Day care in relation to respiratory-tract and gastrointestinal infections in a German birth cohort study

Improving hand hygiene of young children with a digital intervention: a cluster-randomised controlled field trial

Contagious diseases that affect young children place a great burden on them and their families. Proper hand hygiene is an important measure to reduce the disease burden, however, its implementation in day care centres is challenging. This paper introduces a digital intervention to support independent and good handwashing among young children. The intervention leverages animated instructions triggered by water and soap use, together with a symbolic reward shown to children on a screen during and immediately after handwashing. We tested the intervention in a pre-registered, cluster-randomised controlled field trial in 4 day care centres in Finland and Germany with 162 children over 42 days. The intervention increased soaping time, used as a proxy for handwashing quality, by 5.30 s (+ 62%, p < 0.001). The effect occurs immediately at the onset of the intervention and is maintained throughout the intervention phase.

Perinatal and Other Risk Factors for Common Infections in Infancy: A Prospective Cohort Study

OBJECTIVE

Limited data from prospective cohort studies in high-income countries are available on the perinatal risk factors for common infections in children. Our hypothesis was that perinatal factors may be risk factors for infectious episodes during the first year of life.

METHODS

In this prospective Health and Early Life Microbiota birth cohort study of full-term infants (n = 1052) born in 2016-2018, the number and duration of infection episodes were collected online at weekly to monthly intervals. In a multivariate regression model, the main exposures were perinatal factors such as mode of delivery and intrapartum antibiotics. Environmental factors were additional exposures. The outcomes were the number and duration of infectious episodes in the first year of life.

RESULTS

The mean number of infection episodes was 4.2 (2.9 SD). The mean duration of infection symptoms was 44 days (40 SD). Upper respiratory infections accounted for 83% of the episodes (3674/4455). Perinatal factors were not associated with the number nor the duration of infection episodes, but cesarean section was associated with an increased occurrence of urinary tract infections in infancy [adjusted odds ratio (aOR): 3.6; 95% confidence interval (CI): 1.13-11.1]. Of the additional exposures male sex (aOR: 1.1; 95% CI: 1.0-1.2) and the presence of siblings (aOR: 1.3; 95% CI: 1.2-1.4) were associated with the number of infection episodes.

CONCLUSIONS

This prospective cohort study showed that perinatal factors, mode of delivery and intrapartum antibiotics were not associated with the risk of common infections in infancy, but cesarean delivery was associated with a risk of urinary tract infections.

Associations of dietary patterns with common infections and antibiotic use among Finnish preschoolers

Background

Preschoolers suffer frequently from infections. Although nutrition plays a key role in immune function, very little is known about the impact of overall diet on preschoolers' infections.

Objective

To assess the associations between dietary patterns, common infections and antibiotic use among Finnish preschoolers.

Design

The study included 721 3-6-year-old preschoolers participating in the cross-sectional DAGIS survey. Parents retrospectively reported the number of common colds, gastroenteritis episodes and antibiotic courses their children had acquired during the past year. Food consumption outside preschool hours was recorded using a food frequency questionnaire. Dietary patterns were derived from the consumption frequencies using principal component analysis. Associations between the thirds of the dietary pattern scores and the outcomes were analysed using logistic and negative binomial regression models.

Results

Prevalence of common colds was lower in moderate and high adherence to the sweets-and-treats pattern than in low adherence (prevalence ratio [PR]: 0.89, 95% confidence interval [CI]: 0.80-1.00, and PR: 0.88, 95% CI: 0.79-0.99, respectively) and higher in high adherence to the health-conscious pattern than in low adherence (PR: 1.13, 95% CI: 1.01-1.27) after adjusting for age, sex, number of children living in the same household, frequency of preschool attendance, family's highest education and probiotic use. The risk of ≥1 gastroenteritis episode and the prevalence of antibiotic courses were lower in moderate adherence to the sweets-and-treats pattern than in low adherence (odds ratio [OR]: 0.63, 95% CI: 0.44-0.92 and PR: 0.77, 95% CI: 0.59-1.00, respectively).

Conclusions

The results were unexpected. Parents who were most health-conscious of their children's diet might also have been more aware of their children's illness.

Childcare attendance and risk of infections in childhood and adolescence

Background

It has been suggested that the transiently increased infection risk following childcare enrolment is compensated by decreased infection risk later in childhood and adolescence. We investigated how childcare enrolment affected rates of antimicrobial-treated infections during childhood and adolescence.

Methods

In a register-based cohort study of all children born in Denmark 1997–2014 with available exposure information (n = 1 007 448), we assessed the association between childcare enrolment before age 6 years and infection risks up to age 20 years, using antimicrobial exposure as proxy for infections. Nationwide childcare and prescription data were used. We estimated infection rates and the cumulative number of infections using adjusted Poisson regression models.

Results

We observed 4 599 993 independent episodes of infection (antimicrobial exposure) during follow-up. Childcare enrolment transiently increased infection rates; the younger the child, the greater the increase. The resulting increased cumulative number of infections associated with earlier age at childcare enrolment was not compensated by lower infection risk later in childhood or adolescence. Accordingly, children enrolled in childcare before age 12 months had experienced 0.5–0.7 more infections at age 6 years (in total 4.5–5.1 infections) than peers enrolled at age 3 years, differences that persisted throughout adolescence. The type of childcare had little impact on infection risks.

Conclusions

Early age at childcare enrolment is associated with a modest increase in the cumulative number of antimicrobial-treated infections at all ages through adolescence. Emphasis should be given to disrupting infectious disease transmission in childcare facilities through prevention strategies with particular focus on the youngest children.

Beneficial Effects of Limosilactobacillus fermentum CECT 5716 Administration to Infants Delivered by Cesarean Section

Cesarean section (CS) disrupts the natural microbiota colonization process in infants, which might compromise immune system maturation, leading to a higher risk of infections. We evaluated the effect of the probiotic Limosilactobacillus (L.) fermentum CECT 5716 on the incidence of gastrointestinal and respiratory infections in the CS infant subgroups (n = 173) of three randomized clinical trials in which this probiotic strain was demonstrated to be safe and effective for preventing infections. Therefore, the data for the CS infants were extracted to obtain the incidence rate ratio (IRR) and 95% CI for gastrointestinal and respiratory infections for each study and were then combined to obtain a pooled IRR and 95% CI using the generic inverse variance method. There was a significant reduction of 73% in the incidence of gastrointestinal infections in CS infants receiving L. fermentum CECT 5716 compared with those receiving the control formula [n = 173, IRR: 0.27 (0.13, 0.53), p = 0.0002]. Regarding respiratory infections, although pooled results showed a reduction of 14% in the probiotic group, the difference was not statistically significant [n = 173, IRR (95% CI): 0.86 (0.67, 1.11), p = 0.25]. In conclusion, the administration of L. fermentum CECT 5716 to CS-born infants protects them from gastrointestinal infections by reducing the risk by up to 73% in this population.

Child Care Center Hand Hygiene Programs' Cost-Effectiveness in Preventing Respiratory Infections

BACKGROUND

We previously demonstrated that a hand hygiene program, including hand sanitizer and educational measures, for day care center (DCC) staff, children, and parents was more effective than a soap-and-water program, with initial observation, in preventing respiratory infections (RIs) in children attending DCCs. We analyzed the cost-effectiveness of these programs in preventing RIs.

METHODS

A cluster, randomized, controlled and open study of 911 children aged 0 to 3 years, attending 24 DCCs in Almeria. Two intervention groups of DCC-families performed educational measures and hand hygiene, one with soap-and-water (SWG) and another with hand sanitizer (HSG). The control group (CG) followed usual hand-washing procedures. RI episodes, including symptoms, treatments, medical contacts, complementary analyses, and DCC absenteeism days, were reported by parents. A Bayesian cost-effectiveness model was developed.

RESULTS

There were 5201 RI episodes registered. The adjusted mean societal costs of RIs per child per study period were CG: €522.25 (95% confidence interval [CI]: 437.10 to 622.46); HSG: €374.53 (95% CI: 314.90 to 443.07); SWG: €494.51 (95% CI: 419.21 to 585.27). The indirect costs constituted between 35.7% to 43.6% of the total costs. Children belonging to the HSG had an average of 1.39 fewer RI episodes than the CG and 0.93 less than the SWG. It represents a saving of societal cost mean per child per study period of €147.72 and €119.15, respectively. The HSG intervention was dominant versus SWG and CG.

CONCLUSIONS

Hand hygiene programs that include hand sanitizer and educational measures for DCC staff, children, and parents are more effective and cost less than a program with soap and water and initial observation in children attending DCCs.

