8-3·0] of 121 262; p<0·0001). The positivity rate was also higher among consultations done in the incidental testing group (44 [4·1%; 95% CI 3·1-5·5] of 1073; p<0·0001) than in the routine universal testing group. Based on extrapolation, selective testing would have hypothetically missed 64·4% (95% CI 63·5-65·3; 6363 of 9879) of the estimated total of C trachomatis infections. The proportion of pharyngeal-only C trachomatis was comparable between routinely universally tested women (22·9%) and selectively tested women (20·4%), resulting in a difference of 2·5% (95% CI -0·3 to 5·3; p=0·07). When using risk factors for pharyngeal C trachomatis as testing indicators, 15 484 (79·6%) of 19 459 women would be tested to detect 398 (80·6%) of 494 infections.

INTERPRETATION

No optimal testing scenario was available for pharyngeal C trachomatis, in which only a selection of high-risk women needs to be tested to find most pharyngeal C trachomatis infections. The relative low prevalence of pharyngeal-only C trachomatis (0·5%) and probably limited clinical and public health effect do not provide support for routine universal testing.

FUNDING

Public Health Service South Limburg.

Controversies and evidence on Chlamydia testing and treatment in asymptomatic women and men who have sex with men: a narrative review

Background

Chlamydia trachomatis (CT) is the most common bacterial sexually transmitted infection (STI) worldwide. CT is mainly asymptomatic. Test-and-treat strategies are widely implemented to prevent transmission and complications. Strategies are not without controversy in asymptomatic women and men who have sex with men (MSM). Concerns are emerging to test and treat asymptomatic persons for urogenital CT (‘Controversy 1’) and pharyngeal or rectal CT (‘Controversy 2’), whereby testing symptomatic persons is not under debate. Opposed views in CT treatment involve using azithromycin versus doxycycline (‘Controversy 3’). The objective of this review is to provide coverage of these public health and clinical controversies by reviewing the current scientific evidence.

Methods

A literature search was performed using PubMed for relevant publications between 2018 and September 2021, and iterative retrieval of additional relevant publications.

Results

Controversy 1. In women, the majority of asymptomatic CT are at the urogenital site, and detections mostly include viable CT. CT easily transmits to a partner and potentially also between the vaginal and rectal areas; the clinical impact of urogenital CT is established, although risks for adverse outcomes are uncertain. Wide-scale testing in asymptomatic women has not resulted in reduced prevalence. In MSM, evidence for the clinical impact of asymptomatic urogenital CT is lacking. Controversy 2. Rectal CT is common in women diagnosed with urogenital CT, but the clinical impact of asymptomatic rectal CT is uncertain. In MSM, rectal CT is common, and most CT infections are at the rectal site, yet the risk of longer term complications is unknown. In both sexes, pharyngeal CT is uncommon and has no documented clinical impact. Controversy 3. In the treatment of rectal CT, doxycycline has superior effectiveness to azithromycin. Evidence has also accumulated on the harms of test-and-treat strategies.

Conclusions

Current practices vary widely, from widescale test-and-treat approaches to more individual patient- and partner-level case management. Choosing which asymptomatic people to test at what anatomic site, and whether to test or not, requires an urgent (re-)definition of the goals of testing and treating asymptomatic persons. Treatment guidelines are shifting toward universal doxycycline use, and clinical practice now faces the challenge of implementation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07171-2.

Test-and-treat is a key strategy in the control of Chlamydia trachomatis (CT). We discuss recent controversies and present scientific evidence regarding urogenital, rectal, and pharyngeal CT test-and-treat strategies in women and in men who have sex with men (MSM). This should inform best practices for the prevention and management of the most common bacterial sexually transmitted infection (STI) worldwide.

Barriers and facilitators to infection prevention and control in Dutch psychiatric institutions: a theory-informed qualitative study

Background

The unique characteristics of psychiatric institutions contribute to the onset and spread of infectious agents. Infection prevention and control (IPC) is essential to minimise transmission and manage outbreaks effectively. Despite abundant studies regarding IPC conducted in hospitals, to date only a few studies focused on mental health care settings. However, the general low compliance to IPC in psychiatric institutions is recognised as a serious concern. Therefore, this study aimed to assess perceived barriers and facilitators to IPC among professionals working at psychiatric institutions, and to identify recommendations reported by professionals to improve IPC.

