Defining vulnerability subgroups among pregnant women using pre-pregnancy information: a latent class analysis.

BACKGROUND: Early detection of vulnerability during or before pregnancy can contribute to optimizing the first 1000 days, a crucial period for children's development and health. We aimed to identify classes of vulnerability among pregnant women in the Netherlands using pre-pregnancy data on a wide range of social risk and protective factors, and validate these classes against the risk of adverse outcomes. METHODS: We conducted a latent class analysis based on 42 variables derived from nationwide observational data sources and self-reported data. Variables included individual, socioeconomic, lifestyle, psychosocial and household characteristics, self-reported health, healthcare utilization, life-events and living conditions. We compared classes in relation to adverse outcomes using logistic regression analyses. RESULTS: In the study population of 4172 women, we identified five latent classes. The largest 'healthy and socioeconomically stable'-class [n = 2040 (48.9%)] mostly shared protective factors, such as paid work and positively perceived health. The classes 'high care utilization' [n = 485 (11.6%)], 'socioeconomic vulnerability' [n = 395 (9.5%)] and 'psychosocial vulnerability' [n = 1005 (24.0%)] were characterized by risk factors limited to one specific domain and protective factors in others. Women classified into the 'multidimensional vulnerability'-class [n = 250 (6.0%)] shared multiple risk factors in different domains (psychosocial, medical and socioeconomic risk factors). Multidimensional vulnerability was associated with adverse outcomes, such as premature birth and caesarean section. CONCLUSIONS: Co-existence of multiple risk factors in various domains is associated with adverse outcomes for mother and child. Early detection of vulnerability and strategies to improve parental health and well-being might benefit from focussing on different domains and combining medical and social care and support.

Dietary acid load, trabecular bone integrity, and mineral density in an ageing population: the Rotterdam study.

We studied the relation between a diet that is high in acid-forming nutrients (e.g. proteins) and low in base-forming nutrients (e.g. potassium) and bone structure. We showed a negative relation, which was more prominent if proteins were of animal rather than of vegetable origin and if intake of dietary fibre was high. INTRODUCTION: Studies on dietary acid load (DAL) and fractures have shown inconsistent results. Associations between DAL, bone mineral density (BMD) and trabecular bone integrity might play a role in these inconsistencies and might be influenced by renal function and dietary fibre intake. Therefore, our aim was to study (1) associations of DAL with BMD and with the trabecular bone score (TBS) and (2) the potential influence of renal function and dietary fibre in these associations. METHODS: Dutch individuals aged 45 years and over (n = 4672) participating in the prospective cohort of the Rotterdam study were included. Based on food frequency questionnaires, three indices of DAL were calculated: the net endogenous acid production (NEAP) and the ratios of vegetable or animal protein and potassium (VegPro/K and AnPro/K). Data on lumbar spinal TBS and BMD were derived from dual-energy X-ray absorptiometry measurements. RESULTS: Independent of confounders, NEAP and AnPro/K, but not VegPro/K, were associated with low TBS (standardized ß (95%) = -0.04 (-0.07, -0.01) and -0.08 (-0.11, -0.04)) but not with BMD. Associations of AnPro/K and VegPro/K with TBS were non-linear and differently shaped. Unfavourable associations between NEAP, BMD and TBS were mainly present in subgroups with high fibre intake. CONCLUSIONS: High NEAP was associated with low TBS. Associations of AnPro/K and VegPro/K and TBS were non-linear and differently shaped. No significant associations of DAL with BMD were observed, nor was there any significant interaction between DAL and renal function. Mainly in participants with high intake of dietary fibre, DAL might be detrimental to bone.

Protein intake in early childhood and body composition at the age of 6 years: The Generation R Study.