Cost of Illness in Young Children: A Prospective Birth Cohort Study

Childhood illness is extremely common and imposes a considerable economic burden on society. We aimed to quantify the overall economic burden of childhood illness in the first three years of life and the impact of environmental risk factors. The study is based on the prospective, clinical mother-child cohort Copenhagen Prospective Studies on Asthma in Childhood (COPSAC2010) of 700 children with embedded randomized trials of fish-oil and vitamin D supplementations during pregnancy. First, descriptive analyses were performed on the total costs of illness, defined as both the direct costs (hospitalizations, outpatient visits, visit to the practitioner) and the indirect costs (lost earnings) collected from the Danish National Health Registries. Thereafter, linear regression analyses on log-transformed costs were used to investigate environmental determinants of the costs of illness. The median standardized total cost of illness at age 0-3 years among the 559 children eligible for analyses was EUR 14,061 (IQR 9751-19,662). The exposures associated with reduced costs were fish-oil supplementation during pregnancy (adjusted geometric mean ratio (GMR) 0.89 (0.80; 0.98), p = 0.02), gestational age in weeks (aGMR = 0.93 (0.91; 0.96), p < 0.0001), and birth weight per 100 g (aGMR 0.98 (0.97; 0.99), p = 0.0003), while cesarean delivery was associated with higher costs (aGMR = 1.30 (1.15; 1.47), p < 0.0001). In conclusion, common childhood illnesses are associated with significant health-related costs, which can potentially be reduced by targeting perinatal risk factors, including maternal diet during pregnancy, cesarean delivery, preterm birth and low birth weight.

Effectiveness of a hand hygiene program to reduce acute gastroenteritis at child care centers: A cluster randomized trial

We aimed to assess the effectiveness of an educational and hand hygiene program in daycare centers (DCCs) and homes on acute gastroenteritis (AGE) incidence in children attending DCCs.

METHODS

A randomized, controlled, and open study of 911 children aged 0-3 years attending 24 DCCs in Almería (Spain) with an 8-month follow-up was employed. Two intervention groups of DCCs families performed educational and hand hygiene measures, 1 with soap and water (soap and water group; n = 274), another with hand sanitizer (hand sanitizer group [HSG]; n = 339), and the control group (CG; n = 298) followed usual handwashing procedures. We compared AGE episode rates with Poisson regression model.

RESULTS

seven hundred fourteen AGE episodes were registered, significant differences between HSG and CG children were found during December and January. A multivariate model was applied and the adjusted incidence rate ratios by rotavirus vaccination found significant differences when children were previously vaccinated, the children in the soap and water group had a higher risk of AGE episodes (incidence rate ratio: 1.28, 95% confidence interval:1.0-1.64), compared with those in the HSG.

CONCLUSIONS

This study demonstrated that hand hygiene programs that included hand sanitizer were most effective in the winter months. Further, the largest reduction of AGE episodes occurred in the children that followed hand hygiene programs including hand sanitizer and educational measures for DCC staff, parents, and children, and were vaccinated for rotavirus.

Infection control in child daycare centers: logistics, knowledge, and practices of caregivers

Background

Children attending daycare centers (DCCs) are at high risk of contracting infectious diseases due to several factors including lack of knowledge among the caregivers about infection prevention and control practices. The objectives were to describe the DCC features, infrastructure, and infection control logistics, to assess knowledge of DCC caregivers regarding infectious diseases, and to assess their infection control practices.

Methods

Using a cross-sectional design, 402 caregivers working in 59 DCCs in three districts in Alexandria, Egypt were included. Data were collected using a data collection sheet about the DCC features, a structured interviewing questionnaire to collect data on caregivers’ personal characteristics, knowledge about infectious diseases, and the best infection control practices and an observational infection control practices checklist. Multiple analysis of variance was used to test the difference in two or more vectors of means (mean knowledge scores about infectious diseases and about infection control). Post hoc test using Tukey Honest Significant Difference was used to determine which groups in the sample differ. Regression analysis models were used to identify factors affecting knowledge score of caregivers, and to estimate the magnitude of the association between different variables and the level of practice of caregivers (poor/fair and good).

Results

Satisfactory features of the DCCs included the aeration, level of cleanliness, and availability of hand washing facilities, while the availability of gloves and aprons, alcohol-based products, and medical examination rooms were not satisfactory. Only 2.5% of caregivers had a good level of knowledge. Level of education was the only factor statistically associated with the level of knowledge. About 31% and 17% had poor and good practice score percent, respectively. District and daily working hours were the only variables statistically associated with the level of practice.

Conclusion

The level of knowledge and practice of caregivers was below optimum.

Why parents are skeptical about using probiotics preventively for small children: a Danish qualitative study

Background

Research on the health effects of probiotics continues to grow, but less is known about consumers’ perceptions of probiotic products and their health effects, and the impact of these perceptions on consumption. Particularly little is known about the way parents perceive probiotic consumption by small children, and whether parental willingness to use probiotics as a treatment differs from their willingness to use them preventively. The aim of this study was to explore how parents perceive probiotic consumption by their small children, and their willingness to use such products in treatment and prevention.

Methods

Semi-structured qualitative interviews with 17 Danish parents with at least one child aged 8–18 months. The interview guide centered on parental consumer practices and health-related attitudes both in general and in relation to probiotics. The data were coded in Nvivo and analyzed in a four-step analytical approach.

Results

Parents are willing to use probiotics as a treatment but are skeptical about preventive use. Some parents define probiotics as a kind of medicine they use only if their child is ill. Probiotics also conflict with parental understandings of their children as small, perfect parts of nature. Parents worry that probiotics may cause an imbalance in the vulnerable perfection of a small child.

Conclusion

The study shows that parental probiotic consumption practices are embedded in a cultural understanding of the child as both a perfect example of nature and vulnerable. Health authorities need to take this understanding into account if parents are to be successfully encouraged to use probiotics preventively.

Electronic supplementary material

The online version of this article (10.1186/s12906-018-2387-2) contains supplementary material, which is available to authorized users.

Effectiveness of a Hand Hygiene Program at Child Care Centers: A Cluster Randomized Trial

OBJECTIVES

Respiratory infections (RIs) are an important cause of morbidity and excessive antibiotic prescriptions in children attending day care centers (DCCs). We aimed to assess the effectiveness of an educational and hand hygiene program in DCCs and homes in reducing RI incidence and antibiotic prescriptions in children.

METHODS

A cluster, randomized, controlled, and open study of 911 children aged 0 to 3 years attending 24 DCCs in Almería (Spain) with an 8-month follow-up. Two intervention groups of DCC families performed educational and hand hygiene measures, 1 with soap and water (SWG; n = 274), another with hand sanitizer (HSG; n = 339), and the control group (CG; n = 298) followed usual hand-washing procedures. RI episode rates were compared through multilevel Poisson regression models. The percentage of days missed were compared with Poisson exact tests.

RESULTS

There were 5211 RI episodes registered. Children in the HSG had less risk of RI episodes (incidence rate ratio [IRR]: 0.77; 95% confidence interval [CI]: 0.68-0.88) and antibiotic prescriptions (IRR: 0.69; 95% CI: 0.57-0.84) compared with the those in the CG. Children in the SWG had a higher risk of RI episodes (IRR: 1.21; 95% CI: 1.06-1.39) and antibiotic prescriptions (IRR: 1.31; 95% CI: 1.08-1.56) than those in the HSG. Pupils missed 5186 DCC days because of RIs, and the percentage of days absent was significantly lower in the HSG compared with the CG (P < .001) and the SWG (P < .001).

CONCLUSIONS

Hand hygiene programs that include hand sanitizer and educational measures for DCC staff, children, and parents, reduce absent days, RIs, and antibiotic prescriptions for these infections in children at DCCs.

Probiotics for respiratory tract infections in children attending day care centers-a systematic review

Probiotics have been suggested to have a preventive effect on respiratory tract infections (RTIs), but limited evidence exist on strain-specific effects. The main aim of this systematic review and meta-analysis was to evaluate strain-specific probiotic effects on RTIs in children attending day care. We included 15 RCTs with 5121 children in day care settings (aged 3 months to 7 years), but due to high diversity in reported outcomes, different number of RCTs were available for evaluated outcomes. Twelve RCTs (n = 4527) reported results which could be compared in at least one outcome of the meta-analysis. Compared to placebo, Lactobacillus rhamnosus GG (LGG) significantly reduced duration of RTIs (three RCTs, n = 1295, mean difference - 0.78 days, 95% confidence interval (CI) - 1.46; - 0.09), whereas no effect was found on other evaluated outcomes. Based on the results from two studies (n = 343), Bifidobacterium animalis subsp. lactis BB-12 showed no effect on duration of RTIs or on absence from day care. Meta-analyses on other strains or their combination were not possible due to limited data and different outcome measures.Conclusion: LGG is modestly effective in decreasing the duration of RTIs. More RCTs investigating specific probiotic strains or their combinations in prevention of RTIs are needed. What is known: • Previously published systematic reviews have suggested that probiotics may have a preventive effect on respiratory infections, but limited data exist on strain specific effects. What is new: • This systematic review showed that use of Lactobacillus rhamnosus GG modestly reduces the duration of respiratory tract infections.

