Characteristics of mpox positive, versus mpox negative, and mpox unsuspected clients from the Centre of Sexual Health, Public Health Service of Amsterdam, 20 May to 15 September 2022

BACKGROUND

In May 2022, an outbreak of mpox (monkeypox) in men-who-have-sex-with-men (MSM) emerged and quickly affected over 100 countries. In the early stages of the outbreak, overlap in symptoms with sexually transmitted infections (STI) made triage for mpox testing challenging. More information was needed on whom to screen and the main route of transmission.

OBJECTIVES

We aimed to identify characteristics of mpox cases to further strengthen case definitions. We also compared Cycle threshold (Ct) values of the DNA positive mpox samples as a proxy for viral load by body location.

METHODS

From 20 May 2022 to 15 September 2022, we tested all MSM who presented with malaise, and/or ulcerative lesions, and/or proctitis and/or a papular-vesicular-pustular eruption attending the Centre of Sexual Health in Amsterdam, the Netherlands, for mpox, with a PCR test. In the same period, 6932 MSM mpox unsuspected clients were not tested. We compared those tested positive for mpox with those tested negative and those unsuspected for mpox.

RESULTS

Of the 374 MSM tested, 135 (36%) were positive for mpox. The mpox-positive MSM were older (median age, respectively, 36, 34 and 34 years, p = 0.019) and more often lived with HIV (30% vs. 16% and 7%, p < 0.001). Furthermore, mpox-positive patients more often reported receptive anal sex without a condom, sexualized drug use, more sex partners, and were more often diagnosed with bacterial STI (p < 0.001). Systemic symptoms and anogenital lesions were associated with mpox infection. For mpox-positive patients, anal samples (p = 0.009) and lesional samples (p = 0.006) showed significantly lower median mpox Ct values compared to throat samples.

CONCLUSIONS

Mpox-positive patients more often reported receptive anal sex without a condom, had more sex partners and more often lived with HIV. Our results suggest that in the current mpox outbreak among MSM, sexual transmission is the main route.

Final Study Report of Andexanet Alfa for Major Bleeding With Factor Xa Inhibitors

BACKGROUND

Andexanet alfa is a modified recombinant inactive factor Xa (FXa) designed to reverse FXa inhibitors. ANNEXA-4 (Andexanet Alfa, a Novel Antidote to the Anticoagulation Effects of Factor Xa Inhibitors) was a multicenter, prospective, phase-3b/4, single-group cohort study that evaluated andexanet alfa in patients with acute major bleeding. The results of the final analyses are presented.

METHODS

Patients with acute major bleeding within 18 hours of FXa inhibitor administration were enrolled. Co-primary end points were anti-FXa activity change from baseline during andexanet alfa treatment and excellent or good hemostatic efficacy, defined by a scale used in previous reversal studies, at 12 hours. The efficacy population included patients with baseline anti-FXa activity levels above predefined thresholds (≥75 ng/mL for apixaban and rivaroxaban, ≥40 ng/mL for edoxaban, and ≥0.25 IU/mL for enoxaparin; reported in the same units used for calibrators) who were adjudicated as meeting major bleeding criteria (modified International Society of Thrombosis and Haemostasis definition). The safety population included all patients. Major bleeding criteria, hemostatic efficacy, thrombotic events (stratified by occurring before or after restart of either prophylactic [ie, a lower dose, for prevention rather than treatment] or full-dose oral anticoagulation), and deaths were assessed by an independent adjudication committee. Median endogenous thrombin potential at baseline and across the follow-up period was a secondary outcome.

RESULTS

There were 479 patients enrolled (mean age, 78 years; 54% male, 86% White; 81% anticoagulated for atrial fibrillation at a median time of 11.4 hours since last dose, with 245 (51%) on apixaban, 176 (37%) on rivaroxaban, 36 (8%) on edoxaban, and 22 (5%) on enoxaparin. Bleeding was predominantly intracranial (n=331 [69%]) or gastrointestinal (n=109 [23%]). In evaluable apixaban patients (n=172), median anti-FXa activity decreased from 146.9 ng/mL to 10.0 ng/mL (reduction, 93% [95% CI, 94-93]); in rivaroxaban patients (n=132), it decreased from 214.6 ng/mL to 10.8 ng/mL (94% [95% CI, 95-93]); in edoxaban patients (n=28), it decreased from 121.1 ng/mL to 24.4 ng/mL (71% [95% CI, 82-65); and in enoxaparin patients (n=17), it decreased from 0.48 IU/mL to 0.11 IU/mL (75% [95% CI, 79-67]). Excellent or good hemostasis occurred in 274 of 342 evaluable patients (80% [95% CI, 75-84]). In the safety population, thrombotic events occurred in 50 patients (10%); in 16 patients, this occurred during treatment with prophylactic anticoagulation that began after the bleeding event. No thrombotic episodes occurred after oral anticoagulation restart. Specific to certain populations, reduction of anti-FXa activity from baseline to nadir significantly predicted hemostatic efficacy in patients with intracranial hemorrhage (area under the receiver operating characteristic curve, 0.62 [95% CI, 0.54-0.70]) and correlated with lower mortality in patients <75 years of age (adjusted P=0.022; unadjusted P=0.003). Median endogenous thrombin potential was within the normal range by the end of andexanet alfa bolus through 24 hours for all FXa inhibitors.

CONCLUSIONS

In patients with major bleeding associated with the use of FXa inhibitors, treatment with andexanet alfa reduced anti-FXa activity and was associated with good or excellent hemostatic efficacy in 80% of patients.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02329327.

Uptake and impact of COVID-19 preventive measures amongst migrant populations in the Netherlands

 

Uptake of preventive measures to reduce transmission of viruses such as SARS-CoV-2, is crucial in the control of pandemics. To ensure equitable uptake we explored contextual factors that shaped uptake of COVID-19 preventive measures amongst smaller, albeit substantial, migrant populations in the Netherlands. 39 persons of Eritrean, Ghanaian, Indonesian and Filipino origin, with diverse legal status and length of stay in the Netherlands, participated in five online focus group discussions. Thematic analysis of data was informed by concepts from the Precaution Adoption Process Model and Protection Motivation Theory. Awareness and knowledge of preventive measures was shaped by limited Dutch proficiency, access to understandable information and interference of misinformation. Engagement by preventive measures was subject to COVID-19 threat appraisal and the ease with which complex behavioural messages could be translated to individual situations. Perceived vulnerability of undocumented migrants in particular, motivated information-seeking. A strong social norm to keep with cultural and religious practices, and limited opportunity for preventive behaviour in work and home context hindered uptake of preventive behaviour. Preventive measures brought about job, food, and housing insecurity, and increased barriers in access to healthcare for undocumented migrants. Migration-related, sociocultural, and socioeconomic factors shape uptake of preventive measures. Preventive measures negatively impact work, housing and access to healthcare of undocumented migrants. Our results suggest importance of multilingual information tailored to literacy needs; education and modelling of behaviour; and, regulations to ensure continued access to financial and material resources to minimise negative spill-over effects. Results were incorporated in two policy briefs advising local and national government. Collaboration with municipal health services lead to multilingual public health information.

Key messages

• Migration-related, sociocultural, and socioeconomic factors shape uptake of preventive measures.

• Preventive measures negatively impact work, housing and access to healthcare of undocumented migrants.

A randomised controlled trial testing the efficacy of Fit after COVID, a cognitive behavioural therapy targeting severe post-infectious fatigue following COVID-19 (ReCOVer): study protocol

BACKGROUND

Coronavirus disease 2019 (COVID-19) results in debilitating long-term symptoms, often referred to as Post-Acute Sequelae of SARS-CoV-2 Infection (PASC), in a substantial subgroup of patients. One of the most prevalent symptoms following COVID-19 is severe fatigue. Prompt delivery of cognitive behavioural therapy (CBT), an evidence-based treatment that has shown benefit in reducing severe fatigue in other conditions, may reduce post-COVID-19 fatigue. Based on an existing CBT protocol, a blended intervention of 17 weeks, Fit after COVID, was developed to treat severe fatigue after the acute phase of infection with SARS-CoV-2.

METHOD

The ReCOVer study is a multicentre 2-arm randomised controlled trial (RCT) to test the efficacy of Fit after COVID on severe post-infectious fatigue. Participants are eligible if they report severe fatigue 3 up to and including 12 months following COVID-19. One hundred and fourteen participants will be randomised to either Fit after COVID or care as usual (ratio 1:1). The primary outcome, the fatigue severity subscale of the Checklist Individual Strength (CIS-fatigue), is assessed in both groups before randomisation (T0), directly post CBT or following care as usual (T1), and at follow-up 6 months after the second assessment (T2). In addition, a long-term follow-up (T3), 12 months after the second assessment, is performed in the CBT group only. The primary objective is to investigate whether CBT will lead to a significantly lower mean fatigue severity score measured with the CIS-fatigue across the first two follow-up assessments (T1 and T2) as compared to care as usual. Secondary objectives are to determine the proportion of participants no longer being severely fatigued (operationalised in different ways) at T1 and T2 and to investigate changes in physical and social functioning, in the number and severity of somatic symptoms and in problems concentrating across T1 and T2.

DISCUSSION

This is the first trial testing a cognitive behavioural intervention targeting severe fatigue after COVID-19. If Fit after COVID is effective in reducing fatigue severity following COVID-19, this intervention could contribute to alleviating the long-term health consequences of COVID-19 by relieving one of its most prevalent and distressing long-term symptoms.

TRIAL REGISTRATION

Netherlands Trial Register NL8947 . Registered on 14 October 2020.

