Urbanisation and asthma in low-income and middle-income countries: a systematic review of the urban-rural differences in asthma prevalence

APPaRENT 3: Asthma Patients' and Physicians' Perspectives on the Burden and Management of Asthma in Seven Countries

INTRODUCTION

Asthma management is strongly dependent on physician and patient beliefs and perceptions about the disease and its long-term treatment. The APPaRENT 3 study was conducted to explore factors influencing treatment choice and to understand patients' and physicians' attitudes and perspectives on the use of controller inhalers in regular versus flexible dosing for asthma management.

METHODS

This cross-sectional survey of patients with asthma and treating physicians was conducted in seven countries: Indonesia, Malaysia, Philippines, Thailand, Vietnam (patient survey only), Saudi Arabia, and the United Arab Emirates. Assessment was carried out through an online/face-to-face questionnaire, where patients' viewpoints were focused on their attitudes and beliefs about asthma and treatment adherence, whereas physicians' viewpoints were gathered on their attitudes and beliefs about asthma management, knowledge of and adherence to asthma treatment guidelines, and asthma treatment regimens.

RESULTS

Overall, 1400 patients (mean age, 34 years) and 599 physicians (mean age, 43 years) were included in the survey. Physicians similarly prioritised symptom control (39%) and exacerbation reduction (40%) in moderate asthma, whereas patients prioritised symptom control (41%) over exacerbation reduction (22%). Although both groups (physicians, 86%; patients, 84%) perceived asthma as well-controlled, poor management was evident based on Asthma Control Test (ACT) scores (mean, 15.7; standard deviation, 4.14; 82% had an ACT score < 20) and high symptom burden (39% reported nighttime awakenings or early mornings ≥ 2 nights/week). Most patients (76%) with moderate asthma were prescribed regular dosing, with the most common treatment being inhaled corticosteroid (ICS)/long-acting β2-agonist (LABA) with as-needed inhaled short-acting β2-agonist (SABA; 20%). Among patients on maintenance and reliever therapy, 93% of patients received a separate inhaled reliever.

CONCLUSIONS

Despite high symptom burden, patients overestimated their level of asthma control. Physicians prioritised controlling symptoms and reducing exacerbations as treatment goals for moderate asthma, often prescribing regular dosing with ICS/LABA with as-needed inhaled SABA.

A cross-sectional study on the self-management of asthma and asthma control among adult asthmatic patients in the Aseer region, KSA

Proper management of asthma is crucial for maintaining control over the disease and has a significant impact on the patient's overall condition. The purpose of this study was to determine the extent of self-management and the level of Asthma control in the patients from the Aseer region of Saudi Arabia, as well as to investigate determinants of illness control. A study was conducted using quantitative cross-sectional methods. Researchers utilised a web-based, self-administered structured questionnaire to gather data. The questionnaire included three sections: a socio-demographic section, an Asthma Self-Management Questionnaire (ASMQ), and Asthma Control Test (ACT). An analysis using the chi-square test was conducted to determine if there was a notable connection between the socio-demographic characteristics of the participants and the level of asthma control. A total of 305 responses were collected. The average score for the Asthma Self-Management Questionnaire was 5.72, which corresponds to 40.9%. Based on the scores from the Asthma Control Test, it was found that 60 patients (20.0%) had asthma that was not under control, 94 (30.0%) had asthma that was partially controlled, and 151 (50.0%) had asthma that was well controlled. Factors such as gender, non-smoking status, and having asthma for over 10 years (p ˂0.05) were found to be strongly correlated with improved disease control. Significant gaps were found in patients' awareness of the most important and critical aspects concerning the condition, medications, and preventative actions that limit asthma aggravation. To address the current situation, hospitals and clinics must make substantial efforts.

Mediation of FOXA2/IL-6/IL-6R/STAT3 signaling pathway mediates benzo[a]pyrene-induced airway epithelial mesenchymal transformation in asthma

Benzo [a]pyrene (BaP), a toxic pollutant, increases the incidence and severity of asthma. However, the molecular mechanisms underlying the effects of BaP in asthma remain unclear. In terms of research methods, we used BaP to intervene in the animal model of asthma and the human bronchial epithelial (16HBE) cells, and the involved mechanisms were found from the injury, inflammation, and airway epithelial to mesenchymal transition (EMT) in asthma. We also constructed small interfering RNAs and overexpression plasmids to knockdown/overexpress IL-6R and FOXA2 in 16HBE cells and a serotype 9 adeno-associated viral vector for lung tissue overexpression of FOXA2 in mice to determine the mechanism of action of BaP-exacerbated asthma airway EMT. We observed that BaP aggravated inflammatory cell infiltration into the lungs, reduced the Penh value, increased collagen fibres in the lung tissue, and increased serum IgE levels in asthmatic mice. After BaP intervention, the expression of FOXA2 in the lung tissue of asthmatic mice decreased, the production and secretion of IL-6 were stimulated, and STAT3 phosphorylation and nuclear translocation increased, leading to changes in EMT markers. However, EMT decreased after increasing FOXA2 expression and decreasing that of IL-6R and was further enhanced after low FOXA2 expression. Our results revealed that BaP exacerbated airway epithelial cell injury and interfered with FOXA2, activating the IL-6/IL-6R/STAT3 signaling pathway to promote airway EMT in asthma. These findings provide toxicological evidence for the mechanism underlying the contribution of BaP to the increased incidence of asthma and its exacerbations.

Pediatric Asthma Therapy Assessment Questionnaire for the Brazilian population: Cross-cultural adaptation and measurement properties

OBJECTIVE

To cross-culturally adapt the Pediatric Asthma Therapy Assessment Questionnaire (ATAQ) into Brazilian Portuguese and analyze its measurement properties.

METHODS

This exploratory methodological study included eight experts and 30 caregivers in the translation and cross-cultural adaptation steps. Thereafter, 118 caregivers of pediatric patients with asthma aged between 5 and 17 years were involved in the analysis of measurement properties. We analyzed the content, structural (exploratory and confirmatory factorial), construct (convergent and discriminant), and known-groups validities; floor and ceiling effects; and determined the cut-off point (receiver operator characteristic curve) to identify pediatric patients with uncontrolled asthma. Intraclass correlation coefficient (ICC) analyzed test-retest reliability with 54 caregivers, whereas Cronbach's α and composite reliability verified the internal consistency of the items.

