GGD West-Brabant

OBJECTIVE: The study aimed to identify both the frequency and the determinants of drug administration errors in the intensive care unit. DESIGN: Administration errors were detected by using the disguised-observation technique (observation of medication administrations by nurses, without revealing the aim of this observation to the nurses). SETTING: Two Dutch hospitals. PATIENTS: The drug administrations to patients in the intensive care units of two Dutch hospitals were observed during five consecutive days. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 233 medications for 24 patients were observed to be administered (whether ordered or not) or were observed to be omitted. When wrong time errors were included, 104 administrations with at least one error were observed (frequency, 44.6%), and when they were excluded, 77 administrations with at least one error were observed (frequency, 33.0%). When we included wrong time errors, day of the week (Monday, odds ratio [OR] 2.69, confidence interval [CI] 1.42-5.10), time of day (6-10 pm, OR 0.28, CI 0.10-0.78), and drug class (gastrointestinal, OR 2.94, CI 1.48-5.85; blood, OR 0.12, CI 0.03-0.54; and cardiovascular, OR 0.38, CI,0.16-0.90) were associated with the occurrence of errors. When we excluded wrong time errors, day of the week (Monday, OR 3.14, CI 1.66-5.94), drug class (gastrointestinal, OR 3.47, CI 1.76-6.82; blood, OR 0.21, CI 0.05-0.91; and respiratory, OR 0.22, CI 0.08-0.60), and route of administration (oral by gastric tube, OR 5.60, CI 1.70-18.49) were associated with the occurrence of errors. In the hospital without full-time specialized intensive care physicians (which also lacks pharmacy-provided protocols for the preparation of parenteral drugs), more administration errors occurred, both when we included (OR 5.45, CI 3.04-9.78) and excluded wrong time errors (OR 4.22, CI 2.36-7.54). CONCLUSIONS: Efforts to reduce drug administration errors in the intensive care unit should be aimed at the risk factors we identified in this study. Especially, focusing on system differences between the two intensive care units (e.g., presence or absence of full-time specialized intensive care physicians, presence or absence of protocols for the preparation of all parenteral drugs) may help reduce suboptimal drug administration.

Recent technological developments have increased the number of variables being monitored in lakes and reservoirs using automatic high frequency monitoring (AHFM). However, design of AHFM systems and posterior data handling and interpretation are currently being developed on a site-by-site and issue-by-issue basis with minimal standardization of protocols or knowledge sharing. As a result, many deployments become short-lived or underutilized, and many new scientific developments that are potentially useful for water management and environmental legislation remain underexplored. This Critical Review bridges scientific uses of AHFM with their applications by providing an overview of the current AHFM capabilities, together with examples of successful applications. We review the use of AHFM for maximizing the provision of ecosystem services supplied by lakes and reservoirs (consumptive and non consumptive uses, food production, and recreation), and for reporting lake status in the EU Water Framework Directive. We also highlight critical issues to enhance the application of AHFM, and suggest the establishment of appropriate networks to facilitate knowledge sharing and technological transfer between potential users. Finally, we give advice on how modern sensor technology can successfully be applied on a larger scale to the management of lakes and reservoirs and maximize the ecosystem services they provide.

The authors determined the positive predictive value (PPV) for progression to tuberculosis (TB) of two interferon-gamma release assays (IGRAs), QuantiFERON-TB Gold In-tube (QFT-GIT) and T-SPOT.TB, and the tuberculin skin test (TST) in immigrants contacts. Immigrant close contacts of sputum smear-positive TB patients were included when aged > or =16 yrs and their TST result was > or =5 mm 0 or 3 months after diagnosis of the index patient. Contacts were followed for the next 2 yrs for development of TB disease. Of 339 immigrant contacts with TST > or =5 mm, 324 and 299 had valid results of QFT-GIT and T-SPOT.TB, respectively. Nine contacts developed active TB. One patient had not been tested with TST, while another patient had not been tested with QFT-GIT and T-SPOT.TB. The PPV for progression to TB during this period was 9/288 = 3.1% (95% CI 1.3-5.0%) for TST > or =10 mm, 7/184 = 3.8% (95% CI 1.7-5.9%) for TST > or =15 mm, 5/178 = 2.8% (95% CI 1.0-4.6%) for QFT-GIT and 6/181 = 3.3% (95% CI 1.3-5.3%) for T-SPOT.TB. Sensitivity was 100%, 88%, 63% and 75%, respectively. The predictive values of QFT-GIT, T-SPOT.TB and TST for progression to TB disease among immigrant close contacts were comparable.

