Pulmonary embolism (PE) is a serious and sometimes life-threatening condition that refers to a blood clot that occludes the arteries of the lung. Despite all improvements over the past decades,... Show morePulmonary embolism (PE) is a serious and sometimes life-threatening condition that refers to a blood clot that occludes the arteries of the lung. Despite all improvements over the past decades, diagnosing PE is still a difficult process due to the non-specific symptoms, which can frequently overlap with symptoms of other cardiopulmonary diseases. Currently recommended diagnostic strategies for suspected acute PE consist of standardized assessment of the clinical pre-test probability (CPTP) using validated clinical decision rules (CDRs) and D-dimer testing. PE is considered safely ruled out in patients with a non-high CPTP and a normal D-dimer test. Imaging tests as computed tomography pulmonary angiography (CTPA) are required in the case of a high CPTP and/or abnormal D-dimer test to confirm the diagnosis. The first part of this thesis describes the challenges of diagnosing PE in general and in specific clinically relevant patient subgroups. Moreover, this part evaluates the diagnostic performance of non-invasive diagnostic strategies for suspected PE in specific relevant patient subgroups. The second part of this thesis focuses on venous thrombotic complications in hospitalized patients with COVID-19. Show less
Purpose The 14th Acromegaly Consensus Conference was convened to consider biochemical criteria for acromegaly diagnosis and evaluation of therapeutic efficacy.Methods Fifty-six acromegaly experts... Show morePurpose The 14th Acromegaly Consensus Conference was convened to consider biochemical criteria for acromegaly diagnosis and evaluation of therapeutic efficacy.Methods Fifty-six acromegaly experts from 16 countries reviewed and discussed current evidence focused on biochemical assays; criteria for diagnosis and the role of imaging, pathology, and clinical assessments; consequences of diagnostic delay; criteria for remission and recommendations for follow up; and the value of assessment and monitoring in defining disease progression, selecting appropriate treatments, and maximizing patient outcomes.Results In a patient with typical acromegaly features, insulin-like growth factor (IGF)-I > 1.3 times the upper limit of normal for age confirms the diagnosis. Random growth hormone (GH) measured after overnight fasting may be useful for informing prognosis, but is not required for diagnosis. For patients with equivocal results, IGF-I measurements using the same validated assay can be repeated, and oral glucose tolerance testing might also be useful. Although biochemical remission is the primary assessment of treatment outcome, biochemical findings should be interpreted within the clinical context of acromegaly. Follow up assessments should consider biochemical evaluation of treatment effectiveness, imaging studies evaluating residual/recurrent adenoma mass, and clinical signs and symptoms of acromegaly, its complications, and comorbidities. Referral to a multidisciplinary pituitary center should be considered for patients with equivocal biochemical, pathology, or imaging findings at diagnosis, and for patients insufficiently responsive to standard treatment approaches.Conclusion Consensus recommendations highlight new understandings of disordered GH and IGF-I in patients with acromegaly and the importance of expert management for this rare disease. Show less
BackgroundThe recently published 4-level Pulmonary Embolism Clinical Probability Score (4PEPS) integrates different aspects from currently available diagnostic strategies to further reduce imaging... Show moreBackgroundThe recently published 4-level Pulmonary Embolism Clinical Probability Score (4PEPS) integrates different aspects from currently available diagnostic strategies to further reduce imaging testing in patients with clinically suspected pulmonary embolism (PE).AimTo externally validate the performance of 4PEPS in an independent cohort.MethodsIn this post-hoc analysis of the prospective diagnostic management YEARS study, the primary outcome measures were discrimination, calibration, efficiency (proportion of imaging tests potentially avoided), and failure rate (venous thromboembolism (VTE) diagnosis at baseline or follow-up in patients with a negative 4PEPS algorithm). Multiple imputation was used for missing 4PEPS items. Based on 4PEPS, PE was considered ruled out in patients with a very low clinical pre-test probability (CPTP) without D-dimer testing, in patients with a low CPTP and D-dimer <1000 μg/L, and in patients with a moderate CPP and D-dimer below the age-adjusted threshold.ResultsOf the 3465 patients, 474 (14 %) were diagnosed with VTE at baseline or during 3-month follow-up. Discriminatory performance of the 4PEPS items was good (area under ROC-curve, 0.82; 95%CI, 0.80–0.84) as was calibration. Based on 4PEPS, PE could be considered ruled out without imaging in 58 % (95%CI 57–60) of patients (efficiency), for an overall failure rate of 1.3 % (95%CI 0.86–1.9).ConclusionIn this retrospective external validation, 4PEPS appeared to safely rule out PE with a high efficiency. Nevertheless, although not exceeding the failure rate margin by ISTH standards, the observed failure rate in our analysis appeared to be higher than in the original 4PEPS derivation and validation study. This highlights the importance of a prospective outcome study. Show less