RESULTS

The committee of experts and caregivers found the instructions and response options relevant, understandable, and clear (K > 0.75). During the cross-cultural adaptation, three items (2, 4, and 12) were slightly modified by including terms to facilitate understanding. A two-factor structure (asthma control and patient-provider communication) was identified. Internal consistency (α > .67; composite reliability > 0.73) and test-retest reliability (ICC > 0.80) were acceptable. For construct and know-groups validities, 85.71% of the hypothesis were confirmed. A cut-off point of >3 for the control domain was considered adequate to identify pediatric patients with uncontrolled asthma (sensitivity: 86.21%; specificity: 80.90%).

CONCLUSION

The Pediatric ATAQ was adequately adapted for Brazilian pediatric patients with asthma and produced valid and reliable measures for assessing asthma control. Therefore, it may be considered an adequate instrument for monitoring asthma control in the Brazilian pediatric population.

Prevalence of Wheezing and Its Association with Environmental Tobacco Smoke Exposure among Rural and Urban Preschool Children in Mpumalanga Province, South Africa

BACKGROUND

This study aimed to investigate the prevalence of wheezing and its association with environmental tobacco smoke exposure among rural and urban preschool children in Mpumalanga province, South Africa, an area associated with poor air quality.

METHODS

In this study, parents/caregivers of preschool children (n = 3145) completed a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Data were analysed using multiple logistic regression models.

RESULTS

The overall prevalence of Wheeze Ever was 15.14%, with a higher prevalence in urban preschoolers than rural preschoolers (20.71% vs. 13.30%, p < 0.000). Moreover, the total prevalence of Asthma Ever was 2.34%. The prevalence was greater in urban preschoolers than in rural preschoolers (3.92% vs. 1.81%, p < 0.001). In the final adjusted model, both urban- and rural-area children who lived with one or more people who smoked in the same household (WE: OR 1.44, 95% CI 1.11-1.86) (CW: OR 2.09, 95% CI 1.38-3.16) and (AE: OR 2.49, 95% CI 1.12-5.54) were found to have an increased likelihood of having Wheeze Ever, Current Wheeze, and Asthma Ever as compared to those who lived with non-smokers.

CONCLUSIONS

The implementation of smoking limits and prohibition is crucial in areas that are frequented or utilized by children. Hence, it is imperative for healthcare providers to actively champion the rights of those who do not smoke within the society, while also endorsing legislative measures aimed at curtailing the extent of tobacco smoke exposure.

Does having siblings really protect against childhood atopic diseases? A total population and within-family analysis

The association between having older siblings and decreased risk for atopic symptoms is well-established. This has been interpreted as evidence for the microbiota hypothesis, i.e. that increased early-childhood microbial exposure caused by siblings protects from immune hypersensitivities. However, possible confounders of the association have received little attention. We used register data on Finnish cohorts born in 1995-2004 (N = 559,077) to assess medication purchases for atopic diseases: antihistamines, eczema medication, asthma medication and Epinephrine. We modelled the probability of atopic medication purchases at ages 0-15 by birth order controlling for important observed confounders and all unobserved genetic and environmental characteristics shared by siblings in a within-family fixed effects model. We further studied medication purchases among first-borns according to the age difference with younger siblings to assess whether having younger siblings in early childhood is beneficial. Having older siblings was associated with a lower probability of atopic medication purchases. Compared to first-borns, the probability was 10-20% lower among second-borns, 20-40% lower among third-borns, and 30-70% lower among subsequent children, depending on medication type. Confounding accounted for up to 75% of these differences, particularly for asthma and eczema medication, but significant differences by birth order remained across all medication types. Among first-borns, a smaller age difference with younger siblings was related to a lower likelihood of atopic medication use. Our results, based on designs that account for unobserved confounding, show that exposure to siblings in early childhood, protects from atopic diseases, and thus strongly support the microbiota hypothesis.

Differences in the health-related quality of life in patients with asthma living in urban and rural areas in the Amur Region of Russian Federation

BACKGROUND

Asthma usually arises from an interaction between host and environmental factors. Growing attention has been paid to a place of residence as a factor shaping health-related quality of life (QoL). This study investigated the rural-urban disparity in QoL among adult asthma patients in the Amur region of Russian Federation.

MATERIALS AND METHODS

This cross-sectional study included 351 randomly selected adults with asthma. We analyzed QoL (SF-36 and AQLQ scores), asthma control (ACT), and anxiety and depression (HADS) depending on the place of residence (urban vs. rural).

RESULTS

The scale "Role Emotional" (RE) of SF-36 was significantly lower in patients from rural areas compared to urban residents (59.3±3.1 vs. 70.4±2.3 points; p = 0.0042). In the urban group, the correlation analysis demonstrated a clear influence of RE on patients' own assessment of their physical functioning (PF, r = 0.53; p<0.0001). Both groups demonstrated low "Social Functioning" (SF). In the group of urban residents, correlation analysis revealed the presence of positive correlations of SF-36 domains reflecting physical (PF, RP, BP) and social functioning (SF, VT) with most scales of both QoL questionnaires. The domains of the emotional sphere (RE and MH) positively correlated with all scales of both QoL questionnaires among urban residents. In the group of rural residents, a comparative analysis showed the absence of significant correlations between more of the QoL scales. Although Asthma Control Test did not differ between groups, we noted a significantly higher need for β2-agonists in rural areas compared to urban areas (4.2±0.6 vs. 2.7±0.3 inh/day, respectively; p = 0.0221). The frequency of urban residents with a clinically significant level of anxiety (56 persons, or 25.2%) turned out to be lower compared to rural residents (45 persons, or 34.8%; χ2 = 34.08; p<0.001).

CONCLUSION

The burden of asthma introduces a greater imbalance in the health-related QoL of rural residents compared to urban residents in the Amur region of the Russian Federation. The absence of interrelationships of some QoL domains in rural residents suggested a disunity of the physical, psychological and social aspects of life. The rural residents suppress physical discomfort by the more frequent use of short bronchodilators. They often showed emotional instability with a predominance of anxiety, which affected the decrease in QoL in the psycho-emotional sphere.

