[Dietary pattern, asthma, and atopic and non-atopic wheezing in children and adolescents: SCAALA study, Salvador, Bahia State, Brazil]. / Padrão alimentar, asma e sibilo atópico e não atópico em crianças e adolescentes: estudo SCAALA, Salvador, Bahia, Brasil.

A cross-sectional study was conducted on dietary patterns and their influence on the occurrence of wheezing and atopic and non-atopic asthma in a sample of 1,168 children and adolescents in Salvador, Bahia State, Brazil. Wheezing and asthma symptoms in the previous 12 months were obtained using the ISAAC questionnaire. The presence of aeroallergen-specific IgE was identified. A food frequency questionnaire was used to define dietary patterns. The study applied logistic regression and multinomial polytomous logistic regression. Fish consumption was associated with a 27% reduction in wheezing (95%CI: 0.56-0.94), 37% in asthma (95%CI: 0.47-0.83), 51% in non-atopic asthma (95%CI: 0.31-0.79), and 38% in non-atopic wheezing (95%CI: 0.46-0.83). The highest tertile of dietary patterns reduced wheezing by 27% (95%CI: 0.57-0.95), atopic wheezing by 46% (95%CI: 0.30-0.98), asthma by 36% (95%CI: 0.49-0.83), and atopic asthma by 50% (95%CI: 0.28-0.89). Fish consumption may thus have a protective effect against wheezing and non-atopic asthma and dietary pattern against atopic asthma and wheezing.

Padrão alimentar, asma e sibilo atópico e não atópico em crianças e adolescentes: estudo SCAALA, Salvador, Bahia, Brasil / Dietary pattern, asthma, and atopic and non-atopic wheezing in children and adolescents: SCAALA study, Salvador, Bahia State, Brazil / Patrón dietético, asma y sibilancias atópicas y no atópicas en niños y adolescentes: estudio SCAALA, Salvador, Bahía, Brasil

Avaliou-se, em estudo transversal, a influência do padrão alimentar sobre a ocorrência de sibilo e asma atópica e não atópica em 1.168 crianças e adolescentes em Salvador, Bahia, Brasil. Sibilo e sintomas de asma nos últimos 12 meses foram obtidos por meio do questionário ISAAC. Atopia foi definida pela presença de IgE específica a aerolérgenos. Questionário de frequência alimentar foi usado para definir padrões alimentares. Empregou-se regressões logística e logística politômica multivariadas. O consumo de pescados reduziu a ocorrência de sibilo em 27% (IC95%: 0,56-0,94) e asma em 37% (IC95%: 0,47-0,83); asma não atópica em 51% (IC95%: 0,31-0,79) e sibilo não atópico em 38% (IC95%: 0,46-0,83). O maior tercil do padrão alimentar reduziu o sibilo em 27% (IC95%: 0,57-0,95), sibilo atópico em 46% (IC95%: 0,30-0,98), asma em 36% (IC95%: 0,49-0,83) e asma atópica em 50% (IC95%: 0,28-0,89). O consumo de pescados pode conferir efeito protetor para sibilo e asma não atópica e o padrão alimentar para sibilo e asma atópica.

A cross-sectional study was conducted on dietary patterns and their influence on the occurrence of wheezing and atopic and non-atopic asthma in a sample of 1,168 children and adolescents in Salvador, Bahia State, Brazil. Wheezing and asthma symptoms in the previous 12 months were obtained using the ISAAC questionnaire. The presence of aeroallergen-specific IgE was identified. A food frequency questionnaire was used to define dietary patterns. The study applied logistic regression and multinomial polytomous logistic regression. Fish consumption was associated with a 27% reduction in wheezing (95%CI: 0.56-0.94), 37% in asthma (95%CI: 0.47-0.83), 51% in non-atopic asthma (95%CI: 0.31-0.79), and 38% in non-atopic wheezing (95%CI: 0.46-0.83). The highest tertile of dietary patterns reduced wheezing by 27% (95%CI: 0.57-0.95), atopic wheezing by 46% (95%CI: 0.30-0.98), asthma by 36% (95%CI: 0.49-0.83), and atopic asthma by 50% (95%CI: 0.28-0.89). Fish consumption may thus have a protective effect against wheezing and non-atopic asthma and dietary pattern against atopic asthma and wheezing.