OBJECTIVE: To assess the diagnostic test accuracy of two rapid antigen tests in asymptomatic and presymptomatic close contacts of people with SARS-CoV-2 infection on day 5 after exposure. DESIGN: Prospective cross sectional study. SETTING: Four public health service covid-19 test sites in the Netherlands. PARTICIPANTS: 4274 consecutively included close contacts (identified through test-and-trace programme or contact tracing app) aged 16 years or older and asymptomatic for covid-19 when requesting a test. MAIN OUTCOME MEASURES: Sensitivity, specificity, and positive and negative predictive values of Veritor System (Beckton Dickinson) and Biosensor (Roche Diagnostics) rapid antigen tests, with reverse-transcriptase polymerase chain reaction (RT-PCR) testing as reference standard. The viral load cut-off above which 95% of people with a positive RT-PCR test result were virus culture positive was used as a proxy of infectiousness. RESULTS: Of 2678 participants tested with Veritor, 233 (8.7%) had a RT-PCR confirmed SARS-CoV-2 infection of whom 149 were also detected by the rapid antigen test (sensitivity 63.9%, 95% confidence interval 57.4% to 70.1%). Of 1596 participants tested with Biosensor, 132 (8.3%) had a RT-PCR confirmed SARS-CoV-2 infection of whom 83 were detected by the rapid antigen test (sensitivity 62.9%, 54.0% to 71.1%). In those who were still asymptomatic at the time of sampling, sensitivity was 58.7% (51.1% to 66.0%) for Veritor (n=2317) and 59.4% (49.2% to 69.1%) for Biosensor (n=1414), and in those who developed symptoms were 84.2% (68.7% to 94.0%; n=219) for Veritor and 73.3% (54.1% to 87.7%; n=158) for Biosensor. When a viral load cut-off was applied for infectiouness (≥5.2 log10 SARS-CoV-2 E gene copies/mL), the overall sensitivity was 90.1% (84.2% to 94.4%) for Veritor and 86.8% (78.1% to 93.0%) for Biosensor, and 88.1% (80.5% to 93.5%) for Veritor and 85.1% (74.3% to 92.6%) for Biosensor, among those who remained asymptomatic throughout. Specificities were >99%, and positive and negative predictive values were >90% and >95%, for both rapid antigen tests in all analyses. CONCLUSIONS: The sensitivities of both rapid antigen tests in asymptomatic and presymptomatic close contacts tested on day 5 onwards after close contact with an index case were more than 60%, increasing to more than 85% after a viral load cut-off was applied as a proxy for infectiousness.