Slobbe, M. van; Haeringen, A. van; Vissers, L.E.L.M.; Bijlsma, E.K.; Rutten, J.W.; Suerink, M.; ... ; Koene, S. 2023
This study aims to inform future genetic reanalysis management by evaluating the yield of whole-exome sequencing (WES) reanalysis in standard patient care in the Netherlands. Single-center data of... Show moreThis study aims to inform future genetic reanalysis management by evaluating the yield of whole-exome sequencing (WES) reanalysis in standard patient care in the Netherlands. Single-center data of 159 patients with a neurodevelopmental disorder (NDD), in which WES analysis and reanalysis were performed between January 1, 2014, and December 31, 2021, was retrospectively collected. Patients were included if they were under the age of 18 years at initial analysis and if this initial analysis did not result in a diagnosis. Demographic, phenotypic, and genotypic characteristics of patients were collected and analyzed. The primary outcomes of our study were (i) diagnostic yield at reanalysis, (ii) reasons for detecting a new possibly causal variant at reanalysis, (iii) unsolicited findings, and (iv) factors associated with positive result of reanalysis. In addition, we conducted a questionnaire study amongst the 7 genetic department in the Netherlands creating an overview of used techniques, yield, and organization of WES reanalysis. The single-center data show that in most cases, WES reanalysis was initiated by the clinical geneticist (65%) or treating physician (30%). The mean time between initial WES analysis and reanalysis was 3.7 years. A new (likely) pathogenic variant or VUS with a clear link to the phenotype was found in 20 initially negative cases, resulting in a diagnostic yield of 12.6%. In 75% of these patients, the diagnosis had clinical consequences, as for example, a screening plan for associated signs and symptoms could be devised. Most (32%) of the (likely) causal variants identified at WES reanalysis were discovered due to a newly described gene-disease association. In addition to the 12.6% diagnostic yield based on new diagnoses, reclassification of a variant of uncertain significance found at initial analysis led to a definite diagnosis in three patients. Diagnostic yield was higher in patients with dysmorphic features compared to patients without clear dysmorphic features (yield 27% vs. 6%; p = 0.001).Conclusions: Our results show that WES reanalysis in patients with NDD in standard patient care leads to a substantial increase in genetic diagnoses. In the majority of newly diagnosed patients, the diagnosis had clinical consequences. Knowledge about the clinical impact of WES reanalysis, clinical characteristics associated with higher yield, and the yield per year after a negative WES in larger clinical cohorts is warranted to inform guidelines for genetic reanalysis. These guidelines will be of great value for pediatricians, pediatric rehabilitation specialists, and pediatric neurologists in daily care of patients with NDD. Show less
With back pain as one of the most common complaints in the population and with no single disease feature with sufficient sensitivity and specificity to diagnose axial spondyloarthritis (axSpA) on... Show moreWith back pain as one of the most common complaints in the population and with no single disease feature with sufficient sensitivity and specificity to diagnose axial spondyloarthritis (axSpA) on its own, diagnosing axSpA can be challenging. In this article, we discuss clinical, laboratory, and imaging spondyloarthritis features that can be used in diagnosis and explain the general principles underlying an axSpA diagnosis. Moreover, we discuss three pitfalls to avoid when diagnosing axSpA: i) using classification criteria as diagnostic criteria, ii) making a diagnosis by simple counting of spondyloarthritis features, and iii) overreliance on imaging findings. Finally, we have some advice on how to build diagnostic skills and discuss new developments that may help facilitate the diagnosis of axSpA in the future.(c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons. org/licenses/by/4.0/). Show less
Delgado, V.; Marsan, N.; Waha, S. de; Bonaros, N.; Brida, M.; Burri, H.; ... ; ESC Sci Document Grp 2023
