Lead exposure in urban and rural school children in Ghana

Human exposure to lead in non industrial urban areas is commonly ascribed to vehicular combustion of leaded gasoline. This belief is based on results of studies in societies with high vehicular density which show emission of lead fumes into the air by automobiles that use gasoline with high lead content. To assess this view, blood lead levels were evaluated in 11 to 15-year old school children in urban and rural communities of the Greater Accra Region, Ghana. Blood lead levels was significantly higher in all the urban children studied (mean +/-SD: 8.3+/- 12.7g/dl) than in their rural counterparts (4.0+/-7.2g/dl) (P<0.002). The trend was the same when only those who tested positive for blood lead were considered (24.1+/- 9.2g/dl, urban compared with 14.6+/- 5.8g/dl, rural). The prevalence of lead exposure was, however, not significantly different between the two groups (34.3. percent, urban and 27.1 per cent, rural). The presence of anaemia and/or increased urine total protein levels was unrelated to the blood lead levels in the children form both communities. Although a set goal to achieve lead free gasoline is desirable, the closeness of the prevalence rate of lead exposure obtained in the study indicate that factors other than leaded gasoline may be important determinant in exposure to lead in the Ghanaian community.     

Effect of mattress and pillow encasings on children with asthma and house dust mite allergy

BACKGROUND: House dust mite (HDM) allergy is a frequent cause of allergic asthma in children. Reduction of exposure seems to be the most logical way to treat these patients. OBJECTIVE: Our aim was to investigate whether mattress and pillow encasings resulted in an effective long-term control of HDM allergen levels, thereby reducing the need for asthma medication in children with asthma and HDM allergy. METHODS: In a prospective, double-blind, placebo-controlled study 60 children (age range, 6-15 years) with asthma and HDM allergy were randomized to active (allergy control) or placebo mattress and pillow encasings. After a 2-week baseline period, follow-up was performed every 3 months for 1 year. During the entire study period, the dose of inhaled steroids was tapered off to the lowest effective dose according to well-defined criteria. RESULTS: Fifty-two patients completed the trial, and 5 were excluded, leaving data from 47 children (26 in the active treatment group and 21 in the placebo group) for analysis. A significant perennial reduction in HDM allergen concentrations was seen only for the active treatment group. Also, a significant decrease in the dose of inhaled steroids (mean, 408 to 227 microg/d; P <.001) was found for the active treatment group only, with significant differences between groups after 9 and 12 months. After 1 year, the dose of inhaled steroids was reduced by at least 50% in significantly more children in the active treatment group than in the placebo group (73% vs 24%, P <.01). CONCLUSION: Encasing of mattresses and pillows resulted in a significant long-term reduction in HDM allergen concentrations in mattresses and in the need for inhaled steroids in children with asthma and HDM allergy.     

Chronic aircraft noise exposure, stress responses, mental health and cognitive performance in school children

BACKGROUND: Previous research suggests that children are a high risk group vulnerable to the effects of chronic noise exposure. However, questions remain about the nature of the noise effects and the underlying causal mechanisms. This study addresses the effects of aircraft noise exposure on children around London Heathrow airport, in terms of stress responses, mental health and cognitive performance. The research also focuses on the underlying causal mechanisms contributing to the cognitive effects and potential confounding factors. METHODS: The cognitive performance and health of 340 children aged 8-11 years attending four schools in high aircraft noise areas (16 h outdoor Leq > 66 dBA) was compared with children attending four matched control schools exposed to lower levels of aircraft noise (16 h outdoor Leq < 57 dBA). Mental health and cognitive tests were group administered to the children in the schools. Salivary cortisol was measured in a subsample of children. RESULTS: Chronic aircraft noise exposure was associated with higher levels of noise annoyance and poorer reading comprehension measured by standardized scales with adjustments for age, deprivation and main language spoken. Chronic aircraft noise was not associated with mental health problems and raised cortisol secretion. The association between aircraft noise exposure and reading comprehension could not be accounted for by the mediating role of annoyance, confounding by social class, deprivation, main language or acute noise exposure. CONCLUSIONS: These results suggest that chronic aircraft noise exposure is associated with impaired reading comprehension and high levels of noise annoyance but not mental health problems in children.     