Abstract In the Netherlands many water supply companies are upgrading their surface water treatment plants in order to guarantee the water supply and water quality in the coming years. The Water Supply Company North West Brabant (WNWB) has plans to upgrade their treatment plant at Zevenbergen. In the retrofit plant chlorination will be abandoned and probably ozonation will be the major barrier against microorganisms. Pesticide concentrations will be decreased by three barriers: storage, ozonation and activated carbon filtration. If the ozone dosage is restricted just to reach the required disinfection level at pH 7.2, ozonation is a poor barrier against pesticides. Out of 23 selected pesticides, only 6 were effectively degraded: dimethoate, chlortoluron, diuron, isoproturon, metoxuron and vinclozolin (O3/DOC = 0.55 g/g). Application of an (O3/DOC ratio of 1.0 g/g results in an effective barrier for roughly 50% of the tested pesticides (also for diazinon, parathion-methyl, linuron, methabenzthiazuron, metobromuron, MCPA and MCPP). Pesticides were degraded more effectively at high pH and high temperature. For additional degradation of high concentrations of persistent pesticides, advanced oxidation may be applied. Atrazine, propazine, simazine, chlor-fenvinphos, tetrachlorvinphos, 2,4-D, 2,4-DP and 2,4,5-T were degraded by O3/DOC = 1.4 g/g and H2O2/O3 = 0.5 g/g. Dicamba and dikegulac were most persistent. pH has a minor effect on the degradation of pesticides by advanced oxidation. Higher hydrogen peroxide dosages showed no improvement in degradation. After ozonation and advanced oxidation, about 50% of totally reacted atrazine and propazine was converted into desethylatrazine. No desisopropylatrazine formation was observed.

Abstract Sustainable management of lakes requires us to overcome ecological, economic, and social challenges. These challenges can be addressed by focusing on achieving ecological improvement within a multifaceted, co‐beneficial context. In‐lake restoration measures may promote more rapid ecosystem responses than is feasible with catchment measures alone, even if multiple interventions are needed. In particular, we identify restoration methods that support the overarching societal target of a circular economy through the use of nutrients, sediments, or biomass that are removed from a lake, in agriculture, as food, or for biogas production. In this emerging field of sustainable restoration techniques, we show examples, discuss benefits and pitfalls, and flag areas for further research and development. Each lake should be assessed individually to ensure that restoration approaches will effectively address lake‐specific problems, do not harm the target lake or downstream ecosystems, are cost‐effective, promote delivery of valuable ecosystem services, minimize conflicts in public interests, and eliminate the necessity for repeated interventions. Achieving optimal, sustainable results from lake restoration relies on multidisciplinary research and close interactions between environmental, social, political, and economic sectors. This article is categorized under: Science of Water > Water Quality Water and Life > Stresses and Pressures on Ecosystems Water and Life > Conservation, Management, and Awareness

While reduction in nutrient loading is a prerequisite for mitigation of harmful cyanobacterial blooms in nutrient-enriched waters, in certain surface waters eutrophication control is not always feasible due to practical and economic constraints or might be effective only in the long run. Yet, the urgent need to control cyanobacteria in water for drinking, irrigation, aquaculture, industry and recreation has spurred the development of a plethora of alternative methods that claim to be fast acting. Here, we provide a critical overview of several of these end-of-pipe measures: effective microorganisms (EM®), golden algae (Ochromonas), plant/tree extracts, ultrasound and artificial mixing of non-stratifying waters. Most of the end-of the pipe measures claim to provide sustainable control of harmful cyanobacterial blooms, while at best only targeting symptom relief rather than eutrophication relief. Support for “effective” microorganisms, golden algae, plant extracts, ultrasound and artificial mixing of non-stratifying waters to diminish eutrophication problems such that the resulting water quality meets societal and legislation demands is limited, and several proposed underlying mechanisms are doubtful. None of these curative measures seem the desired wide applicable solution to cyanobacterial nuisance; they should not be considered Columbus’s egg. A critical evaluation of end-of pipe measures is crucial for water authorities in their choice for mitigating measures.

SUMMARY Although norovirus infection is generally known to be a mild disease, there is some evidence for severe outcome. An outbreak in a Dutch psychiatric institution, originating from pilgrims returning from Lourdes (France), provided an opportunity for performing a retrospective cohort study in order to identify risk factors for norovirus disease and excess mortality. Relative risks (RR) including 95% confidence intervals (CI) showed that attending the pilgrimage (RR 2·0, 95% CI 1·4–3·0) and age >70 (RR 1·7, 95% CI 1·2–2·2) were risk factors for symptomatic infection. In a subset of patients, for whom more detailed information was available, the use of statins was associated with norovirus disease when adjusted for underlying condition (adjusted odds ratio 3·9, 95% CI 1·2–13·0). Mortality was higher in cases infected during the pilgrimage compared to other residents (RR 20·9, 95% CI 4·7–93·8). Norovirus disease can lead to severe outcome. The newly identified risk of statins for contracting norovirus disease may have considerable consequences for the Western world and needs prospective confirmation.