BACKGROUND: Previous studies suggest that high protein intake in infancy leads to a higher body mass index (BMI) in later childhood. We examined the associations of total, animal and vegetable protein intake in early childhood with detailed measures of body composition at the age of 6 years. METHODS: This study was performed in 2911 children participating in a population-based cohort study. Protein intake at the age of 1 year was assessed with a validated food-frequency questionnaire and was adjusted for total energy intake. At the children's age of 6 years, we measured their anthropometrics and body fat (with dual-energy X-ray absorptiometry). We calculated age- and sex-specific s.d. scores for BMI, fat mass index (FMI) and fat-free mass index (FFMI). RESULTS: After adjustment for confounders, a 10 g per day higher total protein intake at 1 year of age was associated with a 0.05 s.d. (95% confidence interval (CI) 0.00, 0.09) higher BMI at age 6. This association was fully driven by a higher FMI (0.06 s.d. (95%CI 0.01, 0.11)) and not FFMI (-0.01 s.d. (95%CI -0.06, 0.05)). The associations of protein intake with FMI at 6 years remained significant after adjustment for BMI at the age of 1 year. Additional analyses showed that the associations of protein intake with FMI were stronger in girls than in boys (P for interaction=0.03), stronger among children who had catch-up growth in the first year of life (P for interaction<0.01) and stronger for intake of animal protein (both dairy and non-dairy protein) than protein from vegetable sources. CONCLUSIONS: Our results suggest that high protein intake in early childhood is associated with higher body fat mass, but not fat-free mass. Future studies are needed to investigate whether these changes persist into adulthood and to examine the optimal range of protein intake for infants and young children.

Infant dietary patterns and bone mass in childhood: the Generation R Study.

UNLABELLED: Early life nutrition affects peak bone mass attainment. In this prospective cohort study, children with high adherence to a "dairy and whole grains" pattern in infancy had higher bone mineral density at the age of 6 years. Although the observed effects are small, our study provides insight into mechanisms linking early nutrition to bone acquisition in childhood. INTRODUCTION: Nutrition in early life may affect peak bone mass attainment. Previous studies on childhood nutrition and skeletal health mainly focused on individual nutrients, which does not consider the cumulative effects of nutrients. We investigated the associations between dietary patterns in infancy and childhood bone health. METHODS: This study included 2850 children participating in a population-based prospective cohort study. Dietary information was obtained from a food frequency questionnaire at the age of 13 months. Using principal component analysis, three major dietary patterns were extracted, explaining in total 30% of the variation in dietary intake. At the age of 6 years, a total body dual-energy X-ray absorptiometry (DXA) scan was performed, and bone mineral density (BMD), bone mineral content (BMC), area-adjusted BMC (aBMC), and bone area (BA) were analyzed. RESULTS: Higher adherence score to a "dairy and whole grains" pattern was positively associated with BMD and aBMC, but not with BMC and BA. Accordingly, children in the highest quartile of the "dairy and whole grains" pattern had higher BMD (difference 3.98 mg/cm(2), 95% confidence interval (CI) 0.36 to 7.61) and aBMC (difference 4.96 g, 95% CI 1.27 to 8.64) than children in the lowest quartile. Stratification for vitamin D supplementation showed that the positive associations between the "dairy and whole grains" pattern and bone outcomes were only observed in children who did not receive vitamin D supplementation. A "potatoes, rice, and vegetables" and a "refined grains and confectionery" pattern were not consistently associated with bone outcomes. CONCLUSIONS: An infant dietary pattern characterized by high intakes of dairy and cheese, whole grains, and eggs is positively associated with bone development in childhood. Further research is needed to investigate the consequences for bone health in later life.

Genetic taste blindness to bitter and body composition in childhood: a Mendelian randomization design.