Este estudio transversal se llevó a cabo para estudiar la influencia de los hábitos alimentarios en la aparición del asma y sibilancias atópicas y no atópicas en una muestra de 1.168 niños y adolescentes en Salvador, Bahía, Brasil. Las sibilancias y síntomas de asma en los últimos 12 meses se han obtenido a partir del cuestionario ISAAC. Se identificó la presencia de IgE específica de alérgeno aéreo. Se utilizó un cuestionario de frecuencia de alimentos para definir hábitos alimentarios. Se aplicó la regresión logística y el modelo logístico multinomial. El consumo de pescado redujo las sibilancias en un 27% (IC95%: 0,56-0,94) y el asma en un 37% (IC95%: 0,47-0,83), las sibilancias atópicas en un 51% (IC95%: 0,31-0,79) y no atópicas en un 38% (IC95%: 0,46-0,83). El tercil más alto de los hábitos alimentarios reduce sibilancias en un 27% (IC95%: 0,57-0,95), sibilancias atópicas en un 46% (IC95%: 0,30-0,98), el asma en un 36% (IC95%: 0,49-0,83) y un 50% en el asma atópico (IC95%: 0,28-0,89). El consumo de pescado puede promover un efecto protector, dentro el patrón de dieta, contra sibilancias atópicas y no atópicas y asma.

[Dietary patterns of children under five years of age living in the State capital and other counties of Bahia State, Brazil, 1996 and 1999-2000]. / Padrões alimentares de crianças menores de cinco anos de idade residentes na capital e em municípios da Bahia, Brasil, 1996 e 1999/2000.

This cross-sectional study included 3,817 preschool children, of whom 1,770 in Salvador, Bahia State, Brazil, and 2,047 in urban and rural areas from nine other municipalities (counties) in the same State. The study used 24-hour recall and principal components analysis to identify and compare dietary patterns. The sample was stratified by age and area. In the first six months of life, breast milk composed the second and third patterns, with positive loadings for children in all 10 municipalities. For children under 17 months of age, pattern 1 was characterized by cow's milk, flour, and sugar, except in rural areas. Pattern 2 was similar for children aged 6-17 months and consisted of bread/cookies, rice, beans, and meat. For children 18-23 months of age in urban areas, pattern 1 showed negative loadings for sugar, cow's milk, and flour. In children over 24 months of age, fruits were not part of the first pattern. The study showed low consumption of milk and low variety of fruits and vegetables. This food consumption profile indicates the need for early interventions to promote healthy eating habits.

Padroes alimentares de criancas menores de cinco anos de idade residentes na capital e em municipios da Bahia, Brasil, 1996 e 1999/2000 / Dietary patterns of children under five years of age living in the State capital and other counties of Bahia State, Brazil, 1996 and 1999-2000 / Patrones de alimentacion de ninos menores de cinco anos de edad que viven en la capital y los municipios de Bahia, Brasil, 1996 y 1999/2000

Estudo transversal com 3.817 pré-escolares, 1.770 residentes em Salvador, Bahia, Brasil, e 2.047 nas áreas urbana e rural de 10 municípios baianos. Utilizou-se recordatório de 24 horas (R24h) e empregou-se análise fatorial por componentes principais com objetivo de identificar e comparar os principais padrões alimentares dessas crianças. Estratificou-se a amostra por idade e área. Antes dos seis meses de vida o leite materno compôs o 2o e 3o padrões com carga positiva para crianças dos dez municípios. Para menores de 17 meses, o padrão 1 foi caracterizado por leite de vaca, farinhas e açúcares. Em áreas urbanas, pão/biscoito, arroz, feijão e carne integraram o padrão 2 aos 6-17 meses. Aos 18-23 meses, o padrão 1 apresentou carga negativa para açúcares, leite de vaca e farinhas, exceto na área rural. Frutas não fizeram parte do padrão 1 no grupo de 24 meses e mais. Observou-se baixo consumo de leite materno e pouca variação de frutas e legumes a partir dos seis meses. Tal perfil de consumo alimentar indica a necessidade de intervenções cada vez mais precoces para promoção de hábitos alimentares saudáveis. .

This cross-sectional study included 3,817 preschool children, of whom 1,770 in Salvador, Bahia State, Brazil, and 2,047 in urban and rural areas from nine other municipalities (counties) in the same State. The study used 24-hour recall and principal components analysis to identify and compare dietary patterns. The sample was stratified by age and area. In the first six months of life, breast milk composed the second and third patterns, with positive loadings for children in all 10 municipalities. For children under 17 months of age, pattern 1 was characterized by cow’s milk, flour, and sugar, except in rural areas. Pattern 2 was similar for children aged 6-17 months and consisted of bread/cookies, rice, beans, and meat. For children 18-23 months of age in urban areas, pattern 1 showed negative loadings for sugar, cow’s milk, and flour. In children over 24 months of age, fruits were not part of the first pattern. The study showed low consumption of milk and low variety of fruits and vegetables. This food consumption profile indicates the need for early interventions to promote healthy eating habits.