Prognostic value of patient-reported quality of life for survival in oesophagogastric cancer: analysis from the population-based POCOP study

BACKGROUND

Accumulating evidence of trials demonstrates that patient-reported health-related quality of life (HRQoL) at diagnosis is prognostic for overall survival (OS) in oesophagogastric cancer. However, real-world data are lacking. Moreover, differences in disease stages and tumour-specific symptoms are usually not taken into consideration. The aim of this population-based study was to assess the prognostic value of HRQoL, including tumour-specific scales, on OS in patients with potentially curable and advanced oesophagogastric cancer.

METHODS

Data were derived from the Netherlands Cancer Registry and the patient reported outcome registry (POCOP). Patients included in POCOP between 2016 and 2018 were stratified for potentially curable (cT1-4aNallM0) or advanced (cT4b or cM1) disease. HRQoL was measured with the EORTC QLQ-C30 and the tumour-specific OG25 module. Cox proportional hazards models assessed the impact of HRQoL, sociodemographic and clinical factors (including treatment) on OS.

RESULTS

In total, 924 patients were included. Median OS was 38.9 months in potentially curable patients (n = 795) and 10.6 months in patients with advanced disease (n = 129). Global Health Status was independently associated with OS in potentially curable patients (HR 0.89, 99%CI 0.82-0.97), together with several other HRQoL items: appetite loss, dysphagia, eating restrictions, odynophagia, and body image. In advanced disease, the Summary Score was the strongest independent prognostic factor (HR 0.75, 99%CI 0.59-0.94), followed by fatigue, pain, insomnia and role functioning.

CONCLUSION

In a real-world setting, HRQoL was prognostic for OS in patients with potentially curable and advanced oesophagogastric cancer. Several HRQoL domains, including the Summary Score and several OG25 items, could be used to develop or update prognostic models.

Differences in prevalence of hepatitis B virus infection and genotypes between ethnic populations in Suriname, South America

Epidemiological data on hepatitis B virus (HBV) are needed to benchmark HBV elimination goals. We recently assessed prevalence of HBV infection and determinants in participants attending the Emergency Department in Paramaribo, Suriname, South America. Overall, 24.5% (95%CI = 22.7-26.4%) of participants had anti-Hepatitis B core antibodies, which was associated with older age (per year, adjusted Odds Ratio [aOR] = 1.03, 95%CI = 1.02-1.04), Afro-Surinamese (aOR = 1.84, 95%CI = 1.52-2.19) and Javanese ethnicity (aOR = 1.63, 95%CI = 1.28-2.07, compared to the grand mean). 3.2% of participants were Hepatitis B surface Ag-positive, which was also associated with older age (per year, aOR = 1.02, 95%CI = 1.00-1.04), Javanese (aOR = 4.3, 95%CI = 2.66-6.95) and Afro-Surinamese ethnicity (aOR = 2.36, 95%CI = 1.51-3.71). Sex, nosocomial or culturally-related HBV transmission risk-factors were not associated with infection. Phylogenetic analysis revealed strong ethnic clustering: Indonesian subgenotype HBV/B3 among Javanese and African subgenotypes HBV/A1, HBV/QS-A3 and HBV/E among Afro-Surinamese. Testing for HBV during adulthood should be considered for individuals living in Suriname, specifically with Javanese and Afro-Surinamese ancestry.

Adherence to event-driven HIV PrEP among men who have sex with men in Amsterdam, the Netherlands: analysis based on online diary data, 3-monthly questionnaires and intracellular TFV-DP

INTRODUCTION

Event-driven pre-exposure prophylaxis (edPrEP) with oral tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) is highly effective for preventing HIV acquisition in men who have sex with men (MSM) and is preferred over daily PrEP by some MSM. However, it is largely unknown how well MSM adhere to edPrEP. We then aimed to assess PrEP protection during CAS among MSM using edPrEP and participating in the Amsterdam PrEP demonstration project (AMPrEP).

METHODS

We analysed data from participants enrolled in AMPrEP who were taking edPrEP. We measured adherence through (1) a mobile application in which sexual behaviour and PrEP-use were recorded daily, (2) three-monthly self-completed questionnaires and (3) dried blood spot (DBS) samples collected around six, twelve and twenty-four months after PrEP initiation. We assessed the proportion of days with condomless anal sex (CAS) acts that were protected by PrEP, per partner type (i.e. steady partners, known casual partners, unknown casual partners), and the proportion of three-month periods during which PrEP was correctly used. Intracellular TFV-diphosphate (TFV-DP) concentrations were determined from DBS. Good adherence was defined as at least one tablet before and one tablet within 48 hours after a CAS act.

RESULTS

Between 11 September 2015 and 6 October 2019, 182 of 376 MSM (48.4%) used edPrEP for at least one three-month period. Of the 8224 CAS days that were reported in the app during edPrEP-use, we observed good protection for most CAS days involving steady partners (n = 1625/2455, 66.9%), known casual partners (n = 3216/3472, 92.6%) and unknown casual partners (n = 2074/2297, 90.3%). Men reported consistently correct PrEP-use in 851 (81.4%) of the 1046 three-month periods of edPrEP-use. The median TFV-DP concentration was 591 fmol/sample (interquartile range = 270 to 896).

CONCLUSIONS

Adherence to edPrEP was high as determined from the online app and questionnaire. DBS measurements were consistent with two to three tablets per week on average.

Micro-elimination of hepatitis C among people with HIV coinfection: declining incidence and prevalence accompanying a multi-center treatment scale-up trial

BACKGROUND

Gay and bisexual men (GBM) are a key population affected by HIV and hepatitis C (HCV) co-infection. Providing HCV treatment scale-up across specialist and non-hepatitis specialist settings may eliminate HCV in this population. We aimed to (1) deliver and measure HCV treatment effectiveness, and (2) determine the population impact of treatment on HCV prevalence and incidence longitudinally.

METHODS

The co-EC Study (Enhancing care and treatment among HCV/HIV co-infected individuals to Eliminate Hepatitis C transmission) was an implementation trial providing HCV direct-acting antiviral treatment in Melbourne, Australia, from 2016-2018. Individuals with HCV/HIV co-infection were prospectively enrolled from primary and tertiary-care services providing care for 85% of GBM with HIV in our jurisdiction. HCV-viraemic prevalence and HCV-antibody/viraemic incidence were measured using a state-wide, individually-linked, electronic surveillance system.

RESULTS

Among 200 participants recruited, 186 initiated treatment during the study period. Sustained virological response among primary care participants (98%, 95%CI:93-100%) was not different to tertiary care (98%, 95%CI:86-100%). From 2012-2019, between 2434 and 3476 GBM with HIV-infection attended our primary-care sites annually providing 13,801 person-years of follow-up; 50-60% received an HCV test annually, 10-14% were anti-HCV positive. Among those anti-HCV positive, viraemic prevalence declined 83% during the study (54% to 9%; 2016 to 2019). HCV incidence decreased 25% annually from 1.7/100 person-years in 2012 to 0.5/100 person-years in 2019 (incidence rate ratio 0.75; CI:0.68-0.83;p<0.001).

CONCLUSION

High treatment effectiveness by non-specialists demonstrates the feasibility of treatment scale-up in this population. Substantial declines in HCV incidence and prevalence among GBM with HIV-infection provides proof-of-concept for HCV micro-elimination.

REGISTRATION

ClinicalTrials.gov (Identifier: NCT02786758).

Monitoring changes in the organization of Dutch long-term care and their effects on the mental health and wellbeing of people with dementia

Background

The 'Living Arrangements for People with Dementia (LAFD)' monitor-study aims to provide insight into effects of changes in the organization of Dutch long-term care for people with dementia. The objective of this study is to evaluate changes over time in the level of cognitive impairment, the frequency and severity of behavioral symptoms, and quality of life of residents with dementia, and changes in staffing levels. The study allows for detection of trends and developments that are relevant for the quality of nursing home care.

Methods

The LAFD-study is a repeated cross-sectional study. Since 2008, assessments have been conducted in participating nursing homes every two year. Up to 2020, five assessments have been completed. The number of participating nursing homes over time ranged from 47 to 144 and a sample of one third of residents was included in the study. Data collection was performed by care professionals. Cognitive impairment was assessed with the Cognitive Performance Scale, frequency and severity of behavioral symptoms were assessed with the Neuropsychiatric Inventory; quality of life was assessed with de Qualidem. Per nursing home, the amount of direct provided care was inventoried.

Results

Assessments up to 2017/2018 showed an improvement in cognitive functioning and quality of life in Dutch nursing homes. The amount of behavioral problems did not change, as did the amount of direct care. However, the level of professional caregivers increased slightly. In the last assessment, 53 nursing homes participated, and 668 residents were included. The fast majority of participants was over 80 years of age (67.1%) and 68.5% were female. The data are currently being further analyzed and presented at the conference.

Conclusions

There is a trend of improvement in cognitive functioning and quality of life up to 2018. The most recent assessment will indicate whether these positive trends continue.

Changes in mental health and drug use among men who have sex with men using daily and event-driven pre-exposure prophylaxis: Results from a prospective demonstration project in Amsterdam, the Netherlands

BACKGROUND

Gay, bisexual and other men who have sex with men (GBMSM) are at increased risk of mental health disorders and drug use. In GBMSM taking pre-exposure prophylaxis (PrEP) for HIV, the proportion engaging in risk behaviors could increase due to decreased perception in HIV risk. In turn, this could leave them further susceptible to mental health disorders.