BACKGROUND: The ability to taste 6-n-propylthiouracil (PROP) may be associated with body composition, but previous findings from observational studies are conflicting and cannot be interpreted causally. The aim of this study was to estimate the causal association between PROP taster status and body composition in a population-based cohort study. METHODS: The study was embedded in a population-based prospective birth cohort study. The TAS2R38 genotype (rs713598) was used as an instrumental variable (IV) to obtain unbiased effect estimates of the relation between PROP taster status and body weight (n=3778). Adiposity measures included body mass index (BMI) and fat mass measured by dual- energy X-ray absorptiometry scan at the child's age of 6 years. Associations were investigated using both ordinary linear regression (OLS) and two-stage least squares regression (2SLS). RESULTS: Non-taster girls had higher BMI standard deviation scores (SDS) and higher body fat as compared with taster girls (results from linear regression BMI SDS: -0.09, P=0.023, body fat mass (%): -0.49, P=0.028). The TAS2R38 genotype predicted PROP phenotype (F=240), indicating a strong IV. The 2SLS effect estimates were imprecise but similar to the observational estimates (-0.08 for BMI SDS and -0.46 for body fat mass %) and were not significantly different from the OLS results (Hausman test: P>0.10). For boys there were no differences observed between tasters and non-tasters. CONCLUSIONS: Our findings suggest a causal relation between PROP taster status and body weight among 6-year-old girls; Mendelian randomization was consistent with conventional estimates. In contrast, body weight among boys appeared to be independent of the PROP taster status. Further research should focus on possible underlying pathways, such as dietary behavior.

Determinants of and interventions for Proton Pump Inhibitor prescription behavior: A systematic scoping review.

BACKGROUND: Proton Pump Inhibitors (PPI) are frequently prescribed. Long-term use is associated with side-effects and patients often lack a valid indication. Inappropriate PPI prescribing thus needs to be addressed. This review aims to scope 1) what determinants are studied as reasons for PPI prescribing, 2) what strategies are used for changing PPI (de)prescribing, and 3) whether important determinants are addressed in these interventions. METHODS: We searched eight databases for papers on determinants of physician PPI prescribing. Studies were included if they were conducted in a Western country and focused on oral PPIs for an adult population. By following the Behaviour Change Wheel, we extracted information regarding PPI prescribing behavior, behavioral determinants and intervention strategies. FINDINGS: We included 74 papers. Most focused on the determinants knowledge and beliefs about consequences. The latter was consistently related to PPI prescribing. Results for knowledge were mixed. Most interventions used education or enablement (e.g., algorithms, quality check improvements, involvement of pharmacists) as strategies. Enablement consistently improved PPI prescribing, while results for education were mixed. INTERPRETATION: There is an overemphasis on reflective processes in studies on PPI prescribing. Future research should comprehensively identify behavioral determinants, focusing on reflective and impulsive processes, such that interventions can address the most important determinants.

Neonatal folate, homocysteine, vitamin B12 levels and methylenetetrahydrofolate reductase variants in childhood asthma and eczema.

OBJECTIVES: To assess the associations of folate, homocysteine and vitamin B12 levels of children at birth and their methylenetetrahydrofolate reductase (MTHFR) variants with asthma and eczema in childhood. METHODS: This study was embedded in a population-based prospective cohort study (n = 2,001). Neonatal cord blood folate, homocysteine and vitamin B12 levels were measured, and MTHFR C677T and A1298C genotyped. Wheezing and physician-diagnosed eczema were annually obtained by questionnaire until 4 years. At 6 years, we collected information on physician-diagnosed asthma ever and self-reported eczema ever, measured fractional exhaled nitric oxide (FeNO), and interrupter resistance (Rint). Data were analysed with generalized estimating equations or logistic regression: continuous outcomes with linear regression models. RESULTS: Folate, homocysteine and vitamin B12 levels of children at birth were not associated with wheezing or eczema until 4 years, asthma and eczema ever, or FeNO or Rint at 6 years. In children carrying C677T mutations in MTHFR, higher folate levels were associated with an increased risk of eczema (repeated eczema until 4 years: OR 1.40 (95% CI 1.09-1.80) (SD change) P-interaction = 0.003, eczema ever at 6 years: OR 1.41 (0.97-2.03) P-interaction = 0.011). No interactions between MTHFR and child folate and homocysteine levels were observed for wheezing and asthma. CONCLUSIONS: Folate, homocysteine and vitamin B12 levels of children at birth did not affect asthma- and eczema-related outcomes up to the age of 6 years. Further studies are warranted to establish the role of MTHFR variants in these associations.

The introduction of a data-driven population health management approach in the Netherlands since 2019: The Extramural LUMC Academic Network data infrastructure.