Epidemiology and Risk Factors of Infection in Early Childhood

BACKGROUND

There is a large, unexplained variation in the frequency of childhood infections. We described incidence and risk factors of infections in early childhood.

METHODS

Simple infections were captured during the first 3 years of life in the Copenhagen Prospective Studies on Asthma in Childhood 2000 birth cohort. Environmental exposures were analyzed by quasi-Poisson regression and sparse principal component analysis.

RESULTS

The 334 children experienced a median of 14 (range 2-43) infectious episodes at ages 0 to 3 years. The overall rate of infections was associated with the number of children in the day care (adjusted incidence rate ratio [aIRR] 1.09 [1.2-1.16]) and the m² per child in the day care (aIRR 0.96 [0.92-0.99]). Upper respiratory infections were also associated with the number of children in the day care (aIRR 1.11 [1.03-1.20]) and the m² per child in the day care (aIRR 0.95 [0.91-0.99]), whereas lower respiratory infections were associated with caesarean section (aIRR 1.49 [1.12-1.99]), maternal smoking (aIRR 1.66 [1.18-2.33]), older siblings (aIRR 1.54 [1.19-2.01]), and the age at entry to day care (aIRR 0.77 [0.65-0.91]). The sparse principal component analysis revealed a risk factor profile driven by tobacco exposure, social circumstances, and domestic pets, but could only be used to explain 8.4% of the infection burden.

CONCLUSIONS

Children experienced around 14 infections during the first 3 years of life, but incidences varied greatly. Environmental exposures only explained a small fraction of the variation, suggesting host factors as major determinants of infectious burden.

Risk of childhood otitis media with focus on potentially modifiable factors: A Danish follow-up cohort study

INTRODUCTION

Otitis media is the primary cause of antibiotic prescription in children. Two-thirds of all children experience at least one episode of otitis media before the age of 7 years. The aim of this study was to characterise the attributable effect of several modifiable risk exposures on the risk of >3 episodes of otitis media at age 18 months and 7 years within a large prospective national birth cohort.

METHODS

The study used the Danish National Birth Cohort comprising information about otitis media and risk exposures from more than 50,000 mother-child pairs from the period 1996-2002. Logistic regression models were used to estimate odds ratios for the risk factors and to calculate the population attributable fraction.

RESULTS

Short time with breastfeeding, early introduction to daycare, cesarean section, and low compliance to the national vaccination program were all associated with an increased risk of >3 episodes of otitis media at 18 months of age and at 7 years of age. The fraction of children with otitis media attributed from breastfeeding lasting for less than 6 months was 10%. Introduction to daycare before the age of 12 months attributed with 20% of the cases of >3 episodes of otitis media.

CONCLUSIONS

Short duration of breastfeeding, early introduction into daycare, cesarean section, and low compliance with the national vaccination program increased the risk of experiencing >3 episodes of otitis media at 18 months, and at 7 years of age. These are factors that all can be modulated.

What Does Attending Early Childhood Program Mean for Child Health in India?

The health impact of attending early childhood development programs in developing countries remains largely unknown. In this study, we focus on the health consequences of attending preschool programs in India. Using a unique longitudinal dataset, we allow for heterogeneity in the impact of preschool across the distribution of health outcomes while controlling for time-invariant unobservables. We detect unique temporal variation in the effect of preschool attendance - growth of preschool attendees is slower than non-attendees in various parts of the distributions of several anthropometric measures when evaluated in the early years between ages 1 and 5. This effect is likely to reverse in the longer term at age 8. The early years' adverse effect can be explained in part by over-attendance in the form of long daily hours, excessive attendance days, and early entry. The findings are insensitive to nutritional incentives like free meals provided in public schools. The growth-retarding effect remains robust for weight-for-age z-scores, implying that the impact of preschool attendance is not only heterogeneous, but differs across dimensions of health status. Our study highlights the need for strengthening the delivery of childhood programs in developing countries in order to prevent adverse health effects in the critical years. Copyright © 2016 John Wiley & Sons, Ltd.

Daycare attendance and respiratory tract infections: a prospective birth cohort study

OBJECTIVE

We explored the burden of respiratory tract infections (RTIs) in young children with regard to day-care initiation.

DESIGN

Longitudinal prospective birth cohort study.

SETTING AND METHODS

We recruited 1827 children for follow-up until the age of 24 months collecting diary data on RTIs and daycare. Children with continuous daycare type and complete data were divided into groups of centre-based daycare (n=299), family day care (FDC) (n=245) and home care (n=350). Using repeated measures variance analyses, we analysed days per month with symptoms of respiratory tract infection, antibiotic treatments and parental absence from work for a period of 6 months prior to and 9 months after the start of daycare.

RESULTS

We documented a significant effect of time and type of daycare, as well as a significant interaction between them for all outcome measures. There was a rise in mean days with symptoms from 3.79 (95% CI 3.04 to 4.53) during the month preceding centre-based daycare to 10.57 (95% CI 9.35 to 11.79) at 2 months after the start of centre-based daycare, with a subsequent decrease within the following 9 months. Similar patterns with a rise and decline were observed in the use of antibiotics and parental absences. The start of FDC had weaker effects. Our findings were not changed when taking into account confounding factors.

CONCLUSIONS

Our study shows the rapid increase in respiratory infections after start of daycare and a relatively fast decline in the course of time with continued daycare. It is important to support families around the beginning of daycare.

Probiotics and Child Care Absence Due to Infections: A Randomized Controlled Trial

OBJECTIVES

The risk of infections is higher in children attending child care compared with children cared for at home. This study examined the effect of a combination of probiotics on absence from child care because of respiratory and gastrointestinal infections in healthy infants aged 8 to 14 months at the time of enrollment in child care.

METHODS

The ProbiComp study was a randomized, double-blind, placebo-controlled study. A total of 290 infants were randomly allocated to receive a placebo or a combination of Bifidobacterium animalis subsp lactis and Lactobacillus rhamnosus in a dose of 10⁹ colony-forming units of each daily for a 6-month intervention period. Absence from child care, occurrence of infant symptoms of illness, and doctor visits were registered by the parents using daily and weekly Web-based questionnaires.

RESULTS

Median absence from child care was 11 days (interquartile range: 6-16). Intention-to-treat analysis showed no difference between the probiotics and placebo groups (P = .19). Additionally, there was no difference in any of the secondary outcomes between groups; the number of children with doctor-diagnosed upper or lower respiratory tract infections, the number of doctor visits, antibiotic treatments, occurrence and duration of diarrhea, and days with common cold symptoms, fever, vomiting, or caregivers' absence from work.

CONCLUSIONS

A daily administration of a combination of B animalis subsp lactis and L rhamnosus for 6 months did not reduce the number of days absent from child care in healthy infants at the time of enrollment in child care.

Incidence and comparison of retrospective and prospective data on respiratory and gastrointestinal infections in German households

Background

Acute respiratory infections (ARI) and acute gastrointestinal infections (AGI) are the most common childhood infections, and corresponding data can either be collected prospectively or retrospectively. The aim of this study was to estimate the incidence of respiratory and gastrointestinal episodes in German households with children attending day care and to compare results of prospective and retrospective data collection.

Methods

We conducted a 4 months prospective cohort study in the winter period 2014/2015 and recruited parents of children aged 0–6 years in 75 day care centers in Braunschweig, Lower Saxony, Germany. For all household members, we collected information on episodes of ARI and AGI. We applied prospective data collection in one study arm and retrospective data collection with a reporting period of 2 months in the other. Poisson regression was used to model monthly incidence rates for both study arms.

Results

In total, 100 households (including 404 persons) participated in the retrospective group and 77 households (282 persons) in the prospective group. Incidence estimates for ARI (retrospective group: 0.52 per person month, prospective group: 0.47) were higher than for AGI (retrospective group: 0.14, prospective group: 0.13). The adjusted incidence estimates were similar in both study arms for ARI (incidence rate ratio for retrospective versus prospective data collection: 1.11 [confidence interval (CI) 95% 0.99; 1.24], p = 0.42) as well as for AGI (1.10 [CI 95% 0.89; 1.37], p = 0.27).