METHODS

The AMsterdam PrEP study (AMPrEP) is a demonstration project offering a choice of daily PrEP or event-driven PrEP regimen at the STI clinic of the Public Health Service of Amsterdam. Eligible participants were HIV-negative GBMSM and transgender people at risk of HIV, aged ≥18 years. We assessed anxiety and depressive mood disorders (Mental Health Inventory 5), sexual compulsivity (Sexual Compulsivity Scale), alcohol use disorder (Alcohol Use Disorder Identification Test), and drug use disorder (Drug Use Disorder Identification Test) using yearly self-administered assessments (August 2015-September 2018). The proportion of mental health problems were analyzed and changes over time and between regimen were assessed using a logistic regression model. Variables associated with the development or recovery of disorders were assessed using a multistate Markov model.

OUTCOMES

Of 376 enrolled, we analyzed 341 participants with data at baseline and at least one follow-up visit. During a median follow-up of 2.5 years (IQR=2.3-2.7), the proportion assessed with sexual compulsivity decreased from 23% at baseline to 10% at the last visit (p<0.001) and drug use disorder decreased from 38% at baseline to 31% at the last visit (p = 0.004). No changes occurred in proportion assessed with anxiety/depressive mood disorders (20% at baseline, 18% at last visit, p = 0.358) or alcohol use disorder (28% at baseline, 22% at the last visit, p = 0.106). During follow-up, participants reported significant less use of alcohol (p<0.001), nitrites (p<0.001) and ecstasy (p<0.001). We found no differences between daily and event-driven PrEP users. The development and recovery of disorders during follow-up were highly interrelated.

INTERPRETATION

Mental health disorders are prevalent among those initiating PrEP. We did not find increases in mental health disorders during PrEP use, but rather a decrease in sexual compulsivity and drug use disorders. The initial prevalence of mental health disorders in our study point at the continuous need to address mental health disorders within PrEP programs.

FUNDING

ZonMw, H-TEAM, Internal GGD research funds, Aidsfonds, Stichting AmsterdamDiner Foundation, Gilead Sciences, Janssen Pharmaceutica, M A C AIDS Fund, and ViiV Healthcare.

Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) among undocumented migrants and uninsured legal residents in Amsterdam, the Netherlands: a cross-sectional study

BACKGROUND

Nasal carriage of methicillin-resistant Staphylococcus aureus (MRSA) is associated with an increased risk of infection. Colonization with MRSA is observed in < 1% of the general Dutch population. Increased risk for MRSA carriage is known to occur in several key groups, one of which is asylum seekers. However, little is known about MRSA carriage among undocumented migrants and uninsured legal residents. This study aimed to determine the prevalence of nasal MRSA carriage among these groups in Amsterdam, the Netherlands.

METHODS

In this cross-sectional study, between October 2018 and October 2019, undocumented migrants and uninsured legal residents aged 18 years or older who were able to understand one of the study languages were recruited at an NGO health care facility in Amsterdam, the Netherlands, for general practitioner (GP) consultations. Participants were asked questions on demographics, migration history, antibiotic use and other possible risk factors for MRSA carriage and were screened for nasal MRSA carriage by selective culturing e-swabs. Characteristics of MRSA-negative and MRSA-positive participants were compared using univariable logistic regression analysis with Firth's correction.

RESULTS

Of the 3822 eligible patients, 760 were screened for nasal MRSA carriage (19.9%). Of the 760 participants, over half were male (58%; 442/760) and originated mainly from Africa (35%; 267/760), Asia (30%; 229/760) and North or South America (30%; 227/760). In total, 705/760 participants (93%) were undocumented migrants and 55/760 (7%) were uninsured legal residents of Amsterdam. The overall prevalence of nasal MRSA carriage was 2.0% (15/760) (95%CI 1.1 to 3.2%), with no difference between undocumented migrants (14/705) (2.0, 95%CI 1.1 to 3.3%) and uninsured legal residents (1/55) (1.8, 95%CI 0.1 to 9.7%). Genotyping showed no clustering of the 15 isolates. MRSA carriage was not associated with sociodemographic, migration history or other possible risk factors. Nevertheless, this study had limited power to detect significant determinants. Three participants (3/15; 20%) harbored Panton-Valentine leukocidin (PVL)-positive isolates.

CONCLUSION

Even though our study population of undocumented migrants and uninsured legal residents had a higher prevalence of nasal MRSA carriage compared to the general Dutch population, the prevalence was relatively low compared to acknowledged other high-risk groups.

High incidence of HCV in HIV-negative men who have sex with men using pre-exposure prophylaxis

BACKGROUND & AIMS

HCV has emerged as a sexually transmitted infection (STI) among HIV-positive men who have sex with men (MSM). We evaluated HCV incidence and its risk factors among HIV-negative MSM using HIV pre-exposure prophylaxis (PrEP).

METHODS

Participants of the Amsterdam PrEP project were tested for HCV antibodies or HCV-RNA every 6 months. Participants used daily or event-driven PrEP and could switch regimens during follow-up. We calculated incidence rates (IRs) for overall HCV infection and separately for primary and re-infection. A univariable Bayesian exponential survival model was used to identify risk factors associated with incident HCV infection. The HCV NS5B gene fragment (709 bp) was sequenced and compared to HCV isolates from HIV-positive MSM and other risk groups (n = 419) using phylogenetic analysis.

RESULTS

Among 350 participants contributing 653.6 person-years (PYs), we detected 15 HCV infections in 14 participants (IR = 2.30/100PY). There were 8 primary infections (IR = 1.27/100PY) and 7 re-infections (IR = 27.8/100PY). IR was 2.71/100PY in daily and 1.15/100PY in event-driven PrEP users. Factors associated with incident HCV infection were higher number of receptive condomless anal sex acts with casual partners (posterior hazard ratio [HR] 1.57 per ln increase; 95% credibility interval [CrI] 1.09-2.20), anal STI (posterior HR 2.93; 95% CrI 1.24-7.13), injecting drug use (posterior HR 4.69; 95% CrI 1.61-12.09) and sharing straws when snorting drugs (posterior HR 2.62; 95% CrI 1.09-6.02). We identified robust MSM-specific HCV clusters of subtypes 1a, 4d, 2b and 3a, which included MSM with and without HIV.

CONCLUSIONS

HIV-negative MSM using PrEP are at risk of incident HCV infection, while identified risk factors are similar to those in HIV-positive MSM. Regular HCV testing is needed, especially for those with a previous HCV infection and those reporting risk factors.

LAY SUMMARY

We report that hepatitis C virus infections are frequently acquired among HIV-negative men who have sex with men (MSM) using pre-exposure prophylaxis to prevent HIV infection. New infections occurred more frequently in those reporting receptive anal sex without using condoms, having an anal sexually transmitted infection, injecting drugs, and sharing straws when snorting drugs. The viruses found in HIV-negative men using pre-exposure prophylaxis are genetically similar to those in HIV-positive men, but not in other hepatitis C risk groups, suggesting that (sexual) transmission is occurring between HIV-positive MSM and HIV-negative MSM using pre-exposure prophylaxis.

CLINICAL TRIAL NUMBER

Dutch trial registration number NTR5411.

Integrating HBV, HCV and HIV screening in tuberculosis entry screening for migrants in the Netherlands

We evaluated uptake and diagnostic outcomes of voluntary hepatitis B (HBV) and C virus (HCV)

screening offered during routine tuberculosis entry screening to migrants in Gelderland and Amsterdam, the Netherlands, between 2013 and 2015. In Amsterdam, HIV screening was also offered. Overall, 54% (461/859) accepted screening. Prevalence of chronic HBV infection (HBsAg-positive) and HCV exposure (anti-HCVpositive) in Gelderland was 4.48% (9/201; 95% confidence interval (CI): 2.37-8.29) and 0.99% (2/203; 95% CI: 0.27-3.52), respectively, all infections were

newly diagnosed. Prevalence of chronic HBV infection, HCV exposure and chronic HCV infection (HCV RNA-positive) in Amsterdam was 0.39% (1/256; 95% CI: 0.07-2.18), 1.17% (3/256; 95% CI: 0.40-3.39) and 0.39% (1/256; 95% CI: 0.07-2.18), respectively, with all chronic HBV/HCV infections previously diagnosed. No HIV infections were found. In univariate analyses, newly diagnosed chronic HBV infection was more likely in participants migrating for reasons other than work or study (4.35% vs 0.83%; odds ratio (OR) = 5.45; 95% CI: 1.12-26.60) and was less likely in participants in Amsterdam than Gelderland (0.00% vs 4.48%; OR = 0.04; 95% CI: 0.00-0.69). Regional differences in HBV prevalence might be explained by differences in the populations entering compulsory tuberculosis

screening. Prescreening selection of migrants based on risk factors merits further exploration.

Hepatitis E virus seroprevalence and determinants in various study populations in the Netherlands

BACKGROUND

The epidemiology of hepatitis E virus (HEV) is not fully understood. In this study, we assessed putative risk factors for HEV seropositivity in various study populations in the Netherlands.

METHODS

Data and samples from five different study populations were analysed: (A) blood donors (n = 5,239), (B) adults reporting a vegetarian life style since the age of 12 years (n = 231), (C) residents of Amsterdam, the Netherlands, with different ethnic backgrounds (n = 1,198), (D) men who have sex with men (MSM) (HIV positive and HIV negative) (n = 197), and (E) persons who use drugs (PWUD) (HIV positive and HIV negative) (n = 200). Anti-HEV immunoglobulin M (IgM) and immunoglobulin G (IgG) testing was performed using ELISA test (Wantai).

