Onset of allergy and asthma symptoms in extra-European immigrants to Milan, Italy: possible role of environmental factors

Allergic disease and sensitization disparity in urban and rural China: A EuroPrevall-INCO study

BACKGROUND

Studies in comparison with allergic diseases and sensitization between rural and urban environments in westernized countries might be biased and not adequately reflect countries undergoing rapid transition.

METHODS

A total of 5542 schoolchildren from urban area and 5139 from rural area were recruited for the EuroPrevall-INCO survey. A subsequent case-control sample with 196 children from urban area and 202 from rural area was recruited for a detailed face-to-face questionnaire and assessment of sensitization. Skin prick tests and serum-specific IgE measurements were used to assess sensitizations against food and aeroallergens. Logistic regression analysis was used to determine associations between risk/protective factors, food adverse reactions (FAR), allergic diseases, and sensitizations.

RESULTS

Prevalence of self-reported allergic diseases, including asthma (6.6% vs.2.5%), rhinitis (23.2% vs.5.3%), and eczema (34.1% vs.25.9%), was higher in urban than in rural children. Urban children had a significantly higher prevalence of FAR and related allergic diseases, and lower food/inhalation allergen sensitization rate, than those of rural children. In urban children, frequent changing places of residency (odds ratio 2.85, 95% confidence interval: 1.45-5.81) and antibiotic usage (3.54, 1.77-7.32) in early life were risk factors for sensitization, while sensitization and family history of allergy were risk factors for allergic diseases. In rural children, exposure to rural environments in early life was protective against both allergen sensitizations (0.46, 0.21-0.96) and allergic diseases (0.03, 0.002-0.19).

CONCLUSION

We observed a disparity in rates of allergic diseases and allergen sensitization between rural and urban children. In addition to family history, the development of allergic diseases and allergen sensitization were associated with specific urban/rural environmental exposures in early life.

Sensitisation to Pollen Allergens in Children and Adolescents of Different Ancestry Born and Living in the Same Area

Background

Allergy can start at early ages, with genetic and environmental factors contributing to its development.

Aim

The study aimed to describe the pattern of sensitisation and allergy in children and adolescents of Spanish versus Moroccan ancestry but born in the same rural area of Spain.

Methods

Participants were children and adolescents (3–19 years) of Spanish or Moroccan descent, born in Blanca, Murcia (Spain). A detailed questionnaire was completed, and skin prick tests were performed to assess reactions to the most prevalent pollen allergens (O. europaea, P. pratense, S. kali, C. arizonica, P. acerifolia, A. vulgaris and P. judaica) plus molecular components Ole e 1 and Ole e 7. The association with ancestry was verified by studying participants’ parents.

Results

The study included 693 participants: 48% were aged 3–9 years and 52%, 10–19 years; 80% were of Spanish descent and 20% of Moroccan descent. Sensitisation to Olea europaea, Phleum pratense, Salsola kali and Cupressus arizonica were slightly higher in the Spanish group. The only significant differences were observed in sensitisation to Ole e 1 (p=0.02). Rhinitis, conjunctivitis, and rhinitis plus asthma were significantly higher in the Spanish group (p=0.03, p=0.02, p=0.007, respectively). The sensitisation pattern differed between Spanish and Moroccan parents, and between Moroccan parents and their children, but not between Spanish parents and their children.

Conclusion

Both environment and ancestry may influence sensitisation and symptoms. Although the environment seems to have a stronger influence, other factors may contribute to the differences in prevalence and in the clinical entities in people of Spanish versus Moroccan descent.

Health status of female Moldovan migrants to Italy by health literacy level and age group: a descriptive study

BACKGROUND

Migration flows from Eastern Europe to Italy have been large and continue to grow. The purpose of this study was to examine the health status of a population of Moldovan migrant women, and their access to health care services in northern Italy, by age group and health literacy level.

METHODS

We administered an ad-hoc questionnaire to adult Moldovan women. A bivariate analysis was conducted to test the association between health literacy and age groups with other variables (lifestyles, symptoms and diseases, access to health services). A stepwise logistic regression analysis was run to test the association between access to primary care and health literacy. Moreover, the study compare Moldovan women data with a sample of Italian women of the same age range living in North-Eastern region.

RESULTS

Our sample included 170 Moldovan women (aged 46.5 ± 12.3) in five occupational categories: home care workers (28.2%); cleaners (27.1%); health care workers (5.9%); other occupations (28.8%); and unemployed (10%). Active smokers were twice as prevalent among the women with a low health literacy. Health literacy level also determined access to primary healthcare services. For all age groups, the Moldovan sample reported a higher prevalence of allergies, lumbar disorders and depression than the Italian controls.

CONCLUSIONS

The reported prevalence of some diseases was higher among Moldovan migrant women than among Italian resident women. Health literacy was associated with the migrant women's lifestyle and the use of primary health care services, as previously seen for the autochthonous population.

The rising of allergic respiratory diseases in a changing world: from climate change to migration

INTRODUCTION

The rising of allergic respiratory diseases (ARDs) suggests a decisive role of environmental factors, that have dramatically changed in the last decades.

AREAS COVERED

This review addresses various aspects of the external exposome acting on the development, progression, clinical presentation and severity of ARDs. Climate change, air pollution and biodiversity loss act directly and through their complex interactions on atopic risk: reacent foundings on these aspects are discussed herein. The review also focuses on migration studies, underling the possible role of migrant status as an experimental model to study environment effects on atopy onset and progression.

EXPERT OPINION

Future perspective on this topic include prevention and mitigation strategies in regard to pollution and climate change, improvement of environmental monitoring methods, implementation of public health policies, further advances in 'omics' research and knowledge, prospective and immunological research on migrant populations and new policies to face human mobility.

Prevalence of asthma and allergic symptoms in Suzhou, China: Trends by domestic migrant status

Rapid urbanization in developing countries, with significant rural-to-urban and between-urban areas migration, presents a natural epidemiological model to better understand population-level trends in asthma and allergy prevalance without confounding by genetic factors. This cross-sectional study, conducted November 2014 to January 2015 in Suzhou, China, investigated differences in asthma and allergic symptoms between domestic migrant residents and long-term residents and their children. Using multivariate logistic regression, the odds ratios for children in migrant families compared to those in long-term resident families in Suzhou for doctor-diagnosed asthma, pneumonia, rhinitis, and eczema were 0.56 (95% CI: 0.42.0.73), 0.60 (95% CI: 0.49, 0.72), 0.63 (95% CI:0.52, 0.77), and 0.73 (95% CI: 0.60, 0.89), respectively. While there was a lower prevalence of asthma and allergic symptoms for domestic migrants (children and parents) compared to the local population in Suzhou, migrant children had a higher asthma rate than their parents. This follows the trend of increasing asthma rates for children in the urban local population, suggesting an environmental component. Parental migration plays a role in both parental and children's health but further investigations are needed to determine how these results may be shaped by early life exposures, lifestyle differences, and other environmental factors.