Estudio transversal realizado con 3.817 niños en edad preescolar, 1.770 residentes en Salvador, Bahía, Brasil, y 2.047 en las zonas urbanas y rurales de 10 municipios de Bahía. Se utilizó el recordatorio de 24 horas (R24h) y el análisis de componentes principales, con el fin de identificar y comparar los hábitos alimentarios. Se estratificó la muestra según edad y área. Antes de los 6 meses de vida, la leche materna compone los 2o y 3o patrones, con cargas positivas en los niños de 10 municipios. Para los menores de 17 meses, el patrón 1 se caracteriza por leche de vaca, harina y azúcar. El patrón 2 fue similar en niños de 6 a 17 meses y consistía en frijoles, carne, pan/galletas, arroz. Para niños de 18 a 23 meses en las zonas urbanas el patrón 1 mostraron cargas negativas en azúcares, leche y harina. Teniendo en cuenta el grupo de mayores de 24 meses, las frutas no eran parte del primer patrón. Se encontró un bajo consumo de leche y baja variabilidad de frutas y hortalizas. Este perfil indica la necesidad de intervenciones cada vez más tempranas para promover hábitos alimenticios saludables. .

Weight gain in the first two years of life, asthma and atopy: the SCAALA cohort study.

OBJECTIVE: To evaluate the association between weight gain in the first two years of life and the occurrence of wheezing, asthma, serum IgE, skin reactivity and pulmonary function. DESIGN: Cohort study. SETTING: The metropolitan region of Salvador, Bahia, Brazil. SUBJECTS: The association was studied between 1997 and 2005 in 669 children up to 11 years of age. Data were collected on asthma and risk factors, both current factors and those present in the first years of life. Weight gain was considered fast when the Z-score was >0·67. Poisson regression was used in the multivariate statistical analysis. RESULTS: Wheezing was reported in 25·6 % of the children. Weight gain was considered fast (Z-score >0·67) in 29·6 % of the children and slow (Z-score <-0·67) in 13·9 %. Children in the slow weight gain group had 36 % fewer symptoms of asthma (prevalence ratio = 0·65; 95 % CI 0·42, 0·99). CONCLUSIONS: Slower weight gain in the early years of life may constitute a protective factor against symptoms of asthma. The relevance of this finding for public health is not yet certain, since it is known that children with slow and fast weight gain may be more likely to develop adverse health consequences related to both these situations.

Environmental indicators of intra-urban hetererogeneity.

A large number of human diseases are related to poor access to water and sewer systems, inadequate solid waste management and deficient storm water drainage. The goal of this study was to formulate environmental sanitation indicators and classify sanitation conditions in specific sewer basins and their respective neighborhoods. The database used contains information on the following sanitation components in these areas: water supply, sewer systems, urban drainage, road pavement, building typology and public cleaning. Data was analyzed using cluster analysis. The key variable of each component was identified, and eight sewer basins and twenty-three neighborhoods were classified into the following categories: good, regular, and poor. The use of environmental sanitation indicators allows decision makers to identify critical areas and define priorities for improving environmental sanitation conditions.

Environmental indicators of intra-urban hetererogeneity / Indicadores ambientais para detectar heterogeneidade intraurbana / Indicadores ambientales para detectar la heterogeneidad intra-urbana

A large number of human diseases are related to poor access to water and sewer systems, inadequate solid waste management and deficient storm water drainage. The goal of this study was to formulate environmental sanitation indicators and classify sanitation conditions in specific sewer basins and their respective neighborhoods. The database used contains information on the following sanitation components in these areas: water supply, sewer systems, urban drainage, road pavement, building typology and public cleaning. Data was analyzed using cluster analysis. The key variable of each component was identified, and eight sewer basins and twenty-three neighborhoods were classified into the following categories: good, regular, and poor. The use of environmental sanitation indicators allows decision makers to identify critical areas and define priorities for improving environmental sanitation conditions.

Várias patologias que acometem os seres humanos estão ligadas à deficiência de acesso a água e serviços de esgotamento sanitário, inadequado manejo de resíduos sólidos e deficiência do sistema de drenagem das águas pluviais. Este estudo buscou desenvolver indicadores sanitário ambientais e classificar áreas intraurbanas. Utilizou-se uma base de dados contendo informações sobre: abastecimento de água, sistema de esgoto, drenagem e limpeza urbana, pavimentação e tipologia construtiva referentes a bacias de esgotamento sanitário e áreas sentinela. Foi aplicada a técnica de analise de cluster. Identificou-se a variável que melhor representava cada componente, e oito bacias de esgotamento e vinte e três áreas sentinelas foram classificadas em três categorias: boa, regular e insatisfatória. O uso de indicador sanitário ambiental permitiu a identificação de áreas críticas e o estabelecimento de prioridades de investimentos para as melhorias sanitário ambientais.