RESULTS

HEV IgM seroprevalence was low across all study populations (<1% to 8%). The age and gender-adjusted HEV IgG seroprevalence was 24% among blood donors (reference group) and 9% among the vegetarian group (adjusted Relative Risk [aRR]:0.36, 95%CI:0.23-0.57). Among participants of different ethnic backgrounds, the adjusted HEV IgG seroprevalence was 16% among participants with a Dutch origin (aRR:0.64, 95%CI:0.40-1.02), 2% among South-Asian Surinamese (aRR:0.07, 95%CI:0.02-0.29), 3% among African Surinamese (aRR:0.11, 95%CI:0.04-0.34), 34% among Ghanaian (aRR:1.53, 95%CI:1.15-2.03), 19% among Moroccan (aRR:0.75, 95%CI:0.49-1.14), and 5% among Turkish (aRR:0.18, 95%CI:0.08-0.44) origin participants. First generation Moroccans had a higher risk for being IgG HEV seropositive compared to second generation Moroccan migrants. The statistical power to perform these analyses in the other ethnic groups was too low. In the MSM group the IgG HEV seroprevalence was 24% (aRR:0.99, 95%CI:0.76-1.29), and among PWUD it was 28% (aRR:1.19, 95%CI:0.90-1.58). The number of sexual partners in the preceding six months was not significantly associated with IgG HEV seropositivity in MSM. The association between HIV status and HEV seropositivity was significant in PWUD, yet absent in MSM. HIV viral load and CD4 cell count were not associated with HEV seropositivity in HIV positive MSM and PWUD.

CONCLUSIONS

Vegetarians were significantly less often HEV seropositive. Ethnic origin influenced the risk for being IgG HEV seropositive. MSM and PWUD were not at higher risk for being IgG HEV seropositive than blood donors.

Heparin Binding to Plasma Proteins, an Important Mechanism for Heparin Resistance

Heparin dosage requirements vary widely among patients with venous thromboembolism. In this study, we measured the proportion of anticoagulantly-active heparin which was reversibly bound and neutralized by plasma proteins (defined as reversible heparin neutralization) in the pre-treatment plasma (in vitro) and in the 6 h post-treatment plasma (ex vivo) of patients with venous thromboembolism treated with a fixed dose of heparin. Reversible heparin neutralization was assessed by comparing the heparin levels measured as anti-factor Xa activity before and after the addition of low affinity heparin which is essentially devoid of antifactor Xa activity, in order to displace heparin bound to plasma proteins. The results indicate that reversible heparin neutralization due to binding to plasma proteins is a major determinant of the anticoagulant response to a fixed dose of standard heparin 6 h post-treatment and of the eventual heparin dose required to achieve a therapeutic anticoagulant effect on days 3-5 of heparin treatment.

Combat-related foot injuries: impact on gait and functional outcome

Introduction

Prior to deployment of the Netherlands Army Task Force Urozgan in Afghanistan, the Dutch Military and civilian healthcare systems had limited experience in treating blast injuries and their long-term consequences. This meant that guidelines for treatment and rehabilitation were lacking. The aim of this cohort study was to quantify kinematic and kinetic abnormalities in service members with foot injuries in relation to functional outcome using gait analysis.

Method

In nine service members with combat-related talus, calcaneus and/or navicular bone (TCN) fractures and nine controls, gait parameters were measured using Gait Real-Time Analysis Interactive Lab system. High-level mobility was evaluated by the Comprehensive High-Level Activity Mobility Predictor (CHAMP), and functional ability was assessed by Lower Extremity Functional Scale (LEFS) questionnaire.

Results

Significant differences were found for LEFS and CHAMP scores (P<0.01), comfortable walking speed and ankle joint range of motion (ROM) (P<0.05), all lower in the group with TCN fractures. For this group, a trend (0.1>P>0.05) for higher step width and lower stride duration and peak power was found. A strong correlation (0.6>r>0.79) is shown between LEFS and comfortable walking speed and CHAMP and ankle joint ROM. The correlations between LEFS and stride duration, step width, ankle joint ROM and peak power, and between CHAMP and comfortable walking speed and stride duration, were moderate (0.4>r>0.59).

Conclusions

This study demonstrated that service members with TCN fractures, compared with healthy controls, have altered gait characteristics, specifically lower walking speed and ankle joint ROM, both related to lower physical functioning. Patients with bilateral depressed Böhler’s angle had the worse functional performance, and further research is recommended to evaluate the relationship between Böhler’s angle and physical performance.

Clinical Trial

The Dutch Ministry of Defence (MOD) and the Institutional Review Board and Medical Ethics Review Committee Brabant, The Netherlands, approved this study (P1550).

Factors associated with recent unsuppressed viral load in HIV-1-infected patients in care on first-line antiretroviral therapy in South Africa

Unsuppressed viral load (VL) in patients on antiretroviral therapy (ART) occurs when treatment fails to suppress a person's VL and is associated with decreased survival and increased HIV transmission. The objective of this study was to evaluate factors associated with unsuppressed VL (VL > 400 copies/ml) in patients currently in care on first-line ART for ≥ 6 months attending South African public healthcare facilities. We analysed electronic medical records of ART patients with a VL result on record who started ART between January 2004 and April 2016 from 271 public health facilities. We present descriptive and multivariable logistic regression for unsuppressed VL at last visit using a priori variables. We included 244,370 patients (69% female) on first-line ART in April 2016 for ≥ 6 months. Median age at ART start was 33 years (7% were < 15 years old). Median duration on ART was 3.7 years. Adjusting for other variables, factors associated with having an unsuppressed VL at the most recent visit among patients in care included: (1) < 15 years old at ART start (adjusted odds ratio [aOR]=2.58; 95% CI = 2.37, 2.81) versus 15-49 years at ART start, (2) male gender (aOR = 1.29; 95% CI = 1.25, 1.35), (3) 6-12 months on ART versus longer (aOR = 1.34; 95% CI = 1.29, 1.40), (4) on tuberculosis (TB) treatment (aOR = 1.78; 95% CI = 1.48, 2.13), and (5) prior ART exposure versus none (aOR = 1.20; 95% CI = 1.08, 1.32). Approximately 85% of the ART cohort who were in care had achieved viral suppression, though men, youth/adolescents, patients with prior ART exposure, those with short duration of ART, and patients on TB treatment had increased odds of not achieving viral suppression. There is a need to develop and evaluate targeted interventions for ART patients in care who are at high risk of unsuppressed VL.

Duration of Oral Anticoagulant Treatment in Patients with Venous Thromboembolism and a Deficiency of Antithrombin, Protein C or Protein S - A Decision Analysis

Patients with a first venous thromboembolic event and a deficiency of the coagulation inhibitors antithrombin, protein C or protein S have an increased risk of recurrent venous thromboembolism compared to patients without such a deficiency. A decision analysis was performed to assess the effect of continuing treatment with vitamin K antagonists on mortality by a reduction in fatal recurrent pulmonary embolism and an induction of fatal haemorrhages associated with their use. The treatment decision involves continuation or discontinuation of vitamin K antagonists in patients with a first spontaneous or secondary venous thromboembolism and an antithrombin, protein C or S deficiency. Although the efficiency of oral anticoagulation is high in all age groups early after the first thromboembolic event, it decreases over time. Our analysis indicates that the optimal treatment duration will vary, depending on the type of the initial event (spontaneous or secondary; deep venous thrombosis or pulmonary embolism), age, and time passed since the initial thromboembolic episode. Moreover, life-long duration of the prophylaxis seems not warranted in all patients.

Lipoprotein(a) Concentrations in Women with a History of Severe Preeclampsia – a Case Control Study

A high concentration of lipoprotein(a) is associated with athero-sclerotic disease. Atheroma may develop in spiral arteries in both preeclamptic and normal pregnancies, but they are much more common in preeclampsia, particularly in the decidual segments. We hypothesized that a high concentration of lipoprotein(a) is associated with the development of preeclampsia.

We studied 40 women with a history of severe preeclampsia, 35 women with a history of preeclampsia and the (H)ELLP syndrome and 67 controls with a normal obstetric history. Lipoprotein(a) levels were measured at least 10 weeks post partum in the second half of a normal menstrual cycle. None of the women in the study or the control group were pregnant or used oral contraceptives. Lipoprotein(a) levels over the 90th percentile of the lipoprotein(a) distribution of our control group (420 mg/l) were defined as abnormal. There was a statistically significant higher prevalence of abnormal levels of lipoprotein(a) in women with a history of severe preeclampsia (33%) in comparison with women with a history of preeclampsia and (H)ELLP syndrome (9%) and with the control group (10%).

We found that a history of severe preeclampsia and spontaneous abortion was associated with elevated lipoprotein(a) levels as a post-hoc finding. Whether spontaneous abortion and high levels of lipo-protein(a) are related remains to be demonstrated.

Comparison of a Clinical Probability Estimate and Two Clinical Models in Patients with Suspected Pulmonary Embolism

Recent studies have suggested that both the subjective judgement of a physician and standardized clinical models can be helpful in the estimation of the probability of the disease in patients with suspected pulmonary embolism (PE). We performed a multi-center study in consecutive in- and outpatients with suspected PE to compare the potential diagnostic utility of these methods. Of the 517 study patients, 160 (31%) were classified as having PE. Of these patients, 14% had a low probability as estimated by the treating physician, while 25 to 36% were categorized as having a low clinical probability with the use of two previously described clinical models. The objectively confirmed prevalence of PE in these three low probability categories was 19%, 28% and 28%, respectively. The three methods yielded comparable predictive values for PE in the other probability categories. We conclude that a physician’s clinical judgement alone and two standardized clinical models, although comparable, perform disappointingly in categorizing the pre-test probability in patients with suspected PE.