Comorbidity and health-related quality of life in Somali women living in Sweden

Objective: To explore the relationship between low serum vitamin D levels and comorbidity in Somali women, immigrants to Sweden. Design and setting: Cohort study in a Primary Health Care Center and a University Hospital. Subjects: Somali women skin type V, n = 114, aged 18-56 years, from latitude 0-10○ N, living in Sweden, latitude 57○ N > 2 years were compared with women from a population sample, skin type II-III, n = 69, aged 38-56 years, the WHO MONICA study, Gothenburg, Sweden. Main outcome measures: Serum (S)-25(OH)D, S-parathyroid hormone (PTH), comorbidity and Health-Related Quality of Life (HRQoL) using the Short Form-36 (SF-36) and part of the EQ-5D questionnaires. All calculations were corrected for age. Results: Vitamin D deficiency (S-25(OH)D < 25 nmol/l) was found in 73% of the Somali women and in 1% of the controls (p < .0001). S-PTH was elevated (>6.9 pmol/l) in 26% and 9%, respectively (p < .004). Somali women used less medication, 16% vs. 55%, p < .0001) but more allergy medication, 11% vs. 7% (p = .006), had fewer fractures, 2% vs. 28% (p < .0001) and lower HRQoL in 7 out of 9 scales (p < .05-.001), than native controls. There were no differences in the prevalence of diabetes mellitus, hypothyroidism, positive thyroid peroxidase antibodies, vitamin B12 deficiency, celiac disease or hypertension. Conclusions: Vitamin D deficiency was common in Somali women living in Sweden, 73%, but comorbidity was low. Both mental, and especially physical HRQoL scores were lower in the Somali women. The effects of long-lasting deficiency are unknown. Key points The aim was to explore the relationship between vitamin D deficiency (S-25(OH)D < 25 nmol/l) and comorbidity in immigrants. Vitamin D deficiency was common in Somali women living in Sweden, 73%, but comorbidity of hypothyroidism, diabetes mellitus, hypertension, fractures and use of medications was low. Both mental, and especially physical, Health-Related Quality of Life were lower in the Somali women than in native Swedish women. The effects of long-lasting deficiency are unknown.

Effects of Migration on Allergic Diseases

Studies in migrant populations provide vital opportunities to investigate the role of environmental factors in the pathogenesis of allergic disorders. Differences in allergy prevalence have been observed between migrants and native-born subjects living in the same geographical location. Immigrants who migrate from less affluent countries with lower allergy prevalence tend to have a lower prevalence of allergic disorders compared to native-born residents of the more affluent host country. The patterns of allergic disease prevalence also differ between first- and second-generation migrants. The timing of migration in relation to birth, age at migration, and duration of residence in the host country also influence one's atopic risk. A complex interplay of multiple environmental, socioeconomic, and cultural factors is likely responsible for these observed differences. Further research into the roles of various risk factors in modulating differences in allergic disease prevalence between migrant and native populations will enhance our understanding of the complex gene-environment interactions involved in the pathogenesis of allergic disorders.

Epidemiology of adult atopic dermatitis

Atopic dermatitis (AD) is driven by a complex gene-environment interaction. Many of the risk factors and genetic underpinning previously observed for pediatric AD may not apply to adult atopic dermatitis, suggesting that these may largely be different disorders. Whereas AD is classically thought of as a pediatric disease, recent studies have shown high rates of disease in adults as well. Risk factors for persistence of childhood-onset AD, as well as adult-onset AD, are reviewed. Adults with AD are particularly vulnerable to exogenous insults from the outside environment, including climate, ultraviolet exposure, pollution, irritants and pruritogens, and microbes. Finally, adult AD is associated with a substantial health care burden, with increased utilization, direct and indirect costs of care, and lost work productivity.

High burden of atopy in immigrant families in substandard apartments in Sweden - on the contribution of bad housing to poor health in vulnerable populations

Background

Atopic disorders are a global concern. Studies in migrant populations can illuminate the interplay of genetic and environmental factors. Exposures related to bad housing (indoor dampness, mould growth, crowding etc.) are likely to play a role in how socioeconomic inequalities can turn into health disparities for disadvantaged populations. The sizable immigrant population living in very poor-quality housing in Malmö, Sweden, became the focus of a cross-sectional study.

Objective

To describe atopic disorders and sensitizations in a population living in substandard housing in Malmö, Sweden, with an emphasis on their relation to harmful exposures from the built environment.

Methods

Families were recruited via identification of any children with symptomatic airway afflictions from health care records, and also asymptomatic children from school lists. Interviewer-led health questionnaire data and data from self-reports about living conditions were obtained together with data from home inspections carried out by health communicators. Families underwent skin prick tests (SPT) against common aeroallergens.

Results

As could be expected from background demographic information, it turned out that we effectively studied an immigrant population inhabiting very precarious housing outside the center of Malmö. A total of 359 children from 130 families (total 650 participants) were included. Overall the prevalence of potentially harmful environmental exposures was high (signs of moisture or mould in more than 50% of apartments, indoor smoking in 37% of households). Atopic disorders were common among both adults and children. SPTs showed a spectrum of sensitizations consistent with unselected populations in Sweden. Paternal sensitization in the SPT was associated with higher risk of sensitization for offspring than maternal sensitization. Few statistically significant associations of atopic sensitization with studied environmental exposures were detected (for example objective signs of dampness /mould in bathrooms). There were marked discrepancies between asthma diagnoses obtained from the health records and parental reports of such diagnoses and treatment for their children.

Conclusions

The atopic burden in this selected immigrant population was high, and results point to unmet medical needs. Health care systems caring for such populations need to be aware of their specific health needs; comprehensive asthma and allergy care should include consideration of harmful environmental exposures, adhering to the precautionary principle.

Susceptibility to allergy in adoptive children: a cross-sectional study at "Bambino Gesù Children's Hospital"

Background

Prevalence of allergy has steeply increased during the past few decades, particularly in high-income countries. The development of atopy could present different characteristics in internationally adopted children with regard to incidence, specific patterns of allergies and timing of occurrence. We aimed to investigate the occurrence of allergic diseases among adopted children in Italy.

Methods

We collected demographic information, preadoption immunization data, infectious diseases screening results, immunological status, and performed hematological and biochemical tests according to a standardized protocol in 108 adopted children.

Results

At initial visit (mean age was 5.7 ± 3.2 years), 48 children displayed elevated total serum IgE levels with a prevalence of 56.5% (95%CI: 0.45; 0.67). The prevalences of children screened positive for one or more food allergens and inhalants were 30.1% (95%CI: 19.9%; 42.0%) and 34.3% (95%CI: 23.3%; 46.6%) respectively, only 9 children exhibited abnormal absolute eosinophil counts, 23 (21.3%) had a parasitic infection and 60 (55.6%) had received at least one dose of vaccine.

Conclusions

Children without medical records or with a past medical history suggestive of atopy should perform a thorough allergy evaluation at the time of adoption. Our study offers also a glimpse at the vaccination status and immune-allergic profiles of recent migrant children in Italy.

Differences in hospital attendance for anaphylaxis between immigrants and non-immigrants: a cohort study

BACKGROUND

The impact of migration on the risk of anaphylaxis remains unknown. We hypothesized that non-Western immigrants have a lower incidence of anaphylaxis compared to Danish-born. We investigated variations in hospital attendance for anaphylaxis between immigrants and Danish-born including time- and age- trends.

METHODS

A register-based, historical prospective cohort design. Refugees or family reunified immigrants (n = 127 250) who, between January 1, 1994 and December 31, 2010, obtained residency permits in Denmark were included and matched in a 1 : 6 ratio on age and sex with Danish-born individuals (n = 740 600). Personal identification numbers were cross-linked to the Danish National Patient Registry identifying all first-time hospital attendances for anaphylaxis from January 1, 1994 and December 31, 2010. Incidence rate ratios were estimated, stratified for sex and region of birth, adjusting for age using a Cox regression model including the influence of duration of residence and age when residence was obtained.