This paper aims to improve the diagnosis of syncope and transient loss of consciousness (TLOC) in children. Diagnostic problems stem, first, from some causes spanning various disciplines, e.g.... Show moreThis paper aims to improve the diagnosis of syncope and transient loss of consciousness (TLOC) in children. Diagnostic problems stem, first, from some causes spanning various disciplines, e.g. cardiology, neurology and psychiatry, while the most common cause, vasovagal syncope, is not embraced by any specialty. Second, clinical variability is huge with overlapping signs and symptoms. Third, the approach to TLOC/syncope of the European Society of Cardiology (ESC) is underused in childcare. We explain the ESC guidelines using an additional paediatric literature review. Classification of TLOC and syncope is hierarchic and based on history taking. Loss of consciousness (LOC) is defined using three features: abnormal motor control including falling, reduced responsiveness and amnesia. Adding a < 5 min duration and spontaneous recovery defines TLOC. TLOC simplifies diagnosis by excluding long LOC (e.g. some trauma, intoxications and hypoglycaemia) and focussing on syncope, tonic-clonic seizures and functional TLOC. Syncope, i.e. TLOC due to cerebral hypoperfusion, is divided into reflex syncope (mostly vasovagal), orthostatic hypotension (mostly initial orthostatic hypotension in adolescents) and cardiac syncope (arrhythmias and structural cardiac disorders). The initial investigation comprises history taking, physical examination and ECG; the value of orthostatic blood pressure measurement is unproven in children but probably low. When this fails to yield a diagnosis, cardiac risk factors are assessed; important clues are supine syncope, syncope during exercise, early death in relatives and ECG abnormalities.Conclusions: In adults, the application of the ESC guidelines reduced the number of absent diagnoses and costs; we hope this also holds for children. Show less
Ginkel, N. van; Gennep, E.J. van; Oosterbaan, L.; Greidanus, J.; Boellaard, T.N.; Wondergem, M.; ... ; Mertens, L.S. 2023
The value of 18F-fluorodeoxyglucose positron-emission-tomography-computed tomography (FDG-PET/CT) for staging patients with (very) high-risk non-muscle invasive bladder cancer (NMIBC) is unknown.... Show moreThe value of 18F-fluorodeoxyglucose positron-emission-tomography-computed tomography (FDG-PET/CT) for staging patients with (very) high-risk non-muscle invasive bladder cancer (NMIBC) is unknown. In this study among NMIBC patients referred for RC, FDG-PET/CT detected metastases that were not detected by CT, leading to treatment changes in 10% of patients. However, the use of FDG-PET/CT should be weighed against its disad-vantages, including false-positive lesions. Introduction and Objectives: 18F-fluorodeoxyglucose positron-emission tomography-computed tomography (FDG-PET/CT) is increasingly used in the preoperative staging of patients with muscle-invasive bladder cancer. The clinical added value of FDG-PET/CT in high-risk non-muscle invasive bladder cancer (NMIBC) is unknown. In this study, the value of FDG-PET/CT in addition to contrast enhanced (CE)-CT was evaluated in high-risk NMIBC before radical cystec-tomy (RC). Materials and Methods: This is a retrospective analysis of consecutive patients with high risk and very-high risk urothelial NMIBC scheduled for RC in a tertiary referral center between 2011 and 2020. Patients underwent staging with CE-CT (chest and abdomen/pelvis) and FDG-PET/CT. We assessed the clinical disease stage before and after FDG-PET/CT and the treatment recommendation based on the stage before and after FDG-PET/CT. The accuracy of CT and FDG-PET/CT for identifying metastatic disease was defined by the receiver-operating curve using a reference -standard including histopathology/cytology (if available), imaging and follow-up. Results: A total of 92 patients were identified (median age: 71 years). In 14/92 (15%) patients, FDG-PET/CT detected metastasis (12 suspicious lymph nodes and 4 distant metastases). The disease stage changed in 11/92 (12%) patients based on additional FDG-PET/CT findings. FDG-PET/CT led to a different treatment in 9/92 (10%) patients. According to the reference standard, 25/92 (27%) patients had metastases. The sensitivit y, specificit y and accuracy of FDG-PET/CT was 36%, 93% and 77% respectively, versus 12%, 97% and 74% of CE-CT only. The area under the ROC curve was 0.643 for FDG-PET/CT and 0.545 for CT, P = .036. Conclusion: The addition of FDG-PET/CT to CE-CT imaging changed the treatment in 10% of patients and proved to be a valuable diagnostic tool in a selected subgroup of NMIBC patients scheduled for RC. Show less
There are long-standing unsolved issues regarding the diagnosis and classification of central disorders of hypersomnolence. These include delineating and identifying phenotypes and unique... Show moreThere are long-standing unsolved issues regarding the diagnosis and classification of central disorders of hypersomnolence. These include delineating and identifying phenotypes and unique conditions (“sui generis”), sleep deprivation’s impact on phenotypes and how to separate sleep deprivation as a trigger from other causes, as well as the association of excessive sleepiness with other disorders. We discuss these issues and present a novel, straightforward classification system with consistent terminology to get out of the impasse and do justice to people with hypersomnolence. Show less