Risk factors for airway obstruction in school children with respiratory symptoms assessed in a five year prospective study

The aim of this prospective study was to assess age-related changes of the respiratory status and to evaluate risk factors for persistent airflow obstruction in symptomatic school children. One hundred fifty children aged 7-12 years (mean age 9.5 yr.) were followed-up. In 1994 parents--administered questionnaire, skin prick tests and three dynamic spirometries in 4-6 week intervals were performed. Airways flow limitation was defined as FEV1%, MEF50 or MEF25 below minimal value. In 1999 questionnaires and spirometry were repeated by the same methods. The response rate was 74.7%. Children's respiratory status generally improved. Frequency of respiratory symptoms and obstructive disturbances (37.5% in 1994 versus 22.3% in 1999) decreased. Significant risk factors for airways flow limitation in 1999 were nocturnal dry cough, doctor diagnosed asthma, female gender and parental smoking. Advanced or persisting airway obstruction during several month in 1994 was valuable to predict lung function impairment in 1999. No relation between skin tests results and persistent airway obstruction was observed.     

Cortical kynurenic acid bi-directionally modulates prefrontal glutamate levels as assessed by microdialysis and rapid electrochemistry

Using two in vivo methods, microdialysis and rapid in situ electrochemistry, this study examined the modulation of extracellular glutamate levels by endogenously produced kynurenic acid (KYNA) in the prefrontal cortex (PFC) of awake rats. Measured by microdialysis, i.p. administration of KYNA's bioprecursor l-kynurenine dose-dependently elevated extracellular KYNA and reduced extracellular glutamate (nadir after 50 mg/kg kynurenine: 60% decrease from baseline values). This dose-dependent decrease in glutamate levels was also seen using a glutamate-sensitive microelectrode array (MEA) (31% decrease following 50 mg/kg kynurenine). The kynurenine-induced reduction in glutamate was blocked (microdialysis) or attenuated (MEA) by co-administration of galantamine (3 mg/kg i.p.), a drug that competes with KYNA at an allosteric potentiating site of the α7 nicotinic acetylcholine receptor. In separate experiments, extracellular glutamate levels were measured by MEA following the local perfusion (45 min) of the PFC with kynurenine (2.5 μM) or the selective KYNA biosynthesis inhibitor S-ethylsulfonylbenzoylalanine (S-ESBA; 5 mM). In agreement with previous microdialysis studies, local kynurenine application produced a reversible reduction in glutamate (nadir: −29%), whereas perfusion with S-ESBA increased glutamate levels reversibly (maximum: +38%). Collectively, these results demonstrate that fluctuations in the biosynthesis of KYNA in the PFC bi-directionally modulate extracellular glutamate levels, and that qualitatively very similar data are obtained by microdialysis and MEA. Since KYNA levels are elevated in the PFC of individuals with schizophrenia, and since prefrontal glutamatergic and nicotinic transmission mediate cognitive flexibility, normalization of KYNA levels in the PFC may constitute an effective treatment strategy for alleviating cognitive deficits in schizophrenia.     

Low physical activity levels and high levels of sedentary behaviour are characteristic of rural Irish primary school children

There is increasing public health concern that levels of physical activity in children are extremely low. This study aimed to describe objectively levels of physical activity and sedentary behaviour during the waking hours in a sample of 4-5 year old (median 5.4 years range 4.3, 6.0) rural Irish children (n=41) and to test for gender differences in patterns of physical activity and sedentary behaviour. There were significant gender differences in physical activity (Boys (median) 834 accelerometer counts per minute (cpm), girls (median) 628cpm; p = 0.0015), sedentary behaviour (Boys 74% of waking time, girls 81% of waking time, p=0.0011) and moderate-vigorous physical activity (Boys 4% of waking time, girls 2% of waking time; p=0.0175). This study that suggests young rural Irish children lead sedentary lifestyles.     