Lanthanum Modified Bentonite (LMB; Phoslock®) is used to mitigate eutrophication by binding phosphate released from sediments. This study investigated the fate of lanthanum (La) from LMB in water, sediment, macrophytes, and chironomid larvae in Lake Rauwbraken (The Netherlands). Before the LMB application, water column filterable La (FLa) was 0.02 µg L−1, total La (TLa) was 0.22 µg L−1. In sediment the total La ranged 0.03–1.86 g m−2. The day after the application the maximum FLa concentration in the water column was 44 µg L−1, TLa was 528 µg L−1, exceeding the Dutch Maximum Permissible Concentrations (MPC) of 10.1 µg L−1 by three to fourfold. TLa declined below the MPC after 15 days, FLa after 75 days. After ten years, FLa was 0.4 µg L−1 and TLa was 0.7 µg L−1. Over the post-application years, FLa and TLa showed statistically significant downward trends. While the LMB settled homogeneously on sediment, after 3 years it redistributed to 0.2–5.4 g La m−2 within shallow zones, and 30.7 g m−2 to 40.0 g La m−2 in deeper zones. In the upper 20 cm of sediment, La concentrations were 7–6702 mg kg −1 dry weight (DW) compared to 0.5–7.0 mg kg−1 before application. Pre-application anaerobic sediment release of FLa was 0.006 mg m−2 day−1. Three months after the application it was 1.02 mg m−2 day−1. Three years later it was 0.063 mg m−2 day−1. Before application La in plants was 0.8–5.1 mg La kg−1 DW, post-application values were up to 2925 mg La kg−1 DW. In chironomid larvae, La increased from 1.7 µg g−1 DW before application to 1421 µg g−1 DW after one month, 3 years later it was 277 µg g−1 DW. Filtration experiments indicate FLa is not truly dissolved free La3+ cations.