Conclusion

If there is no need to collect biomaterials or data on severity of the diseases, incidence of infections in the household setting over a short time period (2 months) can be assessed retrospectively.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-017-2434-5) contains supplementary material, which is available to authorized users.

Higher serum 25(OH)D concentrations are associated with improved FEV1 and FVC in adolescence

Vitamin D plays a role in the development of the immune system and the lung, as well as in airway remodelling. Therefore, this study investigated the association between serum 25-hydroxyvitamin D (25(OH)D) concentrations and spirometric lung function parameters at age 15 years.

In the German birth cohorts GINIplus and LISAplus, lung function testing by spirometry and 25(OH)D measurements were performed during the 15-year follow-up examinations. Valid lung function measurements pre- and/or post-bronchodilation and serum 25(OH)D concentrations, which were adjusted for the date of blood sampling to account for seasonal variability, were available for 2607 adolescents. Associations between 25(OH)D concentrations and spirometric parameters were analysed using generalised additive models adjusted for confounding factors.

Serum 25(OH)D concentrations were significantly associated with forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and FEV1/FVC measured before bronchodilation after adjustment for potential confounders: FEV1 increased by 10 mL (95% CI 2–17), FVC by 20 mL (95% CI 12–28) and FEV1/FVC decreased by 0.177% (95% CI −0.286 to −0.067) per 10 nmol·L−1 increase in 25(OH)D concentrations. Flow rates (forced expiratory flow rates at 25, 50 and 75% of exhaled FVC (FEF25, FEF50, FEF75) and mean flow rate between 25 and 75% of FVC (FEF25–75)) were not associated with vitamin D. Similar associations were observed for lung function parameters measured after bronchodilation.

Vitamin D concentrations are positively associated with volume-related lung function parameters pre- and post-bronchodilation, suggesting structural changes in peripheral airways.

Fermented Milk Consumption and Common Infections in Children Attending Day-Care Centers: A Randomized Trial

OBJECTIVES

This multicenter, double-blind, randomized, placebo-controlled clinical trial investigated the effect of a fermented milk product containing the Lactobacillus casei National Collection of Microorganisms and Cell Cultures (CNCM) I-1518 strain on respiratory and gastrointestinal common infectious diseases (CIDs) in children attending day-care centers in Russia.

METHODS

Children ages 3 to 6 years received 100 g of a fermented milk product (n = 300) or a control product (n = 299) twice daily for 3 months, followed by a 1-month observation period. The primary outcome was the incidence of CIDs during the product consumption period.

RESULTS

There was no significant difference in the incidence of CIDs between the groups (N = 98 with fermented milk product vs N = 93 with control product). The overall number of CIDs (and no severe cases at all) in both study groups and in all 12 centers, however, was unexpectedly low resulting in underpowering of the study. No differences were found between the groups in the duration or severity of disease, duration of sick leave from day-care centers, parental missed working days, or in quality-of-life dimensions on the PedsQL questionnaire (P > 0.05).There was, however, a significantly lower incidence of the most frequently observed CID, rhinopharyngitis, in children consuming the fermented milk product compared with those consuming the control product (N = 81 vs N = 100, relative risk 0.82, 95% confidence interval 0.69-0.96, P = 0.017) when considering the entire study period.

CONCLUSIONS

Although no other significant differences were shown between the fermented milk and control product groups in this study, lower incidence of rhinopharyngitis may indicate a beneficial effect of this fermented milk product.

Enteroaggregative Escherichia coli in Daycare-A 1-Year Dynamic Cohort Study

Enteroaggregative Escherichia coli (EAEC) has been associated with persistent diarrhea, reduced growth acceleration, and failure to thrive in children living in developing countries and with childhood diarrhea in general in industrialized countries. The clinical implications of an EAEC carrier-status in children in industrialized countries warrants clarification. To investigate the pathological significance of an EAEC carrier-state in the industrialized countries, we designed a 1-year dynamic cohort study and performed follow-up every second month, where the study participants submitted a stool sample and answered a questionnaire regarding gastrointestinal symptoms and exposures. Exposures included foreign travel, consumption of antibiotics, and contact with a diseased animal. In the capital area of Denmark, a total of 179 children aged 0–6 years were followed in a cohort study, in the period between 2009 and 2013. This is the first investigation of the incidence and pathological significance of EAEC in Danish children attending daycare facilities. Conventional microbiological detection of enteric pathogens was performed at Statens Serum Institute, Copenhagen, Denmark, and at Hvidovre Hospital, Copenhagen, Denmark. Parents completed questionnaires regarding gastrointestinal symptoms. The EAEC strains were further characterized by serotyping, phylogenetic analysis, and susceptibility testing. EAEC was detected in 25 (14%) of the children during the observational period of 1 year. One or more gastrointestinal symptoms were reported from 56% of the EAEC-positive children. Diarrhea was reported in six (24%) of the EAEC positive children, but no cases of weight loss, and general failure to thrive were observed. The EAEC strains detected comprised a large number of different serotypes, confirming the genetic heterogeneity of this pathotype. EAEC was highly prevalent (n = 25, 14%) in Danish children in daycare centers and was accompanied by gastrointestinal symptoms in 56% of the infected children. No serotype or phylogenetic group was specifically linked to children with disease.

Potential causative agents of acute gastroenteritis in households with preschool children: prevalence, risk factors, clinical relevance and household transmission

Acute gastroenteritis (AGE) morbidity remains high amongst preschool children, posing a significant societal burden. Empirical data on AGE-causing agents is needed to gauge their clinical relevance and identify agent-specific targets for control. We assessed the prevalence, risk factors and association with symptoms for enteropathogens in households with preschool children. A monthly-repeated cross-sectional survey of enteropathogens in households with preschool children was performed. A parent-child pair per household (n = 907 households) provided faecal samples and reported their symptoms and potential risk exposures. Samples were tested by multiplex reverse transcription polymerase chain reaction (RT-PCR) for 19 enteropathogens. Associations were assessed using logistic regression. 28.3 % of children (n = 981) and 15.6 % of parents (n = 971) carried pathogenic bacteria and/or Escherichia coli-associated pathogenicity genes, and 6.5 % and 3.3 % carried viruses, respectively. Giardia lamblia (4.6 % of children, 2.5 % of parents) and Dientamoeba fragilis (36 %, 39 %, respectively) were the main parasites, and were associated with pet exposure. Living in rural areas was associated with carriage of pathogenic E. coli, norovirus I and D. fragilis. Pathogenic E. coli was associated with summertime and livestock exposure. Attending day-care centres increased the risk of carrying norovirus, sapovirus and G. lamblia. Viruses occurred mainly in winter and were associated with AGE symptoms. Child-parent associations were found for bacterial pathogenicity genes, viruses, G. lamblia and D. fragilis. Enteropathogens spread widely in households with preschool children, particularly viruses, which more often cause symptoms. While bacteria predominate during summer and in those exposed to livestock, viruses predominate in wintertime and, like G. lamblia, are widespread amongst day-care centre attendees.

First-year Daycare and Incidence of Acute Gastroenteritis

BACKGROUND

Daycare attendance has been associated with increased acute gastroenteritis (AGE) incidence in the first years of life. We investigated the effects of first-year daycare attendance on AGE incidence and primary care contact rate up to age 6 years.

METHODS

Children enrolled in the Wheezing Illnesses Study Leidsche Rijn cohort were managed until age 6 years. Data on primary care diagnosed AGE episodes and number of associated contacts per episode were collected from health records. Children were categorized according to first year daycare attendance and age-month at entry when applicable. Generalized estimating equations were used to assess associations between first-year daycare and AGE incidence or primary care contact rate.

RESULTS

A total of 1344 out of 2220 children (83%) attended daycare before age 1 year. Overall, the 6-year primary care AGE incidence rate (IR) among first-year daycare attendees and nonattendees was comparable (IR: 12.2/100 vs 13.3/100 child-years). First-year daycare attendees had a higher AGE incidence during the first year (IRR: 1.13; 95% confidence interval: 1.06-1.21) and lower during the third to sixth year of age compared with nonattendees (P < .001). The daycare-associated increase in AGE incidence was most pronounced during the first 12 months after enrollment into daycare and demonstrated clear seasonality. A similar pattern was observed for primary care contact rate per AGE episode.

CONCLUSIONS

First-year daycare attendance advances the timing of AGE infections, resulting in increased AGE disease burden in the first year and relative protection thereafter. Protection against AGE infection persists at least up to age 6 years. Future studies should address whether this protective effect persists during later childhood.

Childhood diarrhoea in Danish day care centres could be associated with infant colic, low birthweight and antibiotics

AIM

Diarrhoea is very common in children attending day care centres. The aim of this study was to examine certain predisposing risk factors for an association with diarrhoea, including foreign travel, treatment with antibiotics, having household pets, infant colic, bottle feeding, using a pacifier and low birthweight.