Improving population health and reducing inequalities through better integrated health and social care services is high up on the agenda of policymakers internationally. In recent years, regional cross-domain partnerships have emerged in several countries, which aim to achieve better population health, quality of care and a reduction in the per capita costs. These cross-domain partnerships aim to have a strong data foundation and are committed to continuous learning in which data plays an essential role. This paper describes our approach towards the development of the regional integrative population-based data infrastructure Extramural LUMC (Leiden University Medical Center) Academic Network (ELAN), in which we linked routinely collected medical, social and public health data at the patient level from the greater The Hague and Leiden area. Furthermore, we discuss the methodological issues of routine care data and the lessons learned about privacy, legislation and reciprocities. The initiative presented in this paper is relevant for international researchers and policy-makers because a unique data infrastructure has been set up that contains data across different domains, providing insights into societal issues and scientific questions that are important for data driven population health management approaches.

A newly discovered human pneumovirus isolated from young children with respiratory tract disease.

From 28 young children in the Netherlands, we isolated a paramyxovirus that was identified as a tentative new member of the Metapneumovirus genus based on virological data, sequence homology and gene constellation. Previously, avian pneumovirus was the sole member of this recently assigned genus, hence the provisional name for the newly discovered virus: human metapneumovirus. The clinical symptoms of the children from whom the virus was isolated were similar to those caused by human respiratory syncytial virus infection, ranging from upper respiratory tract disease to severe bronchiolitis and pneumonia. Serological studies showed that by the age of five years, virtually all children in the Netherlands have been exposed to human metapneumovirus and that the virus has been circulating in humans for at least 50 years.

Prevalence of and risk factors for extended-spectrum beta-lactamase genes carriership in a population-based cohort of middle-aged and elderly.

INTRODUCTION: Increasing resistance to beta-lactam antibiotics is an alarming development worldwide. Fecal carriership of TEM, SHV, CTX-M and CMY was studied in a community-dwelling population of middle-aged and elderly individuals. PATIENTS AND METHODS: Feces was obtained from individuals of the Rotterdam Study. Carriership of the TEM, SHV, CTX-M and CMY genes was determined using real-time polymerase chain reaction (qPCR). Possible associations were investigated between carriership of these genes and several risk factors, such as the use of antimicrobial drugs, diabetes mellitus, protein pump inhibitor (PPI) use, travelling, the composition of the gut microbiota, and intake of certain foods. RESULTS: The most prevalent gene was TEM (53.0%), followed by SHV (18.4%), CTX-M (5.4%) and CMY (3.6%). Use of penicillins with extended spectrum was associated with TEM carriership, whereas use of macrolides and lincosamides was associated with TEM and SHV carriership. Interestingly, use of PPIs was associated with a higher prevalence of carriership of TEM, SHV and CMY (TEM: odds ratio [OR] 1.34; 95% confidence interval [CI] 1.05-1.77; SHV: OR 2.17; 95%CI 1.55-2.87; CMY: OR 2.26; 95%CI 1.23-4.11). Furthermore, associations were found between the richness and composition of the gut microbiota and TEM and SHV carriership. CONCLUSIONS: The prevalence of carriership of TEM was substantial, but the prevalence of carriership of the extended-spectrum ß-lactamase gene, CTX-M and the AmpC ß-lactamase gene, CMY was relatively low in this community-dwelling, population-based cohort. The composition of the microbiota might play a role in the retention of resistance genes, but future studies are necessary to further elucidate this relationship.

Infant nutritional factors and functional constipation in childhood: the Generation R study.