Benralizumab in severe eosinophilic asthma: A real-world, single-center, observational study from Mexico

INTRODUCTION

Urbanization has increased the prevalence of asthma in lower- and middle-income countries. Severe eosinophilic asthma (SEA), a subtype of asthma, can be refractory to standard therapy. Biologics such as benralizumab target interleukin-5 and have demonstrated effectiveness in managing SEA. There exists no real-world evidence on the effectiveness of benralizumab in Mexico. Therefore, this study presents data on the role of benralizumab in managing SEA in Mexican patients.

OBJECTIVE

The effectiveness of benralizumab on the quality of life (QoL), asthma control, lung function, symptoms of asthma, and benralizumab's safety profile were assessed.

METHODS

The study sample comprised 10 patients with SEA treated with a subcutaneous (SC) administration of benralizumab 30 mg once in 4 weeks for the first three doses followed by a dose every 8 weeks for 2 years. Laboratory tests, resting spirometry, and skin prick tests were conducted. Levels of fractional exhaled nitric oxide (FeNO) were evaluated, when possible, with the intent to phenotype asthma, as T2 high or non-T2, before starting benralizumab therapy. The Asthma Quality of Life Questionnaire (AQLQ), Asthma Control Questionnaire (ACQ), and Asthma Control Test (ACT) were administered to evaluate the effectiveness of benralizumab on asthma control and QoL.

RESULTS

All patients showed significant symptom control, QoL, and lung function over 2 years. Mild adverse effects, such as headache and arthralgia, were observed.

CONCLUSION

Benralizumab appears to be a promising agent in controlling SEA. This study has focused on measuring tangible outcomes, such as a reduction in symptoms, a reduction in exacerbation, and an improvement in QoL. Thus, benralizumab may constitute an important addition to the arsenal of medications against SEA.

Association between dimensions of trauma-related psychopathology and asthma in trauma-exposed women

Introduction

Exposure to traumatic events and stressful life experiences are associated with a wide range of adverse mental and physical health outcomes. Studies have found post-traumatic stress disorder (PTSD), depression, and anxiety sensitivity occurrence to be common in addition to inflammatory diseases like asthma, especially in women. Moreover, overlapping neurobiological mechanisms have been linked to both PTSD and asthma.

Methods

In the current study, n = 508 women reported on presence of lifetime asthma diagnosis and symptoms of trauma-related psychopathology including PTSD and depression. A separate group of female participants (n = 64) reported on asthma, PTSD, depression and anxiety sensitivity, and underwent functional MRI scans during a fearful faces task, and their anterior insula responses were analyzed.

Results

Overall, PTSD and depression severity were significantly higher in those with asthma versus those without asthma. There was a positive association between anterior insula response to social threat cues and depression symptoms only among individuals without a lifetime presence of asthma.

Discussion

These findings provide continued evidence on the interactions between stress, neural mechanisms involved in interoception and salience detection, and trauma-related psychopathology.

Health Equity and Respiratory Diseases in Low- and Middle-Income Countries

Over 80% of the morbidity and mortality related to acute and chronic respiratory diseases occur in low- and middle-income countries (LMICs), a reflection of vast disparities in care for these conditions. Over the next decade, the prevalence of respiratory diseases is expected to increase, as population growth in LMICs exceeds high-income countries (HICs). Pediatric morbidity and mortality from lower respiratory tract infections and asthma occur almost exclusively in LMICs, contributing to a greater loss of quality adjusted life years from these conditions when compared with HICs.

Factors associated with poor asthma symptom control in adult Angolan regularly seen at an outpatient respiratory clinic

Background

Asthma is one of the most common chronic respiratory diseases and one of the most frequent causes of hospital care.

Objectives

To describe the clinical characteristics of asthma and factors associated with its control.

Methods

A cross-sectional study was conducted at the Military Hospital in Luanda, from April 2018 to March 2019. Data collection was performed using questionnaires on asthma symptoms and treatment, socio-demographic and environmental questions, and a Global Initiative for Asthma (GINA) questionnaire to assess the level of asthma control. Ordinal logistic regression analyses were performed. We estimated odds ratios, for higher categories of asthma control. P<0.05 was considered significant.

Results

The sample consisted of 305 asthmatics ≥18-years-old, 56% women, with a mean age of 41.3 years. About 28% of patients had controlled asthma, 36% partially controlled and 35% uncontrolled. Poor asthma control was associated with frequent use of short-acting beta-2 agonists [OR 5.70 (95%CI 2.37;13.7)], oral corticosteroids [OR 3.68 (95%CI 2.24;6.04)], and incorrect inhaler technique [OR 4.08 (95%CI 1.25;13.3)].

Conclusions

A significant number of adults living in Luanda have uncontrolled asthma due to the under-use of inhaled corticosteroid therapy. It is necessary to develop strategic management and prevention plans to improve Angolan asthmatics' medical care.

The hybrid protein BTH2 suppresses allergic airway inflammation in a murine model of HDM-specific immunotherapy

BACKGROUND

Allergen-specific immunotherapy (AIT) is the only disease-modifying treatment approach to change disease-causing allergens. Hypoallergenic derivatives show promise as potential therapeutics, amongst which BTH2 was designed to induce tolerance against Blomia tropicalis allergy. Our aim was to investigate the hypoallergenicity and immunoregulatory activity of BTH2 in vitro and its therapeutic potential in a mouse model of AIT.

METHODS

Recombinant Blo t 5 and Blo t 21 allergens and their hybrid derivatives (BTH1 and BTH2) were expressed and purified. IgE binding capacity was tested by ELISA using sera from Brazilian, Colombian, and Ecuadorian subjects. Secretion of cytokines in supernatants from human cell cultures was measured following stimulation with the four recombinants and controls. The capacity of BTH2 to ameliorate allergic airway inflammation induced by B. tropicalis extract was evaluated in a murine model of AIT.

RESULTS

rBlo t 5 and rBlo t 21 were identified as major allergens in Latin American patients, and BTH2 had the lowest IgE binding. In vitro stimulation of human cells induced greater levels of IL-10 and IFN-γ and reduced the secretion of Th2 cytokines. BTH2 ameliorated allergic airway inflammation in B. tropicalis-challenged A/J mice, as evidenced by the histopathological and humoral biomarkers: decreased Th2 cytokines and cellular infiltration (especially eosinophils), lower activity of eosinophil peroxidase, an increase in IgG blocking antibodies and strong reduction of mucus production by goblet cells.

