Socioeconomic and environmental determinants of adolescent asthma in urban Latin America: an ecological analysis

Social inequalities in childhood asthma

Asthma is a complex, heterogeneous condition, broadly characterized by chronic airway inflammation with variable expiratory airflow limitation, but with several subtypes underpinned by different (although likely overlapping) pathological mechanisms. It is one of the most common chronic diseases of childhood and represents a significant cost for healthcare systems and affected families. Evidence suggests that a disproportionate proportion of this burden falls on families from disadvantaged socioeconomic circumstances (SECs). In this review, we describe the extent to which growing up in disadvantaged SECs is associated with an increased risk of childhood asthma diagnosis and asthma outcomes, including how this differs geographically and across different asthma subtypes. We also discuss the complex and interdependent mediating pathways that may link disadvantaged SECs with childhood asthma and asthma-related outcomes. In high-income countries (HICs), there is a fairly consistent association between growing up in disadvantaged SECs and increased prevalence of childhood asthma. However, evidence suggests that this social patterning differs across different asthma subtypes, with asthma phenotypes associated with disadvantaged SECs being less likely to be associated with atopy and more likely to begin in infancy and persist into adolescence. Disadvantaged SECs are also associated with worse asthma outcomes, which may contribute to the persistence of symptoms among disadvantaged children. In low- and middle-income countries (LMICs), the patterns are more variable and data more limited, but there is some evidence that disadvantaged SECs and atopic asthma are similarly negatively associated. There are also clear disparities in asthma outcomes, with LMICs having disproportionately high asthma-related morbidity and mortality, despite having lower asthma prevalence. A lack of accessibility to essential medication and appropriate care no doubt contributes to these disparities. The pathways leading to social inequalities in asthma are complex and interdependent, and as yet not fully understood. There is a clear need for further research into the relative importance of potential mediating pathways, including how these vary across the life course and across asthma subtypes. A stronger understanding of these pathways will help identify the most effective policy entry points for intervention, ultimately reducing inequalities across the life course.

Social determinants of respiratory health from birth: still of concern in the 21st century?

Respiratory symptoms are ubiquitous in children and, even though they may be the harbinger of poor long-term outcomes, are often trivialised. Adverse exposures pre-conception, antenatally and in early childhood have lifetime impacts on respiratory health. For the most part, lung function tracks from the pre-school years at least into late middle age, and airflow obstruction is associated not merely with poor respiratory outcomes but also early all-cause morbidity and mortality. Much would be preventable if social determinants of adverse outcomes were to be addressed. This review presents the perspectives of paediatricians from many different contexts, both high and low income, including Europe, the Americas, Australasia, India, Africa and China. It should be noted that there are islands of poverty within even the highest income settings and, conversely, opulent areas in even the most deprived countries. The heaviest burden of any adverse effects falls on those of the lowest socioeconomic status. Themes include passive exposure to tobacco smoke and indoor and outdoor pollution, across the entire developmental course, and lack of access even to simple affordable medications, let alone the new biologicals. Commonly, disease outcomes are worse in resource-poor areas. Both within and between countries there are avoidable gross disparities in outcomes. Climate change is also bearing down hardest on the poorest children. This review highlights the need for vigorous advocacy for children to improve lifelong health. It also highlights that there are ongoing culturally sensitive interventions to address social determinants of disease which are already benefiting children.

Asthma in the Americas: An Update: A Joint Perspective from the Brazilian Thoracic Society, Canadian Thoracic Society, Latin American Thoracic Society, and American Thoracic Society

Asthma affects a large number of people living in the Americas, a vast and diverse geographic region comprising 35 nations in the Caribbean and North, Central, and South America. The marked variability in the prevalence, morbidity, and mortality from asthma across and within nations in the Americas offers a unique opportunity to improve our understanding of the risk factors and management of asthma phenotypes and endotypes in children and adults. Moreover, a better assessment of the causes and treatment of asthma in less economically developed regions in the Americas would help diagnose and treat individuals migrating from those areas to Canada and the United States. In this focused review, we first assess the epidemiology of asthma, review known and potential risk factors, and examine commonalities and differences in asthma management across the Americas. We then discuss future directions in research and health policies to improve the prevention, diagnosis, and management of pediatric and adult asthma in the Americas, including standardized and periodic assessment of asthma burden across the region; large-scale longitudinal studies including omics and comprehensive environmental data on racially and ethnically diverse populations; and dissemination and implementation of guidelines for asthma management across the spectrum of disease severity. New initiatives should recognize differences in socioeconomic development and health care systems across the region while paying particular attention to novel or more impactful risk factors for asthma in the Americas, including indoor pollutants such as biomass fuel, tobacco use, infectious agents and the microbiome, and psychosocial stressor and chronic stress.