BackgroundOwing to the rarity and heterogeneity in biology and presentation, there are multiple areas in the diagnosis, treatment and follow-up of soft tissue sarcoma (STS), with no, low-level or... Show moreBackgroundOwing to the rarity and heterogeneity in biology and presentation, there are multiple areas in the diagnosis, treatment and follow-up of soft tissue sarcoma (STS), with no, low-level or conflicting evidence.MethodsDuring the first Consensus Conference on the State of Science in Sarcoma (CSSS), we used a modified Delphi process to identify areas of controversy in the field of sarcoma, to name topics with limited evidence-based data in which a scientific and knowledge gap may remain and a consensus statement will help to guide patient management. We determined scientific questions which need to be addressed in the future in order to generate evidence and to inform physicians and caregivers in daily clinical practice in order to improve the outcomes of patients with sarcoma.We conducted a vote on STS key questions and controversies prior to the CSSS meeting, which took place in May 2022.ResultsSixty-two European sarcoma experts participated in the survey.Sixteen strong consensus (≥95%) items were identified by the experts, as well as 30 items with a ≥75% consensus on diagnostic and therapeutic questions. Ultimately, many controversy topics remained without consensus.ConclusionsIn this manuscript, we summarise the voting results and the discussion during the CSSS meeting. Future scientific questions, priorities for clinical trials, registries, quality assurance, and action by stakeholders are proposed. Platforms and partnerships can support innovative approaches to improve management and clinical research in STS. Show less
Research on the prevalence, diagnostic and prognostic value for treatment of personality pathology – i.e., both personality disorders and problematic personality characteristics – was... Show more Research on the prevalence, diagnostic and prognostic value for treatment of personality pathology – i.e., both personality disorders and problematic personality characteristics – was carried out within a mainly Dutch forensic mental health setting. Issues such as (dis)simulation and unintentional self-deception limit the utility of self-report instruments within a pre-trial setting. Personality disorders and psychopathic traits in suspected offenders in the Netherlands often lead to court rulings of enforced psychiatric treatment – an internationally unique situation. A prospective study on the predictive value of personality disorder isolated factors that can affect enforced treatment length, such as crime type and comorbidity, that can be a focus for policy makers and forensic mental health experts. Caution is advised when using self-report instruments within the forensic context, especially in the absence of response bias scales and in the case of (legal) incentives for certain outcomes. There is urgent need for international standardization of instruments and terminology and a test battery that is specifically designed for and validated within forensic populations. An increase in (detail of) digital registration of patient, treatment and risk characteristics is necessary for meaningful scientific research, a better assessment of personality and risks, fewer incidents, lower recidivism and shorter treatment. Show less
This thesis consists of a number of studies revolving around the leading research theme, i.e., the derivation of new vectorcardiographic diagnostic & prognostic information from the 12-lead... Show moreThis thesis consists of a number of studies revolving around the leading research theme, i.e., the derivation of new vectorcardiographic diagnostic & prognostic information from the 12-lead electrocardiogram (ECG). Various research questions have been addressed, but most studies use a similar data processing approach, consisting of initial mathematical synthesis of a vectorcardiogram (VCG) from a standard 12-lead ECG, followed by the measurement of general VCG characteristics like maximal QRS- and T vectors, QRS- and T integrals, the spatial QRS-T angle (SA) and the ventricular gradient (VG). Studies focus on methodological as well as on clinical issues, and are discussed in the thesis. Show less