OBJECTIVES: Food allergy and celiac disease may lead to childhood constipation. Early introduction of food allergens and gluten in the first year of life has been suggested to have a function in these food intolerances, but it is unclear whether this also holds true for development of childhood constipation. The aim of this study was to assess the association between the timing of introduction of food allergens and gluten early in life and functional constipation in childhood. METHODS: This study was embedded in the Generation R study, a population-based prospective cohort study from fetal life until young adulthood. Functional constipation at 24 months of age was defined in 4,651 children according to the Rome II criteria of defecation frequency <3 times a week or the presence of mainly hard feces for at least 2 weeks. RESULTS: At the age of 24 months, 12% of the children had functional constipation. Children with functional constipation got introduced to gluten more often before or at the age of 6 months than children without functional constipation (37% and 27%, respectively). After adjustment for birth weight, gestational age, gender, ethnicity, maternal education, and family history of atopy and chronic intestinal disorders, functional constipation was significantly associated with early gluten introduction (odds ratio (OR): 1.35; 95% confidence interval (CI): 1.10-1.65). No association was found between timing of introduction of cow's milk, hen's egg, soy, peanuts, and tree nuts with functional constipation. A history of cow's milk allergy in the first year of life was significantly associated with functional constipation in childhood (OR: 1.57; 95% CI: 1.04-2.36). CONCLUSIONS: These results suggest that early gluten introduction in the first year of life provide a trigger for functional constipation in a subset of children. In case of functional constipation, there also might be a role for cow's milk allergy initiated in the first year of life.

Long-term effects of antimicrobial drugs on the composition of the human gut microbiota.

INTRODUCTION: Antimicrobial drugs are known to have effects on the human gut microbiota. We studied the long-term temporal relationship between several antimicrobial drug groups and the composition of the human gut microbiota determined in feces samples. METHODS: Feces samples were obtained from a community-dwelling cohort of middle-aged and elderly individuals (Rotterdam Study). Bacterial DNA was isolated and sequenced using V3/V4 16 S ribosomal RNA sequencing (Illumina MiSeq). The time between the last prescription of several antimicrobial drug groups and the day of sampling was categorized into 0-12, 12-24, 24-48 and >48 months. The effects of the antimicrobial drug groups on the Shannon alpha-diversity (diversity), the Bray-Curtis beta-diversity (community structure), the Firmicutes/Bacteroidetes (F/B) ratio and individual genera were determined. RESULTS: We studied the gut microbiota of 1413 individuals (57.5% female, median age 62.6 years). The alpha-diversity was significantly lower up to 4 years after prescriptions of macrolides and lincosamides. It was also lower in the first year after the use of beta-lactams. The community structure (beta-diversity) of the microbiota was significantly different up to 4 years for macrolides and lincosamides, the first year for beta-lactams and at least the first year for quinolones. For the F/B ratio, drugs with a high anaerobic activity shifted the ratio toward Firmicutes in the first year whereas other antimicrobial drugs shifted the ratio toward Bacteroidetes. CONCLUSION: Use of antimicrobial drugs is associated with a shift in the composition of the gut microbiota.These effects differ in strength and duration, depending on the antimicrobial drug group used. These findings should be considered when prescribing antimicrobial drugs.

The Obesity Paradox in Lung Cancer: Associations With Body Size Versus Body Shape.

BACKGROUND: The association between obesity and lung cancer (LC) remains poorly understood. However, other indices of obesity on the basis of body shape instead of body size have not been examined yet. The aim of this study was to evaluate the association between different indices of body size and body shape and the risk of LC. In particular, this study examined the association between A Body Shape Index, a more precise indicator of abdominal fat than traditional anthropometric measures, and the risk of LC. METHODS: In the prospective cohort the Rotterdam Study, we analysed data of 9,689 participants. LC diagnoses were based on medical records and anthropometric measurements were assessed at baseline. Cox-regression analyses with corresponding Hazard Ratios were used to examine the association between the anthropometric measurements and the risk of LC with adjustment for potential confounders. Potential non-linear associations were explored with cubic splines using the Likelihood ratio (LR) test. RESULTS: During follow-up, 319 participants developed LC. Body mass Index (BMI) was inversely associated with the risk of lung cancer (HR 0.94, 95% CI: 0.91-0.97) and persisted after excluding lung cancer cases during the first 10 years of follow-up. There was evidence for a non-linear association between BMI and the risk of lung cancer (0,04, df = 1), which indicated that the inverse association between BMI and lung cancer was mainly present in non-obese participants. Waist circumference (WC) (HR 1.03 95% CI: 1.01-1.05), Waist-to-Hip Ratio (WHR) (HR 1.23 95% CI: 1.09-1.38) and ABSI (A Body Shape Index) (HR 1.17 95% CI: 1.05-1.30) were positively and linearly associated with the risk of lung cancer. CONCLUSIONS: Body shape rather than body size may be an important risk indicator of LC. Future research should focus on the role of visceral fat and the risk of LC as well as the underlying mechanisms.