Abstract Objective To assess the performance of rapid antigen tests with unsupervised nasal and combined oropharyngeal and nasal self-sampling during the omicron period. Design Prospective cross sectional diagnostic test accuracy study. Setting Three public health service covid-19 test sites in the Netherlands, 21 December 2021 to 10 February 2022. Participants 6497 people with covid-19 symptoms aged ≥16 years presenting for testing. Interventions Participants had a swab sample taken for reverse transcription polymerase chain reaction (RT-PCR, reference test) and received one rapid antigen test to perform unsupervised using either nasal self-sampling (during the emergence of omicron, and when omicron accounted for >90% of infections, phase 1) or with combined oropharyngeal and nasal self-sampling in a subsequent (phase 2; when omicron accounted for >99% of infections). The evaluated tests were Flowflex (Acon Laboratories; phase 1 only), MPBio (MP Biomedicals), and Clinitest (Siemens-Healthineers). Main outcome measures The main outcomes were sensitivity, specificity, and positive and negative predictive values of each self-test, with RT-PCR testing as the reference standard. Results During phase 1, 45.0% (n=279) of participants in the Flowflex group, 29.1% (n=239) in the MPBio group, and 35.4% ((n=257) in the Clinitest group were confirmatory testers (previously tested positive by a self-test at own initiative). Overall sensitivities with nasal self-sampling were 79.0% (95% confidence interval 74.7% to 82.8%) for Flowflex, 69.9% (65.1% to 74.4%) for MPBio, and 70.2% (65.6% to 74.5%) for Clinitest. Sensitivities were substantially higher in confirmatory testers (93.6%, 83.6%, and 85.7%, respectively) than in those who tested for other reasons (52.4%, 51.5%, and 49.5%, respectively). Sensitivities decreased from 87.0% to 80.9% (P=0.16 by χ 2 test), 80.0% to 73.0% (P=0.60), and 83.1% to 70.3% (P=0.03), respectively, when transitioning from omicron accounting for 29% of infections to >95% of infections. During phase 2, 53.0% (n=288) of participants in the MPBio group and 44.4% (n=290) in the Clinitest group were confirmatory testers. Overall sensitivities with combined oropharyngeal and nasal self-sampling were 83.0% (78.8% to 86.7%) for MPBio and 77.3% (72.9% to 81.2%) for Clinitest. When combined oropharyngeal and nasal self-sampling was compared with nasal self-sampling, sensitivities were found to be slightly higher in confirmatory testers (87.4% and 86.1%, respectively) and substantially higher in those testing for other reasons (69.3% and 59.9%, respectively). Conclusions Sensitivities of three rapid antigen tests with nasal self-sampling decreased during the emergence of omicron but was only statistically significant for Clinitest. Sensitivities appeared to be substantially influenced by the proportion of confirmatory testers. Sensitivities of MPBio and Clinitest improved after the addition of oropharyngeal to nasal self-sampling. A positive self-test result justifies prompt self-isolation without the need for confirmatory testing. Individuals with a negative self-test result should adhere to general preventive measures because a false negative result cannot be ruled out. Manufacturers of MPBio and Clinitest may consider extending their instructions for use to include combined oropharyngeal and nasal self-sampling, and other manufacturers of rapid antigen tests should consider evaluating this as well.

Periconceptional folic acid use considerably reduces the risk of neural tube defects. The aim of this study was to measure the effect of the national and the local 'Folic Acid Campaign' on periconceptional folic acid use. Before (1995 survey) and 1 year after the campaign (1996 survey), the awareness and use of folic acid was measured among pregnant women in four regions of the Netherlands. To this end, pregnant women who visited the midwife, general practitioner or obstetrician for the first or second prenatal visit were asked to complete a questionnaire. The results showed that use of folic acid for any period around conception increased from 25.1% in 1995 to 53.5% in 1996. Appropriate use (4 weeks before until 8 weeks after conception) increased from 4.8% in 1995 to 21.0% in 1996. No additional effect of the local Folic Acid Campaign was found (adjusted odds ratio= 1.0; 95% confidence interval = 0.7, 1.4). It was possible to conclude that folic acid use at the recommended time increased considerably as a result of the national and the local Folic Acid Campaign, but the target (use in 46% of women wishing to conceive) was not achieved. New health education programmes are needed to increase further its use at the appropriate times.

Intense sand and gravel mining has created numerous man-made lakes around the world in the past century. These small quarry lakes (1-50 ha) are usually hydrologically isolated, often deep (6-40 m) and stratify during summer and in cold winters. Due to their small size, these deep man-made lakes are usually not included in the regular monitoring campaigns, e.g. as required for the European Water Framework Directive (WFD). Therefore, not much is known about the ecological functioning of these novel ecosystems. During two summers, we determined the macrophyte diversity and measured a range of physico-chemical and biological parameters in 51 quarry lakes in the catchment area of the rivers Meuse and Rhine. We compared the results of this campaign to the chemical and macrophyte sampling as performed for the WFD in the immediate surrounding shallow standing waters. Alpha (local) and beta diversity (regional), and local contribution to beta diversity were calculated for the whole region of which beta diversity was further partitioned into a true species replacement and richness difference component. Quarry lakes contain higher water quality reflected by lower nutrient and chlorophyll-a concentration compared with shallow water bodies. Additionally, quarry lakes contribute significantly to the regional macrophyte diversity pool by harboring distinctly different macrophyte communities (beta diversity - replacement). Specifically quarry lakes with a total phosphorus concentration in the water column below 35 μg P/l contribute most to beta diversity among quarry lakes. Novel ecosystems such as deep quarry lakes are often perceived as less valuable ecosystems, with strong implications regarding their management. Our results show that quarry lakes are in general of better chemical and biological quality compared with shallow standing waters. We therefore call for a more integrated assessment of the quality of quarry lakes and corresponding management strategy of these waters by water managers.