The association of psychiatric diagnoses, health service use, and expenditures in children with obesity-related health conditions

Objective To examine the association of psychiatric diagnosesand use of health care services in children with obesity-relatedhealth conditions. Method A retrospective, longitudinal designwas used to examine Medicaid claims data. The data set consistedof 13,688 youth diagnosed with type 2 diabetes, metabolic syndrome,dyslipidemia, or obesity. Results The presence of any type ofpsychiatric diagnosis was associated with higher health serviceuse. In particular, the presence of an internalizing diagnosiswas more consistently associated with higher service use thanthe presence of an externalizing diagnosis. Children with bothan externalizing and internalizing disorder diagnosis had greaterservice use than children with a diagnosis in only one of thesecategories. Conclusions These data highlight a subgroup of childrenwith obesity-related health conditions who are at greater riskfor higher health service use, and the need for further researchon the association between psychiatric diagnosis and healthservice use.     

Maternal bisphenol a exposure during pregnancy and its association with adipokines in Mexican‐American children

Bisphenol A (BPA) is a high volume production chemical that has been detected in 93% of the United States population. It is thought to have endocrine disrupting activity but human data are limited. In this study, we examined whether prenatal or concurrent urinary BPA concentrations are associated with key metabolism‐related hormones, adiponectin and leptin (adipokines), in 9‐year‐old children. For this analysis, we used 188 mother‐child pairs from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) prospective study. BPA was measured in urinary spot samples during early (12.6 ± 3.9 weeks gestation) and late (26.3 ± 2.5 weeks gestation) pregnancy and in 9‐year‐old children. We found that BPA concentrations during late pregnancy were associated with increased plasma leptin in boys (β = 0.06, P = 0.01), controlling for maternal prepregnancy body mass index (BMI), pregnancy soda consumption, and smoking, years in US prior to pregnancy, maternal education, household poverty status, child BMI and child soda, fast food and sweet snack consumption at 9 years. Additionally, we found that BPA concentrations during early pregnancy are directly associated with plasma adiponectin levels in girls (β = 3.71, P = 0.03). However, we did not find any significant relationships between concurrent BPA concentrations and 9‐year child adiponectin or leptin. Overall, our data suggest that prenatal BPA concentrations may influence adipokine levels in 9‐year‐old children. Environ. Mol. Mutagen. 54:621–628, 2013. © 2013 Wiley Periodicals, Inc.     

Oral health status of school children in Mbarara, Uganda

Background

Despite the need for oral health morbidity surveys to aid in reviewing of the oral health services, dental data of Ugandan children is scanty.

Objectives

To describe the magnitude and distribution of selected oral health conditions among primary school children in Mbarara, Uganda.

Methods

A stratified two-stage cluster sample of 437 children aged 5–6, 8–9 and 11–12 was enrolled. The selected conditions included: dental caries, plaque, calculus, gingivitis, fluorosis and malocclusion (maxillary overjet). These conditions were diagnosed and scored in accordance with World Health Organisation (WHO) criteria.

Results

The mean decayed, missing, filled permanent teeth (DMFT) was 1.5(±0.8 SD). Females had higher DMFT (1.6±0.8SD) than males (1.3±0.8SD). Decayed, filled milk teeth (dt) was 2.7(±1.8SD) but more in males 3.1(±2.1SD) than in females 2.4(±1.6SD). Children in private schools were likely to have more caries in both permanent teeth (DMFT: 1.6±0.9SD) and milk teeth (dt: 3.0±1.9SD). Day-scholars were likely to have more caries in permanent teeth (DFMT: 1.50.8SD). Those in boarding were likely to have more caries in milk teeth (dt: 3±2.2SD). Milk teeth caries decreased with age (p<0.0001). Eight (1.8%) had very mild to moderate fluorosis. Nine (2%) lost permanent canines due to practice of “nylon teeth mutilation.” Majority 325(75%) had dental plaque, which increased with age (p<0.0001). Males significantly had plaque. Children in private schools were associated with less plaque (OR: 0.6, 95%CI: 0.4–0.9), as were those in boarding schools. Some 113(25.9%) had calculus that increased with age (p<0.0001). Calculus was more prevalent in males, government schools, and among day-scholars. Females were less likely to have maxillary overjet (OR: 0.5, 95% CI: 0.3–0.8). Day-scholars were 2 times more likely to have maxillary overjet (OR: 1.9, 95%CI: 1.1–3.5). None had severe gingivitis.