Varias enfermedades que afectan a los seres humanos están vinculadas a la deficiencia en el acceso a servicios de agua y alcantarillado, la gestión inadecuada de los residuos sólidos y el deficiente sistema de drenaje de aguas pluviales. Este estudio trata de desarrollar indicadores de salud ambiental y clasificar las áreas dentro de las ciudades. Se utilizó una base de datos que contiene información sobre: limpieza urbana, abastecimiento de agua, alcantarillado, drenaje y calles, pavimentación de las calles y tipología de construcción en diferentes barrios. Se aplicó la técnica de clúster para el análisis de datos. Se identificó la variable que mejor representa cada componente y veintitrés áreas de la ciudad se clasificaron en tres categorías: buena, regular y mala. El uso de indicadores de salud ambiental permitió la identificación de áreas críticas y el establecimiento de prioridades en la inversión para la salud y mejora del medio ambiente.

[Weight gain rate in early childhood and overweight in children 5-11 years old in Salvador, Bahia State, Brazil]. / Velocidade de ganho de peso nos primeiros anos de vida e excesso de peso entre 5-11 anos de idade, Salvador, Bahia, Brasil.

Overweight children are more prone to become overweight or obese adults. The most effective prevention is intervention in early childhood. We analyzed the association between early weight gain and overweight/obesity in 1,056 children under 11 years of age. Data were collected on lifestyle, sanitation, socioeconomic status, birth weight, and breastfeeding. Weight gain from birth until different age brackets (< 12, > 12 to 18, > 18 to 24, and > 24 to 60 months) was considered a continuous variable in z-scores. Overweight was defined as body mass index (BMI) > +1 z-score, based on 2006 and 2007 World Health Organization (WHO) guidelines. Poisson regression and linear regression were used in the multivariate statistical analysis. Weight gain rate was associated with BMI, and overweight or obesity in the 5-11-year age bracket increased twofold for each unit increase in the weight gain standard deviation between 24 and 60 months of age (RR = 2.08; 95%CI: 1.87-2.32). For all early childhood age brackets, there was an association between rapid weight gain and subsequent overweight or obesity.

Overweight, asthma symptoms, atopy and pulmonary function in children of 4-12 years of age: findings from the SCAALA cohort in Salvador, Bahia, Brazil.

OBJECTIVE: To evaluate the association between overweight and the occurrence of asthma and atopy in a cohort of children of 4-12 years of age living in the city of Salvador in 2005. DESIGN: Cross-sectional study nested in a cohort. SETTING: The metropolitan region of Salvador, Bahia, Brazil. SUBJECTS: The study included 1129 children of 4-12 years age who presented complete information on the variables used here. Skin tests for allergy, spirometry, faecal parasitology, serum IgE and anthropometric surveys were conducted. Poisson's multivariate regression was adopted. RESULTS: Wheezing was found in 29·1% and asthma in 22·8% of children, both conditions being more common in those under 6 years of age and 34% more common in overweight children (prevalence ratio (PR) = 1·34; 95% CI 1·07, 1·67) following adjustment. The ratio between forced expiratory volume in 1s and forced vital capacity was associated with overweight (PR = 1·35; 95% CI 1·11, 1·61). No statistically significant association was found between overweight and allergen-specific IgE or with wheezing. CONCLUSIONS: These results are in agreement with the hypothesis that overweight is associated with asthma and pulmonary function, even following adjustment for intervening variables known to be associated with the pathogeny of asthma.

Velocidade de ganho de peso nos primeiros anos de vida e excesso de peso entre 5-11 anos de idade, Salvador, Bahia, Brasil / Weight gain rate in early childhood and overweight in children 5-11 years old in Salvador, Bahia State, Brazil

Crianças com sobrepeso estão mais propensas a se tornarem adultos com sobrepeso ou obesos, sendo a prevenção mais eficaz a intervenção em fases precoces da vida. Analisou-se a associação entre ganho de peso nos primeiros anos de vida e sobrepeso/obesidade em 1.056 crianças menores de 11 anos de idade. Foram coletadas informações relacionadas ao estilo de vida, saneamento, condições socioeconômicas, peso ao nascer e aleitamento materno. O ganho de peso do nascimento até diferentes intervalos (até 12 meses, > 12 a 18, > 18 a 24, e > 24 a 60 meses) foi considerado de forma contínua em escores-z. Foi considerado excesso de peso o índice de massa corporal (IMC) maior ou igual a +1 escore-z, usando referências da Organização Mundial da Saúde (OMS) de 2006 e 2007. Adotou-se a regressão linear e Poisson multivariada. A velocidade do ganho ponderal mostrou-se associada ao IMC, observando-se duas vezes mais sobrepeso/obesidade a cada incremento de uma unidade no desvio-padrão da velocidade do ganho ponderal para o intervalo de 24 e 60 meses (RR = 2,08; IC95 por cento: 1,87-2,32). Encontrou-se associação entre o rápido ganho de peso em todos os intervalos de idade e a ocorrência de sobrepeso/obesidade anos mais tarde.