RESULTS

In total 1053 hospital attendances for anaphylaxis were identified: 89 among non-Western immigrants, 9 among Western immigrants and 955 among Danish-born patients. Both male (RR = 0.65; 95%CI: 0.46;0.90) and female (RR = 0.64; 95%CI: 0.48;0.85) non-Western immigrants had a significantly lower risk ratio of hospital attendance for anaphylaxis compared to Danish-born. Compared to Danish-born, non-Western immigrants living in Denmark during the entire follow-up period also showed a decreased risk (RR = 0.65; 95%CI: 0.34;1.25). Compared to Danish-born, non-Western immigrants who obtained residence permission as children had a decreased risk of hospital attendance for anaphylaxis (RR = 0.48; 95%CI: 0.25;0.91).

CONCLUSION

This Danish register-based study using nationwide data revealed fewer hospital attendances for anaphylaxis among non-Western immigrants compared to Danish-born; however this protection was lost over time.

Lower Prevalence of Atopic Dermatitis and Allergic Sensitization among Children and Adolescents with a Two-Sided Migrant Background

In industrialized countries atopic diseases have been reported to be less likely in children and adolescents with a migrant background compared to non-migrants. This paper aimed at both examining and comparing prevalence of asthma, allergic rhinoconjunctivitis and atopic dermatitis and allergic sensitization to specific IgE antibodies in children and adolescents with and without a migrant background. Using data of the population-based German Health Interview and Examination Survey for children and adolescents (KiGGS; n = 17,450; 0–17 years), lifetime and 12-month prevalence of atopic diseases and point prevalence of 20 common allergic sensitizations were investigated among migrants compared to non-migrants. Multiple regression models were used to estimate the association of atopic disease and allergic sensitization with migrant background. In multivariate analyses with substantial adjustment we found atopic dermatitis about one-third less often (OR 0.73, 0.57–0.93) in participants with a two-sided migrant background. Statistically significant associations between allergic sensitizations and a two-sided migrant background remained for birch (OR 0.73, 0.58–0.90), soybean (OR 0.72, 0.54–0.96), peanut (OR 0.69, 0.53–0.90), rice (OR 0.64, 0.48–0.87), potato (OR 0.64, 0.48–0.85), and horse dander (OR 0.58, 0.40–0.85). Environmental factors and living conditions might be responsible for the observed differences.

Exploring the Effects of Omega-3 and Omega-6 Fatty Acids on Allergy Using a HEK-Blue Cell Line

BACKGROUND

Allergic reactions can result in life-threatening situations resulting in high economic costs and morbidity. Therefore, more effective reagents are needed for allergy treatment. A causal relationship has been suggested to exist between the intake of omega-3/6 fatty acids, such as docosahexanoic acid (DHA), eicosapentanoic acid (EPA), docosapentanoic acid (DPA) and arachidonic acid (AA), and atopic individuals suffering from allergies. In allergic cascades, the hallmark cytokine IL-4 bind to IL-4 receptor (IL-4R) and IL-13 binds to IL-13 receptor (IL-13R), this activates the STAT6 phosphorylation pathway leading to gene activation of allergen-specific IgE antibody production by B cells. The overall aim of this study was to characterize omega-3/6 fatty acids and their effects on STAT6 signaling pathway that results in IgE production in allergic individuals.

METHODS

The fatty acids were tested in vitro with a HEK-Blue IL-4/IL-13 reporter cell line model, transfected with a reporter gene that produces an enzyme, secreted embryonic alkaline phosphatase (SEAP). SEAP acts as a substitute to IgE when cells are stimulated with bioactive cytokines IL-4 and/or IL-13.

RESULTS

We have successfully used DHA, EPA and DPA in our studies that demonstrated a decrease in SEAP secretion, as opposed to an increase in SEAP secretion with AA treatment. A statistical Student's t-test revealed the significance of the results, confirming our initial hypothesis.

CONCLUSION

We have successfully identified and characterised DHA, EPA, DPA and AA in our allergy model. While AA was a potent stimulator, DHA, EPA and DPA were potential inhibitors of IL-4R/IL-13R signalling, which regulates the STAT6 induced pathway in allergic cascades. Such findings are significant in the future design of dietary therapeutics for the treatment of allergies.

Changes in Expression of Genes Regulating Airway Inflammation Following a High-Fat Mixed Meal in Asthmatics

Consumption of a high fat meal can increase neutrophilic airway inflammation in asthma subjects. This study investigates the molecular mechanisms driving airway neutrophilia following a high fat meal in asthmatics. Subjects with asthma (n = 11) and healthy controls (n = 8) consumed a high-fat/energy meal, containing total energy (TE) of 3846 kJ and 48 g of total fat (20.5 g saturated). Sputum was induced at 0 and 4 h, and gene expression was examined by microarray and quantitative real-time PCR (qPCR). Following the high fat dietary challenge, 168 entities were significantly differentially expressed greater than >1.5 fold in subjects with asthma, whereas, in healthy controls, only 14 entities were differentially expressed. Of the 168 genes that were changed in asthma, several biological processes were overrepresented, with 25 genes involved in "immune system processes". qPCR confirmed that S100P, S100A16, MAL and MUC1 were significantly increased in the asthma group post-meal. We also observed a strong correlation and a moderate correlation between the change in NLRP12 and S100A16 gene expression at 4 h compared to baseline, and the change in total and saturated non-esterified plasma fatty acid levels at 2 h compared to baseline. In summary, our data identifies differences in inflammatory gene expression that may contribute to increased airway neutrophilia following a high fat meal in subjects with asthma and may provide useful therapeutic targets for immunomodulation. This may be particularly relevant to obese asthmatics, who are habitually consuming diets with a high fat content.

Respiratory allergy in immigrants to a highly industrialised area in Italy according to area of origin and time period

BACKGROUND

Migrants from developing to Western countries tend to become more sensitised to host than to origin country allergens, although substantial changes in migration patterns have occurred in recent decades.

METHODS

We investigated adult immigrants with respiratory allergy, first tested for allergic sensitisation between 1985 and 2012 in a highly industrialised area in Italy. A comparison was made of the sensitisation pattern between immigrants and a random sample of native-born subjects affected by a respiratory allergy, and among immigrants according to macro-region of origin and time period.

RESULTS

Between 1985 and 2012, 480 immigrants with respiratory allergy had a first positive allergy test. Immigrants were sensitised mainly to grass (67.1%), house dust mites (HDM) (38.5%) and birch (27.5%), with a pattern of sensitisation very similar to that observed in Italians (native-born). An increase in the proportion of subjects with asthma and of subjects with polysensitisation was observed from the first (1985-2002) to the middle (2003-2007) and the most recent period (2008-2012). In recent years, the proportion of subjects with polysensitisation in immigrants is higher than in Italians (native-born) (53.3% vs. 40.1%). Among immigrants, the risk of sensitisation to grass was higher in those from Sub-Saharan Africa (odds ratio, OR=2.76) and Latin America (OR=2.49), whereas risk of sensitisation to HDM was higher among immigrants from South Asia (OR=2.71), compared to immigrants from Eastern Europe.