Methods

A descriptive, qualitative study involving 16 semi-structured interviews was conducted (before COVID-19) among professionals from five Dutch psychiatric institutions. The interview guide and data analysis were informed by implementation science theories, and explored guideline, individual, interpersonal, organisational, and broader environment barriers and facilitators to IPC. Data was subjected to thematic analysis, using inductive and deductive approaches. This study followed the Consolidated criteria for Reporting Qualitative research (COREQ) guidelines.

Results

Our findings generated six main themes: (1) patients’ non-compliance (strongly related to mental illness); (2) professionals’ negative cognitions and attitude towards IPC and IPC knowledge deficits; (3) monitoring of IPC performance and mutual professional feedback; (4) social support from professional to patient; (5) organisational support and priority; and (6) financial and material resource limitations (related to financial arrangements regarding mental health services). The main recommendations reported by professionals included: (1) to increase awareness towards IPC among all staff members, by education and training, and the communication of formal agreements as institutional IPC protocols; (2) to make room for and facilitate IPC at the organisational level, by providing adequate IPC equipment and appointing a professional responsible for IPC.

Conclusions

IPC implementation in psychiatric institutions is strongly influenced by factors on the patient, professional and organisational level. Professional interaction and professional-patient interaction appeared to be additional important aspects. Therefore, a multidimensional approach should be adopted to improve IPC. To coordinate this approach, psychiatric institutions should appoint a professional responsible for IPC. Moreover, a balance between mental health care and IPC needs is required to sustain IPC.

Linked nosocomial COVID-19 outbreak in three facilities for people with intellectual and developmental disabilities due to SARS-CoV-2 variant B.1.1.519 with spike mutation T478K in the Netherlands

Background

Individuals with intellectual and developmental disabilities (IDD) living in congregated settings have increased risk of COVID-19 infection and mortality. Little is known about variant B.1.1.519 with spike mutation T478K, dominant in Mexico. We describe a linked SARS-CoV-2 B.1.1.519 outbreak in three IDD facilities in the Netherlands.

Methods

Following notification of the index, subsequent cases were identified through serial PCR group testing. Positive specimens were submitted for whole-genome-sequencing. Clinical information was gathered through interviews with staff members of the three facilities.

Results

Attack rate (AR) in clients of the index facility was 92% (23/25), total AR in clients 45% (33/73) and in staff members 24% (8/34). 55% (18/33) of client cases were asymptomatic, versus 25% (2/8) of staff members. Five client cases (15%) were hospitalized, two died (6%). Sequencing yielded the same specific B.1.1.519 genotype in all three facilities. No significant difference in median viral load was established comparing the B.1.1.519 variant with other circulating variants. The index of the linked outbreak reported no travel history or link to suspected or confirmed cases suggesting regional surveillance. Observed peak regional prevalence of B.1.1.519 during the outbreak supports this.

Conclusion

AR, morbidity and mortality prior to control measures taking effect were high, probably related to the specific characteristics of the IDD setting and its clients. We assessed no evidence for intrinsic contributing properties of variant B.1.1.519. Our study argues for enhanced infection prevention protocols in the IDD setting, and prioritization of this group for vaccination against COVID-19.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07121-y.

Incident urogenital and anorectal Chlamydia trachomatis in women: the role of sexual exposure and autoinoculation: a multicentre observational study (FemCure)

BACKGROUND

Anorectal infections with Chlamydia trachomatis (CT) are common in women visiting STI outpatient clinics. We here evaluated the risk posed by sexual exposure and by alternate anatomical site infection for incident anorectal and urogenital CT.

METHODS

Prospective multicentre cohort study, FemCure. Participants were treated for CT, and after 4, 6, 8, 10 and 12 weeks, they self-collected anorectal and urogenital samples (swabs) for CT-DNA testing. We calculated the proportion with incident CT, that is, CT incidence (at weeks 6-12) by 2-week time-periods. Compared with no exposure (A), we estimated the risk of incident CT for (B) sexual exposure, (C) alternate site anatomic site infection and (D) both, adjusted for confounders and expressed as adjusted ORs with 95% CIs.

RESULTS

We analysed data of 385 participants contributing 1540 2-week periods. The anorectal CT incidence was 2.9% (39/1343) (95 CI 1.8 to 3.6); 1.3% (A), 1.3% (B), 27.8% (C) and 36.7% (D). The ORs were: 0.91 (95% CI 0.32 to 2.60) (B), 26.0 (95% CI 7.16 to 94.34) (C), 44.26 (95% CI 14.38 to 136.21) (D).The urogenital CT incidence was 3.3% (47/1428) (95% CI 2.4 to 4.4); 0.7% (A), 1.9% (B), 13.9% (C) and 25.4% (D). The ORs were: 2.73 (95% CI 0.87 to 8.61) (B), 21.77 (95% CI 6.70 to 70 71) (C) and 49.66 (95% CI 15.37 to 160.41) (D).