Overweight children are more prone to become overweight or obese adults. The most effective prevention is intervention in early childhood. We analyzed the association between early weight gain and overweight/obesity in 1,056 children under 11 years of age. Data were collected on lifestyle, sanitation, socioeconomic status, birth weight, and breastfeeding. Weight gain from birth until different age brackets (< 12, > 12 to 18, > 18 to 24, and > 24 to 60 months) was considered a continuous variable in z-scores. Overweight was defined as body mass index (BMI) > +1 z-score, based on 2006 and 2007 World Health Organization (WHO) guidelines. Poisson regression and linear regression were used in the multivariate statistical analysis. Weight gain rate was associated with BMI, and overweight or obesity in the 5-11-year age bracket increased twofold for each unit increase in the weight gain standard deviation between 24 and 60 months of age (RR = 2.08; 95 percentCI: 1.87-2.32). For all early childhood age brackets, there was an association between rapid weight gain and subsequent overweight or obesity.

Condições socioeconômicas e padrões alimentares de crianças de 4 a 11 anos: estudo SCAALA - Salvador/ Bahia / The socio-economic conditions and patterns of food intake in children aged between 4 and 11 years: the SCAALA study - Salvador/ Bahia

OBJETIVOS: identificar os padrões alimentares de crianças e sua associação com o nível socioeconômico das famílias. MÉTODOS: estudo transversal com 1260 crianças de 4 a 11 anos, residentes em Salvador-Bahia que incluiu aplicação de um Questionário de Frequência Alimentar semi-quantitativo. Os padrões alimentares foram identificados, empregando-se análise fatorial por componentes principais. O nível socioeconômico foi avaliado por meio de um indicador socioeconômico composto. Regressão logística multivariada foi empregada. RESULTADOS: identificaram-se quatro padrões que explicaram 45,9 por cento da variabilidade dos dados de frequência alimentar. Crianças que pertencem ao nível socioeconômico mais alto têm 1,60 vezes mais chance (p<0,001) de apresentarem maior frequência de consumo de alimentos do padrão 1 (frutas, verduras, leguminosas, cereais e pescados) e 3,09 vezes mais chance (p<0,001) de apresentarem maior frequência de consumo dos alimentos do padrão 2 (leite/ derivados, catchup/ maionese/ mostarda e frango), quando se compara com aquele de crianças de nível socioeconômico mais baixo. Resultado inverso foi observado no padrão 4 (embutidos, ovos e carnes vermelhas); isto é, quanto maior o nível socioeconômico menor a chance da adoção desse padrão. Tendência similar foi notada para o padrão 3 (frituras, doces, salgadinhos, refrigerante/ suco artificial). CONCLUSÕES: padrões alimentares de crianças são dependentes das condições socioeconômicas das famílias e a adoção de itens alimentares mais saudáveis associa-se aos grupos de mais altos níveis socioeconômicos.

OBJECTIVE: to identify the patterns of food intake in children and the association between these and the socio-economic conditions of their families. METHODS: a cross-sectional study was carried out with 1260 children aged between 4 and 11 years, resident in the city of Salvador, in the Brazilian State of Bahia, including application of a semi-quantitative Food Intake Frequency questionnaire. The pattern of food intake of the children was assessed using factorial analysis by principal components. socio-economic level was assessed using a compound socio-economic indicator. Multivariate logistic regression was employed. RESULTS: four food groups were identified that explained 45.9 percent of the variability in food intake frequency data. Children from a more privileged socio-economic background were found to be 1.6 times more likely (p<0.001) to have a higher frequency of intake of food from group 1 (fruit, vegetables, pulses, cereals and sea food) and 3.09 times more likely (p<0.001) to have a higher frequency of consumption of food from group 2 (milk and dairy products, ketchup/mustard/mayonnaise and chicken), compared with children from a less privileged background. The opposite was found for group 4 (processed meat products, eggs, and red meat); with the children from more privileged backgrounds less likely to consume food from this group. A similar tendency was found for food from group 3 (fried food, sweets, snacks, soda/artificial fruit juice). CONCLUSION: patterns of food intake in children depend on the socio-economic conditions of their families and the choice of healthier food is associated with a more privileged socio-economic background.

Poverty, dirt, infections and non-atopic wheezing in children from a Brazilian urban center.