METHODS

A dynamic one-year follow-up cohort study comprising 179 children from 36 day care centres was conducted from September 2009 to July 2013 in Copenhagen, Denmark. Questionnaires were sent to the children's parents or legal guardians every two months for a year, requesting information on gastrointestinal symptoms and exposure. A logistic regression was performed to identify the odds ratios of different risk factors for diarrhoea.

RESULTS

The odds ratios for diarrhoea were 1.97 (0.93-4.20) for children with a history of infant colic, 1.91 (0.90-4.04) for low birthweight children and 1.45 (0.74-2.82) for children who had used antibiotics. Having a pet in the household had a possible protective effect towards diarrhoeal events, with an odds ratio of 0.47 (0.20-1.09).

CONCLUSION

A history of infant colic, low birthweight, and to a lesser extent antibiotic use, possibly increased the risk of diarrhoea in Danish children in day care centres.

Prevalence and Risk Factors for Colonization With Extended-Spectrum Cephalosporin-Resistant Escherichia coli in Children Attending Daycare Centers: A Cohort Study in the Netherlands

BACKGROUND

The purpose of this study was to determine the prevalence and risk factors for colonization with extended-spectrum cephalosporin-resistant (ESC-R) Escherichia coli in daycare center (DCC)-attending children.

METHODS

This is a prospective cohort study including 44 DCCs in the Netherlands, combining DCC characteristics and monthly collected stool samples from their attendees, and was performed in 2010-2012. During a 22-month study period, 852 stool samples were collected and screened for ESC-R E coli. Risk factors were studied using logistic regression analysis.

RESULTS

In DCC-attending children (<4 years old), the overall prevalence of ESC-R E coli was 4.5%, and it was 8% in <1-year-old attendees. Among the 38 children carrying ESC-R E coli, the most common types were blaCMY-2 (26%), blaCTX-M-1 (16%), and chromosomal AmpC type 3 promoter mutants (13%). Extended-spectrum cephalosporin-resistant E coli was less common in DCCs where stricter hygiene protocols were enforced, eg, not allowing ill children to enter the DCC (odds ratio [OR], 0.34; 95% confidence interval [CI], 0.14-0.84), performing extra checks on handwashing of ill children (OR, 0.42; 95% CI, 0.20-0.87), and reporting suspected outbreaks to local health authorities (OR, 0.27; 95% CI, 0.11-0.69).

CONCLUSIONS

The distribution of ESC-R E coli types in DCCs differs from that of the general population. Extended-spectrum cephalosporin-resistant E coli carriage in DCC-attending children is associated with the hygiene policies enforced in the DCC. Although our results are not conclusive enough to change current DCC practice beyond ensuring compliance with standing policies, they generated hypotheses and defined the degree of ESC resistance among DCC attendees, which may influence empiric antibiotic therapy choices, and tracked the increasing trend in ESC resistance.

Transient and sustained effects of child-care attendance on hospital admission for gastroenteritis

BACKGROUND

There is evidence that children experience a transient increase in mild episodes of gastroenteritis when they start attending out-of-home child care. We assessed the transient and sustained effects of cumulative day-care attendance, age at first enrolment and type of child care facility attended on hospitalization rates for gastroenteritis.

METHODS

Cox proportional hazard models were used to estimate the risk of being hospitalized for gastroenteritis in two large cohorts of preschool (<6 years old) and elementary school-going (6-10 years old) children in Denmark. Day-by-day child-level registry data were used. Together, the two cohorts comprised 443,872 children, 21,038 hospitalizations and 1742,284 child-years (1994-2011).

RESULTS

From first day-care attendance until 12 months of cumulated attendance, preschool children attending day-care centres, but not those attending day-care homes, had an increased risk of hospitalization for gastroenteritis compared with children never attending registered day-care. Such increased risk was highest shortly after starting day-care attendance and then gradually declined. After 12 months of attendance, attending either day-care centres or day-care homes was associated with a lower risk for hospitalization. Such decreased risk was confined to children starting day-care attendance before the age of one year and extended throughout, but not beyond, their preschool years.

CONCLUSIONS

Attending day-care centres is associated with a higher risk for gastroenteritis hospitalization until completing 1 year of attendance. However, if children start attending day-care before the age of 1 year, they experience a lower risk of being hospitalized during their preschool years. This apparent protective effect does not last into the elementary school years.

A hand hygiene intervention to reduce infections in child daycare: a randomized controlled trial

Infections are common in children attending daycare centres (DCCs). We evaluated the effect of a hand hygiene (HH) intervention for caregivers on the incidence of gastrointestinal and respiratory infections in children. The intervention was evaluated in a two-arm cluster randomized controlled trial. Thirty-six DCCs received the intervention including HH products, training sessions, and posters/stickers. Thirty-five control DCCs continued usual practice. Incidence of episodes of diarrhoea and the common cold in children was monitored by parents during 6 months. Using multilevel Poisson regression, incidence rate ratios (IRRs) with 95% confidence intervals (CIs) were obtained. Diarrhoeal incidence was monitored in 545 children for 91 937 days. During follow-up, the incidence was 3·0 episodes per child-year in intervention DCCs vs. 3·4 in control DCCs (IRR 0·90, 95% CI 0·73–1·11). Incidence of the common cold was monitored in 541 children for 91 373 days. During follow-up, the incidence was 8·2 episodes per child-year in intervention DCCs vs. 7·4 in control DCCs (IRR 1·07, 95% CI 0·97–1·19). In this study, no evidence for an effect of the intervention was demonstrated on the incidence of episodes of diarrhoea and the common cold.

Gastroenteritis attributable to 16 enteropathogens in children attending day care: significant effects of rotavirus, norovirus, astrovirus, Cryptosporidium and Giardia

BACKGROUND

Children attending day care experience substantial gastrointestinal morbidity due to circulating seasonal enteropathogens in the day-care environment. The lack of a distinct clinical presentation of gastroenteritis (GE) in these children, in combination with the high diversity of enteropathogenic agents, complicates the assessment of the individual contributions of enteropathogens that may cause GE. We aimed to estimate the proportion of day-care attendees experiencing GE that could be attributed to a range of enteropathogens circulating in day care in the Netherlands in 2010-2013.

METHODS

Using time-series data from a national laboratory-based and syndrome-based surveillance system in Dutch day-care centers and generalized estimating equation analysis, we modelled the variation in prevalence of 16 enteropathogens of bacterial (8), viral (5) and parasitic origin (3) circulating in day care to the variation of GE incidence among children attending day care.

RESULTS

Rotavirus, norovirus, astrovirus, Giardia and Cryptosporidium were significantly associated with GE morbidity among day-care attendees in our time-series analysis. Together, these enteropathogens accounted for 39% of the GE morbidity: 11% by rotavirus, 10% by norovirus, 8% by Giardia, 7% by astrovirus and 3% by Cryptosporidium.

CONCLUSIONS

We demonstrate that circulating viruses and parasites, rather than bacteria, contribute to seasonal GE experienced by children in day care.

Serum 25(OH)D concentrations and atopic diseases at age 10: results from the GINIplus and LISAplus birth cohort studies

Background

Vitamin D is well recognized for its role in skeletal health and its involvement in the modulation of the immune system. In the literature, controversial results are reported for atopic diseases. Thus, we investigated the association between vitamin D status and the prevalence of atopic diseases.

Methods

Serum 25-hydroxy-vitamin D (25(OH)D) concentrations were measured in a sample of 2815 10-years old children from two German birth cohort studies. Self-reported physician-diagnosed eczema, hay fever or allergic rhinitis, and asthma were used as outcome variables as well as specific IgE positivity against common allergens. We applied logistic regression models, deriving adjusted odds ratio estimates (aOR) and 95% confidence intervals (CI).

Results

For asthma and hay fever or allergic rhinitis, no associations existed with serum 25(OH)D concentrations. We observed a significant positive relationship between serum 25(OH)D levels and eczema at age 10 (aOR = 1.09, CI = 1.01-1.17, per 10 nmol/l increase in serum 25(OH)D levels) and for the lifetime prevalence of eczema (aOR = 1.05, CI = 1.01-1.09). Specific IgE positivity for food allergens (aOR = 1.07, CI = 1.02-1.11) and aeroallergens (aOR = 1.05, CI = 1.01-1.08) at age 10, as well as lifetime prevalence, was significantly related to the vitamin D status.

Conclusion

In this study we found no indication that higher blood 25(OH)D levels are associated with decreased risk for any of the atopic outcomes in children. However, we observed a positive association of serum 25(OH)D concentrations with eczema and detectable specific IgE. Due to the given limitations of our study, the clinical relevance of these findings needs further clarification.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-014-0286-3) contains supplementary material, which is available to authorized users.