CONCLUSIONS

Our study shows that BTH2 represents a promising candidate for the treatment of B. tropicalis allergy with hypoallergenic, immune regulatory and therapeutic properties. Further pre-clinical studies are required in murine models of chronic asthma to further address the efficacy and safety of BTH2 as a vaccine against B. tropicalis-induced allergy.

Identifying risk factors for COPD and adult-onset asthma: an umbrella review

BACKGROUND

COPD and adult-onset asthma (AOA) are the most common noncommunicable respiratory diseases. To improve early identification and prevention, an overview of risk factors is needed. We therefore aimed to systematically summarise the nongenetic (exposome) risk factors for AOA and COPD. Additionally, we aimed to compare the risk factors for COPD and AOA.

METHODS

In this umbrella review, we searched PubMed for articles from inception until 1 February 2023 and screened the references of relevant articles. We included systematic reviews and meta-analyses of observational epidemiological studies in humans that assessed a minimum of one lifestyle or environmental risk factor for AOA or COPD.

RESULTS

In total, 75 reviews were included, of which 45 focused on risk factors for COPD, 28 on AOA and two examined both. For asthma, 43 different risk factors were identified while 45 were identified for COPD. For AOA, smoking, a high body mass index (BMI), wood dust exposure and residential chemical exposures, such as formaldehyde exposure or exposure to volatile organic compounds, were amongst the risk factors found. For COPD, smoking, ambient air pollution including nitrogen dioxide, a low BMI, indoor biomass burning, childhood asthma, occupational dust exposure and diet were amongst the risk factors found.

CONCLUSIONS

Many different factors for COPD and asthma have been found, highlighting the differences and similarities. The results of this systematic review can be used to target and identify people at high risk for COPD or AOA.

Geographical Differences of Risk of Asthma and Allergic Rhinitis according to Urban/Rural Area: a Systematic Review and Meta-analysis of Cohort Studies

Several studies have demonstrated an association between the risk asthma/allergic rhinitis and the environment. However, to date, no systematic review or meta-analysis has investigated these factors. We conducted a systematic review and meta-analysis to assess the association between urban/rural living and the risk of asthma and allergic rhinitis. We searched the Embase and Medline databases for relevant articles and included only cohort studies to observe the effects of time-lapse geographical differences. Papers containing information on rural/urban residence and respiratory allergic diseases were eligible for inclusion. We calculated the relative risk (RR) and 95% confidence interval (CI) using a 2 × 2 contingency table and used random effects to pool data. Our database search yielded 8388 records, of which 14 studies involving 50,100,913 participants were finally included. The risk of asthma was higher in urban areas compared to rural areas (RR, 1.27; 95% CI, 1.12-1.44, p < 0.001), but not for the risk of allergic rhinitis (RR, 1.17; 95% CI, 0.87-1.59, p = 0.30). The risk of asthma in urban areas compared to rural areas was higher in the 0-6 years and 0-18 years age groups, with RRs of 1.21 (95% CI, 1.01-1.46, p = 0.04) and 1.35 (95% CI, 1.12-1.63, p = 0.002), respectively. However, there was no significant difference in the risk of asthma between urban and rural areas for children aged 0-2 years, with a RR of 3.10 (95% CI, 0.44-21.56, p = 0.25). Our study provides epidemiological evidence for an association between allergic respiratory diseases, especially asthma, and urban/rural living. Future research should focus on identifying the factors associated with asthma in children living in urban areas. The review was registered in PROSPERO (CRD42021249578).

Adult asthma prevalence and trend analysis by urban-rural status across sociodemographic characteristics-United States, 2012-20

Background

Asthma prevalence estimates among adults are limited for urban-rural classification across sociodemographic characteristics.

Objectives

This study examined current asthma prevalence and annual trends by 6-level urban-rural categories across sociodemographic characteristics among US adults.

Methods

Asthma prevalence for 2020 and annual trends for 2012-20 were estimated using Behavioral Risk Factor Surveillance System data. The 2013 National Center for Health Statistics urban and rural categories were used to define urban-rural status.

Results

Current asthma prevalence was higher in medium (9.7%; prevalence ratio 1.103 [95% CI 1.037, 1.174]) and small (9.9%; 1.111 [1.031, 1.197]) metro than in large fringe metropolitan (8.6%), was higher in micropolitan (10.2%) than in both large fringe (8.6%; 1.115 [1.042, 1.194]) and large central metropolitan (8.8%; 1.080 [1.001, 1.066]) areas. Prevalence by sociodemographic characteristics varied between urban-rural scheme; the prevalence was significantly higher among adults aged 55-64 years in micropolitan (11.9%), women in small metro (12.8%), and other race non-Hispanic in noncore (most rural) (13.6%) areas, adults without a high school diploma in micropolitan areas (13.8%), household income <100% of federal poverty level in micropolitan areas (15.7%), and adults with insurance coverage in micropolitan areas (10.3%) compared to the corresponding populations in other urban-rural categories. During 2012-20, an increasing trend in prevalence was observed only in medium metro areas, with an annual percentage change of 0.81.

Conclusions

Asthma prevalence differed by 6-level urban-rural categories. These findings might be helpful in establishing effective asthma control programs and targeting resource allocation at the local level.

Updates in school-based asthma management

PURPOSE OF REVIEW

School-based asthma management is an important component of pediatric asthma care that has the potential to provide more universal evidence-based asthma care to children and mitigate asthma-related health inequities. The purpose of this review is to highlight relevant developments in school-based asthma management over the past 2 years.

RECENT FINDINGS

There have been considerable recent scientific advances in school-based asthma management including robust clinical trials of environmental interventions in the classroom setting, school-nurse led interventions, stock albuterol policy changes, school-based telemedicine approaches and innovative methods to engage community stakeholders in research that have pushed the frontiers of school-based asthma care.

SUMMARY

Recent scientific work in school-based asthma management demonstrates the potential power of schools in providing access to guideline-based asthma care for all children with asthma and in improving their health outcomes. Future work should focus on the evaluation of methods to promote the adoption of school-based asthma management strategies in real-world practice and support evidence-based policy change and strategic partnerships to improve asthma health outcomes and produce meaningful public health impact for diverse children and families.