BACKGROUND: The causation of asthma is poorly understood. Risk factors for atopic and non-atopic asthma may be different. This study aimed to analyze the associations between markers of poverty, dirt and infections and wheezing in atopic and non-atopic children. METHODS: 1445 children were recruited from a population-based cohort in Salvador, Brazil. Wheezing was assessed using the ISAAC questionnaire and atopy defined as allergen-specific IgE ≥ 0.70 kU/L. Relevant social factors, environmental exposures and serological markers for childhood infections were investigated as risk factors using multivariate multinomial logistic regression. RESULTS: Common risk factors for wheezing in atopic and non-atopic children, respectively, were parental asthma and respiratory infection in early childhood. No other factor was associated with wheezing in atopic children. Factors associated with wheezing in non-atopics were low maternal educational level (OR 1.49, 95% CI 0.98-2.38), low frequency of room cleaning (OR 2.49, 95% CI 1.27-4.90), presence of rodents in the house (OR 1.48, 95% CI 1.06-2.09), and day care attendance (OR 1.52, 95% CI 1.01-2.29). CONCLUSIONS: Non-atopic wheezing was associated with risk factors indicative of poverty, dirt and infections. Further research is required to more precisely define the mediating exposures and the mechanisms by which they may cause non-atopic wheeze.

Impact of a citywide sanitation program in Northeast Brazil on intestinal parasites infection in young children.

BACKGROUND: Sanitation affects health, especially that of young children. Residents of Salvador, in Northeast Brazil, have had a high prevalence of intestinal parasites. A citywide sanitation intervention started in 1996 aimed to raise the level of sewer coverage from 26% to 80% of households. OBJECTIVES: We evaluated the impact of this intervention on the prevalence of Ascaris lumbricoides, Trichuris trichuria, and Giardia duodenalis infections in preschool children. METHODS: The evaluation was composed of two cross-sectional studies (1998 and 2003-2004), each of a sample of 681 and 976 children 1-4 years of age, respectively. Children were sampled from 24 sentinel areas chosen to represent the range of environmental conditions in the study site. Data were collected using an individual/household questionnaire, and an environmental survey was conducted in each area before and after the intervention to assess basic household and neighborhood sanitation conditions. Stool samples were examined for the presence of intestinal parasites. The effect of the intervention was estimated by hierarchical modeling, fitting a sequence of multivariate regression models. FINDINGS: The prevalence ofA. lumbricoides infection was reduced from 24.4% to 12.0%, T. trichuria from 18.0% to 5.0%, and G. duodenalis from 14.1% to 5.3%. Most of this reduction appeared to be explained by the increased coverage in each neighborhood by the sewage system constructed during the intervention. The key explanatory variable was thus an ecological measure of exposure and not household-based, suggesting that the parasite transmission prevented by the program was mainly in the public (vs. the domestic) domain. CONCLUSION: This study, using advanced statistical modeling to control for individual and ecological potential confounders, demonstrates the impact on intestinal parasites of sanitation improvements implemented at the scale of a large population.

Reductions in the prevalence and incidence of geohelminth infections following a city-wide sanitation program in a Brazilian Urban Centre.

OBJECTIVE: In the city of Salvador, a large urban centre in Northeast Brazil, a city-wide sanitation intervention started in 1997, aimed at improving the sewerage coverage of households from 26% to 80%. Our aim was to study the impact of the intervention on the prevalence and incidence of geohelminths in the school-aged population. METHODS: THE STUDY COMPRISED TWO COMPARABLE COHORTS: the first assembled in 1997, before the intervention, and the second assembled in 2003, after the intervention. Both were sampled from 24 sentinel areas chosen to represent the different environmental conditions throughout the city. Copro-parasitological examinations were carried out on every individual from both cohorts, at baseline and nine months later. Demographic, socio-economic, and environmental data were collected using semi-structured questionnaires and environmental surveys. A hierarchical modelling approach fitting a sequence of Poisson multivariate linear models was undertaken to test the effect of the intervention variables on the prevalence and incidence rate ratios. FINDINGS: 729 and 890 children aged 7-14 years (mean = 10.4 y, SD = 0.05 y) were analysed over the first and the second cohorts, respectively. The adjusted reductions of the prevalence and incidence rates at the second in relation to the first cohort were 27% and 34%, 25% and 32%, 33% and 26%, and 82% and 42% for geohelminths overall, Ascaris lumbricoides, Trichuris trichiura, and hookworm, respectively. Hierarchical modelling showed that a major part of each of these reductions was explained by the intervention. CONCLUSION: Our results show that a city-wide sanitation program may reduce significantly the prevalence and incidence of geohelminths.

Giardia duodenalis infection and anthropometric status in preschoolers in Salvador, Bahia State, Brazil.

