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ObjectiveTo evaluate the association between food and nutrition insecurity and asthma in children from Latin America.DesignCross-sectional study.SettingSão Francisco do Conde, Bahia, north-eastern Brazil.SubjectsThe study included 1307 children aged 6–12 years from public elementary schools. Asthma symptoms were collected using a questionnaire that was translated and adapted from the International Study of Asthma and Allergies in Childhood, phase III. The diagnosis of asthma was determined based on reports of wheezing in the previous 12 months. The Brazilian Food Insecurity Scale was used to identify food insecurity. We also obtained demographic, socio-economic and anthropometric information for each participant. We used multivariate logistic regression analyses to assess the associations of interest.ResultsOf the children surveyed, 10·4 % had a history of wheezing and 64·5 % had some degree of food and nutrition insecurity. We found a positive dose–response relationship and statistically significant associations of asthma with moderate (OR = 1·71, 95 % CI 1·01, 2·89) and severe (OR = 2·51, 95 % CI 1·28, 4·93) food and nutrition insecurity.ConclusionsThe results show that moderate and severe food and nutrition insecurity are markers of vulnerability to wheezing. It is important to note that the results of studies in this field have potential implications for social policies that promote food security. Further studies to identify the mechanisms involved in the relationship between food and nutrition insecurity and asthma are needed. [ABSTRACT FROM AUTHOR]

Background: The current epidemic of asthma and atopy has been explained by alterations in immune responses related to reduction in childhood infections. However, the findings of epidemiologic studies investigating the association between infection with atopy and asthma have been inconsistent. Objective: We sought to investigate the effect of single or multiple infections (pathogen burden) on atopy and wheeze in urban children from Latin America. Methods: Specific IgE against aeroallergens (sIgE) and skin prick test (SPT) reactivity for the most common local allergens were measured in 1128 children aged 4 to 11 years. Data on wheezing and potential confounders were collected by questionnaire. Infections by 8 pathogens were assessed by using serology and stool examination. Associations of wheeze and atopic outcomes with single and multiple infections were analyzed by means of logistic regression. Results: Negative results for Toxoplasma gondii were associated with a higher prevalence of sIgE (≥0.70 kU/L), whereas negative results for Ascaris lumbricoides, T gondii, herpes simplex virus, and EBV were associated with a higher prevalence of SPT reactivity. Children with 3 or fewer infection markers had a higher prevalence of sIgE and SPT reactivity compared with those with 4 or more infection markers. However, isolated infections or pathogen burden were not associated with the prevalence of atopic or nonatopic wheeze. Conclusion: The findings provide support for the idea that the hygiene hypothesis is operating in an urban Latin American context, but its expression is thus far restricted to the atopic status of patients and not the perceived asthma symptoms. [ABSTRACT FROM AUTHOR]

Asthma is a complex disease with worldwide public health relevance, is related to environmental causes and a genetic predisposition. The chromosomal 17q12-21 locus has been consistently demonstrated to be associated with asthma risk. The effects of variants in the 17q12-21 locus on childhood asthma were first identified in a genome wide- association study. Since that time, those findings have been replicated in different populations but not in South American populations. This study aimed to investigate the role of variants in the 17q12-21 locus on asthma in a sample of Brazilian children. This was a cross-sectional study conducted on a cohort of 1247 children. These analyses used 50 Single Nucleotide Variants (SNVs) in the 17q12-21 locus were genotyped as part of a genome wide association study (GWAS). Four SNVs (rs4065275, rs12603332, rs73985228 and rs77777702) were associated with childhood asthma. The rs73985228 exhibited the strongest association across the different genetic models (OR, 95%CI 2.8, 1.44–3.21, p < 0.01). In an analysis that was stratified by atopy, two SNVs (rs73985228 and rs2715555) were found to be associated with atopic and non-atopic asthma. For the first time, we observed a significant interaction with seropositivity for the Varicella zoster virus (for rs4065275, p = 0.02, and for rs12603332, p = 0.04); i.e., the association was found in those who were seropositive but not in those who were seronegative for this virus. We confirmed the associations of variants in the 17q12-21 locus with atopic and non-atopic asthma and identified an interaction with seropositivity for the Varicella zoster virus. • Childhood asthma is associated with the 17q21 region in admixed populations. • Both, allergic and non-allergic childhood asthma, are associated with the 17q21 region. • The association of childhood asthma with the 17q21 region is independent of sex or ancestry. • Seropositivity for Herpes zoster virus infection modifier the association of childhood asthma with the 17q21 region [ABSTRACT FROM AUTHOR]