Prevalence of Asthma in East Azerbaijan Adult Population and Its Determinants Factors: A Cross-Sectional Study from the Northwest of Iran

Background

Asthma is one of the most common chronic respiratory diseases. It is estimated that more than 400 million people will suffer from it by 2025. This study aims to determine the prevalence of asthma in East Azerbaijan and investigate the association between asthma and some environmental and demographic factors.

Materials and Methods

This is a cross-sectional study based on a major Lifestyle Promotion Project (LPP) conducted in the districts of East Azerbaijan, including 2641 participants aged 15 to 65 years of the general population selected through probability proportional to size (PPS) multistage stratified cluster sampling. We used the World Health Survey questionnaire about doctor-diagnosed asthma to determine the prevalence of asthma. Age, smoking status, physical activity level, socioeconomic variables such as job and education level, and body mass index (BMI) were used as covariates in regression models. A questionnaire was used to obtain socio-demographic information and smoking status. The short form of the International Physical Activity Questionnaire was used to estimate the level of physical activity (IPAQ).

Results

The mean age of participants was 40.9 ± 12.05 years including 1242 (47 %) males and 1399 (53 %) females. The prevalence of asthma was 3.3 %. The frequency of smokers was significantly higher in the asthmatic group compared with the non-asthmatic group (OR=2.33 [1.76-3.31]; p=0.03). There was no significant association between asthma and other demographic and lifestyle characteristics. Obesity has also played a significant role in the development of asthma.

Conclusion

According to the results of this study, obesity and smoking have played a significant role in the development of asthma but there is no statistically significant relationship between socioeconomic and demographic factors.

Allergic diseases in India - Prevalence, risk factors and current challenges

Epidemiological studies have shown a rise in the prevalence of allergic diseases in India during the last two decades. However, recent evidence from the Global Asthma Network study has observed a decrease in allergic rhinitis, asthma and atopic dermatitis in children. Still, with a population over 1.3 billion, there is a huge burden of allergic rhinitis, asthma and atopic dermatitis, and this is compounded by an unmet demand for trained allergy specialists and poor health service framework. There is wide variation in the prevalence of allergic diseases between different geographical locations in India, and the reasons are unclear at present. This may at least in part be attributable to considerable heterogeneity in aero-biology, weather, air pollution levels, cultural and religious factors, diet, socioeconomic strata and literacy. At present, factors enhancing risks and those protecting from development of atopy and allergic diseases have not been well delineated, although there is some evidence for the influence of genetic factors alongside cultural and environmental variables such as diet, exposure to tobacco smoke and air pollution and residence in urban areas. This narrative review provides an overview of data from India regarding epidemiology, risk factors and genetics and highlights gaps in evidence as well as areas for future research.

Epidemiology of Asthma: Prevalence and Burden of Disease

Asthma, a common airway disease, results in a significant burden to both patients and society worldwide. Yet, despite global political commitment backed by the United Nations, progress to reduce the burden of asthma remains inadequate. This is particularly true in low-income countries. To date, progress has been delayed by the lack of uniform data collection, imperfect surveillance methods, inadequate resources, poor access to effective therapies, substandard asthma education, ineffective governmental policies, rapid urbanization, progressive increase in asthma prevalence, increased life expectancy and obesity rates worldwide, asthma heterogeneity and disease complexity, smoking, and environmental exposures to allergens and pollution. A thorough understanding of the challenges facing the international community is essential to define future strategies to improve the burden of asthma.

Influence of the environment on the characteristics of asthma

Few studies have compared the prevalence of asthma in urban and rural settings or explored the issue of whether these two manifestations of the disease may represent different phenotypes. The aim of this study was: (a) to establish whether the prevalence of asthma differs between rural and urban settings, and b) to identify differences in the clinical presentation of asthma in these two environments. Descriptive epidemiological study involving individuals aged 18 or over from a rural (n = 516) and an urban population (n = 522). In the first phase, individuals were contacted by letter in order to organize the administration of a first validated questionnaire (Q1) designed to establish the possible prevalence of bronchial asthma. In the second phase, patients who had presented association patterns in the set of variables related to asthma in Q1 completed a second validated questionnaire (Q2), designed to identify the characteristics of asthma. According to Q1, the prevalence of asthma was 15% (n = 78) and 11% (n = 59) in rural and urban populations respectively. Sixty-five individuals with asthma from the rural population and all 59 individuals from the urban population were contacted and administered the Q2. Thirty-seven per cent of the individuals surveyed had previously been diagnosed with bronchial asthma (35% in the rural population and 40% in the urban setting). In the urban asthmatic population there was a predominance of women, a greater personal history of allergic rhinitis and a family history of allergic rhinitis and/or eczema. Asthma was diagnosed in adulthood in 74.8% of the patients, with no significant differences between the two populations. Regarding symptoms, cough (morning, daytime and night) and expectoration were more frequent in the urban population. The prevalence of asthma does not differ between urban and rural settings. The differences in exposure that characterize each environment may lead to different manifestations of the disease and may also affect its severity.

Implementation of Coach McLungsSM into primary care using a cluster randomized stepped wedge trial design

Background

Asthma is a prevalent chronic disease that is difficult to manage and associated with marked disparities in outcomes. One promising approach to addressing disparities is shared decision making (SDM), a method by which the patient and provider cooperatively make a decision about asthma care. SDM is associated with improved outcomes for patients; however, time constraints and staff availability are noted implementation barriers. Use of health information technology (IT) solutions may facilitate the utilization of SDM. Coach McLungs^SM is a collaborative web-based application that involves pediatric patients, their caregivers, and providers in a personalized experience while gathering patient-reported data. Background logic provides decision support so both audiences can develop a well-informed treatment plan together. The goal of this study is to evaluate the implementation of the Coach McLungs^SM intervention into primary care.

Methods

Implementation will be evaluated using a stepped wedge randomized control study design at 21 pediatric and family medicine practices within a large, integrated, nonprofit healthcare system. We will measure changes in emergency department visits, hospitalizations, and oral steroid use, which serve as surrogate measures for patient-centered asthma outcomes. We will use a generalized linear mixed models with logit link to test the hypothesis for the reduction in exacerbation rates specifying the fixed effects of intervention and time and random effects for practice and practice*time. This design achieves 84% power to detect the hypothesized effect size difference of 10% in overall exacerbation between control (40%) and intervention (30%) periods (two-sided, p = 0.05). Implementation will be guided using the Expert Recommendations for Implementing Change (ERIC), a compilation of implementation strategies, and evaluated using the CFIR (Consolidated Framework for Implementation Research) and RE-AIM (Reach Effectiveness, Adoption, Implementation, Maintenance).