CONCLUSIONS

After initial treatment, an alternate anatomical site CT infection increased the risk for an incident CT in women, especially when also sex was reported. This may suggest a key role for autoinoculation in the re-establishment or persistence of urogenital and anorectal chlamydia infections.

HIV testing behaviour and associated factors in men who have sex with men by level of urbanisation: a cross-sectional study in the Netherlands

OBJECTIVES

Regular HIV testing in men who have sex with men (MSM) enables timely entry into care and reduces the likelihood of HIV transmission. We aimed to assess HIV-testing behaviour and associated factors in MSM by urbanisation of place of residence.

DESIGN

Data were derived from online survey ('Men & Sexuality') in the Netherlands, which was mainly advertised on social media (Facebook and Instagram), dating websites, apps for MSM (Grindr and PlanetRomeo) and gay media.

PRIMARY AND SECONDARY OUTCOME MEASURES

HIV testing was defined as recent (<1 year), not recent (≥1 year) or never. Using multinominal regression analyses, factors associated with not recent testing and never testing, compared with recent testing, were assessed among MSM living in highly (>2500 residences/km²) or non-highly (≤2500 residences/km²) urbanised areas.

PARTICIPANTS

The study sample included 3815 MSM, currently living in the Netherlands. The mean age was 36 years (SD 14.7), and 67.6% were highly educated.

RESULTS

In highly urbanised areas, 11.8% was never and 19.8% was not recently HIV-tested. In non-highly urbanised areas, this was 25.2% and 19.6%. Among MSM living in highly urbanised areas, independently associated with never and not recent testing were younger age, self-identification as bisexual, fewer sex partners, never notified of HIV and no recent condomless anal intercourse. Among MSM living in non-highly urbanised areas, lower perceived HIV severity, higher perceived HIV risk and a lower proportion gay friends were associated with never and not recent testing. Among never tested MSM, those in non-highly urbanised areas preferred self-sampling/self-testing over facility-based testing; those in highly urbanised areas preferred testing at healthcare facilities.

CONCLUSIONS

The proportion of never tested MSM was high (25%) in non-highly urbanised areas in the Netherlands. MSM living in non-highly urbanised areas may possibly be reached with targeted approaches to increase HIV testing uptake such as self-testing/self-sampling strategies.

Feasibility of anorectal chlamydia testing in women: a cross-sectional survey among general practitioners

BACKGROUND

Anorectal Chlamydia trachomatis (CT) may be clinically relevant for women in general practice. Although anorectal CT testing in this setting may prevent underdiagnosis and undertreatment, its feasibility is questioned as GPs currently rarely order anorectal CT tests, for yet unknown reasons.

OBJECTIVE

To explore the feasibility of anorectal CT testing in women in general practice.

METHODS

GPs across the Netherlands were invited directly (n = 1481) and by snowball sampling (n = 330) to join an online cross-sectional survey that asked about the acceptability of and barriers for (standard) anorectal testing in women during CT-related consultations. Data were analysed with univariable and multivariable logistic regression models.

RESULTS

The questionnaire was opened by 514 respondents (28%, 514/1811) and 394 fully completed it. GPs' acceptability of anorectal testing by either self-sampling or provider-sampling was high (86%). Twenty-eight percent of GPs felt neutral, and 43% felt accepting towards standard anorectal testing. Nevertheless, 40% of GPs had never tested for anorectal CT in women, which was associated with a reported difficulty in asking about anal sex (odds ratio [OR]: 3.07, 95% confidence interval [CI]: 1.21-7.80), infrequency of anal sexual history taking (OR: 11.50, 95% CI: 6.39-20.72), low frequency of urogenital CT testing (OR 3.44, 95%-CI: 1.86-6.38) and with practicing in a non-urban area (OR: 2.27, 95% CI: 1.48-3.48). Acceptability of anorectal testing was not associated with the studied factors.

CONCLUSION

This quantitative survey shows that anorectal CT testing is feasible based on its acceptability, but is likely hindered by a lower awareness of (anorectal) CT in GPs.