Increased Fibrinolytic Activity during Use of Oral Contraceptives Is Counteracted by an Enhanced Factor XI-independent down Regulation of Fibrinolysis

The effect of oral contraceptives (OC) on fibrinolytic parameters was investigated in a cycle-controlled cross-over study in which 28 non-OC using women were randomly prescribed either a representative of the so-called second (30 µg ethinylestradiol, 150 µg levonorgestrel) or third generation OC (30 µg ethinylestradiol, 150 µg desogestrel) and who switched OC after a two month wash out period. During the use of OC, the levels of tissue-type plasminogen activator (tPA) activity, plasminogen, plasmin-α2-antiplasmin complexes and D-dimer significantly increased (by 30 to 80%), while the levels of plasminogen activator inhibitor-1 (PAI-1) antigen, PAI-1 activity and tPA antigen significantly decreased (25 to 50%), suggesting an increase in endogenous fibrinolytic activity. These OC-induced changes were not different between the two contraceptive pills. TAFI (thrombin-activatable fibrinolysis inhibitor) levels increased on levonorgestrel, and even further increased on desogestrel. A clot lysis assay that probes both fibrinolytic activity and the efficacy of the coagulation system to generate thrombin necessary to down regulate fibrinolysis via TAFI showed no change of the clot lysis time during OC use. This finding suggests that the OC-induced increase in endogenous fibrinolytic activity is counteracted by an increased capacity of the coagulation system to down regulate fibrinolysis via TAFI. Indeed we observed that during OC use there was a significant increase of F1+2 generation during clot formation. When these assays were performed in the presence of an antibody against factor XI, we observed that the clot lysis time was significantly increased during OC use and that the increase in F1+2 generation during OC therapy was due to a factor XI-independent process, which was significantly higher on desogestrel than on levonorgestrel. These data indicate that the OC-induced inhibition of endogenous fibrinolysis takes place in a factor XI-independent way and is more pronounced on desogestrel than on levonorgestrel-containing OC.

Effects on Coagulation of Levonorgestrel- and Desogestrel-containing Low Dose Oral Contraceptives: a Cross-over Study

Combined oral contraceptives (OC) are known to increase the risk of venous thromboembolism. The aim of this randomized, cycle-controlled, cross-over study in 28 healthy volunteers was to assess potential differences between the effects of an OC containing 150 µg levonorgestrel (as representative of the so-called second generation OC) and an OC containing 150 µg desogestrel (as representative of the third generation OC) in combination with 30 µg ethinylestradiol on several coagulation factors and markers of thrombin formation. All participants used each OC for two cycles, and were switched to the other OC after a washout period of two menstrual cycles. The plasma concentrations of factors II, VII, X, and fibrinogen significantly increased during use of both the levonorgestrel- and desogestrel-containing OC’s. The plasma concentrations of factor VIII increased, and of factor V decreased, changes which only reached statistical significance during the use of the desogestrel-containing OC. During exposure to the desogestrel-containing OC, as compared with the levonorgestrel-containing OC, both factor VII and factor II showed a greater increase (FVII: 32% and 12% respectively; p <0.0001; FII: 16% and 12% respectively; p = 0.048), whereas factor V showed a greater decrease (–11% and –3% respectively; p = 0.010). Only one of the markers for ongoing coagulation (prothrombin fragment 1+2) showed a significant increase during OC use, whereas concentrations of thrombin-antithrombin complexes and soluble fibrin remained unchanged. For these markers, there was no difference between the tested OC’s. We conclude that there are differences between the effects of levonorgestrel and desogestrel-containing OC’s on some coagulation factors. Whether these changes provide a biological explanation for the reported differences in venous thromboembolic risk is as yet unclear. The real challenge now becomes to define a pattern of changes in the various systems which, if affected simultaneously, may tip the hemostatic balance towards a prethrombotic state and may lead to overt clinical venous thromboembolism.

A Randomized Cross-over Study on the Effects of Levonorgestrel- and Desogestrel-containing Oral Contraceptives on the Anticoagulant Pathways

The use of oral contraceptives (OC) causes disturbances of the procoagulant, anticoagulant and fibrinolytic pathways of blood coagulation which may contribute to the increased risk of venous thrombosis associated with OC therapy. Here we report the results of a cyclecontrolled randomized cross-over study, in which we determined the effects of so-called second and third generation OC’s on a number of anticoagulant parameters. In this study, 28 non-OC using women were randomly prescribed either a second generation (150 µg levonorgestrel/30 µg ethinylestradiol) or a third generation OC (150 µg desogestrel/30 µg ethinylestradiol) and who switched to the other OC after a two month wash out period. The anticoagulant parameters determined were: antithrombin (AT), α2-macroglobulin (α2-M), α1-antitrypsin, protein C inhibitor (PCI), protein C, total and free protein S and activated protein C sensitivity ratios (APC-sr) measured with two functional APC resistance tests which quantify the effect of APC on either the activated partial thromboplastin time (aPTT) or on the endogenous thrombin potential (ETP). During the use of desogestrel-containing OC the plasma levels of αc2-M, α1-antitrypsin, PCI and protein C significantly increased, whereas AT and protein S significantly decreased. Similar trends were observed with levonorgestrel-containing OC, although on this kind of OC the changes in AT, PCI and protein S (which was even slightly increased) did not reach significance. Compared with levonorgestrel, desogestrel-containing OC caused a significant decrease of total (p <0.005) as well as free protein S (p <0.0001) and more pronounced APC resistance in both the aPTT (p = 0.02) and ETPbased (p <0.0001) APC resistance tests. These observations indicate that the activity of the anticoagulant pathways in plasma from users of desogestrel-containing OC is more extensively impaired than in plasma from users of levonorgestrel-containing OC.

Do Heparins Do More than Just Treat Thrombosis? The Influence of Heparins on Cancer Spread

The influence of unfractionated heparin (UFH) and other anticoagulants on the spread of cancer has been reported since the early 1960s.1 However, clinical studies investigating the use of heparins in cancer patients have not produced consistent results.2 Intravenous, adjusted-dose UFH for 5 to 10 days has been the standard initial treatment for venous thrombosis. More recently, subcutaneous, fixed-dose, low molecular weight heparins (LMWHs), which are fractions of the parent compound, have been shown to be safe and effective alternatives to UFH in the initial treatment for venous thromboembolism.3-5

In one of our randomized clinical trials comparing LMWH and UFH in the initial treatment of deep vein thrombosis (DVT), we observed an unexpected difference in 6-month mortality among cancer patients in favor of LMWH, which could not be attributed to a difference in the incidence of thrombotic or bleeding complications.6 A similar observation in favor of LMWH was reported in a subsequent study and in a meta-analysis of trials.7,8 The number of cancer patients included in these studies was small, and adjustment of the observed effect for the baseline characteristics of the cancer patients was not possible. However, these findings suggested an inhibitory effect of LMWH on tumor growth or metastasis, which is less apparent or absent for UFH, resulting in a beneficial effect on the survival of cancer patients. This hypothesis is supported by the observations, in experimental studies, that LMWH and low molecular weight heparan sulfate, in comparison to UFH, effectively suppressed angiogenesis, a process necessary for tumor growth and metastasis.9,10

On the other hand, animal studies that investigated the effect of chemically-modified heparins on the spread of cancer did not detect a superior anti-tumor effect of LMWH compared to UFH; both were found to inhibit metastasis.11,12 To date, the effect of LMWH on cancer survival in humans has not been investigated as a primary objective. If a consistent and beneficial effect of LMWH on mortality is indeed present, such a study would be warranted.

We performed a meta-analysis of all available randomized clinical trials where LMWH was compared with UFH in the treatment of venous thromboembolism (VTE) to estimate the crude treatment effect of LMWH on mortality in cancer patients compared to UFH. Subsequently, we adjusted this treatment effect for age, gender, and primary malignancy site by reanalyzing data from three of those trials.3-5 This effect was further adjusted for other prognostic factors, including cancer histology, tumor stage, presence of metastases, duration of cancer, and concomitant use of cancer treatment, by analyzing individual patient data from the largest randomized trial.5

Antithrombotic Drugs in the Primary Medical Management of Intermittent Claudication: A Meta-analysis

Background. There is no consensus on the efficacy of the antithrombotic drugs available for patients with intermittent claudication. Methods. A Medline and manual search was used to identify relevant publications. Uncontrolled or retrospective studies, double reports or trials without clinical outcomes were excluded. Included studies were graded as level 1 (randomised and double- or assessor-blind), level 2 (open randomised), or level 3 (non-randomised comparative). Mortality, cerebro- or cardiovascular events, amputations, arterial occlusions or number of revascularization procedures performed in the lower limbs, pain-free and total walking distance, ankle brachial index and calf blood flow, were the main outcomes considered. When feasible, end of treatment results, either continuous or binary, were combined with appropriate statistical methods. Results. Mortality was significantly decreased by ticlopidine compared to placebo (common odds ratio 0.68, 95% C.I., 0.49 - 0.95); clopidogrel decreased vascular events in comparison to aspirin (odds ratio 0.76, 95% C.I., 0.63 - 0.92) in level 1 studies. Arterial occlusions and the number of revascularization procedures performed were statistically significantly decreased by aspirin and ticlopidine, respectively. A small but statistically significant improvement in pain-free walking distance was determined by picotamide, indobufen, low molecular weight heparins, sulodexide and defibrotide, in small studies. Conclusions. Clopidogrel and ticlopidine do reduce clinically important events in patients with intermittent claudication and could be added to the primary medical treatment of these patients. The use of aspirin in these patients cannot be based on direct evidence, but only on analogy with coronary and cerebral atherosclerosis, where it has documented efficacy. Other antithrombotic drugs were not properly evaluated in patients with intermittent claudication.

Is the Prevalence of the Factor V Leiden Mutation in Patients with Pulmonary Embolism and Deep Vein Thrombosis Really Different?