Discussion

We anticipate that a tailored implementation of Coach McLungs^SM across diverse primary care practices will lead to a decrease in emergency department visits, hospitalizations, and oral steroid use for patients in the intervention group as compared to the control condition.

Trial Registration: Clincaltrials.gov, NCT05059210. Registered 28 September 2021, https://www.clinicaltrials.gov/ct2/show/NCT05059210

Supplementary Information

The online version contains supplementary material available at 10.1186/s12911-022-02030-1.

Demographic and Socioeconomic Factors Associated with Fungal Infection Risk, United States, 2019

Diagnosis disproportionately affected minority and low-income populations, underscoring the need for broad public health interventions.

Fungal infections cause substantial rates of illness and death. Interest in the association between demographic factors and fungal infections is increasing. We analyzed 2019 US hospital discharge data to assess factors associated with fungal infection diagnosis, including race and ethnicity and socioeconomic status. We found male patients were 1.5–3.5 times more likely to have invasive fungal infections diagnosed than were female patients. Compared with hospitalizations of non-Hispanic White patients, Black, Hispanic, and Native American patients had 1.4–5.9 times the rates of cryptococcosis, pneumocystosis, and coccidioidomycosis. Hospitalizations associated with lower-income areas had increased rates of all fungal infections, except aspergillosis. Compared with younger patients, fungal infection diagnosis rates, particularly for candidiasis, were elevated among persons >65 years of age. Our findings suggest that differences in fungal infection diagnostic rates are associated with demographic and socioeconomic factors and highlight an ongoing need for increased physician evaluation of risk for fungal infections.

Risk Factors of Childhood Asthma Among Patients Attending a Tertiary Care Centre in North-East India

Introduction

Asthma is a chronic lung illness marked by a reversible airway blockage. Both genetic and environmental factors influence higher asthma rates. The present study aims to assess the various socio-demographic and environmental factors influencing the causation of childhood asthma among patients attending the Paediatric Department of Gauhati Medical College and Hospital (GMCH), Assam.

Materials and Methods

A total of 150 clinically diagnosed asthma patients of 3–12 years as cases and patients of the same age group free from respiratory diseases with no history of asthma in a 1:1 ratio as controls were selected. A predesigned and pretested proforma was used to collect data, and written informed consent was obtained from all the legal guardians of the participants. Data were analyzed by chi-square test and binary logistic regression using SPSS V20, considering a p-value <0.05 significant.

Results

Urban and male children were found to be at higher risk of developing asthma. Children belonging to the urban locality (OR= 4.53; 95% CI: 1.57–13.09; p<0.05), damp environment (OR= 5.21; 95% CI: 1.23–22.10; p<0.05), lower socioeconomic status (OR= 3.48; 95% CI: 1.34–9.01; p<0.05), presence of pets (OR= 6.77; 95% CI: 1.76–25.99; p<0.05), family history of atopy/ allergy (OR= 43.29; 95% CI: 5.80–323.15 p<0.05), smoking/passive smoking (OR=23.54; 95% CI: 1.41–394.21 p<0.05) and mixed feeding (OR= 4.47; 95% CI: 1.46–13.63 p<0.05) were the significant risk factors of childhood asthma.

Conclusion

Children are vulnerable to environmental-induced asthma. Awareness and preventive measures are necessary to control and reduce the burden of childhood asthma.

Trends and age-period-cohort effects on incidence and mortality of asthma in Sichuan Province, China, 1990-2019

Background

The provinces in western China have undergone rapid urbanization and industrialization, particularly since the Chinese government launched the Great Western Development Strategy in 2000. We examined the time trends and contributions of age, period, and cohort effects to asthma incidence and mortality in Sichuan Province, a populous province in western China, from 1990 to 2019.

Methods

The data of Sichuan Province from 1990 to 2019 were extracted from the Global Burden of Disease study 2019. Trends and average annual percentage change were estimated using joinpoint regression. Age, period, and cohort effects were estimated using an age-period-cohort model with the intrinsic estimator method.

Results

In the latest period (2015–2019), the highest incidence of asthma was 2004.49/100,000 in children aged < 5 years, and the highest mortality rate was 22.04/100,000 for elderly people aged > 80 years. Age-standardized rates generally remained stable (95% confidence interval [CI]  − 0.21, 0.11) for incidence and declined by 4.74% (95% CI − 5.09, − 4.39) for mortality over the last 30 years. After controlling for other effects, the age effect on asthma showed that the incidence rate ratio (RR) was highest in the < 5 years age group, and the mortality RR was highest in the > 80 years age group. The period effect on incidence and mortality decreased from 1990 to 2019, respectively. A cohort effect was found the incidence RR increased slowly from the early birth cohorts to the later birth cohorts, especially after the 2005 birth cohort, whereas the mortality RR continued to decline.

Conclusions

There was a significant effect of older age on the asthma mortality rate over the last 30 years, and the incidence rate in children aged < 5 years increased. The relative risk of asthma incidence in the later birth cohorts increased. Effective preventive measures and public health policies should be to protect children and elderly people from potentially harmful chronic diseases.

Urban Aerobiome and Effects on Human Health: A Systematic Review and Missing Evidence

Urban air pollutants are a major public health concern and include biological matters which composes about 25% of the atmospheric aerosol particles. Airborne microorganisms were traditionally characterized by culture-based methods recognizing just 1.5–15.3% of the total bacterial diversity that was evaluable by genome signature in the air environment (aerobiome). Despite the large number of exposed people, urban aerobiomes are still weakly described even if recently advanced literature has been published. This paper aims to systematically review the state of knowledge on the urban aerobiome and human health effects. A total of 24 papers that used next generation sequencing (NGS) techniques for characterization and comprised a seasonal analysis have been included. A core of Proteobacteria, Actinobacteria, Firmicutes, and Bacteroides and various factors that influenced the community structure were detected. Heterogenic methods and results were reported, for both sampling and aerobiome diversity analysis, highlighting the necessity of in-depth and homogenized assessment thus reducing the risk of bias. The aerobiome can include threats for human health, such as pathogens and resistome spreading; however, its diversity seems to be protective for human health and reduced by high levels of air pollution. Evidence of the urban aerobiome effects on human health need to be filled up quickly for urban public health purposes.