Conclusion

The oral hygiene of school children was poor with high plaque prevalence demonstrating a lack of established oral hygiene practices. A comprehensive community-focused oral health care intervention that includes oral health education in homes and the strengthening of school health programme is needed to improve the oral health status of children in Mbarara.     

Characteristics of teach-back as practiced in a university health center,and its association with patient understanding,self-efficacy,and satisfaction

ObjectivesThe purpose of this research was to investigate the extent to which recommended characteristics of teach-back were employed by providers in a university Student Health Services department, and to evaluate its association with patient understanding, self-efficacy, and satisfaction.MethodThe study employed a causal comparative design. Audio recordings of 87 primary care interviews were transcribed and coded for presence and characteristics of teach-back. Patients and providers filled out post-encounter questionnaires.ResultsWhen teach-back was used, most recommended characteristics of teach-back were regularly employed. However, providers rarely placed the onus for understanding on themselves, and almost never “closed the loop” by asking patients to repeat back information until they got it correct. Teach-back was associated with higher patient self-efficacy, and high fidelity of implementation with better patient understanding of the reason for the treatment plan.ConclusionsFindings add to existing evidence regarding effectiveness of teach-back. Additional benefits may be realized when implementation is true to recommended characteristics. More research is needed into the necessity of closing the loop and placing onus on the provider.Practice implicationsGiven that neither patients nor providers accurately gauged the level of patient understanding in the medical encounter, teach-back may offer a simple, quick means of reinforcing provider health information and raising patient self-efficacy.     

Exposure to pets, and the association with hay fever, asthma, and atopic sensitization in rural children

BACKGROUND: An increasing number of studies report pet exposure to be associated with lower risk of asthma and allergies. This 'protective pet effect' has been suggested to result from a modified T-helper (Th)2-cell response, or because of increased microbial load in homes where pets are kept. We examined the associations between pet contact and the occurrence of asthma and allergies in children of the rural Allergy and Endotoxin (ALEX) population, taking farm animal contact, endotoxin and cat allergen levels in mattress dust into account. METHODS: Information about contact with pets and farm animals, asthma and allergy were collected for 812 children by a standardized parents' questionnaire and an interview. Mattress dust endotoxin and cat allergen levels as well as specific IgE and IgG4 antibodies to Fel d1 were determined. RESULTS: Current contact with dogs was inversely associated with diagnosed hay fever (OR 0.26, 95% CI 0.11-0.57), diagnosed asthma (OR 0.29, 95% CI 0.12-0.71), sensitization to cat allergen (OR 0.48, 95% CI 0.23-0.99) and to grass pollen (OR 0.55, 95% CI 0.33-0.94), but not with increased IgG4 levels. Early and current contact with cats were associated with reduced risk of wheezing (OR 0.48, 95% CI 0.23-1.00, and OR 0.49, 95% CI 0.26-0.92, respectively) and grass pollen sensitization. Adjustment for farm animal contact but not for endotoxin and cat allergen exposure attenuated these associations and the effect of pet was stronger among farmers' children. CONCLUSION: Although pet exposure was very frequent in this rural population, the inverse relation between current dog contact, asthma and allergy was mostly explained by simultaneously occurring exposure to stable animals or was restricted to farm children. In addition, a subtle form of pet avoidance may contribute to the protective effect of pet.     

