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Wastewater-based epidemiological surveillance at municipal wastewater treatment plants has proven to play an important role in COVID-19 surveillance. Considering international passenger hubs contribute extensively to global transmission of viruses, wastewater surveillance at this type of location may be of added value as well. The aim of this study is to explore the potential of long-term wastewater surveillance at a large passenger hub as an additional tool for public health surveillance during different stages of a pandemic. Here, we present an analysis of SARS-CoV-2 viral loads in airport wastewater by reverse-transcription quantitative polymerase chain reaction (RT-qPCR) from the beginning of the COVID-19 pandemic in Feb 2020, and an analysis of SARS-CoV-2 variants by whole-genome next-generation sequencing from Sep 2020, both until Sep 2022, in the Netherlands. Results are contextualized using (inter)national measures and data sources such as passenger numbers, clinical surveillance data and national wastewater surveillance data. Our findings show that wastewater surveillance was possible throughout the study period, irrespective of measures, as viral loads were detected and quantified in 98.6 % (273/277) of samples. Emergence of SARS-CoV-2 variants, identified in 91.0 % (161/177) of sequenced samples, coincided with increases in viral loads. Furthermore, trends in viral load and variant detection in airport wastewater closely followed, and in some cases preceded, trends in national daily average viral load in wastewater and variants detected in clinical surveillance. Wastewater-based epidemiology at a large international airport is a valuable addition to classical COVID-19 surveillance and the developed expertise can be applied in pandemic preparedness plans for other (emerging) pathogens in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: Surveillance of acute respiratory infections (ARI) in the Netherlands and other European countries is based mostly on primary care data, with little insight into the severe spectrum of the disease. We compared time-trends for ARI in secondary care with influenza-like illness (ILI), ARI and pneumonia in primary care, and crude mortality, in order to assess the value of routinely collected data on respiratory infections in hospitals and the added value of severe acute respiratory infections (SARI) surveillance., Methods: We calculated incidence of ARI in secondary care, ILI, ARI, and pneumonia in primary care, and crude mortality using five historical databases (2008-2016)., Results: Over eight years, seasonal incidence peaks of ARI in secondary care occurred earlier than ILI and ARI incidence peaks in primary care, except during the 2009 influenza A(H1N1) pandemic and post-pandemic season. The median time-lag between ARI in secondary care and ILI, ARI and pneumonia in primary care was 6.5 weeks, 7 weeks, and 1 week, respectively. Crude mortality lagged a median 5 weeks behind ARI in secondary care., Conclusion: This observational study demonstrates that routinely collected data can be used for describing trends of ARI in secondary care and may be suitable for near real-time SARI surveillance. In most seasons, the incidence peaks for ARI in secondary care preceded the peaks in primary care and crude mortality with a considerable time-lag. It would be of great value to add microbiological test results to the incidence data to better explain the difference in time-lag between these surveillance systems.

Objectives: The benefit of oseltamivir treatment in patients admitted with influenza virus infection and the design of studies addressing this issue have been questioned extensively. As the burden of influenza disease is substantial and oseltamivir treatment is biologically plausible, this study assessed the clinical benefit of oseltamivir treatment in adult patients admitted with severe seasonal influenza virus infection in daily practice., Patients and Methods: A multi-centre, retrospective cohort study was conducted to compare the effectiveness of treatment with and without oseltamivir <48 h after admission in patients admitted with laboratory-confirmed influenza virus infection in three large hospitals in the Netherlands. Propensity score matching was used to compare clinically relevant outcome variables., Results: In total, 390 patients were included in this study, of whom 80% had comorbidities. Thirty-day mortality, as well as the composite endpoint of 30-day mortality or intensive care unit admission >48 h after admission, were reduced by 9% (P=0.04) and 11% (P=0.02), respectively. Length of hospital stay and in-hospital mortality rates all showed a trend towards reduction. The median duration between symptom onset and initiation of treatment was 3 days., Conclusions: This study supports that, in daily practice, patients admitted with influenza virus infection should be treated with oseltamivir within 48 h of admission, even if they have had complaints for >48 h., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: Influenza virus infections cause a high disease and economic burden during seasonal epidemics. However, there is still a need for reliable disease burden estimates to provide a more detailed picture of the impact of influenza. Therefore, the objectives of this study is to estimate the incidence of hospitalisation for influenza virus infection and associated hospitalisation costs in adult patients in the Netherlands during two consecutive influenza seasons., Methods: We conducted a retrospective study in adult patients with a laboratory confirmed influenza virus infection in three Dutch hospitals during respiratory seasons 2014-2015 and 2015-2016. Incidence was calculated as the weekly number of hospitalised influenza patients divided by the total population in the catchment populations of the three hospitals. Arithmetic mean hospitalisation costs per patient were estimated and included costs for emergency department consultation, diagnostics, general ward and/or intensive care unit admission, isolation, antibiotic and/or antiviral treatment. These hospitalisation costs were extrapolated to national level and expressed in 2017 euros., Results: The study population consisted of 380 hospitalised adult influenza patients. The seasonal cumulative incidence was 3.5 cases per 10,000 persons in respiratory season 2014-2015, compared to 1.8 cases per 10,000 persons in 2015-2016. The arithmetic mean hospitalisation cost per influenza patient was €6128 (95% CI €4934-€7737) per patient in 2014-2015 and €8280 (95% CI €6254-€10,665) in 2015-2016, potentially reaching total hospitalisation costs of €28 million in 2014-2015 and €20 million in 2015-2016., Conclusions: Influenza virus infections lead to 1.8-3.5 hospitalised patients per 10,000 persons, with mean hospitalisation costs of €6100-€8300 per adult patient, resulting in 20-28 million euros annually in The Netherlands. The highest arithmetic mean hospitalisation costs per patient were found in the 45-64 year age group. These influenza burden estimates could be used for future influenza cost-effectiveness and impact studies.