CONCLUSIONS

Immigrants develop multiple sensitisations more frequently than native-born people, and are especially sensitised to local allergens; the country of origin seems to play a role.

Influences of large sets of environmental exposures on immune responses in healthy adult men

Environmental factors have long been known to influence immune responses. In particular, clinical studies about the association between migration and increased risk of atopy/asthma have provided important information on the role of migration associated large sets of environmental exposures in the development of allergic diseases. However, investigations about environmental effects on immune responses are mostly limited in candidate environmental exposures, such as air pollution. The influences of large sets of environmental exposures on immune responses are still largely unknown. A simulated 520-d Mars mission provided an opportunity to investigate this topic. Six healthy males lived in a closed habitat simulating a spacecraft for 520 days. When they exited their “spacecraft” after the mission, the scenario was similar to that of migration, involving exposure to a new set of environmental pollutants and allergens. We measured multiple immune parameters with blood samples at chosen time points after the mission. At the early adaptation stage, highly enhanced cytokine responses were observed upon ex vivo antigen stimulations. For cell population frequencies, we found the subjects displayed increased neutrophils. These results may presumably represent the immune changes occurred in healthy humans when migrating, indicating that large sets of environmental exposures may trigger aberrant immune activity.

Hispano-Americans in Europe: what do we know about their health status and determinants? A scoping review

Background

Policy makers and health practitioners are in need of guidance to respond to the growing geographic mobility of Hispano-American migrants in Europe. Drawing from contributions from epidemiology, social sciences, demography, psychology, psychiatry and economy, this scoping review provides an up-to-date and comprehensive synthesis of studies addressing the health status and determinants of this population. We describe major research gaps and suggest specific avenues of further inquiry.

Methods

We identified systematically papers that addressed the concepts “health” and “Hispano Americans” indexed in five data bases from Jan 1990 to May 2014 with no language restrictions. We screened the 4,464 citations retrieved against exclusion criteria and classified 193 selected references in 12 thematic folders with the aid of the reference management software ENDNOTE X6. After reviewing the full text of all papers we extracted relevant data systematically into a table template to facilitate the synthesising process.

Results

Most studies focused on a particular disease, leaving unexplored the interlinkages between different health conditions and how these relate to legislative, health services, environmental, occupational, and other health determinants. We elucidated some consistent results but there were many heterogeneous findings and several popular beliefs were not fully supported by empirical evidence. Few studies adopted a trans-national perspective and many consisted of cross-sectional descriptions that considered “Hispano-Americans” as a homogeneous category, limiting our analysis. Our results are also constrained by the availability and varying quality of studies reviewed.

Conclusions

Burgeoning research has produced some consistent findings but there are huge gaps in knowledge. To prevent unhelpful generalisations we need a more holistic and nuanced understanding of how mobility, ethnicity, income, gender, legislative status, employment status, working conditions, neighbourhood characteristics and social status intersect with demographic variables and policy contexts to influence the health of the diverse Hispano-American populations present in Europe.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1799-x) contains supplementary material, which is available to authorized users.

Epidemiology of childhood atopic dermatitis

Atopic dermatitis (AD) or eczema is a chronic inflammatory skin disorder with significant morbidity and quality of life impairment. Elucidating the epidemiology of AD is important for understanding disease risk factors and facilitates development of interventions for disease prevention. This contribution aims to summarize recent developments in the epidemiology of AD, including the US prevalence, regional differences, and secular trends of disease prevalence, genetic and environmental determinants, distribution, and determinants of disease severity and health care use for AD.

Association between birthplace, prevalence, and age of asthma onset in adults: a United States population-based study

BACKGROUND

Previous studies have found associations between region of birth and asthma prevalence.

OBJECTIVE

To study the association among birthplace, US prevalence, age of onset, and disease course of adult asthma.

METHODS

Data from 447,801 adults from the 1997 to 2011 National Health Interview Survey were reviewed. History of asthma was compared with birthplace using Rao-Scott χ(2) tests, survey logistic, propensity score, and Cox regression. Trends of asthma prevalence were analyzed using logistic regression. Multivariate models controlled for sociodemographics, health care access, smoking history, and body mass index.

RESULTS

Adults born outside the United States had lower odds of ever asthma (adjusted odds ratio [OR] 0.52, 95% confidence interval [CI] 0.49-0.55) or current asthma (OR 0.50, 95% CI, 0.46-0.54). The inverse association between foreign birthplace and asthma prevalence was significant in all regions of birth (P < .0001). Adults born outside the United States who resided in the United States for longer than 10 years compared with only 0 to 4 years had higher odds of ever asthma (OR 1.28, 95% CI, 1.18-1.38) and current asthma (OR 1.70, 95% CI, .31-2.19). Foreign-born compared with US-born adults also had delayed onset of asthma (adjusted hazard ratio 0.27, 95% CI, 0.27-0.28). The US prevalence of asthma increased in a linear manner from 1997 (9.1%, 8.77%-9.37%) to 2011 (12.5%, 12.1%-12.8%, P < .0001), which paralleled the trend for US-born adults. However, the prevalence of asthma in foreign-born adults was consistently lower and increased to a lesser extent (P < .0001).

CONCLUSION

Foreign-born American adults from all regions of birth have a lower prevalence of asthma, which increases after prolonged US residency. Foreign-born Americans may have a higher risk of adult-onset asthma.

Cross-sectional comparison of the characteristics of respiratory allergy in immigrants and Italian children

BACKGROUND

Immigrants represent a good epidemiological model to evaluate the relative influence of environmental and inherited factors on the development of allergy. Several studies on allergy in adults have been published, but few data in children are available. We aimed to investigate the differences, between Italian and immigrant children, in clinical characteristics of respiratory allergy.

METHODS

This was a multicentre cross-sectional study involving children born in Italy from Italian parents and children born either in Italy or abroad from immigrants. Children referred firstly for allergic respiratory disease (rhinitis/asthma), with an ascertained clinical diagnosis and IgE sensitization to inhalants, were included. Demographic features, comorbidities, severity of disease, and sensitization profile were compared between Italians and immigrants, separating also those born in Italy from immigrant parents and those born abroad.

RESULTS

One hundred and sixty-five immigrant allergic children were enrolled (100 male, mean age 8.3 yr), 128 of whose had both parents immigrated. Italian children were 237 (156 male, mean age 8.4 yr). The Italian and immigrant children were similar, apart from pet's ownership and family size. There was no difference in the severity of rhinitis/asthma between the groups, whereas significant differences were found in the pattern of sensitization: immigrant children were more frequently sensitized to house dust mites (73.3% vs. 51%, respectively; p = 0.002) and less to grass (41.8% vs. 57.8%; p = 0.002); this was retained also in monosensitized children. Immigrant children born in Italy (n = 105) had a lower prevalence of rhinitis vs. Italians (68.3% vs. 87.6%, respectively, p = 0.003) and of sensitization to grass (28.3% vs. 49.5%, respectively, p = 0.008). No difference was found among macro-regions of origin and demographic or clinical features.

CONCLUSIONS

Immigrant children born either in Italy or abroad did not show significant differences in the clinical pattern of the respiratory allergic disease when compared to children born from Italian parents.