The eutrophic Bouvigne pond (Breda, The Netherlands) regularly suffers from cyanobacterial blooms. To improve the water quality, the external nutrient loading and the nutrient release from the pond sediment have to be reduced. An enclosure experiment was performed in the pond between March 9 and July 29, 2020 to compare the efficiency of dredging, addition of the lanthanum-modified bentonite clay Phoslock® (LMB), the aluminum-modified zeolite Aqual-P™ (AMZ) and FeCl2 to mitigate nutrient release from the sediment. The treatments improved water quality. Mean total phosphorus (TP) concentrations in water were 0.091, 0.058, 0.032, 0.031, and 0.030 mg P L-1 in controls, dredged, FeCl2, LMB and AMZ treated enclosures, respectively. Mean filterable P (FP) concentrations were 0.056, 0.010, 0.009, 0.005, and 0.005 mg P L-1 in controls, dredged, FeCl2, LMB and AMZ treatments, respectively. Total nitrogen (TN) and dissolved inorganic nitrogen (DIN) were similar among treatments; lanthanum was elevated in LMB treatments, Fe and Cl in FeCl2 treatments, and Al and Cl in AMZ treatments. After 112 days, sediment was collected from each enclosure, and subsequent sequential P extraction revealed that the mobile P pool in the sediments had reduced by 71.4%, 60.2%, 38%, and 5.2% in dredged, AMZ, LMB, and FeCl2 treatments compared to the controls. A sediment core incubation laboratory experiment done simultaneously with the enclosure experiment revealed that FP fluxes were positive in controls and cores from the dredged area, while negative in LMB, AMZ and FeCl2 treated cores. Dissolved inorganic nitrogen (DIN) release rate in LMB treated cores was 3.6 times higher than in controls. Overall, the applied in-lake treatments improved water quality in the enclosures. Based on this study, from effectiveness, application, stakeholders engagement, costs and environmental safety, LMB treatment would be the preferred option to reduce the internal nutrient loading of the Bouvigne pond, but additional arguments also have to be considered when preparing a restoration.

Abstract Objectives This study was primarily conducted to evaluate clinical sensitivity and specificity of the SARS-CoV-2 rapid antigen test ‘BD Veritor System for Rapid Detection of SARS-CoV-2’ (VRD) compared to real time reverse transcriptase polymerase chain reaction (qRT-PCR). Furthermore, the VRD sensitivity for different Ct-value groups (Ct <20; Ct 20-25, Ct 25-30 and Ct ≥30) and different intervals since symptom onset (< 7 days; ≥ 7 days) were examined. Design Prospective performance evaluation study. Setting Municipal Health Service (GGD) COVID-19 test centres in West-Brabant, the Netherlands Participants In order to evaluate clinical specificity, 352 symptomatic adults (≥18 years) who presented at a participating GGD test centre for a COVID-19 test between September 28 and October 7 2020 were included. In order to evaluate clinical sensitivity, 123 symptomatic adults (≥18 years) who were tested positive with qRT-PCR in a participating GGD test centre between September 26 and October 6 were included. Results An overall clinical specificity of 100% (95%CI: 98.9%-100%) and sensitivity of 80.7% (95% CI: 73,2%-86,9%) was found for the VRD compared to qRT-PCR. Sensitivity was the highest for low Ct-value categories and for specimen obtained within the first days after disease onset. For specimen obtained within 7 days after onset of symptoms, the overall sensitivity was 91.0% (95% CI: 82,4%-96,3%) and 98,6% (95% CI: 92,3%-100%) for samples with qRT-PCR Ct-value beneath 30. Conclusion The VRD is a promising diagnostic test for COVID-19 community screening for symptomatic individuals within 7 days after symptom onset in function of disease control. The clinical sensitivity was highest when viral load was high, which correlated with the duration of symptoms. Further research on practical applicability and the optimal position of the test within the current testing landscape is needed.