Risk Factors Associated With Health Care Utilization in Preschool Recurrent Wheezers in a Tropical Environment

Introduction: The severity of wheezing episodes is related with the need for health services, but the factors associated with health care utilization in preschool recurrent wheezers in underdeveloped regions are unclear. Objective: To evaluate the factors associated with health care utilization in preschool recurrent wheezers in Cartagena, Colombia. Methods: One hundred twenty-seven recurrent wheezers (age 2-6 years old) who were admitted to the emergency room (ER) due to wheezing in a Pediatric reference hospital in Cartagena were included. Children were evaluated by means of questionnaires and classified according to the number of ER visits, need for hospitalization and history of intensive care unit (ICU) admission due to wheezing within the last year. Total serum IgE and specific IgE to house dust mite allergens (HDM) were measured by ImmunoCAP® and allergen sensitization was evaluated by skin prick tests (SPT). Results: The maternal report of nocturnal cough without fever in their children increased the risk to have ≥5 ER visits in the last year due to wheezing. The use of montelukast was negatively associated with hospitalization, while a history of pneumonia and lack of tap water, increased the risk of hospitalization due to wheezing. A history of bronchiolitis, family history of asthma, cohabiting with two or more siblings, passive exposure to smoke and lack of sewage facilities increased the risk of ICU admission due to wheezing. The presence of atopy evaluated by SPT reactivity, total IgE levels or specific IgE to HDM were not associated with health care utilization. We also found that seroprevalence of positive IgE (≥0.35 kU/L) was 27% to B. tropicalis and 20.3% to D. pteronyssinus but the prevalence of positive IgE sensitization to these allergens was below 2% and 8% when evaluated by SPT, respectively. Conclusions: Poverty indicators are associated with ICU admission in a group of preschool recurrent wheezers and should be considered as aggravating factors for wheezing. These factors must be systematically assessed in the medical approach in underdeveloped regions in the tropics. Nocturnal cough without fever is a symptom associated with frequent ER visits while atopy was not associated with health care utilization in preschool recurrent wheezers.

Beyond Smoking: Environmental Determinants of Asthma Prevalence in Western Nepal

BACKGROUND

Asthma is widely prevalent in Nepal, but the causes are not well known aside from some general associations with ambient air pollution and microbial exposures. Information on the wide-ranging determinants of asthma prevalence among the population at risk can help policy makers to reduce risk.

OBJECTIVE

The present study is a preliminary investigation of the environmental, socioeconomic and behavioral determinants of asthma prevalence in western Nepal.

METHODS

A survey was conducted among 420 randomly selected households in western Nepal. A cross-sectional analytical study design was employed with the primary data using econometric tools of probit and logistic regression.

RESULTS

Environmental variables such as extreme cold winter, deteriorating river water quality and air pollution were associated with an increase in asthma prevalence. However, individual or household characteristics such as advancing age of household head, use of pesticides in the home for the control of pests, piped drinking water with old pipes and lack of participation in awareness programs were associated with an increase in asthma prevalence.

DISCUSSION

Among environmental factors, decreasing river water quality, increasing air pollution, and extremely cold winters are more likely to contribute to asthma prevalence. In light of the effects of environmental factors on the prevalence of asthma in Nepal, the high public and private costs of asthma could further impoverish the rural poor.

CONCLUSIONS

Environmental health policy makers should design adaptation strategies along with additional community programs addressing asthma-instigating factors. Programs to reduce environmental pollution can reduce morbidity due to asthma.

PARTICIPANT CONSENT

Obtained.

ETHICS APPROVAL

This study was approved by the Ethical Committee of the Nepal Health Research Council.

COMPETING INTERESTS

The authors declare no competing financial interests.

Rural residence, farming environment, and allergic diseases in Argentinean adolescents

RATIONALE

Little is known about residence in a rural or farming environment and allergic diseases in Latin America.

METHODS

Cross-sectional study of rural residence and current wheeze, current asthma and current symptoms of allergic rhino-conjunctivitis in 1,804 adolescents (ages 13-14 years) attending 31 schools in urban and rural areas of San Francisco (Córdoba, Argentina). Rural residence was classified as never, previous, and current. Duration of rural residence was categorized as 0, >0 but ≤5 years, and >5 years. Current wheeze, current asthma, and current allergic rhino-conjunctivitis were defined on the basis of responses to an extensively validated questionnaire from the International Study of Asthma and Allergies in Childhood. Logistic regression was used for the multivariable analysis of rural residence and the outcomes of interest.

RESULTS

After adjustment for current smoking and other covariates, current rural residence (odds ratio [OR] = 0.15, 95% confidence interval [CI] = 0.03-0.81) and rural residence for >5 years (OR = 0.32, 95%CI = 0.12-0.84) were significantly associated with reduced odds of current wheeze. In a multivariable analysis, current residence in a rural area (OR = 0.52, 95%CI = 0.32-0.86) and rural residence for >5 years (OR = 0.44, 95%CI = 0.26-0.73) were significantly associated with reduced odds of allergic rhino-conjunctivitis. This association was no longer significant after additional adjustment for current residence in a dairy farm, which was significantly associated with reduced odds of allergic rhino-conjunctivitis. Similarly, current regular contact with farm animals was significantly associated with reduced odds of allergic rhino-conjunctivitis.

CONCLUSIONS

Among Argentinean adolescents, current rural residence and rural residence for >5 years were associated with reduced odds of current wheeze and allergic rhino-conjunctivitis. These potential protective effects may be explained by a dairy farm environment, including regular contact with farm animals. Pediatr Pulmonol. 2017;52:21-28. © 2016 Wiley Periodicals, Inc.