The national vaccination rate in young children in the Netherlands has decreased in recent years. This has led to social and political discussions, for instance about compulsory vaccination for children in child-care. The national commission on child-care and vaccination has advised that vaccination should be made compulsory when the rate of vaccination has declined to a pre-determined lower threshold, to be determined by the government. A frequently quoted lower threshold is 95%. The idea behind this is the concept of a critical vaccination rate, a threshold needed for elimination of an infection in a large, well-mixed population. In this article we argue why the critical vaccination rate does not offer a scientific basis for a lower threshold to the national vaccination rate.

In 2019, 1 in 4 deaths was caused by infectious diseases. In addition to the big 3 - HIV, malaria and tuberculosis - these diseases are mainly respiratory infections, infectious diarrhoea and sepsis. The burden of disease caused by infections also remains high in the Netherlands. This could still get worse because of several factors: ageing, 'vaccination doubts', increased use of immunosuppressive drugs, increased mobility of people and globalisation of food chains. Global warming also affects the spread of pathogens and disease vectors. Pathogens have an impressive ability to adapt and, for example, to develop resistance to antimicrobial agents. In order to cope with these threats, we would do well to consider the emergence of new infectious diseases as well as the threat of old ones. What can we learn from decades past? Why do new infections keep emerging? What does the future look like?

Background: There are many prognostic models and scoring systems in use to predict mortality in ICU patients. The only general ICU scoring system developed and validated for patients after cardiac surgery is the APACHE-IV model. This is, however, a labor-intensive scoring system requiring a lot of data and could therefore be prone to error. The SOFA score on the other hand is a simpler system, has been widely used in ICUs and could be a good alternative. The goal of the study was to compare the SOFA score with the APACHE-IV and other ICU prediction models., Methods: We investigated, in a large cohort of cardiac surgery patients admitted to Dutch ICUs, how well the SOFA score from the first 24 h after admission, predict hospital and ICU mortality in comparison with other recalibrated general ICU scoring systems. Measures of discrimination, accuracy, and calibration (area under the receiver operating characteristic curve (AUC), Brier score, R 2 , and Ĉ-statistic) were calculated using bootstrapping. The cohort consisted of 36,632 Patients from the Dutch National Intensive Care Evaluation (NICE) registry having had a cardiac surgery procedure for which ICU admission was necessary between January 1st, 2006 and June 31st, 2018., Results: Discrimination of the SOFA-, APACHE-IV-, APACHE-II-, SAPS-II-, MPM 24 -II - models to predict hospital mortality was good with an AUC of respectively: 0.809, 0.851, 0.830, 0.850, 0.801. Discrimination of the SOFA-, APACHE-IV-, APACHE-II-, SAPS-II-, MPM 24 -II - models to predict ICU mortality was slightly better with AUCs of respectively: 0.809, 0.906, 0.892, 0.919, 0.862. Calibration of the models was generally poor., Conclusion: Although the SOFA score had a good discriminatory power for hospital- and ICU mortality the discriminatory power of the APACHE-IV and SAPS-II was better. The SOFA score should not be preferred as mortality prediction model above traditional prognostic ICU-models.

Leprosy is a human infectious disease caused by Mycobacterium leprae or Mycobacterium lepromatosis that can also occur in animals and even manifest as zoonosis. Recently, both mycobacteria were detected in red squirrels (Sciurus vulgaris) from the British Isles. To further explore the presence of leprosy bacilli in North-West Europe, we screened Belgian and Dutch squirrels. Tissue samples from 115 animals tested by qPCR were negative for both pathogens. No molecular or pathological evidence was found of the presence of these zoonotic pathogens in North-West Europe., (© 2019 Blackwell Verlag GmbH.)