Indoor air pollution effects on pediatric asthma are submicron aerosol particle-dependent

The school environment is crucial for the child's health and well-being. On the other hand, the data about the role of school's aerosol pollution on the etiology of chronic non-communicable diseases remain scarce. This study aims to evaluate the level of indoor aerosol pollution in primary schools and its relation to the incidence of doctor's diagnosed asthma among younger school-age children. The cross-sectional study was carried out in 11 primary schools of Vilnius during 1 year of education from autumn 2017 to spring 2018. Particle number (PNC) and mass (PMC) concentrations in the size range of 0.3-10 µm were measured using an Optical Particle Sizer (OPS, TSI model 3330). The annual incidence of doctor's diagnosed asthma in each school was calculated retrospectively from the data of medical records. The total number of 6-11 years old children who participated in the study was 3638. The incidence of asthma per school ranged from 1.8 to 6.0%. Mean indoor air pollution based on measurements in classrooms during the lessons was calculated for each school. Levels of PNC and PMC in schools ranged between 33.0 and 168.0 particles/cm³ and 1.7-6.8 µg/m³, respectively. There was a statistically significant correlation between the incidence of asthma and PNC as well as asthma and PMC in the particle size range of 0.3-1 µm (r = 0.66, p = 0.028) and (r = 0.71, p = 0.017) respectively. No significant correlation was found between asthma incidence and indoor air pollution in the particle size range of 0.3-2.5 and 0.3-10 µm.   Conclusion: We concluded that the number and mass concentrations of indoor air aerosol pollution in primary schools in the particle size range of 0.3-1 µm are primarily associated with the incidence of doctor's diagnosed asthma among younger school-age children. What is Known: • Both indoor and outdoor aerosol pollution is associated with bronchial asthma in children. What is New: • The incidence of bronchial asthma among younger school age children is related to indoor air quality in primary schools. • Aerosol pollutants in the size range of 0.3-1 µm in contrast to larger size range particles can play major role in the etiology of bronchial asthma in 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.

Publicly available data reveals association between asthma hospitalizations and unconventional natural gas development in Pennsylvania

Since the early 2000s, unconventional natural gas development (UNGD) has rapidly grown throughout Pennsylvania. UNGD extracts natural gas using a relatively new method known as hydraulic fracturing (HF). Here we addressed the association of HF with asthma Hospitalization Admission Rates (HAR) using publicly available data. Using public county-level data from the Pennsylvania Department of Health (PA-DOH) and the Pennsylvania Department of Environmental Protection for the years 2001-2014, we constructed regression models to study the previously observed association between asthma exacerbation and HF. After considering multicollinearity, county-level demographics and area-level covariables were included to account for known asthma risk factors. We found a significant positive association between the asthma HAR and annual well density for all the counties in the state (3% increase in HAR attributable to HF, p<0.001). For a sensitivity analysis, we excluded urban counties (urban counties have higher asthma exacerbations) and focused on rural counties for the years 2005-2014 and found a significant association (3.31% increase in HAR attributable to HF in rural counties, p<0.001). An even stronger association was found between asthma hospitalization admission rates (HAR) and PM2.5 levels (7.52% increase in HAR attributable to PM2.5, p<0.001). As expected, asthma HAR was significantly higher in urban compared to rural counties and showed a significant racial disparity. We conclude that publicly available data at the county-level supports an association between an increase in asthma HAR and UNGD in rural counties in Pennsylvania.

Asthma control and its predictors in Ethiopia: Systematic review and meta-analysis

BACKGROUND

Determining the status of asthma control and identifying risk factors for poor asthma control is a key strategy for curbing the negative health impacts and the financial burden of the disease. Therefore, this review was aimed to determine the rate of asthma control and assess the predictors of uncontrolled asthma in Ethiopia.

METHODS

PubMed, Web of Science, and Google Scholar searches were performed using key terms; "asthma, bronchial asthma, control, controlled, uncontrolled and Ethiopia" up to October 16, 2020. University repositories were also searched to retrieve gray literature. The results were presented as a prevalence rate with a 95% confidence interval (CI). Subgroup analysis and meta-regression were performed to identify the sources of heterogeneity in the outcomes.

RESULTS

From 1,388 patients, based on the Global Initiative for Asthma (GINA) symptom control, the rate of the uncontrolled asthma was 45.0% (95% CI 34.0% - 56.0%) with a considerable heterogeneity between the studies; (I2: 94.55, p< 0.001). About 19.0% (95% CI 10.0% - 29.0%); (I2: 96.04, p< 0.001) of the asthma patients had a well-controlled asthma. Moreover, 36.0% (95% CI 22.0% - 50.0%), (I2: 97.11, p< 0.001) of patients had a partly controlled asthma. Similarly, based on the asthma control test (ACT), the rate of well-controlled asthma was 22.0% (95% CI 3% - 42.0%), with considerable heterogeneity between the studies; (I2: 97.75, p< 0.001). The most frequent predictors of uncontrolled asthma were incorrect inhalation techniques, frequent SABA use, moderate/severe persistent asthma, history of exacerbations, presence of comorbidities, use of oral corticosteroids, and irregular follow-up.

CONCLUSION

The rate of uncontrolled asthma in Ethiopia was high. Several factors are associated with uncontrolled asthma. Comprehensive asthma educations at each follow-up visit should be strengthened to minimize the morbidity and the cost of uncontrolled asthma.

Long-term trends in urban NO2 concentrations and associated paediatric asthma incidence: estimates from global datasets

BACKGROUND

Combustion-related nitrogen dioxide (NO₂) air pollution is associated with paediatric asthma incidence. We aimed to estimate global surface NO₂ concentrations consistent with the Global Burden of Disease study for 1990-2019 at a 1 km resolution, and the concentrations and attributable paediatric asthma incidence trends in 13 189 cities from 2000 to 2019.

METHODS

We scaled an existing annual average NO₂ concentration dataset for 2010-12 from a land use regression model (based on 5220 NO₂ monitors in 58 countries and land use variables) to other years using NO₂ column densities from satellite and reanalysis datasets. We applied these concentrations in an epidemiologically derived concentration-response function with population and baseline asthma rates to estimate NO₂-attributable paediatric asthma incidence.