Associations between ambient air pollution and bone turnover markers in 10-year old children: results from the GINIplus and LISAplus studies

Negative associations between bone turnover markers and bone mineral density have been reported. In order to study the association between ambient air pollution and bone turnover markers, as indicators of bone loss, we investigated associations between land-use regression modeled air pollution (NO2, PM2.5 mass, PM2.5 - 10 [coarse particles], PM10 mass and PM2.5 absorbance) and bone turnover markers in 2264 children aged 10 years. Serum osteocalcin and C-terminal telopeptide of type I collagen (CTx), measured by Modular-System (Roche), were the two bone turnover markers considered in this analysis. In total population, NO2, PM2.5 - 10 and PM10 mass exposure were positively and significantly associated with both osteocalcin and CTx. A 2.5 (95% CI: 0.6, 4.4) ng/ml increase in osteocalcin and a 24.0 (95% CI: 6.7, 41.3) ng/L increase in CTx were observed per IQR (6.7μg/m(3)) increase in NO2, independent of socioeconomic status, sex, age, pubertal status, fasting status and total physical activity. The estimated coefficients were 3.0 (95% CI: 0.1, 5.8) for osteocalcin and 32.3 (95% CI: 6.1, 58.5) for CTx with PM2.5 - 10; 3.2 (95% CI: 0.0, 6.4) for osteocalcin and 30.7 (95% CI: 1.7, 59.7) for CTx with PM10. Children living close to a major road (≤ 350m) had higher levels of both osteocalcin (1.4 [-1.2, 4.0] ng/ml) and CTx (16.2 [-7.4, 39.8] ng/L). The adverse impact of ambient air pollution on bone turnover rates observed in one of the study areas showed stimulation of more such studies.

Impact of early daycare on healthcare resource use related to upper respiratory tract infections during childhood: prospective WHISTLER cohort study

BACKGROUND

Daycare attendance is an established risk factor for upper respiratory tract infections (URTI) and acute otitis media (AOM). Whether this results in higher use of healthcare resources during childhood remains unknown. We aim to assess the effect of first year daycare attendance on the timing and use of healthcare resources for URTI and AOM episodes during early childhood.

METHODS

In the Wheezing-Illnesses-STudy-LEidsche-Rijn birth cohort, 2,217 children were prospectively followed up to age six years. Children were categorized according to first-year daycare attendance (yes versus no) and age at entry when applicable (age 0 to 2 months, 3 to 5 months and 6 to 12 months). Information on general practitioner (GP) diagnosed URTI and AOM, GP consultations, antibiotic prescriptions and specialist referral was collected from medical records. Daycare attendance was recorded by monthly questionnaires during the first year of life.

RESULTS

First-year daycare attendees and non-attendees had similar total six-year rates of GP-diagnosed URTI and AOM episodes (59/100 child-years, 95% confidence interval 57 to 61 versus 56/100 child-years, 53 to 59). Daycare attendees had more GP-diagnosed URTI and AOM episodes before the age of one year and fewer beyond the age of four years than non-attendees (Pinteraction <0.001). Daycare attendees had higher total six-year rates for GP consultation (adjusted rate ratio 1.15, 1.00 to 1.31) and higher risk for specialist referrals (hazard ratio: 1.43, 1.01 to 2.03). The number of antibiotic prescriptions in the first six years of life was only significantly increased among children who entered daycare between six to twelve months of age (rate ratio 1.32, 1.04 to 1.67). This subgroup of child-care attendees also had the highest overall URTI and AOM incidence rates, GP consultation rates and risk for specialist referral.

CONCLUSIONS

Children who enter daycare in the first year of life, have URTI and AOM at an earlier age, leading to higher use of healthcare resources compared to non-attendees, especially when entering daycare between six to twelve months. These findings emphasize the need for improved prevention strategies in daycare facilities to lower infection rates at the early ages.

Increased risk of pneumonia and bronchiolitis after bacterial colonization of the airways as neonates

RATIONALE

The frequency of pneumonia and bronchiolitis exhibits considerable variation in otherwise healthy children, and suspected risk factors explain only a minor proportion of the variation. We hypothesized that alterations in the airway microbiome in early life may be associated with susceptibility to pneumonia and bronchiolitis in young children.

OBJECTIVES

To investigate the relation between neonatal airway colonization and pneumonia and bronchiolitis during the first 3 years of life.

METHODS

Participants comprised children of the Copenhagen Prospective Studies on Asthma in Childhood2000 (COPSAC2000) cohort, a prospective birth cohort study of 411 children born to mothers with asthma. Aspirates from the hypopharynx at age 4 weeks were cultured for Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus. Clinical information on pneumonia and bronchiolitis within the first 3 years of life was prospectively collected by the research physicians at the center. Analyses were adjusted for covariates associated with pneumonia and bronchiolitis and bacterial airway colonization.

MEASUREMENTS AND MAIN RESULTS

Hypopharyngeal aspirates and full clinical follow-up until 3 years of age were available for 265 children. Of these, 56 (21%) neonates were colonized with S. pneumoniae, H. influenzae, and/or M. catarrhalis at 4 weeks of age. Colonization with at least one of these microorganisms (but not S. aureus) was significantly associated with increased incidence of pneumonia and bronchiolitis (adjusted incidence rate ratio, 1.79 [1.29-2.48]; P < 0.005) independently of concurrent or later asthma.

CONCLUSIONS

Neonatal airway colonization with S. pneumoniae, H. influenzae, or M. catarrhalis is associated with increased risk of pneumonia and bronchiolitis in early life independently of asthma. This suggests a role of pathogenic bacterial colonization of the airways in neonates for subsequent susceptibly to pneumonia and bronchiolitis.

Is a child's growth pattern early in life related to serum adipokines at the age of 10 years?

BACKGROUND/OBJECTIVES

Growth parameters during infancy and early childhood might predict adipokine levels later in life. This study investigates the association between peak growth velocities, body mass index (BMI) and age at adiposity rebound (AR), with leptin and adiponectin levels at age 10 years.

SUBJECTS/METHODS

Peak height (PHV) and weight (PWV) velocities were calculated from height and weight measurements obtained between birth and age 2 years from 2880 children participating in the GINIplus (German Infant Nutritional Intervention plus environmental and genetic influences on allergy development) and LISAplus (Influences of Lifestyle-Related Factors on the Immune System and the Development of Allergies in Childhood plus Air Pollution and Genetics) birth cohorts. BMI and age at AR were calculated using BMI measurements between age 1.5 and 12 years. Blood samples were collected during a physical examination at age 10. Adiponectin and leptin levels were measured by radioimmunoassay. Linear regression models were fitted after adjustment for potential confounding factors and results are presented per interquartile range increase in the exposure.

RESULTS

Age at AR was negatively associated with leptin in males and females (percent difference β*: -41.71%; 95% confidence interval: (-44.34;-38.96) and β*: -43.22%; (-45.59; -40.75), respectively). For both males and females PWV (β*: 14.23%; (7.60; 21.26) and β*: 18.54%; (10.76; 26.87), respectively) and BMI at AR (β*: 63.08%; (55.04; 71.53) and β*: 67.02%; (59.30; 75.10), respectively) were positively associated with leptin levels. PHV showed a positive effect on leptin in females only (β*: 10.75%; (3.73; 18.25)). Growth parameters were not significantly associated with adiponectin except for age at AR among females (β: 0.75 ng/ml; (0.42; 1.09)) and PWV among males (β: 0.45 ng/ml; (0.11; 0.79)).

CONCLUSION

Growth patterns in early life may be associated with leptin levels at age 10 years.

The associations between traffic-related air pollution and noise with blood pressure in children: results from the GINIplus and LISAplus studies

Although traffic emits both air pollution and noise, studies jointly examining the effects of both of these exposures on blood pressure (BP) in children are scarce. We investigated associations between land-use regression modeled long-term traffic-related air pollution and BP in 2368 children aged 10 years from Germany (1454 from Munich and 914 from Wesel). We also studied this association with adjustment of long-term noise exposure (defined as day-evening-night noise indicator "Lden" and night noise indicator "Lnight") in a subgroup of 605 children from Munich inner city. In the overall analysis including 2368 children, NO2, PM2.5 mass (particles with aerodynamic diameters below 2.5μm), PM10 mass (particles with aerodynamic diameters below 10μm) and PM2.5 absorbance were not associated with BP. When restricting the analysis to the subgroup of children with noise information (N=605), a significant association between NO2 and diastolic BP was observed (-0.88 (95% confidence interval: -1.67, -0.08)). However, upon adjusting the models for noise exposure, only noise remained independently and significantly positively associated with diastolic BP. Diastolic BP increased by 0.50 (-0.03, 1.02), 0.59 (0.05, 1.13), 0.55 (0.03, 1.07), and 0.58 (0.05, 1.11)mmHg for every five decibel increase in Lden and by 0.59 (-0.05, 1.22), 0.69 (0.04, 1.33), 0.64 (0.02, 1.27), and 0.68 (0.05, 1.32)mmHg for every five decibel increase in Lnight, in different models of NO2, PM2.5 mass, PM10 mass and PM2.5 absorbance as the main exposure, respectively. In conclusion, air pollution was not consistently associated with BP with adjustment for noise, noise was independently and positively associated with BP in children.