Background: Diagnosing pneumonia can be challenging in general practice but is essential to distinguish from other respiratory tract infections because of treatment choice and outcome prediction. We determined predictive signs, symptoms and biomarkers for the presence of pneumonia in patients with acute respiratory tract infection in primary care., Methods: From March 2012 until May 2016 we did a prospective observational cohort study in three radiology departments in the Leiden-The Hague area, The Netherlands. From adult patients we collected clinical characteristics and biomarkers, chest X ray results and outcome. To assess the predictive value of C-reactive protein (CRP), procalcitonin and midregional pro-adrenomedullin for pneumonia, univariate and multivariate binary logistic regression were used to determine risk factors and to develop a prediction model., Results: Two hundred forty-nine patients were included of whom 30 (12%) displayed a consolidation on chest X ray. Absence of runny nose and whether or not a patient felt ill were independent predictors for pneumonia. CRP predicts pneumonia better than the other biomarkers but adding CRP to the clinical model did not improve classification (- 4%); however, CRP helped guidance of the decision which patients should be given antibiotics., Conclusions: Adding CRP measurements to a clinical model in selected patients with an acute respiratory infection does not improve prediction of pneumonia, but does help in giving guidance on which patients to treat with antibiotics. Our findings put the use of biomarkers and chest X ray in diagnosing pneumonia and for treatment decisions into some perspective for general practitioners.

Background: In patients with an acute lower respiratory tract infection (LRTI), general practitioners (GPs) often find it challenging to decide to prescribe antibiotics or not. C-reactive protein (CRP) point of care test (POCT), and chest X-ray are diagnostic tests that can optimize the treatment decision. However, their usefulness in clinical practice is unknown. Objectives: To determine the proportion of Dutch GPs using CRP and chest X-ray in patients with an acute LRTI. To determine whether clinical factors and C-reactive protein point of care test affect the behaviour in requesting chest X-rays. Methods: In 2014, a questionnaire was sent to a random sample of 900 Dutch GPs. Outcome parameters are the use of CRP and chest X-ray, the percentage of GPs who guide their decision in requesting chest X-rays by CRP testing and the GP's expectation regarding presence or absence of pneumonia. In addition, considerations for requesting chest X-rays were assessed. Results: Two hundred and fifty-five completed questionnaires (29%) were returned. In 2014, 54% of the responding GPs used the CRP test. These GPs tend to use fewer chest X-rays ( p  = 0.07). GPs overestimate the chance that pneumonia will be present on the radiograph. Seventy percent consider the possibility of abnormalities other than pneumonia as the main reason for requesting a chest X-ray. Conclusion: In patients with an acute lower respiratory tract infection, GPs report that CRP results affect their behaviour regarding the request of a chest X-ray in patients with lower respiratory tract infection and therefore research is needed to substantiate the use of these diagnostic tools for this purpose.

Background: The inflammatory response in pneumococcal infection is primarily driven by immunoreactive bacterial cell wall components [lipoteichoic acid (LTA)]. An acute release of these components occurs when pneumococcal infection is treated with β-lactam antibiotics., Objectives: We hypothesized that non-lytic rifampicin compared with lytic β-lactam antibiotic treatment would attenuate the inflammatory response in patients with pneumococcal pneumonia., Methods: In the PRISTINE (Pneumonia treated with RIfampicin aTtenuates INflammation) trial, a randomized, therapeutic controlled, exploratory study in patients with community-acquired pneumococcal pneumonia, we looked at LTA release and inflammatory and clinical response during treatment with both rifampicin and β-lactam compared with treatment with β-lactam antibiotics only. The trial is registered in the Dutch trial registry, number NTR3751 (European Clinical Trials Database number 2012-003067-22)., Results: Forty-one patients with community-acquired pneumonia were included; 17 of them had pneumococcal pneumonia. LTA release, LTA-mediated inflammatory responses, clinical outcomes, inflammatory biomarkers and transcription profiles were not different between treatment groups., Conclusions: The PRISTINE study demonstrated the feasibility of adding rifampicin to β-lactam antibiotics in the treatment of community-acquired pneumococcal pneumonia, but, despite solid in vitro and experimental animal research evidence, failed to demonstrate a difference in plasma LTA concentrations and subsequent inflammatory and clinical responses. Most likely, an inhibitory effect of human plasma contributes to the low immune response in these patients. In addition, LTA plasma concentration could be too low to mount a response via Toll-like receptor 2 in vitro, but may nonetheless have an effect in vivo., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.)

Seven hospitals participated in the Dutch national surveillance for ventilator-associated pneumonia (VAP) and its risk factors. We analysed time-independent and time-dependent risk factors for VAP using the standard Cox regression and the flexible Weighted Cumulative Effects method (WCE) that evaluates both current and past exposures. The prospective surveillance of intensive care patients aged ≥16 years and ventilated ≥48 hours resulted in the inclusion of 940 primary ventilation periods, comprising 7872 ventilation days. The average VAP incidence density was 10.3/1000 ventilation days. Independent risk factors were age (16-40 years at increased risk: HR 2.42 95% confidence interval 1.07-5.50), COPD (HR 0.19 [0.04-0.78]), current sedation score (higher scores at increased risk), current selective oropharyngeal decontamination (HR 0.19 [0.04-0.91]), jet nebulizer (WCE, decreased risk), intravenous antibiotics for selective decontamination of the digestive tract (ivSDD, WCE, decreased risk), and intravenous antibiotics not for SDD (WCE, decreased risk). The protective effect of ivSDD was afforded for 24 days with a delay of 3 days. For some time-dependent variables, the WCE model was preferable over standard Cox proportional hazard regression. The WCE method can furthermore increase insight into the active time frame and possible delay herein of a time-dependent risk factor., Competing Interests: The authors have declared that no competing interests exist.