Diet as a risk factor for antimicrobial resistance in community-acquired urinary tract infections in a middle-aged and elderly population: a case-control study.

OBJECTIVES: There is an ongoing debate as to what extent antimicrobial resistance (AMR) can be transmitted from animals to humans via the consumption of animal products. Because epidemiological data on the role of diet in AMR in humans are lacking, we investigated this association between diet and AMR for different antimicrobial drugs in Escherichia coli (E. coli) in urinary tract infections (UTIs). METHODS: Susceptibility of E. coli in urinary cultures and information on diet (with food frequency questionnaires) were obtained from participants of the Rotterdam study, a population-based prospective cohort study. The association between intake of several food groups (meat, seafood, eggs, dairy products, crops) and resistance of E. coli to several antimicrobial drugs (amoxicillin, amoxicillin-clavulanic acid, trimethoprim, sulfamethoxazole-trimethoprim, first-generation cephalosporins, cefotaxime, nitrofurantoin, norfloxacin) was studied. RESULTS: Urinary cultures with E. coli were obtained from 612 individuals, of whom 481 (78.6%) were women. Resistance rates varied from 246/611 (40.3%) for amoxicillin and 167/612 (27.3%) for trimethoprim to only 29/612 (4.7%) for nitrofurantoin and 16/462 (3.5%) for cefotaxime. A higher intake of chicken was associated with cefotaxime resistance (OR 2.18; 95% CI 1.05-4.51 per tertile increase); a higher intake of pork was associated with norfloxacin resistance (OR 1.42; 95% CI 1.04-1.95 per quartile increase). In contrast, a higher intake of cheese was associated with lower AMR to amoxicillin (OR 0.84; 95% CI 0.72-0.99 per quartile increase) and amoxicillin-clavulanic acid (OR 0.67; 95% CI 0.53-0.86 per quartile increase). CONCLUSIONS: These findings support the hypothesis that diet may play a role in the AMR of E. coli in UTIs.

[The practice guideline 'Influenza and influenza vaccination' (first revision) from the Dutch College of General Practitioners; a response from the perspective of virology]. / De standaard 'Influenza en influenzavaccinatie' (eerste herziening) van het Nederlands Huisartsen Genootschap; reactie vanuit de virologie.

The main value of the new guideline on influenza and influenza vaccination developed by the Dutch College of General Practitioners is that it provides an update of the old version from 1993. Developments in the fields of vaccination and treatment are adequately described and clearly explained in more detail in numerous notes to the main text. Notable updates include the fact that vaccination will be recommended for people aged more than 60 years rather than 65 years in the coming season, and the introduction ofneuraminidase inhibitors. The complex virological aspects of influenza are well covered.

[Registration of the first human vaccine against the highly pathogenic avian influenza A(H5N1) virus: considerations]. / Het eerste in Europa geregistreerde humane vaccin tegen de hoogpathogene vorm van een vogelgriepvirus: overwegingen.

Since its emergence in 1997, the highly pathogenic avian influenza A(H5N1) virus has posed the threat of causing a human pandemic. The question is whether it is feasible and advisable to attempt to give the population a certain degree of basic immunity to this virus. The recent development of effective adjuvants, which culminated this year in the approval of such a vaccine for human use in the European Union, indicates that the approach is possible, although many logistical problems remain. Pre-pandemic vaccination could be considered for the total population or for the most vulnerable groups, i.e. individuals receiving annual influenza vaccination. Another option is stock-piling vaccine, preferably separately from the adjuvant.

[Influenza season 2007/'08 in the Netherlands: antigenic variation, oseltamivir resistance and vaccine composition for the 2008/'09 season]. / Het influenzaseizoen 2007/'08 in Nederland: antigene variatie, resistentie tegen oseltamivir en de vaccinsamenstelling voor het seizoen 2008/'09.