Distale radius fracturen komen veel voor. Bij ongeveer de helft van de distale radius fracturen komt een processus styloideus ulnae (PSU, distale ulna fractuur) voor. Een PSU fractuur is een... Show moreDistale radius fracturen komen veel voor. Bij ongeveer de helft van de distale radius fracturen komt een processus styloideus ulnae (PSU, distale ulna fractuur) voor. Een PSU fractuur is een indicator voor toegenomen instabiliteit. In een meta-analyse wordt geen verschil aangetoond in uitkomst van een distale radius fracturen met of zonder PSU fractuur. Hetzelfde geldt voor het al dan niet vastgroeien van het PSU. In ongeveer 33% van de distale radius fracturen komt distale radioulnaire (DRU) instabiliteit voor. Klinische testen en radiologische onderzoeken om dit te diagnosticeren zijn weinig betrouwbaar. Een CT-scan additioneel aan een r_ntgenfoto zorgt niet voor toename in overeenstemming over de uitslag. De overeenstemming tussen beoordelaars van CT-scans valt tegen, naast een grote normale spreiding. Wanneer DRU instabiliteit gediagnostiseerd is, zal de ossale anatomie genormaliseerd moeten worden. In dit proefschrift worden operatie-technieken beschreven die veilig en effectief zijn voor het oplossen van DRU instabiliteit. De auteur concludeert dat DRU instabiliteit een diagnostisch dilemma is. Onderzoek zal zich moeten richten op individuele normaalwaarden, zodat de diagnose makkelijker te stellen is. De aanbeveling wordt gedaan dat distale radius fracturen behandeld dienen te worden door gespecialiseerde teams zodat de complicaties beperkt blijven en indien nodig herkend en optimaal behandeld worden. Show less
Venous thromboembolism is a common disease that can lead to potential fatal complications. The diagnosis and treatment of a first venous thromboembolism has been well studied, however the... Show moreVenous thromboembolism is a common disease that can lead to potential fatal complications. The diagnosis and treatment of a first venous thromboembolism has been well studied, however the diagnostic management and therapy of recurrent venous thromboembolism still have limitations. This thesis discusses a new imaging technique for recurrent deep venous thrombosis and the duration of treatment after a recurrent venous thromboembolism. It shows that Magnetic Resonance Direct Thrombus Imaging might be a potential diagnostic tool for the diagnostic management of recurrent venous thromboembolism. Furthermore the prognosis after a first deep vein thrombosis is discussed by means of recurrence and bleeding risks. Show less
Spondyloarthritis (SpA) is a heterogeneous group of rheumatic diseases, characterized by sacroiliac-joint inflammation (sacroiliitis), peripheral and extra-articular complaints. The lack of... Show moreSpondyloarthritis (SpA) is a heterogeneous group of rheumatic diseases, characterized by sacroiliac-joint inflammation (sacroiliitis), peripheral and extra-articular complaints. The lack of diagnostic criteria makes diagnosing SpA challenging, yet, classification criteria are available. We tested the performance (sensitivity, specificity) of various classification criteria; the recently developed Assessment of SpondyloArthritis international Society (ASAS) criteria outperformed all other criteria. We investigated the discrepancies in interpretation MRIs and conventional radiographs on the presence of sacroiliitis; agreement on radiographic sacroiliitis between different readers is only moderate, but agreement regarding sacroiliitis on MRI is substantial. Rheumatologists take into account all clinical and laboratory results in addition to the imaging results in the diagnostic process. The diagnostic Berlin algorithm - in which all relevant results are taken into account __ can assist rheumatologists. We proposed a modification of this algorithm, which is accepted by ASAS and also included in the recently published guidelines for the diagnosis and treatment of SpA by the Dutch Society for Rheumatology. Besides, we performed systematic literature reviews, forming the base for the update of the ASAS management recommendations. With these results, SpA-patients can be recognized earlier, offering better treatment options and better outcomes. However, further improvements of care for SpA-patients are necessary. Show less
Since a decade, Clostridium difficile infection (CDI) has increased progressively in incidence and severity of disease. Currently, CDI is considered the leading cause of nosocomial diarrhoea,... Show moreSince a decade, Clostridium difficile infection (CDI) has increased progressively in incidence and severity of disease. Currently, CDI is considered the leading cause of nosocomial diarrhoea, associated with an increased duration of hospitalization, healthcare expenses, morbidity and mortality. This thesis describes our findings with outbreak control, diagnosis, identification of specific risk factors and treatment of CDI after the discovery of the emergence of C. difficile PCR-ribotype 027 in the Netherlands. The studies illustrate the role of antibiotics in relation to persistence, severeness and spreading of CDI. Antibiotics are shown to be a primary risk factor for the development of (ribotype-specific) CDI and an essential part of the outbreak control measures (__bundle-approach__), namely antibiotic stewardship. The use of antibacterials is a risk for selection of novel endemic C. difficile strains in e.g. animals, which introduce an increasing risk of alternative zoonotic transmission routes. Except for very mild CDI, which is clearly induced by usage of specific antibiotics, antibacterial treatment is advised. This thesis reviews the comparative effectiveness of the currently available treatment modalities, thereby providing evidence-based recommendations for CDI remedies. Treatment options include: oral and non-oral antibiotics, toxin-binding resins and polymers, immunotherapy, probiotics, faecal or bacterial intestinal transplantation. Show less