Barriers and facilitators to infection prevention and control in Dutch residential care facilities for people with intellectual and developmental disabilities: A theory-informed qualitative study

BACKGROUND

Care institutions are recognised to be a high-risk setting for the emergence and spread of infections and antimicrobial-resistant organisms, which stresses the importance of infection prevention and control (IPC). Accurate implementation is crucial for optimal IPC practice. Despite the wide promotion of IPC and research thereof in the hospital and nursing home setting, similar efforts are lacking in disability care settings. Therefore, this study aimed to assess perceived barriers and facilitators to IPC among professionals working at residential care facilities (RCFs) for people with intellectual and developmental disabilities (IDD), as well as to identify professional-reported recommendations to improve IPC.

METHODS

This qualitative study involved semi-structured interviews (before COVID-19) with twelve professionals from five Dutch RCFs for people with IDD. An integrated theoretical approach was used to inform data collection and analysis. Thematic analysis using inductive and deductive approaches was conducted. This study followed the COnsolidated criteria for REporting Qualitative research (COREQ) guidelines.

RESULTS

Our findings revealed barriers and facilitators at the guideline, client, professional, professional interaction, professional client interaction, client interaction, organisational, community, and societal level. Six main themes covering multiple barriers and facilitators were identified: (1) guidelines' applicability to (work)setting; (2) professionals' cognitions and attitude towards IPC (related to educational background); (3) organisational support and priority; (4) educational system; (5) time availability and staff capacity; and (6) task division and change coaches. The main professional-reported recommendations were the introduction of tailored and practical IPC guidelines, structural IPC education and training among all professionals, and client participation.

CONCLUSIONS

To promote IPC, multifaceted and multilevel strategies should be implemented, with a preliminary need for improvements on the guideline, professional, and organisational level. Given the heterogeneous character, i.e., different professionals, clients and care needs, there is a need for a tailored approach to implement IPC and sustain it successfully in disability care. Our findings can inform future IPC practice improvements.

Combining stool and stories: exploring antimicrobial resistance among a longitudinal cohort of international health students

BACKGROUND

Antimicrobial resistance (AMR) is a global public health concern that requires transdisciplinary and bio-social approaches. Despite the continuous calls for a transdisciplinary understanding of this problem, there is still a lack of such studies. While microbiology generates knowledge about the biomedical nature of bacteria, social science explores various social practices related to the acquisition and spread of these bacteria. However, the two fields remain disconnected in both methodological and conceptual levels. Focusing on the acquisition of multidrug resistance genes, encoding extended-spectrum betalactamases (CTX-M) and carbapenemases (NDM-1) among a travelling population of health students, this article proposes a methodology of 'stool and stories' that combines methods of microbiology and sociology, thus proposing a way forward to a collaborative understanding of AMR.

METHODS

A longitudinal study with 64 health students travelling to India was conducted in 2017. The study included multiple-choice questionnaires (n = 64); a collection of faecal swabs before travel (T0, n = 45), in the first week in India (T1, n = 44), the second week in India (T2, n = 41); and semi-structured interviews (n = 11). Stool samples were analysed by a targeted metagenomic approach. Data from semi-structured interviews were analysed using the method of thematic analysis.

RESULTS

The incidence of ESBL- and carbapenemase resistance genes significantly increased during travel indicating it as a potential risk; for CTX-M from 11% before travel to 78% during travel and for NDM-1 from 2% before travel to 11% during travel. The data from semi-structured interviews showed that participants considered AMR mainly in relation to individual antibiotic use or its presence in a clinical environment but not to travelling.

CONCLUSION

The microbiological analysis confirmed previous research showing that international human mobility is a risk factor for AMR acquisition. However, sociological methods demonstrated that travellers understand AMR primarily as a clinical problem and do not connect it to travelling. These findings indicate an important gap in understanding AMR as a bio-social problem raising a question about the potential effectiveness of biologically driven AMR stewardship programs among travellers. Further development of the 'stool and stories' approach is important for a transdisciplinary basis of AMR stewardship.

Pharyngeal Chlamydia trachomatis in Men Who Have Sex With Men (MSM) in The Netherlands: A Large Retrospective Cohort Study

Pharyngeal Chlamydia trachomatis (CT) was diagnosed in 1.2% and pharyngeal-only CT in 0.5% of routinely universally tested men who have sex with men (MSM). In these 3-anatomic-site tested MSM, pharyngeal-only CT comprised 4.8% of all CT. The low positivity of pharyngeal-only CT indicates low public health impact of pharyngeal CT.