Background: A reduction in duration of antibiotic therapy is crucial in minimizing the development of antimicrobial resistance, drug-related side effects and health care costs. The minimal effective duration of antimicrobial therapy for febrile urinary tract infections (fUTI) remains a topic of uncertainty, especially in male patients, those of older age or with comorbidities. Biomarkers have the potential to objectively identify the optimal moment for cessation of therapy., Methods: A secondary analysis of a randomized placebo-controlled trial among 35 primary care centers and 7 emergency departments of regional hospitals in the Netherlands. Women and men aged ≥18 years with a diagnosis of fUTI were randomly assigned to receive antibiotic treatment for 7 or 14 days. Patients indicated to receive antimicrobial treatment for more than 14 days were excluded from randomization. The biomarkers procalcitonin (PCT), mid-regional proadrenomedullin (MR-proADM), and C-reactive protein (CRP) were compared in their ability to predict clinical cure or failure through the 10-18 day post-treatment visit., Results: Biomarker concentrations were measured in 249 patients, with a clinical cure rate of 94% in the 165 randomized and 88% in the 84 non-randomized patients. PCT, MR-proADM and CRP concentrations did not differ between patients with clinical cure and treatment failure, and did not predict treatment outcome, irrespective of 7 or 14 day treatment duration (ROC AUC 0.521; 0.515; 0.512, respectively). PCT concentrations at presentation were positively correlated with bacteraemia (τ = 0.33, p < 0.001) and presence of shaking chills (τ = 0.25, p < 0.001), and MR-proADM levels with length of hospital stay (τ = 0.40, p < 0.001), bacteraemia (τ = 0.33, p < 0.001), initial intravenous treatment (τ = 0.22, p < 0.001) and time to defervescence (τ = 0.21, p < 0.001). CRP did not display any correlation to relevant clinical parameters., Conclusions: Although the biomarkers PCT and MR-proADM were correlated to clinical parameters indicating disease severity, they did not predict treatment outcome in patients with community acquired febrile urinary tract infection who were treated for either 7 or 14 days. CRP had no added value in the management of patients with fUTI., Trial Registration: The study was registered at ClinicalTrials.gov [ NCT00809913 ; December 16, 2008] and trialregister.nl [ NTR1583 ; December 19, 2008].

Objectives: Febrile urinary tract infections (fUTI) can often be treated safely with oral antimicrobials in an outpatient setting. However, a minority of patients develop complications that may progress into septic shock. An accurate assessment of disease severity upon emergency department (ED) presentation is therefore crucial in order to guide the most appropriate triage and treatment decisions., Methods: Consecutive patients were enrolled with presumptive fUTI across 7 EDs in the Netherlands. The biomarkers mid-regional proadrenomedullin (MR-proADM), procalcitonin (PCT), C-reactive protein (CRP), and a clinical score (PRACTICE), were compared in their ability to predict a clinically severe course of fUTI, initial hospital admission and subsequent readmission using area under the receiver operating characteristic (AUROC) curves., Results: Biomarker concentrations were measured in 313 patients, with 259 (83%) hospitalized upon ED presentation, and 54 (17%) treated as outpatients. Of these outpatients, 12 (22%) were later hospitalized. MR-proADM had the highest diagnostic accuracy for predicting a complicated fUTI (AUROC [95% CI]: 0.86 [0.79-0.92]), followed by PCT (AUROC [95% CI]: 0.69 [0.58-0.80]). MR-proADM concentrations were unique in being significantly elevated in patients directly admitted and in outpatients requiring subsequent hospitalization, compared to those completing treatment at home. A virtual triage algorithm with an MR-proADM cut-off of 0.80  nmol/L resulted in a hospitalization rate of 66%, with only 2% secondary admissions., Conclusion: MR-proADM could accurately predict a severe course in patients with fUTI, and identify greater patient numbers who could be safely managed as outpatients. An initial assessment on ED presentation may focus resources to patients with highest disease severities., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: This longitudinal study aimed to investigate (risk factors for) persistence of carriage and molecular characteristics of extended-spectrum and plasmid-encoded AmpC β-lactamase-producing (ESBL/pAmpC) Escherichia coli and Klebsiella pneumoniae (ESBL-E/K) in adults in the Dutch community., Methods: Following a cross-sectional study (ESBL-E/K prevalence, 4.5%), a subset of ESBL-E/K-positive (n = 76) and -negative (n = 249) individuals volunteered to provide 5 monthly fecal samples and questionnaires. ESBL-E/K was cultured using selective enrichment/culture, and multilocus sequence types (MLSTs) were determined. ESBL/pAmpC-genes were analyzed using polymerase chain reaction (PCR) and sequencing. Plasmids were characterized and subtyped by plasmid MLST. Risk factors for persistent carriage were analyzed using logistic regression., Results: Of the initially ESBL-E/K-positive participants, 25 of 76 (32.9%) remained positive in all subsequent samples; 51 of 76 persons (67.1%) tested ESBL-E/K negative at some time point during follow-up, of which 31 (40.8%) stayed negative throughout the longitudinal study. Carriers often carried the same ESBL gene and plasmid, but sometimes in different ESBL-E/K strains, indicative for horizontal transfer of plasmids. Of the 249 initially ESBL-E/K-negative participants, the majority (n = 218 [87.6%]) tested negative during 8 months of follow-up, whereas 31 of 249 (12.4%) participants acquired an ESBL-E/K. Escherichia coli phylogenetic group B2 and D and travel to ESBL high-prevalence countries were associated with prolonged carriage., Conclusions: ESBL-E/K carriage persisted for >8 months in 32.9% of the initially ESBL-positive individuals, while 12.4% of initially negative individuals acquired ESBL-E/K during the study. A single positive test result provides no accurate prediction for prolonged carriage. Acquisition/loss of ESBL-E/K does not seem to be a random process, but differs between bacterial genotypes.