Introduction. Previous investigations have suggested a lower prevalence of the factor V Leiden mutation in patients with pulmonary embolism, as compared to patients with deep leg vein thrombosis. Methods. We studied unselected patients with pulmonary embolism, in whom we also assessed the presence of deep vein thrombosis by ultra-sonography. We assessed the prevalence of heterozygosity for the factor V Leiden mutation and compared the outcome of patients with a normal ultrasound (primary pulmonary embolism) to those with an abnormal ultrasound (combined form of venous thromboembolism). Furthermore, we performed a literature search to identify all articles regarding the prevalence of heterozygous factor V Leiden mutation in patients with primary deep vein thrombosis, primary pulmonary embolism and a combined form of venous thromboembolism. We calculated a (common) odds ratio for these 3 manifestations of venous thromboembolism, including the current findings. Results. In 92 patients with proven pulmonary embolism, 25 (27%) had also an abnormal ultrasound. In these patients, the prevalence of the factor V Leiden mutation was 24% (95% CI 9%-45%), whereas the mutation was present in 5 of 67 patients with primary pulmonary embolism (7%; 95% CI 2%-16%). The literature analysis indicated the common odds ratio for the presence of heterozygous factor V Leiden mutation in patients with primary deep vein thrombosis, primary pulmonary embolism and the combined form of venous thromboembolism to be 7.9 (95% CI 5-12), 3.5 (95% CI 2-6) and 6.8 (95% CI 3-14), respectively. Conclusion. In patients with primary pulmonary embolism the prevalence of the factor V Leiden mutation appears to be half of that reported in patients with primary deep vein thrombosis. The mechanism remains unclear.

Long-Term Treatment of Venous Thromboembolic Disease

After an initial 5- to 10-day course of treatment with either unfractionated or low molecular weight heparin, secondary prophylaxis is usually prescribed to patients with venous thromboembolic disease for a variable period of time. The primary aim of both initial and secondary treatment is to prevent recurrent thrombotic events, including deep vein thrombosis and fatal pulmonary embolism. This objective has to be achieved at a minimal risk of bleeding. There is general consensus that the initial treatment should be with low molecular weight or unfractionated heparin. For secondary prophylaxis, however, there are currently several options. Among these are continued unfractionated heparin or low molecular weight heparin and oral vitamin K-antagonists. In addition, compression stockings and caval vein filters are available.

In this chapter, we will first examine the available evidence for each of these options, then discuss the results of randomized trials that have studied the duration of secondary prophylaxis. Finally, we will attempt to synthesize this information using decision analytic techniques.

Replacing Inpatient Care by Outpatient Care in the Treatment of Deep Venous Thrombosis – An Economic Evaluation

Two clinical trials in patients with acute deep venous thrombosis have indicated that the outpatient management with fixed-dose, subcutaneous low-molecular-weight heparin is at least as effective and safe as inpatient treatment with unfractionated intravenous heparin with respect to recurrent venous thromboembolism and major bleeding. We performed an economic evaluation alongside one of these trials to assess the cost consequences of the outpatient management strategy. Data were collected through case record forms, complemented by a prospective questionnaire in 78 consecutive patients, interviews with health care providers, and hospital data bases. Our study demonstrated that seventy-five percent of patients allocated to low-molecular-weight heparin received treatment either entirely at home or after a brief hospital stay. Fifteen percent of these patients required professional domiciliary care. Within-centre comparisons of resource utilisation in terms of natural units showed that outpatient management with low-molecular-weight heparin reduced the average number of hospital days in the initial treatment period in nine centres by 59 percent (95% CI: 43 to 71 percent) accompanied by a limited increase in outpatient and professional domiciliary care. The average reduction in hospital days at the end of follow up was 40 percent (95% CI: 25 to 54 percent). A cost-minimisation analysis, focusing on resource utilisation directly related to the treatment of deep venous thrombosis and associated costs in one centre demonstrated a cost reduction of 64 percent (95% CI: 56 to 72 percent) with the outpatient management with low-molecular-weight heparin. These data suggest that outpatient management of patients with proximal venous thrombosis using low-molecular-weight heparin reduces resource utilisation and total treatment cost. Implementation should be preceded by a cautious evaluation of a potential cost shifting and organisational prerequisites.

Incidence of Venous Thromboembolism in Families with Inherited Thrombophilia

The risk of spontaneous or risk-period related venous thromboembolism in family members of symptomatic carriers of antithrombin (AT), protein C (PC) or protein S (PS) defects, as well as of the Factor V Leiden mutation is still undefined. We performed a retrospective cohort study in family members (n = 793) of unselected patients with a documented venous thromboembolism and one of these deficiencies to make an estimate of this risk. The annual incidences of total and spontaneous venous thromboembolic events in carriers of AT, PC or PS defects (n = 181) were 1.01% and 0.40%, respectively, as compared to 0.10% and 0.04% in non-carriers, respectively (relative risks both 10.6). In carriers of Factor V Leiden (n = 224), the annual incidences of total and spontaneous venous thromboembolism were 0.28% and 0.11%, respectively, as compared to 0.09% and 0.04% in non-carriers, respectively (relative risks 2.8 and 2.5). Additional risk factors (immobilisation, surgery and trauma; oral contraceptive use; and pregnancy/ post-partum) increased the risk of thrombosis in carriers of AT, PC and PS defects as compared to non-carriers (relative risks 8.3, 6.4 and 8.2, respectively). Oral contraceptive use and pregnancy/ post-partum period increased the risk of thrombosis in carriers of Factor V Leiden to 3.3-fold and 4.2-fold, respectively, whereas other risk factors had only a minor effect.

These data lend some support to the practice of screening family members of symptomatic carriers of a AT, PC and PS deficiency. For family members of symptomatic carriers of Factor V Leiden, screening does not seem to be justified except for women in fertile age.

Comparison of Three Methods to Assess Therapeutic Quality Control of Treatment with Vitamin K Antagonists

During treatment with vitamin K antagonists, International Normalized Ratios (INR) are determined periodically to maintain a therapeutic level of anticoagulation. We evaluated two existing methods for therapeutic quality control (linear interpolation and equidivision), with regard to their validity and reproducibility. In addition, we proposed and evaluated a (hybrid) method that takes into account potential effects of dosage modifications when INRs are far out of the target range. Validity was assessed by deleting intermediary INR results and estimating this INR based on the two surrounding INRs with each of the three methods. The estimated INRs were then compared with the observed INR.

Reproducibility of time spent in an INR range was evaluated for each of the three methods by deleting at random increasing proportions of INRs and comparing these estimates with the situation without deletions. We found that estimates of time spent in INR categories obtained with equidivision were most reproducible, but least valid. The hybrid method showed slightly higher validity and reproducibility in comparison with linear interpolation. Since these differences were small, linear interpolation is preferable to the hybrid method, since the calculations involved are easier.

Quality of life and the duration of treatment with vitamin K antagonists in patients with deep venous thrombosis

In clinical practice, decisions on the duration of treatment with vitamin K antagonists are usually based on the presence of persistent risk factors, the risk of bleeding and centre policy. Little is known about the influence of patients’ experienced quality of life. The objectives of this study were: 1) to explore the course of quality of life in patients with venous thrombosis treated for 3 months versus patients treated for 6 months with vitamin K antagonists; 2) to investigate the factors that were associated with the duration of treatment with vitamin K antagonists. The study sample comprised patients participating in a multi-centre clinical trial. Quality of life was assessed at study entry, after 10-14 days,3 and 6 months in 360 patients. Overall, no dif-ferences in quality of life were found between the 2 patient groups. An interaction effect between group and time was found for physical functioning. Regression analyses indicated that the presence of one or more permanent risk factors, duration of hospitalisation, mobility prior to deep-vein thrombosis and study centre were associated with the duration of treatment with vitamin K antagonists. Interestingly, quality of life was not associated with treatment duration. Since study centre was the most important factor associated with treatment duration, local policy appears to have a great influence on decisions regarding the duration of treatment with vitamin K antagonists.

Part of this manuscript has been included in a poster presentation at the International Society for Quality of Life Research in Amsterdam, The Netherlands, November 8, 2001.

High Plasma Concentration of Factor VIIIc Is a Major Risk Factor for Venous Thromboembolism

Established risk factors, including deficiencies of protein C, protein S or antithrombin and the factor V Leiden and prothrombin mutation, are present in about one third of unselected patients with venous thromboembolism. In addition to these inherited thrombophilic defects, elevated plasma levels of factor VIIIc have been suggested to be important in the pathogenesis of (recurrent) venous thromboembolism. The objective of this study was to assess the relevance of factor VIIIc plasma concentration in consecutive patients with venous thromboembolism.

We studied the prevalence of elevated plasma levels of factor VIIIc in 65 patients with a proven single episode and in 60 matched patients with documented recurrent venous thromboembolism. The reference group consisted of 60 ageand sex-matched patients who were referred for suspected venous thromboembolism, which was refuted by objective testing and longterm clinical follow-up. To minimalize the influence of the acute phase, blood was obtained at least 6 months after the thromboembolic event and results were adjusted for fibrinogen and C-reactive protein. Factor VIIIc was re-determined several years after the first measurement in a subset of patients to evaluate the variability over time. To study a possible genetic cause, a family study was done.

In the control, single and recurrent episode group, the prevalences of plasma levels of factor VIIIc above 175 IU/dl (90th percentile of controls) were 10% (95% CI: 4 to 21%), 19% (95% CI: 10 to 30%) and 33% (95% CI: 22 to 47%), respectively. For each 10 IU/dl increment of factor VIIIc, the risk for a single and recurrent episode of venous thrombosis increased by 10% (95% CI: 0.9 to 21%) and 24% (95% CI: 11 to 38%), respectively. Both low and high plasma levels of factor VIIIc were consistent over time (R = 0.80, p = 0.01). A family study indicated a high concordance for elevated factor VIIIc plasma concentrations among first degree family members. Adjustment for fibrinogen, C-reactive protein and known thrombophilic risk factors did not change the observed association of elevated factor VIIIc with thrombosis.