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.

Culture-Independent Genotyping Revealed 3 Strain Clusters in a Potential Neisseria gonorrhoeae Outbreak in Young Heterosexuals (<25 Years), the Netherlands, October 2017 to March 2019

BACKGROUND

Investigation was undertaken to determine the genetic relatedness of Neisseria gonorrhoeae (NG) isolates of young (<25 years) heterosexuals of a potential outbreak from October 2017 to March 2019 in South-Limburg, the Netherlands.

METHODS

Data and residual sample material of routine diagnostics were retrieved for outbreak cases (78/81), young heterosexuals at baseline (January 2016 to September 2017, n = 30), and men who have sex with men (2018, n = 47). Total DNA was isolated, and NG was genotyped using culture-free NG multiantigen sequence typing. Sanger sequence data were used to construct a phylogenetic tree. Cases of outbreak clusters were geographically mapped, and descriptive analyses were performed on patient characteristics, comparing these clusters.

RESULTS

Outbreak investigation showed 81 cases of young heterosexuals between October 2017 and March 2019 (4.5 per month) compared with 30 between January 2016 and September 2017 (1.4 per month), which was considered as baseline. Culture-independent genotyping of NG was performed to assess the genetic relatedness, as only 21 outbreak cases were culture confirmed. This revealed 3 independent outbreak clusters G2 (n = 18), G13113 (n = 11), and GNewST (n = 24). None of the clusters were geographically linked or introduced by bridging with men who have sex with men networks. Number of sex partners reported by men and Chlamydia trachomatis coinfection were associated with clusters G2 and GNewST, respectively.

CONCLUSIONS

Culture-independent typing proved to be essential to identify the 3 outbreak clusters. However, targeted interventions were difficult because information on sex partners was limited. Therefore, prospective culture-independent typing could be used for early outbreak detection and aid in transmission prevention.

Who is providing HIV diagnostic testing? Comparing HIV testing by general practitioners and sexual health centres in five regions in the Netherlands, 2011-2018

OBJECTIVES

General practitioners (GPs) and sexual health centres (SHCs) are the main providers of HIV testing and diagnose two-thirds of HIV infections in the Netherlands. We compared regional HIV testing and positivity by GPs versus SHCs to gain insight into strategies to improve HIV testing, to enable timely detection of HIV infections.

METHODS

Laboratory data (2011-2018) on HIV testing by GPs and SHCs in five Dutch regions with varying levels of urbanisation were evaluated. Regional HIV testing rates per 10 000 residents ≥15 years (mean over period and annual) were compared between providers using negative binomial generalised additive models and additionally stratified by sex and age (15-29 years, 30-44 years, 45-59 years, ≥60 years). χ² tests were used to compare positivity percentage between the two groups of providers.

RESULTS

In the study period, 505 167 HIV tests (GP 36%, SHC 64%) were performed. The highest HIV testing rates were observed in highly urbanised regions, with large regional variations. The HIV testing rates ranged from 28 to 178 per 10 000 residents by GPs and from 30 to 378 per 10 000 by SHCs. Testing rates by GPs were lower than by SHCs in three regions and comparable in two. In all regions, men were tested less by GPs than by SHCs; for women, this varied by region. Among those aged 15-29 years old, GPs' testing rates were lower than SHCs', while this was reversed in older age categories in four out of five regions. The overall mean HIV positivity was 0.4%. In contrast to other regions, positivity in Amsterdam was significantly higher among individuals tested by GPs than by SHCs.

CONCLUSIONS

This retrospective observational study shows that besides SHCs, who perform opt-out testing for key groups, GPs play a prominent role in HIV testing, especially in non-key populations, such as women and older individuals. Large regional variation exists, requiring region-specific interventions to improve GPs' HIV testing practices.

Where to go to in chlamydia control? From infection control towards infectious disease control

OBJECTIVES

The clinical and public health relevance of widespread case finding by testing for asymptomatic chlamydia infections is under debate. We wanted to explore future directions for chlamydia control and generate insights that might guide for evidence-based strategies. In particular, we wanted to know the extent to which we should pursue testing for asymptomatic infections at both genital and extragenital sites.

METHODS

We synthesised findings from published literature and from discussions among national and international chlamydia experts during an invitational workshop. We described changing perceptions in chlamydia control to inform the development of recommendations for future avenues for chlamydia control in the Netherlands.