A seasonal reassortant A(H1N2) influenza virus harbouring genome segments from seasonal influenza viruses A(H1N1)pdm09 (HA and NS) and A(H3N2) (PB2, PB1, PA, NP, NA and M) was identified in March 2018 in a 19-months-old patient with influenza-like illness (ILI) who presented to a general practitioner participating in the routine sentinel surveillance of ILI in the Netherlands. The patient recovered fully. Further epidemiological and virological investigation did not reveal additional cases.

Case Presentation: We analysed a 38-year-old woman with disseminated histoplasmosis for primary immunodeficiency. Her blood showed no IFN-γ response while her peripheral blood mononuclear cells (PBMCs) did. We identified IFN-γ autoantibodies of the IgG class in her serum., Conclusion: IFN-γ autoantibodies leading to infections were so far mainly detected in people from Asian descent, where it was found to be associated with certain HLA types. This may be the first patient of African descent, and without the typical HLA types that predispose to this problem, that produces IFN-γ autoantibodies.

Objective: To investigate the prevalence and incidence of tuberculosis (TB) among the two largest groups of asylum-seekers in the Netherlands, i.e. Syrians and Eritreans/Ethiopians., Design: Descriptive study., Method: We collected data from the screening of Syrian and Eritrean/Ethiopian asylum-seekers for the period January 2013 - September 2015 and linked these to notifications in the Netherlands Tuberculosis Register., Results: Asylum-seekers from Syria and Eritrea/Ethiopia represented 65% and 72% of all asylum applications in 2014 and in the first nine months of 2015 respectively. Fourteen Syrian asylum-seekers applying during the study period were diagnosed with tuberculosis. The prevalence was 22 cases per 100,000 persons screened upon arrival (95% CI: 10-44), while the incidence within the first year after arrival was 19 per 100,000 persons (95% CI: 3-62). Tuberculosis was diagnosed in 133 Eritrean/Ethiopian asylum-seekers applying during the study period. The prevalence was 283 cases per 100,000 persons screened upon arrival (95% CI: 198-393) and the incidence in the first year after arrival was 1394 per 100,000 persons (95% CI: 1095-1751)., Conclusion: In the last two years, most asylum-seekers have originated from Syria and among them tuberculosis is relatively uncommon. However, among Eritrean/Ethiopian asylum-seekers, prevalence and incidence in the first year in the Netherlands are high. This suggests that many of them have been recently infected, in their country of origin or during the journey. Other interventions are required, such as screening for latent infection, to prevent tuberculosis among high-risk asylum-seekers and further reduce the incidence of this disease in the Netherlands.

Purpose: To analyze the data of the national registry of all Dutch primary immune deficiency (PID) patients, according to the European Society for Immunodeficiencies (ESID) definitions., Results: In the Netherlands, 745 patients had been registered between 2009 and 2012. An overall prevalence of 4.0 per 100,000 inhabitants was calculated. The most prevalent PID was 'predominantly antibody disorder (PAD)' (60.4%). In total, 118 transplantations were reported, mostly hematopoietic stem cell transplantations (HSCT). Almost 10% of the PID patients suffered from a malignancy, in particular 'lymphoma' and 'skin cancer'. Compared to the general Dutch population, the relative risk of developing any malignancy was 2.3-fold increased, with a >10-fold increase for some solid tumors (thymus, endocrine organs) and hematological disease (lymphoma, leukemia), varying per disease category., Conclusions: The incidence rate and characteristics of PID in the Netherlands are similar to those in other European countries. Compared to the general population, PID patients carry an increased risk to develop a malignancy., (Copyright © 2014 Elsevier Inc. All rights reserved.)