BACKGROUND: SARS-CoV-2 real-time reverse transcriptase polymerase chain reaction (qRT-PCR) is well suited for the diagnosis of clinically ill patients requiring treatment. Application for community testing of symptomatic individuals for disease control purposes however raises challenges. SARS-CoV-2 rapid antigen tests might offer an alternative, but quality evidence on their performance is limited. METHODS: We conducted an evaluation of the test accuracy of the 'BD Veritor System for Rapid Detection of SARS-CoV-2' (VRD) compared to qRT-PCR on combined nose/throat swabs obtained from symptomatic individuals at Municipal Health Service (MHS) COVID-19 test centers in the Netherlands. In part one of the study, with the primary objective to evaluate test sensitivity and specificity, all adults presenting at one MHS test center were eligible for inclusion. In part two, with the objective to evaluate test sensitivity stratified by Ct (cycle threshold)-value and time since symptom onset, adults who had a positive qRT-PCR obtained at a MHS test center were eligible. FINDINGS: In part one (n = 352) SARS-CoV-2 prevalence was 4.8%, overall specificity 100% (95%CI: 98·9%-100%) and sensitivity 94·1% (95%CI: 71·1%-100%). In part two (n = 123) the sensitivity was 78·9% (95%CI: 70·6%-85·7%) overall, 89·4% (95% CI: 79·4%-95·6%) for specimen obtained within seven days after symptom onset and 93% (95% CI: 86%-97.1%) for specimen with a Ct-value below 30. INTERPRETATION: The VRD is a promising diagnostic for COVID-19 testing of symptomatic community-dwelling individuals within seven days after symptom onset in context of disease control. Further research on practical applicability and the optimal position within the testing landscape is needed.

In The Netherlands, periconceptional folic acid use to prevent neural tube defects was promoted through a national 'Folic Acid Campaign'. In two regions, a local campaign supplemented the national campaign to increase the chances of reaching women with low socio-economic status (SES). A framework of outcome criteria, defined as awareness knowledge, perceived safety, attitudes and subjective norms, was developed to evaluate the effectiveness of the two local campaigns. Data were gathered by means of two cross-sectional studies conducted just before and 1 year after the campaigns took place. Before the campaigns were conducted, there were already differences in all effect criteria and folic acid use between women of different educational levels, mostly in favour of women with a high level of education. Although both educational campaigns appeared to have a positive impact on all outcome criteria, they failed to reduce the existing differences in these outcome criteria between women of different educational levels. Folic acid use can be promoted effectively by mass media campaigns, certainly in a large group of women with no prior knowledge of the health benefits associated with periconceptional folic acid use. However, in order to achieve more equal health outcomes among women of low and high SES, it seems that more tailored interventions for women of low SES are needed.

The combination of a low-dose coagulant (polyaluminium chloride—‘Floc’) and a ballast able to bind phosphate (lanthanum modified bentonite, LMB—‘Sink/Lock’) have been used successfully to manage cyanobacterial blooms and eutrophication. In a recent ‘Floc and Lock’ intervention in Lake de Kuil (the Netherlands), cyanobacterial chlorophyll-a was reduced by 90% but, surprisingly, after one week elevated cyanobacterial concentrations were observed again that faded away during following weeks. Hence, to better understand why and how to avoid an increase in cyanobacterial concentration, experiments with collected cyanobacteria from Lakes De Kuil and Rauwbraken were performed. We showed that the Planktothrix rubescens from Lake de Kuil could initially be precipitated using a coagulant and ballast but, after one day, most of the filaments resurfaced again, even using a higher ballast dose. By contrast, the P. rubescens from Lake Rauwbraken remained precipitated after the Floc and Sink/Lock treatment. We highlight the need to test selected measures for each lake as the same technique with similar species (P. rubescens) yielded different results. Moreover, we show that damaging the cells first with hydrogen peroxide before adding the coagulant and ballast (a ‘Kill, Floc and Lock/Sink’ approach) could be promising to keep P. rubescens precipitated.