House dust mite allergen levels and an anti-mite mattress spray (natamycin) in the treatment of childhood asthma

Natamycin, a fungicide marketed as Tymasil, is claimed to reduce house dust mite numbers and would therefore be expected to improve asthma in children with mite sensitivity. We have tested this assertion by a double-blind, placebo-controlled trial. There was no significant effect on levels of Der p I in mattress dust between active and placebo groups at the end of the spraying period. Histamine inhalation challenge PC20, clinic visit symptom scores and lung function tests reflecting either large or small airways obstruction were also unchanged. Therefore this product is not a therapeutic option for mite-allergic patients using the manufacturer's recommended dose and method of administration. Other factors influencing the Der p I levels were also investigated. Of these, only month of measurement and bedroom wall humidity showed any association.     

Cat and dust mite allergen levels, specific IgG and IgG4, and respiratory symptoms in adults

BACKGROUND: Exposure to allergen may induce a modified T(H)2 response characterized by high IgG(4) levels, absence of IgE sensitization, and a decreased risk of allergic respiratory symptoms. OBJECTIVE: To assess the association of IgG(4) level with allergic respiratory symptoms in a community-based sample of adults. METHODS: Information on exposure to cats, respiratory symptoms, and mattress allergen levels was obtained from 2780 adults. Levels of cat and house dust mite (HDM) specific IgE, IgG, and IgG(4) were measured. The association of exposure to allergen with IgG(4) and of IgG(4) with symptoms was assessed. RESULTS: Geometric mean (GM) cat specific IgG and IgG(4) was higher in subjects who had a cat that was allowed in the bedroom than in subjects without a cat (adjusted ratio of GM IgG(4), 1.41; 95% CI, 1.25-1.57). Levels of HDM specific IgG and IgG(4) were similar in subjects with undetectable and high (>20.22 microg/g) mattress Der 1 levels (adjusted ratio of GM IgG(4), 1.02; 95% CI, 0.89-1.17). There was no evidence that high cat or HDM specific IgG(4) levels were associated with less IgE sensitization or with fewer symptoms. CONCLUSION: In this community-based sample of adults, high IgG(4) levels to cat or HDM were not associated with a lower risk of allergic respiratory symptoms. CLINICAL IMPLICATIONS: In adults, high cat allergen exposure does not protect against respiratory symptoms.     

Bacterial and fungal components in house dust of farm children, Rudolf Steiner school children and reference children--the PARSIFAL Study

BACKGROUND: Growing up on a farm and an anthroposophic lifestyle are associated with a lower prevalence of allergic diseases in childhood. It has been suggested that the enhanced exposure to endotoxin is an important protective factor of farm environments. Little is known about exposure to other microbial components on farms and exposure in anthroposophic families. OBJECTIVE: To assess the levels and determinants of bacterial endotoxin, mould beta(1,3)-glucans and fungal extracellular polysaccharides (EPS) in house dust of farm children, Steiner school children and reference children. METHODS: Mattress and living room dust was collected in the homes of 229 farm children, 122 Steiner children and 60 and 67 of their respective reference children in five European countries. Stable dust was collected as well. All samples were analysed in one central laboratory. Determinants were assessed by questionnaire. RESULTS: Levels of endotoxin, EPS and glucans per gram of house dust in farm homes were 1.2- to 3.2-fold higher than levels in reference homes. For Steiner children, 1.1- to 1.6-fold higher levels were observed compared with their reference children. These differences were consistently found across countries, although mean levels varied considerably. Differences between groups and between countries were also significant after adjustment for home and family characteristics. CONCLUSION: Farm children are not only consistently exposed to higher levels of endotoxin, but also to higher levels of mould components. Steiner school children may also be exposed to higher levels of microbial agents, but differences with reference children are much less pronounced than for farm children. Further analyses are, however, required to assess the association between exposure to these various microbial agents and allergic and airway diseases in the PARSIFAL population.     

Inhalant allergy in asthmatic children: skin prick test, radioallergosorbent test and chemiluminescent assay compared with allergen levels in their mattress dusts

Mattress dusts from the beds of 51 asthmatic children with positive skin tests to house dust mite were assayed for Der p I, Fel d I and certain viable fungi. The results of skin tests to grass, cat, dog, Alternaria, Aspergillus, Cladosporium and Penicillium, radioallergosorbent tests to cat, mite, dog and grass and the chemiluminescent assay were compared and correlations made with allergen concentrations in the dust. The sensitivity of the three tests appeared comparable (percentage agreement = 54.5-94), however, an increased level of allergen in the mattress dust was not a good indicator of the degree of sensitization of the child (p greater than 0.05).     