A retrospective nationwide study on the use of intravenous (IV) zanamivir in patients receiving intensive care who were pretreated with oseltamivir in the Netherlands was performed. In 6 of 13 patients with a sustained reduction of the viral load, the median time to start IV zanamivir was 9 days (range, 4-11 days) compared with 14 days (range, 6-21 days) in 7 patients without viral load reduction (P = .052). Viral load response did not influence mortality. We conclude that IV zanamivir as late add-on therapy has limited effectiveness. The effect of an immediate start with IV zanamivir monotherapy or in combination with other drugs need to be evaluated.

Following the outbreak of haemolytic uraemic syndrome (HUS) and haemorrhagic colitis in Germany, two patients returning from a stay in Germany developed HUS due to Escherichia coli O104:H4 in the Netherlands. The index case developed symptoms eight days, and her child 15 days after their return. It is very likely that transmission resulted from secondary spread from mother to child. Recommendations should be made to prevent secondary transmission within households.

Background: Dectin-1 is the major receptor for fungal β-glucans on myeloid cells. We investigated whether defective Dectin-1 receptor function, because of the early stop codon polymorphism Y238X, enhances susceptibility to invasive aspergillosis (IA) in at-risk patients., Methods: Association of Dectin-1 Y238X polymorphism with occurrence and clinical course of IA was evaluated in 71 patients who developed IA post hematopoietic stem cell transplantation (HSCT) and in another 21 non-HSCT patients with IA. The control group consisted of 108 patients who underwent HSCT. Functional studies were performed to investigate consequences of the Y238X Dectin-1 polymorphism., Results: The Y238X allele frequency was higher in non-HSCT patients with IA (19.0% vs 6.9%-7.7%; P < .05). Heterozygosity for Y238X polymorphism in HSCT recipients showed a trend toward IA susceptibility (odds ratio, 1.79; 95% CI, .77-4.19; P = .17) but did not influence clinical course of IA. Functional assays revealed that although peripheral blood mononuclear cells with defective Dectin-1 function due to Y238X responded less efficiently to Aspergillus, corresponding macrophages showed adequate response to Aspergillus., Conclusions: Dectin-1 Y238X heterozygosity has a limited influence on susceptibility to IA and may be important in susceptible non-HSCT patients. This is partly attributable to redundancy inherent in the innate immune system. Larger studies are needed to confirm these findings.

Enterohaemorrhagic Escherichia coli (EHEC) is a group of pathogenic Shiga toxin-producing E. coli that can cause haemorrhagic colitis and haemolytic uraemic syndrome (HUS). The disease usually occurs sporadically, but sometimes also occurs in large outbreaks such as that which recently occurred in northern Germany. EHEC infection is a zoonosis and its reservoir is in ruminant farm animals (cattle, sheep and goats). EHEC infection should be considered in patients with bloody diarrhoea, but in the course of many severe EHEC infections a picture resembling HUS may also occur. Antibiotic treatment is contraindicated because it does not reduce the duration of the disease and may have negative complications. Patients with EHEC infection may spread the bacteria and their care includes contact isolation measures with their own toilet facilities. The E. coli type O104:H4 that occurred in Germany has a combination of specific virulence characteristics. This outbreak affected many people who developed HUS and neurological symptoms following bloody diarrhoea.

To elucidate the prevalence, characteristics and risk factors of community-onset Clostridium difficile infection (CO-CDI), an uncontrolled prospective study was performed. For 3 months in 2007-2008, three laboratories in The Netherlands tested all unformed stool samples submitted by general practitioners (GPs) for C. difficile by enzyme immunoassay for toxins A and B, irrespective of whether GPs specifically requested this. Patients with positive results were asked to complete a questionnaire. Positive stool samples were cultured for C. difficile, and isolates were characterized. In all, 2443 stool samples from 2423 patients were tested, and 37 patients (1.5%) with positive toxin test results were identified. Mixed infections were not found. Age varied from 1 to 92 years, and 18% were under the age of 20 years. Diarrhoea was typically frequent and watery, sometimes with admixture of blood or fever. Eight of 28 patients (29%) suffered recurrences. Among 31 patients with toxin-positive stool samples for whom information was available, 20 (65%) had not been admitted to a healthcare institution in the year before, 13 (42%) had not used antibiotics during the 6 months before, and eight (26%) had neither risk factor. A separate analysis for patients whose samples were both toxin-positive and culture-positive produced similar results. Cultured C. difficile isolates belonged to 13 different PCR ribotypes, and 24% of the isolates were non-typeable (rare or new) PCR ribotypes. In conclusion, CO-CDI can affect all age groups, and many patients do not have known risk factors. Several PCR ribotypes not encountered in hospital-associated outbreaks were found, suggesting the absence of a direct link between outbreaks and community-onset cases.