A hand hygiene intervention to decrease infections among children attending day care centers: design of a cluster randomized controlled trial

Background

Day care center attendance has been recognized as a risk factor for acquiring gastrointestinal and respiratory infections, which can be prevented with adequate hand hygiene (HH). Based on previous studies on environmental and sociocognitive determinants of caregivers’ compliance with HH guidelines in day care centers (DCCs), an intervention has been developed aiming to improve caregivers’ and children’s HH compliance and decrease infections among children attending DCCs. The aim of this paper is to describe the design of a cluster randomized controlled trial to evaluate the effectiveness of this intervention.

Methods/design

The intervention will be evaluated in a two-arm cluster randomized controlled trial among 71 DCCs in the Netherlands. In total, 36 DCCs will receive the intervention consisting of four components: 1) HH products (dispensers and refills for paper towels, soap, alcohol-based hand sanitizer, and hand cream); 2) training to educate about the Dutch national HH guidelines; 3) two team training sessions aimed at goal setting and formulating specific HH improvement activities; and 4) reminders and cues to action (posters/stickers). Intervention DCCs will be compared to 35 control DCCs continuing usual practice. The primary outcome measure will be observed HH compliance of caregivers and children, measured at baseline and one, three, and six months after start of the intervention. The secondary outcome measure will be the incidence of gastrointestinal and respiratory infections in 600 children attending DCCs, monitored over six months by parents using a calendar to mark the days their child has diarrhea and/or a cold. Multilevel logistic regression will be performed to assess the effect of the intervention on HH compliance. Multilevel poisson regression will be performed to assess the incidence of gastrointestinal and respiratory infections in children attending DCCs.

Discussion

This is one of the first DCC intervention studies to assess HH compliance of both caregivers and children, as well as the incidence of gastrointestinal and respiratory infections in children, as outcome measures. When an effect of the intervention on improving HH compliance and/or reducing incidence of infections is shown, (inter)national dissemination of the intervention in other DCCs may be considered.

Trial registration

Netherlands trial registry: NTR3000

The KIzSS network, a sentinel surveillance system for infectious diseases in day care centers: study protocol

Background

Day care-associated infectious diseases are widely recognized as a public health problem but rarely studied. Insights into their dynamics and their association with the day care setting are important for effective decision making in management of infectious disease control. This paper describes the purpose, design and potential of our national multi-center, day care-based sentinel surveillance network for infectious diseases (the KIzSS network). The aim of the KIzSS network is to acquire a long-term insight into the syndromic and microbiological aspects of day care-related infectious diseases and associated disease burden and to model these aspects with day care setting characteristics.

Methods/design

The KIzSS network applies a prospective cohort design, following day care centers rather than individual children or staff members over time. Data on infectious disease symptoms and related morbidity (children and staff), medical consumption, absenteeism and circulating enteric pathogens (children) are collected on a daily, weekly or monthly basis. Every two years, a survey is performed to assess the characteristics of participating day care centers.

Discussion

The KIzSS network offers a unique potential to study infectious disease dynamics in the day care setting over a sustained period of time. The created (bio)databases will help us to assess day care-related disease burden of infectious diseases among attending children and staff and their relation with the day care setting. This will support the much needed development of evidence-based and pragmatic guidelines for infectious disease control in day care centers.

Evaluation of risk factors for severe pneumonia in children: the Pneumonia Etiology Research for Child Health study

As a case-control study of etiology, the Pneumonia Etiology Research for Child Health (PERCH) project also provides an opportunity to assess the risk factors for severe pneumonia in hospitalized children at 7 sites. We identified relevant risk factors by literature review and iterative expert consultation. Decisions for inclusion in PERCH were based on comparability to published data, analytic plans, data collection costs and logistic feasibility, including interviewer time and subject fatigue. We aimed to standardize questions at all sites, but significant variation in the economic, cultural, and geographic characteristics of sites made it difficult to obtain this objective. Despite these challenges, the depth of the evaluation of multiple risk factors across the breadth of the PERCH sites should furnish new and valuable information about the major risk factors for childhood severe and very severe pneumonia, including risk factors for pneumonia caused by specific etiologies, in developing countries.

Gestational weight gain and body mass index in children: results from three german cohort studies

Introduction

Previous studies suggested potential priming effects of gestational weight gain (GWG) on offspring’s body composition in later life. However, consistency of these effects in normal weight, overweight and obese mothers is less clear.

Methods

We combined the individual data of three German cohorts and assessed associations of total and excessive GWG (as defined by criteria of the Institute of Medicine) with offspring’s mean body mass index (BMI) standard deviation scores (SDS) and overweight at the age of 5–6 years (total: n = 6,254). Quantile regression was used to examine potentially different effects on different parts of the BMI SDS distribution. All models were adjusted for birth weight, maternal age and maternal smoking during pregnancy and stratified by maternal pre-pregnancy weight status.

Results

In adjusted models, positive associations of total and excessive GWG with mean BMI SDS and overweight were observed only in children of non- overweight mothers. For example, excessive GWG was associated with a mean increase of 0.08 (95% CI: 0.01, 0.15) units of BMI SDS (0.13 (0.02, 0.24) kg/m² of ‘real’ BMI) in children of normal-weight mothers. The effects of total and excessive GWG on BMI SDS increased for higher- BMI children of normal-weight mothers.

Discussion

Increased GWG is likely to be associated with overweight in offspring of non-overweight mothers.

Growth velocity during infancy and onset of asthma in school-aged children

BACKGROUND

Growth velocities during infancy might affect the risk of asthma in childhood. This study examines the association between peak height and weight velocities during the first 2 years of life and onset of asthma and wheeze up to 10 years of age.

METHODS

Data from 9086 children who participated in the GINIplus and LISAplus birth cohorts were analyzed. Information on asthma was requested annually from 1 to 10 years and information on wheeze at 1, 2, 4, 6, and 10 years. Peak height and weight velocities were calculated using height and weight measurements obtained between birth and 2 years of age. Cox proportional hazards models and generalized linear mixed models were calculated after adjustment for potential confounding factors including birth weight and body mass index at 10 years of age.

RESULTS

Per interquartile range increase in peak weight velocity (PWV), the risk of asthma increased significantly (adjHR: 1.22; CI: 1.02-1.47). The relationship between peak height velocity (PHV) and onset of asthma was nonsignificant (adjHR: 1.08; CI: 0.88-1.31). Wheeze was not significantly associated with PHV or with PWV (adjOR: 1.07; CI: 0.64-1.77 and adjOR: 1.11; CI: 0.68-1.79, respectively).

CONCLUSIONS

Weight gain during infancy is positively associated with physician-diagnosed asthma in school-aged children.

Probiotics for prevention and treatment of diarrhea

Probiotics have been extensively studied over the past several years in the prevention and, to a larger extent, in the treatment of diarrheal diseases, especially in pediatric populations. Diarrhea is a symptom, and not a disease. This review will not address chronic disorders associated with diarrhea, or Clostridium difficile-induced diarrhea. Rather it will focus on published clinical trials performed on acute-onset, likely infectious diarrhea occurring in the settings of day-care centers, in the community, acquired in the hospital, antibiotic-associated diarrhea, and treatment of acute infectious diarrhea. For prevention of diarrhea acquired in day-care centers, 9 randomized and placebo-controlled trials have been published, conducted in different parts of the world. Probiotics tested were Lactobacillus GG, Bifidobacterium lactis (alone or in combination with Streptococcus thermophilus, and Lactobacillus reuteri, Lactobacillus rhamnosus (not GG), and Lactobacillus acidophilus, in various trials either alone or in comparison with each other. The evidence of their efficacy in these settings is only modest for the prevention of diarrhea, although somewhat better for prevention of upper respiratory infections. In the community, new trails conducted in underprivileged areas of India, again with modest efficacy. Previous trials that examined the potential role of probiotics in preventing the spreading of diarrhea in hospitalized children had yielded conflicting results. More recently, a large trial in Poland showed, however, rather good evidence of efficacy for Lactobacillus GG. The prevention of antibiotic-associated diarrhea has been the subject of many investigations, both in children and in adults. Most commonly used probiotics were Lactobacillus GG, Lactobacillus acidophilus, Lactobacillus casei, Bifidobacterium ssp, Streptococcus ssp, and the yeast Saccharomyces boulardii. In general, most of these trials do show clear evidence of efficacy, with the 2 most effective strains being Lactobacillus GG and S. boulardii. Evidence is also emerging on the importance of the dose in reducing the incidence of this type of diarrhea, and the incidence of Clostridium difficile-associated postantibiotic diarrhea. As for treatment, a large body of data is available, especially in children, on the effect of several strains of probiotics in treating sporadic infectious diarrhea. The vast majority of the published trials show a statistically significant benefit and moderate clinical benefit of a few, well-identified probiotic strains-mostly Lactobacillus GG and S. boulardii-in the treatment of acute watery diarrhea, and particularly those due to rotavirus. Such a beneficial effect results, on average, in a reduction of diarrhea duration of approximately 1 day. The effect is strain-dependent and dose-dependent.