Immunoglobulin levels and function in pre-school children with recurrent respiratory infections.

Thirty pre-school children with recurrent respiratory infections had a higher age adjusted mean serum IgG level than their siblings or a reference group. One index child had persistently low serum IgA, but mean serum IgA and IgM levels for the index children were normal. All of the 23 index children and 17 siblings studied had a four-fold or greater rise in virus neutralizing antibody titre. There was no correlation between serum immunoglobulin levels and frequency of infections. There was, however, a significant inverse correlation between salivary IgA levels when healthy and the number of infections experienced by each child in the study year. Salivary IgA levels rose considerably during acute infections.     

Negative association of Enterobius infestation with asthma and rhinitis in primary school children in Taipei

BACKGROUND: The relationship between allergy and parasites has been controversial, especially in non-tropical countries. Enterobius vermicularis (human pinworm) is the most prevalent intestinal parasite in industrialized countries. OBJECTIVE: To examine the association between pinworm infestation and allergy in primary school children. METHOD: Peri-anal tape test for pinworm is routinely performed in Taipei primary schools. We collected data from school records and questionnaires distributed to all children in four primary schools grades 1 through 6 (n = 3107). RESULTS: The prevalence of physician-diagnosed asthma (9.3% vs. 14.1%, P = 0.007) and allergic rhinitis (27.4% vs. 38.3%, P = 0.001) was lower in pinworm-positive compared to uninfested children. Pinworm was not correlated with atopic dermatitis or parent allergy. With logistic regression controlling for sex, parent allergy and lower respiratory infection, current asthma (OR = 0.25, 95% CI 0.10-0.63) and rhinitis (OR = 0.61, 95% CI 0.45-0.84) were negatively associated with pinworm. Among children in grades 3-6 who had no asthma or rhinitis before age 7, those with early infestation (pinworm diagnosis at or before grade 1) had a lower risk of having diagnosis of rhinitis during school years, compared to the uninfected group (5.4% vs. 12.3%, P = 0.03; adjusted OR = 0.47, 95% CI 0.21-1.02). CONCLUSIONS: We identified a negative association between pinworm infestation and allergic airway diseases, which could in part be attributed to protective effect of pinworm infestation on development of allergic symptoms. Other mechanisms of association could not be ruled out.     

Natural exposure and serum antibodies to house dust mite of mite-allergic children with asthma in Atlanta

Pyroglyphid mites in house dust are important allergens associated with asthma in Europe, but comparable studies of house dust mites in the homes of patients with asthma have not been done in the United States. We examined the distribution of mites and mite allergen in the houses of 20 mite-sensitive children with asthma in Atlanta and measured IgE antibodies to mite allergens in their sera. One or more dust samples from bedding, bedroom floor, television room floor, or television room furniture from 17/20 houses contained greater than 10,000 ng of antigen P1 equivalent per gram of fine dust; amounts ranged from 280 to 230,400 ng/gm. Allergen levels were higher in dust samples from furniture and bedding than from floors. Dust samples obtained from houses in June to September had more mites and mite allergen than those houses sampled in March to April; relative humidity in the room also was higher in June to September. Mite numbers and allergen in floor and furniture samples were correlated with relative humidity in the room and were high when relative humidity was greater than 50%; antigen P1 equivalent was greater than 10,000 ng/gm in 21/39 such samples. Dermatophagoides pteronyssinus was present in all houses and dominant in 11/20. D. farinae was found in 17 houses and was dominant in six. All children studied had high IgE antibody with either D. farinae or D. pteronyssinus RAST; 16 of the 20 children also had IgE to antigen P1. It is likely that the IgE antibody responses in these 20 children with asthma were a direct result of exposure to high levels of mite allergen.(ABSTRACT TRUNCATED AT 250 WORDS)