T-SPOT.TB is a specific assay for the diagnosis of tuberculosis. The assay needs to be performed with freshly isolated cells, and interpretation requires training. T-SPOT.TB has been used in various clinical-epidemiological settings, but so far no studies have evaluated the effect of interobserver variation in test reading. Our aim was to evaluate variation between different observers in reading T-SPOT.TB results. The study was nested within an ongoing cohort study, in which part of the T-SPOT.TB had been performed with frozen material. Culture plates were read visually by four different observers from two laboratories and by two automated readers. Of 313 T-SPOT.TB assays, 235 were performed with fresh cells and 78 were performed with frozen cells. No significant difference was found between results obtained with fresh cells and those obtained with frozen cells. The percentage of positive results varied between readers by maximally 15%; five/six raters were within a 6% difference in positive results. Analysis of the observed interrater differences showed that some individuals systematically counted more spots than others did. Because test interpretation includes subtraction of background values, this systematic variance had little influence on interindividual differences. The test result as positive or negative varied between independent raters, mainly due to samples with values around the cutoff. This warrants further study regarding determinants affecting the reading of T-SPOT.TB.

On July 10, 2008, Marburg hemorrhagic fever was confirmed in a Dutch patient who had vacationed recently in Uganda. Exposure most likely occurred in the Python Cave (Maramagambo Forest), which harbors bat species that elsewhere in Africa have been found positive for Marburg virus. A multidisciplinary response team was convened to perform a structured risk assessment, perform risk classification of contacts, issue guidelines for follow-up, provide information, and monitor the crisis response. In total, 130 contacts were identified (66 classified as high risk and 64 as low risk) and monitored for 21 days after their last possible exposure. The case raised questions specific to international travel, postexposure prophylaxis for Marburg virus, and laboratory testing of contacts with fever. We present lessons learned and results of the follow-up serosurvey of contacts and focus on factors that prevented overreaction during an event with a high public health impact.

This report of an accidental exposure to Mycobacterium tuberculosis in a microbiological laboratory illustrates the value of gamma interferon enzyme-linked immunospot assay using peptides of ESAT-6, CFP-10, TB37.6, and TB7.7 for the diagnosis of latent infection. In particular, positive responses to peptides 2 to 6 of TB37.6 were observed exclusively in recently infected persons.

Mycobacterium kansasii consists of 5 genetically distinct groups, of which 2 are associated with human disease. Determinants of the differences in virulence are unknown. Potential genes of interest are esat-6 and cfp-10, which are associated with virulence of Mycobacterium tuberculosis and Mycobacterium bovis but are lacking in bacille Calmette-Guérin and in most environmental mycobacteria (M. kansasii is an exception). We investigated esat-6 and cfp-10 genes in 22 clinical and 14 environmental isolates of M. kansasii. Both were present in all isolates; each genetic group had its own characteristic Southern-blot pattern corresponding to a highly conserved fingerprint pattern. Nucleotide sequences of the genes differed 12.6% and 10.1%, respectively, from the M. tuberculosis homologues, but the deduced amino acid sequences were <5% different. In vitro, clinical and environmental genotypes of M. kansasii expressed CFP-10 and ESAT-6. Thus, virulence of M. kansasii is not directly related to esat-6 and cfp-10 genes or gene expression.

We performed a prospective, 2-year nationwide study to assess incidence and disease characteristics of suspected infections with nontuberculous mycobacteria (NTM) in children, via the Netherlands Pediatric Surveillance Unit. Data for 61 children were reported (median age, 31 months; interquartile range, 22-50 months; female sex, 37 subjects); 2 subjects had an underlying disease. Most children (53 [87%] of 61) had cervical lymph node enlargement, with abscess in 25 (47%) and fistula in 11 (21%). The estimated annual incidence of NTM infection was 77 cases per 100,000 children. In 16 children, the diagnosis was based solely on the results of skin tests with mycobacterial antigens. Cultures were performed in 36 cases and yielded mycobacteria in 27 (75%); Mycobacterium avium was isolated from 18 cultures. Children with a culture positive for mycobacteria did not differ in presentation, complications, or treatment from those whose cultures showed no growth. Thirty children underwent surgery, and chemotherapy was the single treatment in 24 (39%) of the cases. The treatment of localized NTM infection in immunocompetent children by antimycobacterial drugs should be evaluated further.

Background: HIV-infected patients responding to HAART can show a diverse spectrum of symptoms caused by inflammatory reaction. The pathogenesis of this phenomenon, called immune restoration disease (IRD), is unclear. This study describes the spectrum of IRD and analyses the immunological and clinical parameters that could be related to its development., Methods: In a retrospective, matched case-control study, 17 HIV-infected individuals who developed inflammatory symptoms < 12 months after initiation of HAART were included. HIV-infected controls were matched for age, gender and CDC classification. Factors included in the analysis were: CD4+ and CD8+ cell counts, deltaCD4+ and deltaCD8+, CD4/CD8 ratios, HIV-1-RNA load (VL), AVL and the number of CDC events prior to HAART., Results: The median time after initiation of HAART and developing IRD (n = 17) was 72 days (range 2-319). In nine cases (53%) a mycobacterial infection was identified as the underlying cause. HAART was started at a mean CD4+ count (+/- SD) of 55 x 10(6) /l (+/- 59) and 85 x 10(6) /l (+/- 78.0) for cases and controls, respectively (p = 0.13). After initiation of HAART, the CD4+ count showed a 10.6 fold increase at the onset of IRD in the cases and a 2.7 fold increase in the controls in an equal period of time (p = 0.020). The other parameters analysed did not differ significantly between cases and controls., Conclusion: We conclude that the risk of developing IRD is associated with a high-fold increase in CD4+ lymphocytes. In this study, mycobacteria are the pathogens most frequently associated with IRD.