Trends in migrant mortality rates in Australia 1981-2007: a focus on the National Health Priority Areas other than cancer

INTRODUCTION

Migrants generally have more favourable mortality outcomes than the Australian-born population. The aim of this study is to update knowledge and inform future research in this field by examining mortality from musculoskeletal conditions, asthma, cardiovascular disease, diabetes mellitus, injuries and mental conditions between 1981 and 2007 among migrants in Australia.

METHODS

Average annual sex- and age-standardised mortality rates were calculated for each migrant group, period of death registration and cause of death.

RESULTS AND CONCLUSIONS

Mortality rates decreased among most groups for asthma, cardiovascular disease and motor vehicle accidents, with rates diverging in the later time periods. The reverse was true for mental disorders, where Australian-born individuals experienced the greatest increase in mortality. Migrants generally displayed more favourable mortality outcomes than their Australian-born counterparts. Migrants from Southern Europe appeared to have the greatest advantage. However, some migrants appeared to be over-represented in the areas of diabetes, suicide and mental health.

Association between birthplace and current asthma: the role of environment and acculturation

OBJECTIVES

We evaluated associations between current asthma and birthplace among major racial/ethnic groups in the United States.

METHODS

We used multivariate logistic regression methods to analyze data on 102,524 children and adolescents and 255,156 adults in the National Health Interview Survey (2001-2009).

RESULTS

We found significantly higher prevalence (P < .05) of current asthma among children and adolescents (9.3% vs 5.1%) and adults (7.6% vs 4.7%) born in the 50 states and Washington, DC (US-born), than among those born elsewhere. These differences were among all age groups of non-Hispanic Whites, non-Hispanic Blacks, and Hispanics (excluding Puerto Ricans) and among Chinese adults. Non-US-born adults with 10 or more years of residency in the United States had higher odds of current asthma (odds ratio = 1.55; 95% confidence interval = 1.25, 1.93) than did those who arrived more recently. Findings suggested a similar trend among non-US-born children.

CONCLUSIONS

Current asthma status was positively associated with being born in the United States and with duration of residency in the United States. Among other contributing factors, changes in environment and acculturation may explain some of the differences in asthma prevalence.

The second generation and asthma: Prevalence of asthma among Israeli born children of Ethiopian origin

BACKGROUND

Immigrant populations moving from undeveloped countries with low asthma prevalence have shown increased asthma prevalence in their new Westernized environment. We compared the prevalence of asthma among Israeli born children of Ethiopian origin to that in non-Ethiopian children.

METHODS

Cross sectional study. Data was retrieved for children aged 6-18 years in four clinics with a large proportion of patients of Ethiopian origin. For each Israeli born child from Ethiopian origin we matched an Israeli born child of any other origin of the same age and gender, receiving primary care from the same physician at the same clinic. Asthma was defined as any visit to a primary care physician, emergency room or hospitalization related to asthma symptoms or subsequent purchasing of any asthma medication during 2008.

RESULTS

1217 children of Ethiopian origin and 1217 matched controls were studied. More Ethiopian children came from families with a low socioeconomic status (23.9% vs. 17%, p < 0.001), and with significantly lower parental smoking (5.1% vs. 40.1%, p < 0.001). The prevalence of asthma was 92/1217 (7.5%) among children of Ethiopian origin, compared to 122/1217 (10.0%) among the control group (OR = 0.74, 95% CI: 0.56-0.98, p = 0.032). When adjusted for tobacco exposure, the OR for risk of asthma in the Ethiopian children was 0.80 (95% CI: 0.59-1.09, p = 0.16).

CONCLUSION

Asthma prevalence in the second generation of Israeli born children of Ethiopian origin does not seem to differ from other children in their community. This observation supports the theory that environmental exposures, rather than genetic factors, dictated the increase in asthma in this immigrant population.

"United airways disease" and phenotypic peculiarities of respiratory allergy in immigrants

Allergy is the result of a complex interaction between genetic background and environmental factors, including exposure to allergens and lifestyle. Migration is a process that involves many radical changes in the environment, including diet, pollutants, allergens, different housing conditions, and patterns of infections. Thus, studies in immigrants may provide important information about the role of environmental factors in the development of allergic respiratory diseases. Several studies addressed this aspect and consistently found that migrants develop allergies at different rates from the local population, and very often the symptoms appear with a delay of 3 to 5 years after migration. More recent data showed that the severity of allergic diseases is greater in migrants, and that usually the onset is with associated asthma and rhinitis. The immigration model strongly suggests that environmental factors overcome the genetic background, and that the clinical phenotype of respiratory allergy in migrants has some peculiarities.

Lessons for primary prevention of asthma: foreign-born children have less association of SES and pests with asthma diagnosis

There are no proven interventions for primary prevention of asthma. As asthma prevalence varies globally, comparing asthma in native and foreign-born children might provide insights. We pooled data from five cross sectional asthma surveys (N = 962). Place of birth was associated with asthma (OR = 3.4, P < 0.001). In children not born in the US, lower socio-economic status had no significant effect on asthma (OR = 0.71, P = 0.53), while for children born in the US, the effect was significant (OR = 2.1, P = 0.001). The odds ratio for exposure to household pests was significant (OR = 1.6, P < 0.008) for children born in the US but was non-significant for children born outside the US (OR = 0.29, P = 0.11). Our findings are consistent with foreign-born children experiencing protective factors or US born children experiencing detrimental environmental exposures.

The possible influence of the environment on respiratory allergy: a survey on immigrants to Italy

BACKGROUND

Respiratory allergy is influenced and determined by genetic and environmental factors. Migration is a good model to indirectly evaluate the possible influence of environment.

OBJECTIVE

To assess the clinical characteristics of respiratory allergy in immigrants to Italy, in comparison with the Italian population.

METHODS

The clinical/demographic data of those immigrants stably living in Italy and referred for the first time to allergy services for respiratory allergy were collected in a multicenter survey. All the patients underwent a standard diagnostic workup. A matched Italian population was also examined.

RESULTS

Six hundred ninety-eight immigrants and 859 Italians had at least one positive skin test and were analyzed. Most of the patients were referred to the allergy units by their general practitioners. In those patients, the demographic characteristics were not different, except for family size. Immigrants had less family history of atopy. Only 16% had a clinical history of allergy before migration. The time elapsed between migration and onset of symptoms was 5.3 ± 3.1 years, with a minimum of 0.5 and a maximum of 7 years. A higher rate of monosensitization was seen among immigrants, and the severity of their asthma/rhinitis was greater than in Italians. No difference was seen in the pattern of sensitizations.

CONCLUSION

In this population of immigrants, environmental factors play a relevant role in the onset of respiratory allergies.

Climate change, migration, and allergic respiratory diseases: an update for the allergist

Local climate changes can impact on a number of factors, including air pollution, that have been shown to influence both the development and attacks of allergic respiratory diseases, and thus, they represent an important consideration for the allergist. Migration involves exposure to a new set of pollutants and allergens as well as changes in housing conditions, diet, and accessibility to medical services, all of which are likely to affect migrants' health. This review provides an update on climate change, migration, and allergy and discusses factors for consideration when making recommendations for local allergy service provision and for assessing an individual patient's environmental exposures.

Early onset of allergic rhinitis and asthma in recent extra-European immigrants to Milan, Italy: the perspective of a non-governmental organisation

BACKGROUND

Allergy is determined by genetic and environmental factors. People immigrating from under-developed to industrialised countries are at higher risk of developing allergic diseases and immigration is as a good epidemiological model to quantify the influence of the environment. We performed the allergological assessment of 32,555 recent immigrants from different areas of the world to a polluted metropolitan area of Northern Italy.