The aim of this study was to estimate the association between Giardia duodenalis infection and anthropometric deficits, as measured by weight-for-age and height-for-age. This cross-sectional study included 629 children from 12 to 48 months of age, selected from 30 geographic areas in the city of Salvador, Bahia State, Brazil. Poisson regression and linear regression were used for the multivariate statistical analyses. G. duodenalis was diagnosed in 13.5% of the children. The children's breastfeeding duration and living conditions (garbage collection and paved streets or sidewalks) modified the effect of G. duodenalis infection on anthropometric status. Among infected children, there were statistically significant associations between weight deficit and shorter breastfeeding (PR=2.22; 95%CI: 1.56-3.14) and inadequate paving of streets and sidewalks (PR=2.00; 95%CI: 1.37-2.92), while height deficit was associated with deficient public garbage collection (PR=2.21; 95%CI: 1.31-2.51). In the linear regression, the association with the anthropometric indicators remained positive and statistically significant. The child's unhealthy living environment aggravated the negative effect of G. duodenalis infection on anthropometric status, and breastfeeding was a protective factor in the outcome.

Impact of a city-wide sanitation intervention in a large urban centre on social, environmental and behavioural determinants of childhood diarrhoea: analysis of two cohort studies.

BACKGROUND: Poor socioeconomic status (SES) increases diarrhoea risk, mostly mediated by lack of sanitation, poor infrastructure and living conditions. The effectiveness of a city-wide sanitation intervention on diarrhoea in a large urban centre in Northeast Brazil has recently been demonstrated. This article aims to explore how this intervention altered the magnitude of relative and attributable risks of diarrhoea determinants and the pathways by which those factors affect diarrhoea risk. METHODS: We investigated determinants of prevalence of diarrhoea in two cohort studies conducted before and after the intervention. Each study enrolled pre-school children followed up for 8 months. For both cohorts, we calculated relative, attributable and mediated risks of diarrhoea determinants by a hierarchical effect decomposition strategy. RESULTS: The intervention reduced diarrhoea and also changed attributable and relative risks of diarrhoea determinants by altering the pathways of mediation. Before the intervention SES was a major distal diarrhoea determinant (attributable risk: 24%) with 90% of risk mediated by other factors, mostly by lack of sanitation and poor infrastructure (53%). After the intervention, only 13% of risk was attributed to SES, with only 42% mediated by other factors (18% by lack of sanitation and poor infrastructure). CONCLUSION: The intervention reduced diarrhoea risk by reducing direct exposure to unfavourable sanitation conditions. At the same time it altered the effect and mediation pathways of most distal diarrhoea determinants, especially SES. This finding corroborates the importance of public sanitation measures in reducing the impact of poverty on diarrhoea. It also underlines the value of studying the impact of public health interventions to improve our understanding of health determinants.

Giardia duodenalis infection and anthropometric status in preschoolers in Salvador, Bahia State, Brazil / Infecção por Giardia duodenalis e estado antropométrico em pré-escolares de Salvador, Bahia, Brasil

The aim of this study was to estimate the association between Giardia duodenalis infection and anthropometric deficits, as measured by weight-for-age and height-for-age. This cross-sectional study included 629 children from 12 to 48 months of age, selected from 30 geographic areas in the city of Salvador, Bahia State, Brazil. Poisson regression and linear regression were used for the multivariate statistical analyses. G. duodenalis was diagnosed in 13.5 percent of the children. The children's breastfeeding duration and living conditions (garbage collection and paved streets or sidewalks) modified the effect of G. duodenalis infection on anthropometric status. Among infected children, there were statistically significant associations between weight deficit and shorter breastfeeding (PR = 2.22; 95 percentCI: 1.56-3.14) and inadequate paving of streets and sidewalks (PR = 2.00; 95 percentCI: 1.37-2.92), while height deficit was associated with deficient public garbage collection (PR = 2.21; 95 percentCI: 1.31-2.51). In the linear regression, the association with the anthropometric indicators remained positive and statistically significant. The child's unhealthy living environment aggravated the negative effect of G. duodenalis infection on anthropometric status, and breastfeeding was a protective factor in the outcome.

Este estudo tem como objetivo estimar a associação entre a infecção por Giardia duodenalis e os déficits antropométricos segundo os indicadores peso por idade e altura/comprimento por idade. Trata-se de um estudo transversal envolvendo 629 crianças de 12 a 48 meses de idade, selecionadas em trinta áreas geográficas da cidade de Salvador, Bahia, Brasil. Adotou-se a regressão de Poisson e adicionalmente regressão linear nas análises estatísticas multivariadas. G. duodenalis foi diagnosticada em 13,5 por cento das crianças. O tempo de amamentação e as condições de residência das crianças (coleta de lixo e pavimentação da rua/calçada) modificaram o efeito da infecção por G. duodenalis sobre o estado antropométrico. Entre os infectados, observaram-se associações estatisticamente significantes do déficit ponderal com o menor tempo de amamentação (RP = 2,22; IC95 por cento: 1,56-3,14) e com as condições inadequadas de pavimentação da rua/calçada (RP = 2,00; IC95 por cento: 1,37-2,92), e do déficit linear com a coleta pública de lixo (RP = 2,21; IC95 por cento: 1,31-2,51). Na análise da regressão linear, a associação se manteve positiva e estatisticamente significante com a média dos indicadores antropométricos. O ambiente insalubre em que vive a criança acentuou o efeito negativo da infecção por G. duodenalis sobre o estado antropométrico, e a amamentação ao peito constituiu-se em fator de proteção para este desfecho.