Severe acute respiratory syndrome (SARS) is caused by a recently identified Coronavirus (SARS-CoV). The clinical symptoms are non-specific and during the first few days in particular, are not clinically distinguishable from those of many other viral or bacterial infections. The majority of infected patients develop pneumonia within a week of the first symptoms appearing. Since November 2002 the virus has spread from South China to almost 30 other countries, where about 8500 infected individuals have been registered; about 800 people have already died from the disease (9.5%). The number of infected persons includes a noticeably high percentage of health workers. This fact underlines the importance of good infection prevention measures for each patient contact. The implementation of hygienic measures requires attention, because the infection of personnel in Toronto hospitals still occurred after the virus and transmission routes were known. It appears that transmission can be prevented with relatively simple precautions, as long as these are consistently implemented. Early recognition and isolation of a possible source are an essential part of this. SARS is a group A notifiable disease (report if suspected). In the Netherlands the general practitioner has a prominent role in assessing and treating individuals who are infected or might be infected with SARS-CoV. A protocol and a detailed action plan are available. In addition to this hospitals should be prepared for the initial reception of a patient with SARS, who presents directly to the outpatients' clinic or Casualty Department.

Objective: To ascertain the correlation between chills, bacteraemia, infection type and clinical progress in patients presenting with fever to the casualty department., Design: Prospective, descriptive., Method: Anamnestic, clinical and microbiological data were registered from patients with fever (> 38.2 degrees C rectal) presenting to the Casualty Department of the Leiden University Hospital and the Bronovo Hospital, in the period 1 February 1994-31 July 1995 respectively 1 February 1996-31 July 1997., Results: A total of 764 patients (424 men and 340 women; median age: 66 years) were included in the study. A chill was reported by 270 patients (35%). Bacteria were isolated from the blood culture in the case of 141 patients (18%). The relative risk (RR) for bacteraemia in the case of a chill was 2.8 (95% CI: 2.1-3.8); the positive predictive value of a chill for bacteraemia was 31% and the negative predictive value 89%. For 683 (89%) of the 764 patients the cause of the fever was probably or certainly an infection, which was mostly pulmonary (319 patients; 42%) or urogenital (112 patients; 15%) in origin. The positive predictive value was 24% for patients with respiratory tract infections and 48% for patients with urinary tract infections. Mortality occurred in the case of 62 patients (8%) after a median admission period of 11 days. The patients who died were older than the patients discharged (p < 0.01) and there was a statistically significant correlation between mortality with bacteraemia (RR: 1.1) and serious comorbidity (RR: 6.1)., Conclusion: There was a strong correlation between the chill indicated in the anamnesis and bacteraemia, especially in patients with a urinary tract infection. Bacteraemia, advanced age and serious comorbidity were unfavourable prognostic factors.

Anthrax is a zoonosis which is particularly prevalent in cattle, goats and sheep and is caused by Bacillus anthracis, a Gram-positive spore forming aerobic microorganism. The endospores can survive outside of the body for many decades. The natural form of anthrax has a cutaneous, pulmonary and intestinal form. The pulmonary form can be rapidly fatal but is difficult to recognise due to an initially non-specific, flu-like clinical picture. As a result of spores being inhaled, a mediastinal lymphadenitis arises from which a systemic disease develops with a violent toxaemia, damage to the vascular endothelium, oedema, internal haemorrhages and circulatory collapse. Anthrax is diagnosed by demonstrating the presence of the bacteria in the cutaneous abnormality, in blood or another sterile body component such as cerebrospinal fluid, by means of a direct preparation, immunofluorescence or surface antigens, molecular diagnostics with PCR, or by means of culturing. B. anthracis is sensitive to quinolones, clindamycin and tetracyclines, and often to penicillin. Although naturally acquired cutaneous anthrax can be effectively treated with a short antibiotic cure, it is nevertheless advised in the USA to complete the full 60-day cure and to regard the cutaneous manifestation as a telltale sign of possible respiratory exposure. Anthrax is not transmitted from one person to another.

We describe a woman who was repeatedly tuberculin (PPD) skin test negative after exposure to smear-positive tuberculosis (TB), but developed active TB with a positive skin test 7 years later. Molecular epidemiologic evidence is presented that the infection was contracted 7 years previously from the original source case. PPD skin testing is subject to many technical and biological variables and this report underscores that this tool can fail to detect latent TB infection in some cases. The causes of false-negative and false-positive PPD skin test results are reviewed.