METHODS

We evaluated time of onset of allergic rhinitis and/or asthma, sensitisations and clinical characteristics of 395 subjects (3.74 ± 2.94 yrs, mean ± SD) from four macro-areas (Asia, Africa, East-Europe, South America) arriving to Milan, Italy from June 2005 to June 2009. Data were compared with immigrants having access to the same medical facility for any medical problem and with resident Italians living in the same area.

RESULTS

Immigrants with allergic rhinitis and/or asthma days since arrival in Italy correlated with number of sensitisations (p=0.0030). Moreover, personal (2.02%) or familial (2.78%) history of allergic diseases was lower in allergic immigrants as compared to allergic residents (37.77 and 29.39%, respectively; p<0.0001 for both comparisons). Finally, the frequency of allergic immigrants from South America (63.3%) was higher than expected from the overall proportion of individuals from this macro-area who sought medical help at the same facility (40.4%; p<0.0001, OR 2.289, CI 2.1670-3.255).

CONCLUSIONS

Environmental factors play a relevant role in the induction of allergies in immigrants to Northern Italy. Genetics appears as a further promoting factor in the case of immigrants from South America.

Incidence of respiratory and allergic symptoms in Italian and immigrant children

BACKGROUND

Immigration usually implies a complete change of the environment where one lives. Hence, studies on immigrants may help to disentangle genetic and environmental determinants of disease. We investigated whether the incidence of allergic and respiratory symptoms differed for Italian and immigrant children living in one area of Northern Italy.

METHODS

In December 2006, all the children (3-14 years) living in the Viadana district were surveyed through a parental questionnaire (response rate = 99%, n = 3854). Retrospective incidences of several symptoms were compared across different ethnic groups.

RESULTS

Parental asthma, allergic rhinitis and eczema were less frequent in immigrant children than in Italian children. Wheezing and eczema incidences were lower in children born to foreign parents (especially if born abroad, incidence rate ratio (IRR) = 0.47, 95% CI: 0.26-0.82 and IRR = 0.43, 95% CI: 0.23-0.83, respectively), with respect to Italian children, while the occurrence of nasal allergies was similar among the ethnic groups. The greatest incidence of persistent cough/phlegm was observed in children born in Italy to foreign parents (IRR = 1.98, 95% CI: 1.06-3.71) and in children whose parents had chronic bronchitis (IRR = 2.57, 95% CI: 1.52-4.33).

CONCLUSIONS

Considering the distribution of parental atopic diseases and the low disease prevalence in the immigrants' countries of origin, we suggest that nasal allergies may be more sensitive than wheezing or eczema to the change in the environment related to migration. Genetic or environmental factors clustered into families seem to have a role on chronic bronchitis.

The role of culture in health literacy and chronic disease screening and management

Cultural and language differences and socioeconomic status interact with and contribute to low health literacy, defined as the inability to understand or act on medical/therapeutic instructions. Health literacy is increasingly recognized as an important factor in patient compliance, cancer screening utilization, and chronic disease outcomes. Commendable efforts have been initiated by the American Medical Association and other organizations to address low health literacy among patients. Less work has been done, however, to place health literacy in the broader context of socioeconomic and cultural differences among patients and providers that hinder communication and compliance. This review examines cultural influences on health literacy, cancer screening and chronic disease outcomes. We argue that cultural beliefs around health and illness contribute to an individual's ability to understand and act on a health care provider's instructions. This paper proposes key aspects of the intersection between health literacy and culturally varying beliefs about health which merit further exploration.

Demographic data in asthma clinical trials: a systematic review with implications for generalizing trial findings and tackling health disparities

The prevalence of asthma, and the morbidity, adverse events, mortality and healthcare utilisation of asthmatic patients vary widely among racial/ethnic and other socio-demographic groups. Debates over the meanings of race and ethnicity and the strategic need to resolve health inequalities have prompted extensive recommendations for reporting and analyzing racial/ethnic and demographic information in clinical trials. We conducted a systematic review to determine the extent to which race/ethnicity, socio-economic status and other demographic variables are analyzed and reported in publications from randomized controlled trials of asthma interventions. Randomized controlled trials of inhaled corticosteroids and long-acting beta-agonists in asthmatic patients were identified by systematically searching 12 electronic bibliographic databases. We identified peer-reviewed papers reporting 87 relevant trials published during 1985-2006, from which we extracted data on patients' race/ethnicity, ancestry, gender, socio-economic variables and geographical attributes. The proportion of the papers reporting the race/ethnicity of their participants was lower than would be expected by chance and has recently declined. None of the papers included race/ethnicity or gender in statistical analyses or reported socio-economic variables, ancestry, or genetic data for their participants, and few discussed the generalizability of their findings. The frequency of reporting race/ethnicity was statistically significantly lower in trials conducted in the UK than in the US, but 23 of the 87 papers did not identify countries. Despite extensive recommendations in the literature, guidance from health agencies on analyzing and reporting demographic data in clinical trials still appears inconsistent and vague. There remains a need to improve guidance on the representation and analysis of minority populations in asthma clinical trials, in order to encourage transparent reporting of population selection, analysis approaches, and trial generalizability. To assist this process, asthma clinical trials should be based on clear hypotheses that link both to existing demographic evidence and to demographic healthcare goals.

Prevalence of asthma among Chinese adolescents living in Canada and in China

BACKGROUND

Studies of the prevalence of asthma among migrating populations may help in identifying environmental risk factors.

METHODS

We analyzed data from Vancouver, Canada, and from Guangzhou, Beijing and Hong Kong, China, collected during phase 3 of the International Study of Asthma and Allergies in Childhood. We subdivided the Vancouver adolescents according to whether they were Chinese immigrants to Canada, Canadian-born Chinese or Canadian-born non-Chinese. We compared the prevalence of asthma and wheezing among Chinese adolescents born in Canada, Chinese adolescents who had immigrated to Canada and Chinese adolescents living in China.

RESULTS

Of 7794 Chinese adolescents who met the inclusion criteria, 3058 were from Guangzhou, 2824 were from Beijing, and 1912 were from Hong Kong. Of 2235 adolescents in Vancouver, Canada, 475 were Chinese immigrants, 617 were Canadian-born Chinese, and 1143 were Canadian-born non-Chinese. The prevalence of current wheezing among boys ranged from 5.9% in Guangzhou to 11.2% in Canadian-born Chinese adolescents. For girls, the range was 4.3% in Guangzhou to 9.8% in Canadian-born Chinese adolescents. The prevalence of ever having had asthma ranged from 6.6% to 16.6% for boys and from 2.9% to 15.0% for girls. Prevalence gradients persisted after adjustment for other environmental variables (odds ratios for ever having had asthma among Canadian-born Chinese compared with native Chinese in Guangzhou: 2.72 [95% confidence interval 1.75-4.23] for boys and 5.50 [95% confidence interval 3.21-9.44] for girls; p < 0.001 for both). Among Chinese adolescents living in Vancouver, the prevalence of ever wheezing increased with duration of residence, from 14.5% among those living in Canada for less than 7 years to 20.9% among those living their entire life in Canada. The same pattern was observed for the prevalence of ever having had asthma, from 7.7% to 15.9%.