Elevated plasma levels of factor VIIIc are a significant, prevalent, independent and dose-dependent risk factor for venous thromboembolism. It also predisposes to recurrent venous thromboembolism.

Two doses of rivaroxaban versus aspirin for prevention of recurrent venous thromboembolism

Patients with unprovoked venous thromboembolism (VTE) are at high risk for recurrence. Although rivaroxaban is effective for extended VTE treatment at a dose of 20 mg once daily, use of the 10 mg dose may further improve its benefit-to-risk ratio. Low-dose aspirin also reduces rates of recurrent VTE, but has not been compared with anticoagulant therapy. The EINSTEIN CHOICE study is a multicentre, randomised, double-blind, active-controlled, event-driven study comparing the efficacy and safety of two once daily doses of rivaroxaban (20 and 10 mg) with aspirin (100 mg daily) for the prevention of recurrent VTE in patients who completed 6–12 months of anticoagulant therapy for their index acute VTE event. All treatments will be given for 12 months. The primary efficacy objective is to determine whether both doses of rivaroxaban are superior to aspirin for the prevention of symptomatic recurrent VTE, while the principal safety outcome is the incidence of major bleeding. The trial is anticipated to enrol 2,850 patients from 230 sites in 31 countries over a period of 27 months. In conclusion, the EINSTEIN CHOICE study will provide new insights into the optimal antithrombotic strategy for extended VTE treatment by comparing two doses of rivaroxaban with aspirin (clinicaltrials.gov NCT02064439).

Absolute annual incidences of first events of venous thromboembolism and arterial vascular events in individuals with elevated FVIII:c

Elevated levels of factor VIII:c (elevated FVIII:c) are associated with an increased risk for venous thromboembolism (VTE) and arterial vascular events, and are at least in part determined genetically. We prospectively followed 192 asymptomatic individuals with elevated FVIII:c (>150%) and 340 with normal levels for an average duration of 31 months (range 7 to 56 months) to investigate the risk of VTE and arterial vascular events. Participants were first degree relatives of consecutive patients with elevated FVIII:c and VTE or arterial vascular events before the age of 50 years. The incidences ofVTE were 1.25% (0.46–2.73) per year in the subjects with elevated FVIII:c, versus 0.23% (0.03–0.82) in those with normal levels (OR 5.5 [1.1–27.3]). The annual incidences of arterial vascular events were 1.04% (0.34–2.42) and 0.23% (0.03–0.82) in relatives with and without elevated levels of FVIII:c, respectively (OR: 4.5 [0.9–23.5]). After adjustment for age, smoking, known diabetes mellitus, hyperlipidemia, and hypertension, the odds ratio for any event was 3.7 (1.1–13.1). In conclusion, asymptomatic individuals with elevated FVIII:c levels and a positive family history of VTE or arterial vascular events before the age of 50 appear to have a high annual incidence of first VTE and arterial vascular events. Elevated FVIII:c may be a common risk factor for both clinical entities.

The risk of venous and arterial thrombosis in hyperhomocysteinaemia is low and mainly depends on concomitant thrombophilic defects

As homocysteine-lowering treatment has not reduced the risk of recurrent thrombosis in recent clinical trials, we hypothesized that mild hyperhomocysteinaemia is an epiphenomenon or associated with a low absolute risk of thrombosis. In this retrospective study, we enrolled 478 evaluable first-degree relatives of consecutive patients with venous thrombosis or premature atherosclerosis, and hyperhomocysteinemia. Absolute risks of thrombosis and effects of concomitant thrombophilic defects were compared. Relative risks were adjusted for clustering in families, age, sex, and atherosclerotic risk factors, where appropriate. Annual incidence of venous thrombosis was 0.16% (95% confidence interval [CI], 0.08–0.30) in hyperhomocysteinemic relatives versus 0.11% (CI, 0.05–0.20) in normohomocysteinemic relatives; adjusted relative risk 1.6 (CI, 0.6–4.5). Annual incidences of arterial thrombosis were 0.34% (CI, 0.21–0.52) and 0.24% (CI, 0.15–0.37) in hyperhomocysteinemic and normohomocysteinemic relatives, respectively; adjusted relative risk 1.5 (CI, 0.6–3.5). Concomitance of multiple thrombophilic risk factors increased the risk of venous thrombosis in hyperhomocysteinemic relatives 20 fold, but a comparable effect was demonstrated in normohomocysteinemic relatives. We conclude that hyperhomocysteinaemia is associated with a low absolute risk of venous and arterial thrombosis. Concomitant thrombophilic defects are probably main determinants on the risk of venous thrombosis, rather than hyperhomocysteinaemia itself.

Darexaban (YM150) versus enoxaparin for the prevention of venous thromboembolism after total hip arthroplasty: a randomised phase IIb dose confirmation study (ONYX-3)

This double-blind, double-dummy, randomised, phase IIb study (NCT00902928) evaluated different dosing regimens of darexaban compared with enoxaparin (randomised 1:1:1:1:1 to 15 mg twice daily [bid], 30 mg once daily [qd], 30 mg bid or 60 mg qd or enoxaparin 40 mg qd) in patients undergoing elective total hip arthroplasty. Patients, investigators, pharmacists and sponsor were all blinded to treatment allocation. Darexaban administration started 6-10 hours (h) post-surgery. Enoxaparin 40 mg qd administration started 12 ± 2 h before surgery. Treatment continued for 35 days. Bilateral venography was performed on Day 10 ± 2. The primary efficacy outcome was total VTEs (composite of proximal/distal deep-vein thrombosis, pulmonary embolism) or death, at Day 12. Total VTE rates were similar across all groups. There was no apparent difference in efficacy between onceand twice-daily darexaban (odds ratio [OR] 1.00; 95% confidence interval [CI] 0.71–1.42; p=0.988), or total daily dose (30 mg/day vs 60 mg/day; OR 0.81; 95% CI 0.57–1.15; p=0.244). There was no significant difference in major and/or clinically relevant non-major bleeding between darexaban qd or bid, or between total daily doses of 30 mg or 60 mg, and also for any dosing regimen of darexaban vs enoxaparin. Darexaban was well tolerated, without signs of liver toxicity. In conclusion, darexaban, administered qd or bid, and at total daily doses of 30 mg or 60 mg, appears to be effective for VTE prevention and was well tolerated. Data suggest no significant differences between a once- or twice-daily dosing regimen.

Clinically suspected acute recurrent pulmonary embolism: A diagnostic challenge

It is unknown whether strategies validated for diagnosing pulmonary embolism (PE) are valid in patients with a history of PE. It was the objective of this study to investigate whether a diagnostic algorithm consisting of sequential application of a clinical decision rule (CDR), a quantitative D-dimer test and computed tomography (CT) safely ruled out a clinical suspicion of acute recurrent PE. Data were obtained from a diagnostic outcome study of patients suspected of PE. Acute recurrent PE was ruled out by an unlikely probability of PE (CDR score ≤4 points) combined with a normal D-dimer test (≤500 ng/ml) or by a normal CT in all other patients. The primary outcome was the incidence of acute recurrent venous thromboembolism during three months of follow-up in patients with normal tests and not treated with anticoagulants. Of 3,306 patients suspected of acute PE, 259 patients (7.8%) had a history of PE of whom 234 were not treated with anticoagulants. The probability of PE was unlikely in 82 of 234 patients (35%), and 42 had a normal D-dimer test (18%), excluding recurrent PE. None of these patients had a thrombotic event during follow-up (0%, 95%CI: 0–6.9). A CT was indicated in all other patients (192) and ruled out recurrent PE in 127 patients (54%). Only one patient with a negative CT had a fatal recurrent PE during follow-up (0.8%; 95%CI: 0.02–4.3). In conclusion, this prospective study demonstrates the safety of ruling out a clinical suspicion of acute recurrent PE by a simple diagnostic algorithm in patients with a history of PE.

Treatment of venous thromboembolism in patients with cancer: Subgroup analysis of the Matisse clinical trials

In the initial treatment of venous thromboembolism (VTE) fondaparinux, a pentasaccharide, is a good alternative to heparin. Whether this is also true for cancer patients is unknown. We performed two post-hoc analyses of two randomized studies to compare efficacy, safety and overall survival of fondaparinux to standard initial (low-molecular-weight) heparin (LMWH) treatment in cancer patients with venous thromboembolism. Two hundred thirty-seven cancer patients with deep venous thrombosis (DVT) were initially treated with fondaparinux or enoxaparin. Two hundred forty cancer patients with pulmonary embolism (PE) received fondaparinux or unfractionated heparin. The initial treatment was followed by vitamin K antagonists. In DVT patients, the three-month recurrence rate was 5.4% in the enoxaparin recipients compared to 12.7% in those treated with fondaparinux [absolute difference 7.3%, 95% CI 0.1, 14.5]. A recurrence was observed in 8.9% of the PE patients treated with fondaparinux compared to 17.2% in the unfractionated heparin recipients [absolute difference –8.3, 95% CI –16.7, 0.1]. In both studies no difference in bleeding and overall survival was observed. Regarding overall survival and bleeding fondaparinux is comparable to enoxaparin and unfractionated heparin in cancer patients. No significant differences in recurrent VTE were observed when comparing fondaparinux with unfractionated or LMWH. Because of study limitations these results should be considered hypothesis-generating.