Performance of the modified Poisson regression approach for estimating relative risks from clustered prospective data

Modified Poisson regression, which combines a log Poisson regression model with robust variance estimation, is a useful alternative to log binomial regression for estimating relative risks. Previous studies have shown both analytically and by simulation that modified Poisson regression is appropriate for independent prospective data. This method is often applied to clustered prospective data, despite a lack of evidence to support its use in this setting. The purpose of this article is to evaluate the performance of the modified Poisson regression approach for estimating relative risks from clustered prospective data, by using generalized estimating equations to account for clustering. A simulation study is conducted to compare log binomial regression and modified Poisson regression for analyzing clustered data from intervention and observational studies. Both methods generally perform well in terms of bias, type I error, and coverage. Unlike log binomial regression, modified Poisson regression is not prone to convergence problems. The methods are contrasted by using example data sets from 2 large studies. The results presented in this article support the use of modified Poisson regression as an alternative to log binomial regression for analyzing clustered prospective data when clustering is taken into account by using generalized estimating equations.

The effect of day care attendance on infant and toddler's growth

AIM

We aimed to study the association between day care attendance and changes in the height, weight and weight/height ratio over a 6-month period.

METHODS

Data were retrieved from three maternal and child health care centres. Parents were asked to fill a short questionnaire regarding the infant/toddler life style, the day care facilities and the family demographic information.

RESULTS

One hundred and seventy infants participated in the study. The research group consisted of 85 infants that had placed in day care centre prior to the age of 18 months. The control group consisted of 85 infants who had placed in day care at a later age. The research group had significantly shorter stature 3 months after day care enrolment (mean height percentiles of 56.9 versus 66.3, respectively, p = 0.024,). This trend was more pronounced after 6 months (mean height percentiles of 52.3 versus 63.7, p = 0.022). We could not, however, demonstrate a concomitant significant deceleration in weight or weight/height percentiles.

CONCLUSIONS

The explanation for this rather dramatic finding remains speculative. Possible mechanisms are stress-related growth hormone suppression. Our findings reinforce the importance of monitoring infant/toddler weight and height growth velocities, especially when he/she is introduced to day care.

Association between attendance of day care centres and increased prevalence of eczema in the German birth cohort study LISAplus

BACKGROUND

Day care centre attendance is much more common in East than in West Germany. Although there is evidence that early day care might be protective against atopic diseases, several studies have shown a higher prevalence of childhood eczema in East Germany compared to West Germany.

OBJECTIVES

To compare prevalence and cumulative incidence of eczema in a birth cohort study in East and West Germany and to identify risk factors that are associated with eczema, which might explain regional differences.

METHODS

We used data from the ongoing population-based birth cohort study Influence of Life-style factors on the development of the Immune System and Allergies in East and West Germany Plus the influence of traffic emissions and genetics. In 1997, 3097 children from study areas in East and West Germany were recruited. Cumulative incidence and 1-year prevalences of eczema up to the age of 6 years were determined from yearly questionnaires. Cox regression and generalized estimating equations/logistic regression were used to quantify regional differences and to identify risk factors that might explain them.

RESULTS

Prevalence and incidence of eczema were higher in children living in East Germany than those living in West Germany. We identified 11 risk factors that showed significant regional differences. From these factors, only 'day care attendance during the first 2 years of life' was significantly associated with eczema (odds ratio 1.56, 95% confidence interval CI 1.31-1.86). The regional differences in eczema could be explained by differences in early day care utilization.

CONCLUSION

Day care centre attendance is associated with an increased prevalence and incidence of eczema. Regional differences in eczema prevalence could be explained by regional differences in utilization of early day care.

Use of homeopathy in pediatric oncology in Germany

Homeopathy is a frequently used complementary and alternative medicine (CAM) treatment. We present results comparing responses of homeopathy users (HUs) and users of other forms of CAM (NHUs) in pediatric oncology (PO) in Germany. Differences between these two groups (usage, associated demographic characteristics, previous experience with CAM) are investigated. 186 (45.2%) of the 367 CAM users were exposed to homeopathy. The treatment duration amounted to a median of 601 days for HUs and 282 days for NHUs. Parents with p (127; 76.5%) also used homeopathy for their child's cancer. Nonmedical practitioners played a considerably greater role as source of information than did treating physician. In the majority HUs received their prescriptions from nonmedical practitioners (56%; 29.4% of NHUs). HUs communicate more frequently with their physicians about the CAM-use (77.7% versus 65.2%) and recommend CAM more often than NHUs (94% versus 85.6%). Homeopathy is the most frequently used CAM treatment in PO in Germany. HUs sustain treatment and therapies considerably longer than NHUs. Most families who had used homeopathy before their child was diagnosed with cancer also used homeopathy for the treatment of their child's cancer. Compared to other CAM treatments, patient satisfaction with homeopathy appears to be very high.

Associations between BMI and the FTO gene are age dependent: results from the GINI and LISA birth cohort studies up to age 6 years

OBJECTIVE

The association between polymorphisms in intron 1 of the fat mass and obesity associated gene (FTO) and obesity-related traits is one of the most robust associations reported for complex traits and is established both in adults and children. However, little is known about the longitudinal dynamics of these polymorphisms on body mass index (BMI), overweight, and obesity.

METHODS

This study is based on the 2,732 full-term neonates of the German GINI-plus and LISA-plus birth cohorts, for whom genotyping data on the FTO variants rs1558902 (T>A) or rs9935401 (G>A) were available. Children were followed from birth up to age 6 years. Up to 9 anthropometric measurements of BMI were obtained. Fractional-Polynomial-Generalized-Estimation-Equation modeling was used to assess developmental trends and their potential dependence on genotype status.

RESULTS

We observed no evidence for BMI differences between genotypes of both variants for the first 3 years of life. However, from age 3 years onwards, we noted a higher BMI for the homozygous minor alleles carriers in comparison to the other two genotype groups. However, evidence for statistical significance was reached from the age of 4 years onwards.

CONCLUSIONS

This is one of the first studies investigating in detail the development of BMI depending on FTO genotype between birth and the age of 6 years in a birth cohort not selected for the phenotype studied. We observed that the association between BMI and FTO genotype evolves gradually and becomes descriptively detectable from the age of 3 years onwards.

Burden of otitis media and pneumonia in children up to 6 years of age: results of the LISA birth cohort

Infections play an important role in childhood. For Germany, few data are available on the epidemiology of infectious diseases such as otitis media and pneumonia in children. We therefore described the prevalence, first episode proportions and recurrence of these childhood infection diseases in selected regions of Germany in children up to 6 years of age. The analysis was based on data from the LISA Study, a prospective population-based birth cohort study including 3,097 full-term infants. Information was collected by parent questionnaire. The first episode proportions for the first 6 years of life were high for otitis media (66.7%; 95%CI 0.65-0.69) and pneumonia (13.5%; 95%CI 0.12-0.15). The annual first episode proportions for otitis media ranged from 7.3% to 25.6% and for pneumonia from 1.4% to 3.4%; both peaked during the second year. The average number of otitis media episodes was 2.2 (SD 2.0) episodes per child within the first 2 years. During the first 2 years of life, hospitalisations due to otitis and pneumonia occurred in up to 7.8 per thousand and 3.0 per thousand of the children, respectively. On average, 50.6% of the children with otitis media were treated with antibiotics during the first year of life. In conclusion, this analysis shows that infectious diseases, especially otitis media, are very frequent childhood diseases in Germany. Thus, parents and physicians should not per se worry about a high frequency of otitis media during early childhood.