INTERPRETATION

Asthma symptoms in Chinese adolescents were lowest among residents of mainland China, were greater for those in Hong Kong and those who had immigrated to Canada, and were highest among those born in Canada. These findings suggest that environmental factors and duration of exposure influence asthma prevalence.

Prevalence of asthma in a large group of Israeli adolescents: influence of country of birth and age at migration

BACKGROUND

The occurrence of asthma has geographic variations and is lower in developing compared with industrialized countries. Both environmental and genetic factors may influence its prevalence. We aimed to evaluate the importance and effect of immigration (country of birth and age at immigration to Israel) on the prevalence of asthma in a large group of Israeli adolescents.

METHODS

Computerized medical records of 17-year-old adolescents, who underwent routine examination before military recruitment, were studied. The sample comprised both native-born Israelis (NBI) and immigrants from Ethiopia, the Former Soviet Union (FSU), and Western countries (WC). Asthma was defined as clinical symptoms and signs compatible with the disease accompanied by abnormal spirometry or documented chronic use of inhaled steroids.

RESULTS

Our cohort consisted of 1 466 654 adolescents, including 1 317 556 (89.8%) NBI and 149 098 (10.2%) immigrants. The prevalence of asthma at age 17 was higher in NBI compared with Ethiopian immigrants [4.7% (61 921) vs 2.6% (418), respectively, P < 0.0005], lower compared with immigrants from WC [5.6% (2177), P < 0.0005], and similar to immigrants from the FSU. Further analysis of the association between age at immigration and the risk for developing asthma showed that the younger immigrants from the FSU and Ethiopia arrived to Israel, the higher their prevalence of asthma at the age of 17 was.

CONCLUSIONS

Both environmental and genetic factors seem to influence the prevalence of asthma in 17-year-old adolescents. However, the higher risk for developing asthma associated with young age of immigration points toward an environmental predominance.

The clinical characteristics of respiratory allergy in immigrants in northern Italy

BACKGROUND

Respiratory allergy is influenced and determined by genetic and environmental factors. Migration is a good epidemiological model to indirectly assess the influence of the environment. We assessed the clinical characteristics of respiratory allergy in immigrants in Brescia, Italy.

METHODS

We prospectively collected the data of all immigrants referred to our allergy service for respiratory complaints since 1992. All patients underwent a standard diagnostic workup. The records of a matched Italian population of 1,534 patients were examined for comparison.

RESULTS

Two hundred and thirty-seven patients were evaluated (108 male, mean age 36.3 years). Their countries of origin were uniformly distributed among 4 macroareas (Asia, Africa, South America, Eastern Europe). All patients were referred less than 1 month after the onset of symptoms. Family history for atopy was positive in 9% and clinical history of respiratory allergy was positive in 2%. The mean time of onset of symptoms after immigration was 5.21 years, and the onset symptoms were rhinitis and asthma in 68% patients. Twenty-five percent were monosensitized subjects and 20% of patients had cockroach positivity. Some characteristics (family history, previous clinical history and severity of rhinitis) were clearly different from those of the Italian control population.

CONCLUSION

In this population of immigrants, it seems that environmental factors, more than genetic ones, play a role in the onset of respiratory allergy.

[Prevalence of childhood asthma in Baranya County, Hungary, between 2003 and 2006]

INTRODUCTION

The prevalence of bronchial asthma, allergic rhinitis and atopic dermatitis (AD) in children has constantly and significantly increased worldwide in the past decades. Recent publications, however, reported a moderate decrease or levelling off in this parameter. The authors estimated the prevalence of bronchial asthma and asthmatic complaints among schoolchildren in Baranya county in the years 2003 and 2006 in order to register the possible changes.

MATERIALS AND METHODS

Both surveys were carried out by means of identical questionnaires which were consistent with the ISAAC Phase III. protocol. The data were collected in 16 primary schools (6 in a city, 10 in small settlements and villages) in February 2006. Finally 2404 questionnaires (1124 boys, 1280 girls) in two age groups, among 6-7 and 13-14-year-old children were processed and compared to the data derived from the survey done in 2003.

RESULTS

The prevalence of the "wheezing-ever" and "physician diagnosed asthma" did not change during the observation period (2006: 20.2% and 6.7%; 2003: 19.8% and 8.2%) but there was a significant increase in the frequency of "wheezing in the last 12 months" (2006: 9.6%; 2003: 6.8%). As expected, significantly higher prevalence rates were detected among boys and in the 6-7-year-old age group than among girls and in the 13-14-year-old age group in both surveys. There was no significant difference in the two surveys in the prevalence of bronchial asthma and asthmatic signs between children from a city and from small settlements.

CONCLUSION

During the observation period of three years there was a significant increase "wheezing in the last 12 months", but the prevalence of "wheezing-ever" as well as the "physician-diagnosed asthma" remained unchanged.

Health Services Utilization by Low-Income Limited English Proficient Adults

OBJECTIVES

We evaluated the health care utilization of limited English proficiency (LEP) compared to English proficient (EP) adults with the same health insurance (Medicaid managed care) and full access to professional medical interpreters.

METHODS

Health care utilization over two years was compared for 567 LEP and 1162 EP adults. Multivariate analysis controlled for age, gender, months enrolled in Medicaid and morbidity.

RESULTS

LEP compared to EP subjects were enrolled longer and more continuously in Medicaid, were 94% more likely to use primary care and 78% less likely to use the emergency department. Specialty visits and hospitalization did not differ.

CONCLUSIONS

When language barriers are reduced and health insurance coverage is the same, LEP patients show ambulatory health care utilization associated with lower cost and more access to preventive care through establishing a primary care home.

T and B cell responses to HDM allergens and antigens

House dust mites provide well-characterized proteins to study human responses to inhaled antigens. Even in the absence of allergy they induce a high frequency of T cell precursors. The healthy response manifests by T cell proliferation and Th1 cytokines with little antibody. Responses of allergic people include Th1 and Th2 cytokines and IgE, IgG1, and IgG4 antibodies. Regulatory cells limit effector responses in healthy people. About half the IgE and IgG antibodies bind the group 1 and 2 allergens and 30% bind the group 4, 5, and 7 allergens. Although HLA independent, the recognition of the group 1 allergen shows an immunodominant region and a T cell receptor bias. The major allergens are not produced in higher amounts than many of the poorly non-allergenic proteins. The non-allergenic mite ferritin antigen shows high T cell proliferative responses with mixed cytokine production.

Prevalence of respiratory symptoms in migrant children to Italy: the results of SIDRIA-2 study

BACKGROUND

Epidemiological studies have documented large international variations in the prevalence of asthma, and 'westernization' seems to play an important role in the development of the disease. The aims of this study were to compare the prevalence of respiratory symptoms in migrant and nonmigrant children resident in Italy, and to examine the effect of length of time living in Italy.

METHODS

Data were collected in a large cross-sectional study (SIDRIA-2) performed in 12 Italian centres, using standardized parental questionnaires. For the 29 305 subjects included in the analysis (6-7 and 13-14 years old), information about place of birth and parental nationality was available.