The first signs of influenza activity during the 2007/'08 influenza season in the Netherlands were sporadic isolations of influenza viruses between week 40 and week 52 of 2007. The frequency of virus isolations and clinical influenza activity increased after week 1 of 2008 and peaked around week 9. In this week, 7.2 patients with influenza-like illness were recorded per 10,000 inhabitants. The influenza epidemic was caused primarily by influenza A/H1N1 viruses and influenza B viruses. Two antigenically distinct variants of influenza A/H1N1 viruses were isolated, which resembled the 2007/'08 vaccine reference strain A/Solomon Islands/3/06 and the new vaccine reference strain A/Brisbane/59/07, respectively. The most remarkable finding was that 27% of the A/H1N1 viruses isolated in the Netherlands during the 2007/'08 epidemic were resistant to the neuraminidase inhibitor oseltamivir. The isolated influenza B viruses originated from the B/Yamagata/16/88 lineage and did not match the vaccine strain, which originated from a different and antigenically distinct lineage of influenza B viruses (B/Victoria/2/87). Only a small number of influenza A/H3N2 viruses was isolated, which were related to the vaccine strain for this subtype (A/Wisconsin/67/05). Thus in contrast to previous influenza seasons, A/H3N2 viruses did not play a major role in the 2007/'08 influenza season in the Netherlands. For the 2008/'09 influenza season, the World Health Organization has recommended the following vaccine composition: A/Brisbane/59/07 (H1N1), A/Brisbane/10/07 (H3N2) and B/Florida/4/06.

[New target populations for influenza vaccination; recommendations of the Health Council of the Netherlands]. / Nieuwe doelgroepen voor influenzavaccinatie; advies van de Gezondheidsraad.

The Health Council of the Netherlands has revised the recommendations for influenza vaccination. The council has preserved most of the target populations of the indications defined in 1998, including asthma patients up to the age of 18 years, has cancelled the group offurunculosis patients and their families and has added four groups, i.e. healthy persons aged 60-64, care home staff, other health care workers with direct contact with patients, and family members of individuals at very high risk for complications from influenza.

[Influenza vaccination in health-care workers: an effective method to reduce the consequences of influenza in health care users]. / Influenzavaccinatie van gezondheidswerkers: effectieve methode om de gevolgen van influenza bij zorggebruikers te verminderen.

Only few usable studies into the effect of influenza vaccination of health-care workers on sick leave and influenza among their patients are available in the literature. However, together these studies provide consistent evidence that this vaccination is effective and cost effective, reducing the death rate from all causes of residents of nursing homes for the elderly by 27-44%. Therefore, measures to raise the vaccination rate among health-care workers, which is at present under 25%, are highly recommended. However, more studies in this field are needed.

[The 2006/'07 influenza season in the Netherlands and the vaccine composition for the 2007/'08 season]. / Het influenzaseizoen 2006/'07 in Nederland en de vaccinsamenstelling voor het seizoen 2007/'08.

The influenza epidemic of 2006/'07 began late in the season, like the two previous influenza epidemics. In week 8 a peak of modest height was reached. As usual, the causal strains were mainly A/H3N2 viruses and to a lesser extent A/H1N1 and B viruses. A new A/H1N1 virus variant has emerged, an event that on average takes place only every 10 years. However, almost all A/H1N1 virus isolates belonged to the old variant and were similar to the vaccine virus. The A/H3N2 virus isolates appeared to deviate from the vaccine strain, but after antigenic cartographic analysis and correction for low avidity they proved also closely related to the vaccine strain. The few type B virus isolates belonged to the B/Yamagata/16/88 lineage, whereas the used B vaccine virus had been chosen from the B/Victoria/2/87 lineage. The vaccine therefore will have provided almost optimal protection against the circulating influenza A/H1N1 and A/H3N2 viruses but not against the influenza B viruses. For the 2007/'08 influenza season the World Health Organization has recommended the following vaccine composition: A/Solomon Islands/3/06 (H1N1) (new), A/Wisconsin/67/05 (H3N2), and B/Malaysia/2506/04.