Determinants of cognitive function in childhood: a cohort study in a middle income context.

BACKGROUND: There is evidence that poverty, health and nutrition affect children's cognitive development. This study aimed to examine the relative contributions of both proximal and distal risk factors on child cognitive development, by breaking down the possible causal pathways through which poverty affects cognition. METHODS: This cohort study collected data on family socioeconomic status, household and neighbourhood environmental conditions, child health and nutritional status, psychosocial stimulation and nursery school attendance. The effect of these on Wechsler Pre-School and Primary Scale of Intelligence scores at five years of age was investigated using a multivariable hierarchical analysis, guided by the proposed conceptual framework. RESULTS: Unfavourable socioeconomic conditions, poorly educated mother, absent father, poor sanitary conditions at home and in the neighbourhood and low birth weight were negatively associated with cognitive performance at five years of age, while strong positive associations were found with high levels of domestic stimulation and nursery school attendance. CONCLUSION: Children's cognitive development in urban contexts in developing countries could be substantially increased by interventions promoting early psychosocial stimulation and preschool experience, together with efforts to prevent low birth weight and promote adequate nutritional status.

Determinants of early cognitive development: hierarchical analysis of a longitudinal study.

The study describes the relationship between anthropometric status, socioeconomic conditions, and quality of home environment and child cognitive development in 320 children from 20 to 42 months of age, randomly selected from 20,000 households that represent the range of socioeconomic and environmental conditions in Salvador, Bahia, Northeast Brazil. The inclusion criterion was to be less than 42 months of age between January and July 1999. Child cognitive development was assessed using the Bayley Scales for Infant Development, and the Home Observation for Measurement of the Environment Inventory (HOME) was applied to assess quality of home environment. Anthropometric status was measured using the indicators weight/age and height/age ratios (z-scores), and socioeconomic data were collected through a standard questionnaire. Statistical analysis was conducted through univariate and hierarchical linear regression. Socioeconomic factors were found to have an indirect impact on early cognitive development mediated by the child's proximal environment factors, such as appropriate play materials and games available and school attendance. No independent association was seen between nutritional status and early cognitive development.

Determinants of early cognitive development: hierarchical analysis of a longitudinal study

The study describes the relationship between anthropometric status, socioeconomic conditions, and quality of home environment and child cognitive development in 320 children from 20 to 42 months of age, randomly selected from 20,000 households that represent the range of socioeconomic and environmental conditions in Salvador, Bahia, Northeast Brazil. The inclusion criterion was to be less than 42 months of age between January and July 1999. Child cognitive development was assessed using the Bayley Scales for Infant Development, and the Home Observation for Measurement of the Environment Inventory (HOME) was applied to assess quality of home environment. Anthropometric status was measured using the indicators weight/age and height/age ratios (z-scores), and socioeconomic data were collected through a standard questionnaire. Statistical analysis was conducted through univariate and hierarchical linear regression. Socioeconomic factors were found to have an indirect impact on early cognitive development mediated by the child's proximal environment factors, such as appropriate play materials and games available and school attendance. No independent association was seen between nutritional status and early cognitive development.

Trata-se de um estudo longitudinal sobre a relação entre estado antropométrico, condições sócio-econômicas, qualidade do ambiente doméstico e desenvolvimento cognitivo de 320 crianças de 20 a 42 meses de idade, selecionadas através de amostragem aleatória estratificada em um conjunto de 20 mil residências de diferentes níveis econômicos e condições ambientais em Salvador, Bahia, Brasil. O critério de inclusão foi ter menos de 42 meses entre janeiro e julho de 1999. O desenvolvimento cognitivo foi avaliado pela escala Bayley de desenvolvimento infantil, e o inventário HOME de observação doméstica avaliou a qualidade do ambiente doméstico. Os indicadores peso/idade e altura/idade (escores-z) identificaram o estado antropométrico, e as informações sócio-econômicas foram obtidas utilizando-se questionário padronizado. Utilizou-se a técnica da regressão linear univariada e regressão linear hierarquizada para as análises estatísticas. Encontrou-se que os fatores sócio-econômicos influenciam o curso do desenvolvimento cognitivo na primeira infância de maneira indireta, sendo mediados por fatores do contexto proximal da criança, como disponibilidade de materiais e jogos adequados e freqüência escolar. Não se encontrou uma associação independente entre estado nutricional infantil e desenvolvimento cognitivo na primeira infância.