RESULTS

There were 1012 children (3%) born outside of Italy, mainly in East Europe. Lifetime asthma and current wheeze were generally significantly less common among children born abroad than among children born in Italy (lifetime asthma: 5.4% and 9.7% respectively, P < 0.001; current wheeze: 5.2% and 6.9%, respectively, P = 0.04). Lower risks for lifetime asthma (prevalence odds ratio, POR = 0.39; 95% CI: 0.23-0.66) and current wheeze (POR = 0.72; 95% CI: 0.47-1.10) were found for children who had lived in Italy <5 years, while migrant children who had lived in Italy for 5 years or more had risks very similar to Italian children.

CONCLUSIONS

Migrant children have a lower prevalence of asthma symptoms than children born in Italy. Prevalence increased with the number of years of living in Italy, suggesting that exposure to environmental factors may play an important role in the development of asthma in childhood.

Relationship between specific serum IgE to Ascaris lumbricoides and onset of respiratory symptoms in Bangladesh immigrants

The role of helminths in asthma and/or rhinitis and in allergic sensitization is still unclear. We assessed the relationship between Ascaris-specific IgE, respiratory symptoms and allergic sensitization in Bangladesh immigrants. 246 individuals were examined from 1996 to 2001. Serum total IgE, Ascaris IgE, specific IgE to inhalant allergens, skin prick tests (SPT) and parasitological evaluation of the stool were performed. Total serum IgE were significantly higher in Ascaris-IgE positive (> 0.35 kU/L) individuals (806.5 [409.0-1436.0] kU/L vs. 207.0 [127.0-332.5] kU/L; P < 0.0001) and in subjects with respiratory symptoms (413.0 [239.0-1096.0] kU/L vs. 259.5 [147.0-387.0] kU/L), (P < 0.0001), but not in SPT positive subjects (413.0 [179.0-894.0] kU/L vs. 404.6 [305.0-1201.0] kU/L (P = 0.5). Ascaris-specific IgE were detected in 48 subjects with respiratory symptoms (40.0%) and in 46 subjects without respiratory symptoms (36.5%) (P = 0.5). The SPT positivity was similar between Ascaris-IgE seropositive (38.2%) and Ascaris-IgE seronegative (38.1%) subjects (P = 0.9). Total IgE and length of stay in Italy correlated with SPT positivity (OR 5.6 [CI 95% 1.5-19.8], P = 0.007, and OR 1.5 [CI 95% 1.3-1.7], P< 0.0001), and with respiratory symptoms (OR 13.7 [CI 95% 3.0-62.4];, P = 0.0007, and OR 2.4 [CI 95% 1.9-3.0], P < 0.0001). Ascaris-IgE were negatively associated with SPT positivity (OR 0.3 [CI 95% 0.1-0.8], P = 0.02) and with respiratory symptoms (OR 0.1 [CI 95% 0.04-0.7], P = 0.01). Our findings favour the role of environmental factors in the development of respiratory symptoms in immigrants, irrespective of Ascaris-IgE.

Associations of acculturation and country of birth with asthma and wheezing in Mexican American youths

BACKGROUND

Mexican Americans have lower rates of asthma than other ethnic groups in the United States.

OBJECTIVE

To examine the relationship between country of birth and acculturation with asthma and wheezing among Mexican American youths.

METHODS

We used Chi-squared statistics and logistic regression analyses to determine the associations of country of birth and acculturation with asthma and wheezing among 1,770 Mexican Americans age 12-19 years who participated in the National Health and Nutrition Examination Survey 1999-2002.

RESULTS

Mexican American adolescents born in the United States and those with high acculturation levels reported significantly higher prevalence rates of asthma, wheezing, and hay fever than their peers with low acculturation levels and born in Mexico. In multivariate analyses, youths with a high acculturation level had a higher risk of asthma than those with a low acculturation level independent of country of birth. Highly acculturated youths born in the US had a higher risk for wheezing compared with less acculturated US-born or Mexico-born participants after adjusting for confounding variables. In contrast, associations of asthma and wheezing with country of birth were not significant after controlling for acculturation. CONCLUSIONS. Our findings showed that both acculturation and country of birth were linked with the risk of asthma and wheezing, with acculturation having stronger effects than country of birth, among Mexican American youths. These findings may imply that factors modified by immigration and acculturation could influence the risk of asthma and wheezing. Identification of such factors could help in the design of asthma prevention programs.

Atopy and asthma in migrants

Atopy and asthma result from the effects of environmental factors on genetically susceptible persons, and different prevalence rates have been documented worldwide. In developed and industrialized countries a higher prevalence of atopy and asthma is observed as compared with undeveloped and less affluent countries. Migration involves exposure to a new set of pollutants and allergens. In addition, it involves several socioeconomic and cultural issues such as housing conditions, diet and accessibility to medical services, all of which are likely to affect migrants' health. Migration studies provide information on the role of environmental factors in the development of atopy and asthma. Immigration to allergy-prevalent countries causes more allergies and asthma in immigrants as compared to the prevalence of atopy in their countries of origin. The increase in allergy and asthma is usually not related to ethnicity, but in certain populations may play an important role. Studies on migrants support the notion that lifestyle and environmental factors in western industrialized countries facilitate atopy and asthma. The effect is time-dependent. Acquiring allergy is influenced by the age at the time of immigration. Migrants, in general, are more prone to the development of allergies than the local population. Low hygiene prior to immigration does not seem to protect against the development of atopy or asthma. Vaccinations do not affect the development of atopy or asthma in the general population and in migrants. Migrants should be aware of the potential of developing allergies and/or asthma. Strategies for primary prevention in high-risk atopic individuals and secondary prevention guidelines should be developed both for populations in developing countries as well as for immigrants from such countries to atopy-prevalent developed countries.

Country of birth as a risk factor for asthma among Mexican Americans

In the United States, among Hispanics, Mexican Americans have the lowest rate of asthma. However, this population includes Mexican Americans born in the United States and in Mexico, and risk factors that might impact the prevalence of asthma differ between these groups. To determine the prevalence of and risk factors for asthma among U.S.- and Mexican-born Mexican Americans, we analyzed data from two U.S. surveys that included 4,574 persons who self-reported their ethnicity as Mexican American from the Third National Health and Nutrition Examination Survey (NHANES III) 1998-1994 and 12,980 persons who self-reported their ethnicity as Mexican American from National Health Interview Survey (NHIS) 1997-2001. U.S.-born Mexican Americans were more likely than Mexican-born Mexican Americans to report ever having asthma in both the NHANES III (7% [SE 0.5] vs. 3% [SE 0.3], p < 0.001) and NHIS surveys (8.1% [0.4] vs. 2.5% [0.2], p < 0.001). In a multivariate regression model controlling for multiple demographic variables and health care, the risk for asthma was higher among U.S.-born Mexicans in NHANES III (odds ratio 2.1, 95% confidence interval 1.4-3.3) and NHIS (odds ratio 2.7, 95% confidence interval 1.6-5.5). In conclusion, the prevalence of asthma was higher in U.S.-born than in Mexican-born Mexican Americans. This finding highlights the importance of environmental exposures in developing asthma in a migratory population.

Immunization and atopy: possible implications of ethnicity

The possible effects of immunization on subsequent development of asthma and atopy remains a matter of controversy. Although some studies have suggested that immunization might increase the risk for atopic disease, a number of studies have found no association or have even reported a protective effect for immunization against atopy. Recent studies have provided evidence that ethnicity might affect the susceptibility to the immunomodulatory effects of vaccination. In this review the association between immunization and atopy and the effect of ethnicity on this association are briefly outlined. The focus will be particularly on BCG vaccination.