Idraparinux versus standard therapy in the treatment of deep venous thrombosis in cancer patients: A subgroup analysis of the Van Gogh DVT trial

Standard treatment with heparin followed by vitamin K antagonists is frequently complicated by bleeding and recurrent venous thromboembolism (VTE) in cancer patients with VTE. To compare the efficacy, safety and overall survival of long-term idraparinux treatment to standard therapy in cancer patients we conducted a post-hoc analysis in the subgroup of non-active and active cancer patients included in the Van Gogh DVT clinical trial. The cancer patients with deep venous thrombosis (DVT) and without pulmonary embolism (PE) were randomised to standard treatment or a once-weekly subcutaneous injection of idraparinux (2.5 mg), a synthetic pentasaccharide. 421 cancer patients were included. A total of 220 patients received idraparinux and 201 were allocated to standard therapy for three months (8%) or six months (92%). A recurrent VTE was observed during the first six months in 2.5% (n=5) of the idraparinux recipients compared to 6.4% (n=12) in the standard therapy group (hazard ratio 0.39, 95% confidence interval [CI]; 0.14–1.11). The rate of bleeding was comparable (odds ratio 0.89, 95% CI; 0.50–1.59). The outcomes were similar at three months after randomisation in all patients. Of the idraparinux recipients, 22.7% (n=50) died during the study period compared to 48 patients (23.9%) in the standard treatment group (hazard ratio 0.99, 95% CI; 0.66–1.48). In conclusion, no significant safety or survival differences were observed between cancer patients with DVT treated with idraparinux for six months compared to standard therapy. Fewer recurrent VTEs were observed in the idraparinux group; however, this was not statistically significant and also because of study limitations this should be interpreted with caution.

Optimisation of the diagnostic strategy for suspected deep-vein thrombosis in primary care

Recently, a diagnostic score was developed to safely exclude deep-vein thrombosis (DVT) in primary care. A large prospective study, in which general practitioners used this diagnostic score to decide which patients needed referral, revealed that the number of referrals for ultra-sound measurements was reduced by almost 50%, at the cost of an acceptably low risk (1.4%, 95% confidence interval [CI] 0.6% to 2.9%) of venous thromboembolic events in non-referred patients. However, simple adjustments to the diagnostic score (so-called updating) might further improve the accuracy; i.e. reduce the proportion of missed diagnoses (safety) or increase the proportion of patients who do not need to be referred (efficiency). We applied two updating methods to determine whether adjusting the weights of the predictors or adding new predictors could further improve the accuracy of the diagnostic score. The weights of the predictors did not need to be adjusted, but inclusion of ‘history of DVT’ and ‘prolonged travelling’ significantly added predictive value (p-values 0.014 and 0.023, respectively). However, adding these predictors to the diagnostic score did not improve the safety and efficiency: at equal safety (1.4% missed diagnoses among the non-referred patients), the efficiency was lower (43.5%, 95% CI 40.4% to 46.6% compared to 49.4%, 95% CI 46.3% to 52.5%). The diagnostic score for excluding DVT in primary care has good accuracy in its original form and could not be improved by including additional predictors. This suggests that the original diagnostic score can be used to safely exclude clinically suspected DVT in primary care.

NK cells in self-limited HCV infection exhibit a more extensively differentiated, but not memory-like, repertoire

Natural killer (NK) cells have long been thought of as a purely innate immune cell population, but increasing reports have described developmental and functional qualities of NK cells that are commonly associated with cells of the adaptive immune system. Of these features, the ability of NK cells to acquire functional qualities associated with immunological memory and continuous differentiation resulting in the formation of specific NK cell repertoires has recently been highlighted in viral infection settings. By making use of a unique cohort of monitored, at-risk intravenous drug users in this study, we were able to dissect the phenotypic and functional parameters associated with NK cell differentiation and NK cell memory in patients 3 years after acute HCV infection and either the subsequent self-clearance or progression to chronicity. We observed increased expression of cytolytic mediators and markers CD56^bright and NKp46⁺ of NK cells in patients with chronic, but not self-limited HCV infection. Patients with a self-limited infection expressed higher levels of differentiation-associated markers CD57 and KIRs, and lower levels of NKG2A. A more extensively differentiated NK cell phenotype is associated with self-clearance in HCV patients, while the NK cells of chronic patients exhibited more naïve and effector NK cell phenotypic and functional characteristics. The identification of these distinct NK cell repertoires may shed light on the role NK cells play in determining the outcome of acute HCV infections, and the underlying immunological defects that lead to chronicity.

High-risk human papillomavirus seroprevalence in men and women of six different ethnicities in Amsterdam, the Netherlands: The HELIUS study

Background

Ethnic variations in the (sero)prevalence of Human Papillomavirus (HPV) and HPV related diseases have been observed previously. We explored if high-risk HPV (hrHPV) seropositivity indeed differs among 6 ethnic groups in Amsterdam the Netherlands and assessed if hrHPV seroprevalence is higher among women than men within each ethnic group, both after adjustment for confounders.

Methods

From the multi-ethnic HEalthy Life In an Urban Setting (HELIUS) study in Amsterdam (the Netherlands) we randomly selected 4637 men and women aged 18–44 years with a Dutch, South-Asian Surinamese, African Surinamese, Ghanaian, Moroccan, or Turkish ethnicity. Blood samples were tested for HPV-16,−18,−31,−33,−45,−52, and −58 antibodies using a validated Luminex-based multiplex serology assay. We assessed the association of both ethnicity and gender with hrHPV seropositivity using logistic regression models with generalised estimating equations.

Results

The hrHPV seroprevalence in Dutch, South-Asian Surinamese, African Surinamese, Ghanaian, Moroccan, and Turkish participants was 18%, 12%, 23%, 19%, 17%, and 15% in men, and 30%, 22%, 34%, 31%, 14%, and 15% in women, respectively. HrHPV seroprevalence of non-Dutch men did not differ significantly from Dutch men. HrHPV seroprevalence was significantly higher among African Surinamese women, and significantly lower among Moroccan and Turkish women when compared to Dutch women. These differences were not significant anymore after adjustment for demographic, health, and sexual behavioural differences between ethnicities. HrHPV seroprevalence varied by age, age of sexual debut, and lifetime sexual partners among women but not among men. Seroprevalence of hrHPV was higher among women than among men, except in the Turkish group.

Conclusion

Among women hrHPV seroprevalence differed by ethnicity, yet among men no pronounced differences were observed across ethnicities.

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Women have a higher hrHPV seroprevalence than men, except in the Turkish group.

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Seroprevalence of hrHPV varies by ethnicity among women in Amsterdam.

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Among men no pronounced differences in hrHPV seroprevalence by ethnicity are observed.

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Differences by ethnicity in women are attributable to differences in sexual behaviour.

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HPV serology is not a useful indicator of sexual exposure among heterosexual men.

Acute cardioversion vs a wait-and-see approach for recent-onset symptomatic atrial fibrillation in the emergency department: Rationale and design of the randomized ACWAS trial

BACKGROUND

Current standard of care for patients with recent-onset atrial fibrillation (AF) in the emergency department aims at urgent restoration of sinus rhythm, although paroxysmal AF is a condition that resolves spontaneously within 24 hours in more than 70% of the cases. A wait-and-see approach with rate-control medication only and when needed cardioversion within 48 hours of onset of symptoms is hypothesized to be noninferior, safe, and cost-effective as compared with current standard of care and to lead to a higher quality of life.

DESIGN

The ACWAS trial (NCT02248753) is an investigator-initiated, randomized, controlled, 2-arm noninferiority trial that compares a wait-and-see approach to the standard of care. Consenting adults with recent-onset symptomatic AF in the emergency department without urgent need for cardioversion are eligible for participation. A total of 437 patients will be randomized to either standard care (pharmacologic or electrical cardioversion) or the wait-and-see approach, consisting of symptom reduction through rate control medication until spontaneous conversion is achieved, with the possibility of cardioversion within 48 hours after onset of symptoms. Primary end point is the presence of sinus rhythm on 12-lead electrocardiogram at 4 weeks; main secondary outcomes are adverse events, total medical and societal costs, quality of life, and cost-effectiveness for 1 year.

CONCLUSIONS

The ACWAS trial aims at providing evidence for the use of a wait-and-see approach for patients with recent-onset symptomatic AF in the emergency department.

Low and declining attack rates of imported typhoid fever in the Netherlands 1997-2014, in spite of a restricted vaccination policy

Background

Typhoid fever mainly occurs in (sub) tropical regions where sanitary conditions remain poor. In other regions it occurs mainly among returning travelers or their direct contacts. The aim of this study was to evaluate the current Dutch guidelines for typhoid vaccination.

Method

Crude annual attack rates (AR) per 100,000 Dutch travelers were calculated during the period 1997 to 2014 by dividing the number of typhoid fever cases by the estimated total number of travelers to a specific country or region. Regions of exposure and possible risk factors were evaluated.

Results

During the study period 607 cases of typhoid fever were reported. Most cases were imported from Asia (60%). Almost half of the cases were ethnically related to typhoid risk regions and 37% were cases visiting friends and relatives. The overall ARs for travelers to all regions declined significantly. Countries with the highest ARs were India (29 per 100,000), Indonesia (8 per 100,000), and Morocco (10 per 100,000). There was a significant decline in ARs among travelers to popular travel destinations such as Morocco, Turkey, and Indonesia. ARs among travelers to intermediate-risk areas according to the Dutch guidelines such as Latin America or Sub-Saharan Africa remained very low, despite the restricted vaccination policy for these areas compared to many other guidelines.

Conclusion

The overall AR of typhoid fever among travelers returning to the Netherlands is very low and has declined in the past 20 years. The Dutch vaccination policy not to vaccinate short-term travelers to Latin-America, Sub-Saharan Africa, Thailand and Malaysia seems to be justified, because the ARs for these destinations remain very low. These results suggest that further restriction of the Dutch vaccination policy is justified.