In conclusion, the results of the present studies show how schizotypal symptoms may develop following child psychiatric psychopathology and how these symptoms unfavorably influence a persons__... Show moreIn conclusion, the results of the present studies show how schizotypal symptoms may develop following child psychiatric psychopathology and how these symptoms unfavorably influence a persons__ quality of life. It is important for clinicians to be aware of the complex dynamics of psychopathology and the higher risk for adult schizotypal symptomatology following behavioral problems and psychiatric disorders at child and adolescent age. Show less
The objectives of this thesis are to simplify, to validate and compare diagnostic strategies in patients with clinical suspicion of acute pulmonary embolism (PE). The revised Geneva score was... Show moreThe objectives of this thesis are to simplify, to validate and compare diagnostic strategies in patients with clinical suspicion of acute pulmonary embolism (PE). The revised Geneva score was simplified and validated. Furthermore, four widely used clinical decision rules (CDRs) were directly compared in excluding PE. It was concluded that the four CDRs in combination with a D-dimer test performed similarly in the exclusion of acute PE. And we confirmed that a normal CT-scan alone can safely exclude PE in patients in whom CTPA is required to rule out VTE in these patients. We showed that the algorithm consisting of a CRD, D-dimer test and CT-scan is also effective in the management of patients with clinically suspected recurrent acute PE. In addition, the role of NT-pro-BNP has been evaluated for the risk assessment for adverse clinical outcome for patients with proven acute PE and we showed the ability to distinguish an increased risk with elevated NT-pro-BNP values for complications during the hospital stay and 30-day mortality. Finally, it is concluded that home treatment with anticoagulant seems effective and safe in patients with acute PE, when selected according to pre defined criteria. Show less
The current health care system is severely challenged by for instance rising costs, fewer new blockbuster drugs and increasing numbers of hospitalizations due to side effects. Especially in the... Show moreThe current health care system is severely challenged by for instance rising costs, fewer new blockbuster drugs and increasing numbers of hospitalizations due to side effects. Especially in the area of chronic diseases the current disease fighting strategy is failing and a more personalized medicine approach is needed. In this thesis new sub-types of rheumatoid arthritis are characterized with metabolomics analysis and symptoms patterns. The sub-types are based on diagnostic knowledge from Chinese medicine. The two sub-types of RA patients were found to have differences in apoptosis regulation of T-cells and differences in urine acylcarnitine levels. A questionnaire was designed to distinguish the two sub-types and to evaluate symptom patterns of arthritis patients. In the future the response to treatment of these sub-types of patients can be studied and specific treatment can be targeted to these sub-types. Show less
In this dissertation we present the results of our research on Helicobacter pylori infections in childhood, focusing on the prevalence, diagnosis and treatment of the infection. Our studies were... Show moreIn this dissertation we present the results of our research on Helicobacter pylori infections in childhood, focusing on the prevalence, diagnosis and treatment of the infection. Our studies were conducted in the Netherlands, Europe and Indonesia. We discuss diagnostic tests, therapeutic regimens, resistance and preventive measurements. We highlight clinical and pathophysiological aspects of the infection and describe which particular strains are prevalent and how transmission occurs. Presently, there are no established correlations between a Helicobacter pylori infection and recurrent abdominal pain, gastroesophageal reflux disease or growth retardation. We present data on the prevalence of Helicobacter pylori in young infants in the Netherlands and observe that children with at least one non-Dutch parent form a risk group. We assess risk factors in a Europe-wide study on gastroduodenal erosions and ulcers in childhood. In our study, Helicobacter pylori infection and gastrotoxic medications were relatively little implicated as etiology of that pathology. The prevalence of Helicobacter pylori infection in Indonesian young children is relatively high and points at an early acquisition of the infection. Finally, the resistance of Helicobacter pylori to clarithromycin and metronidazole was assessed for adults and children in the Netherlands. Low resistance rates were found, but the resistance in adults is increasing. We conclude that a test-and-treat regimen is justified for the Netherlands. Show less