RESULTS

Despite implementing a range of interventions to control chlamydia, there is no practice-based evidence that population prevalence can be reduced by screening programmes or widespread opportunistic testing. There is limited evidence about the beneficial effect of testing on pelvic inflammatory disease prevention. The risk of tubal factor infertility resulting from chlamydia infection is low and evidence on the preventable fraction remains uncertain. Overdiagnosis and overtreatment with antibiotics for self-limiting and non-viable infections have contributed to antimicrobial resistance in other pathogens and may affect oral, anal and genital microbiota. These changing insights could affect the outcome of previous cost-effectiveness analysis.

CONCLUSION

The balance between benefits and harms of widespread testing to detect asymptomatic chlamydia infections is changing. The opinion of our expert group deviates from the existing paradigm of 'test and treat' and suggests that future strategies should reduce, rather than expand, the role of widespread testing for asymptomatic chlamydia infections.

Social networks and infectious diseases prevention behavior: A cross-sectional study in people aged 40 years and older

Background

Social networks, i.e., our in-person and online social relations, are key to lifestyle behavior and health, via mechanisms of influence and support from our relations. We assessed associations between various social network aspects and practicing behavior to prevent respiratory infectious diseases.

Methods

We analyzed baseline-data (2019) from the SaNAE-cohort on social networks and health, collected by an online questionnaire in Dutch community-dwelling people aged 40–99 years. Outcome was the number of preventive behaviors in past two months [range 0–4]. Associations between network aspects were tested using ordinal regression analyses, adjusting for confounders.

Results

Of 5,128 participants (mean age 63; 54% male), 94% regularly washed hands with water and soap, 55% used only paper (not cloth) handkerchiefs/tissues; 19% touched their face as little as possible; 39% kept distance from people with respiratory infectious disease symptoms; median score of behaviors was 2. Mean network size was 11 (46% family; 27% friends); six network members were contacted exclusively in-person and two exclusively via phone/internet. Participants received informational, emotional, and practical support from four, six, and two network members, respectively. Independently associated with more preventive behaviors were: ‘strong relationships’, i.e., large share of friends and aspects related to so called ‘weak relationships’, a larger share of distant living network members, higher number of members with whom there was exclusively phone/internet contact, and more network members providing informational support. Club membership and a larger share of same-aged network members were inversely associated.

Conclusion

Friends (‘strong’ relationships) may play an important role in the adoption of infection-preventive behaviors. So may ‘weak relationships’, e.g. geographically more distant network members, who may provide informational support as via non-physical modes of contact. Further steps are to explore employment of these types of relationships when designing infectious diseases control programs aiming to promote infection-preventive behavior in middle aged-and older individuals.

Systematic Development of an Intervention to Promote Self-Sampling for HIV and Sexually Transmitted Infections for Men Who Have Sex With Men: An Intervention Mapping Approach

Sexual healthcare aims to reduce HIV and sexually transmitted infections (STIs) by promoting testing and prevention. To better reach men who have sex with men (MSM), additional strategies are needed. Here, we describe development of an intervention, which is part of a broader HIV/STI home-care program, targeted to reach MSM and motivate them to use self-sampling tests. Self-sampling includes blood sampling (finger prick) for HIV, hepatitis B, and syphilis, and a urine sample and oral and anorectal swab samples for chlamydia and gonorrhea. Intervention mapping, a systematic six-step approach, was used to guide the development process: (1) needs assessment including interviews with MSM, (2) create a matrix of change, (3) selection of theory-based methods and practical strategies, (4) intervention development, (5) implementation plan, and (6) evaluation (not included in this paper). Stakeholders were involved to increase program support and feasibility. The needs assessment revealed that testing barriers among MSM related to stigma, time, and privacy concerns. Barriers among healthcare providers related to time, competing priorities, lack of expertise, and guideline restrictions. Included intervention components are designed to overcome these barriers, e.g., engaging role models, with a website with a role model story, and providing tailored information. Methods to reach MSM were a variety of information channels (posters, flyers, and audio-visual displays) and delivery modes, such as advertisements on websites and invitational cards (online and paper) distributed by healthcare providers and MSM themselves (social network testing/peer testing). Our intervention aims to encourage MSM to engage in testing, re-testing, and providing a test to peer MSM. Evidence-based methods to overcome barriers were included to reach and motivate an increased number of MSM. Using intervention mapping stimulated systematic evidence-based decision making and adapting the intervention to the target audience and setting. The next step (step 6) is to implement and evaluate the intervention.