BACKGROUND: Students' health and school absenteeism affect educational level, with adverse effects on their future health. This interdependence is reflected in medical absenteeism. In the Netherlands, a public health intervention has been developed to address medical absenteeism in pre-vocational secondary education. This study aims to investigate the effectiveness of this intervention on students' medical absenteeism, compared to "medical absenteeism policy as usual". METHODS: A quasi-experimental design with an intervention group (493 students) and a control group (445 students) was applied. Multilevel analysis was used to study differences in the development of the level of a student's medical absence over time (after 3 and 12 months). RESULTS: In the intervention group, the level of absenteeism decreased from 8.5 days reported sick in 12 school weeks to 5.7 days after 3 months, and to 4.9 days after 12 months. The number of absence periods fell from 3.9 in 12 school weeks to 2.5 after 3 months, and to 2.2 after 12 months. In the control group, the absence days initially decreased from 9.9 days reported sick in 12 school weeks to 8.4 days after 3 months, after which an increase to 8.9 days was measured. The number of absence periods initially decreased from 4.5 in 12 school weeks to 3.5, after which an increase to 3.7 was measured. The number of absence days per period remained about the same in both groups. CONCLUSIONS: The study provides first indications for the intervention to be effective for Dutch pre-vocational secondary students with increased medical absence rates. The intervention, which consists of personalised management of medical absenteeism by systematic identification of students with extensive medical absenteeism and consistent referral to youth health care physicians, appears to reduce the absence rates more effectively than "medical absenteeism policy as usual". The effectiveness of the intervention is shown primarily by a decrease in the number of periods reported sick.

Harmful algal blooms are symptomatic of eutrophication and lead to deterioration of water quality and ecosystem services. Extreme climatic events could enhance eutrophication resulting in more severe nuisance algal blooms, while they also may hamper current restoration efforts aimed to reduce nutrient loads. Evaluation of restoration measures on their efficacy under climate change is essential for effective water management. We conducted a two-month mesocosm experiment in a hypertrophic urban canal focussing on the reduction of sediment phosphorus (P)-release. We tested the efficacy of four interventions, measuring phytoplankton biomass, nutrients in water and sediment. The measures included sediment dredging, water column aeration and application of P-sorbents (lanthanum-modified bentonite - Phoslock® and iron-lime sludge, a by-product from drinking water production). An extreme heatwave (with the highest daily maximum air temperature up to 40.7 °C) was recorded in the middle of our experiment. This extreme heatwave was used for the evaluation of heatwave-induced impacts. Dredging and lanthanum modified bentonite exhibited the largest efficacy in reducing phytoplankton and cyanobacteria biomass and improving water clarity, followed by iron-lime sludge, whereas aeration did not show an effect. The heatwave negatively impacted all four measures, with increased nutrient releases and consequently increased phytoplankton biomass and decreased water clarity compared to the pre-heatwave phase. We propose a conceptual model suggesting that the heatwave locks nutrients within the biological P loop, which is the exchange between labile P and organic P, while the P fraction in the chemical P loop will be decreased. As a consequence, the efficacy of chemical agents targeting P-reduction by chemical binding will be hampered by heatwaves. Our study indicates that current restoration measures might be challenged in a future with more frequent and intense heatwaves.

Between mid-September and 19 October 2008, nine clusters of norovirus infection involving around 90 primary cases and over a hundred secondary cases were identified in patients from the Netherlands, Ireland, Italy and France, linked to pilgrimage to Lourdes, France.