FINDINGS

We estimated that 1·85 million (95% uncertainty interval [UI] 0·93-2·80 million) new paediatric asthma cases were attributable to NO₂ globally in 2019, two thirds of which occurred in urban areas (1·22 million cases; 95% UI 0·60-1·8 million). The proportion of paediatric asthma incidence that is attributable to NO₂ in urban areas declined from 19·8% (1·22 million attributable cases of 6·14 million total cases) in 2000 to 16·0% (1·24 million attributable cases of 7·73 million total cases) in 2019. Urban attributable fractions dropped in high-income countries (-41%), Latin America and the Caribbean (-16%), central Europe, eastern Europe, and central Asia (-13%), and southeast Asia, east Asia, and Oceania (-6%), and rose in south Asia (+23%), sub-Saharan Africa (+11%), and north Africa and the Middle East (+5%). The contribution of NO₂ concentrations, paediatric population size, and asthma incidence rates to the change in NO₂-attributable paediatric asthma incidence differed regionally.

INTERPRETATION

Despite improvements in some regions, combustion-related NO₂ pollution continues to be an important contributor to paediatric asthma incidence globally, particularly in cities. Mitigating air pollution should be a crucial element of public health strategies for children.

FUNDING

Health Effects Institute, NASA.

Urban-Rural Differences in the Epidemiology of Asthma and Allergies in Nigeria: A Population-Based Study

Purpose

Urbanization is associated with the risk of developing allergic conditions. Few studies have evaluated the urban-rural disparity of allergic diseases in sub-Saharan Africa.

Objective

To compare the epidemiology of adult asthma and allergies in urban and rural Nigeria.

Subjects and Methods

A population-based cross-sectional study was performed among 910 subjects in Kwara State, North Central Nigeria, comprising 635 urban and 275 rural adults who were randomly selected. We used standardized questionnaires for data collection.

Results

The age-adjusted prevalence of adults reporting a previous "asthma attack" or "currently taking asthma medication" within the preceding 12 months (ECRHS asthma definition) was 3.4% urban, 0.5% rural, current allergic rhinoconjunctivitis (26.2% urban, 22.2% rural), and current skin allergy (13.9% urban, 10.5% rural). The age-adjusted prevalence of "physician-diagnosed allergic conditions": asthma (3.3% urban, 1.5% rural), allergic rhinoconjunctivitis (4.9% urban, 3.2% rural), and skin allergy (4.8% urban, 4.6% rural) were higher in urban areas than in rural areas. Urban areas recorded a higher age-adjusted 12 months prevalence of wheezing, night waking by breathlessness, night waking by chest tightness, asthma attack (p=0.042), and current use of asthma medication (p=0.031) than the rural areas. In the urban areas, 81% of those with asthma significantly had current allergic rhinoconjunctivitis, and 40.5% had current skin allergy, whereas in the rural areas, all subjects with asthma had current allergic rhinoconjunctivitis and 12.5% had current skin allergy (p=0.482). The most common trigger for asthma attack/respiratory symptoms among the urban household was exposure to environmental smoke (17.2%), and among the rural household, it was dust exposure (18.2%). Living in urban areas significantly increased the odds of having asthma [aOR: 5.6 (95% CI:1.6-19.6)] and allergic rhinoconjunctivitis [aOR: 1.7 (95% CI: 1.2-2.4)].

Conclusion

This study shows that urban residents frequently reported more allergic and respiratory symptoms and were at risk of having asthma and allergic rhinitis compared to rural residents. The findings would assist the physicians in understanding the urban-rural differences in the occurrence of allergic conditions, symptom triggers, and comorbidity, which are relevant in patient's clinical evaluation, treatment, and disease prevention.

Understanding socio-economic inequalities in the prevalence of asthma in India: an evidence from national sample survey 2017-18

Background

Today, over 300 million people reside with asthma worldwide and India alone is home for 6% of children and 2% of adults suffering from this chronic disease. A common notion of disparity persists in terms of health outcomes across the poor and better-off section of the society. Thus, there is a need to explore socio-economic inequality in the contribution of various factors associated with asthma prevalence in India.

Methods

Data for the study were carved out from the 75th round of National Sample Survey (NSS), collected by the National Sample Survey Organization (NSSO) during 2017–18. The sample size for this study was 555,289 individuals, for which data was used for the analysis. Descriptive statistics were used to show the distribution of the study population. Further, bivariate and multivariate analysis was performed to identify the factors associated with Asthma prevalence. The concentration index was used to measure the inequality. Further, we used decomposition analysis to find the contribution of factors responsible for socio-economic status-related inequality in asthma prevalence.

Results

The prevalence of asthma was 2 per 1000 in the whole population; however, the prevalence differs by age groups in a significant manner. Age, sex, educational status, place of residence, cooking fuel, source of drinking water, household size and garbage disposal facility were significantly associated with asthma prevalence in India. It was found that asthma was more concentrated among individuals from higher socioeconomic status (concentration index: 0.15; p < 0.05). While exploring socio-economic inequality for asthma, richest wealth status (53.9%) was the most significant contributor in explaining the majority of the inequality followed by the urban place of residence (37.9%) and individual from age group 45–65 years (33.3%). Additionally, individual aged 65 years and above (27.9%) and household size less than four members (14.7%) contributed in explaining socio-economic inequality for asthma.

Conclusion

Due to the heterogeneous nature of asthma, associations between different socio-economic indicators and asthma can be complex and may point in different directions. Hence, considering the concentration of asthma prevalence in vulnerable populations and its long-term effect on general health, a comprehensive programme to tackle chronic respiratory diseases and asthma, in particular, is urgently needed.

Asthma, rhinitis and eczema symptoms in Quito, Ecuador: a comparative cross-sectional study 16 years after ISAAC

Background

In 2003, the International Study of Asthma and Allergies in Childhood (ISAAC) estimated the prevalence of asthma, rhinitis and eczema symptoms in Quito, Ecuador. Since then, no update of this study has been done in the last years. This study examined changes in the prevalence of asthma–rhinitis–eczema symptoms over a 16 years period in Quito and explored possible risk factors.

Methods

We conducted a comparative cross-sectional study in an adolescent population following the Global Asthma Network (GAN) methodology. A written questionnaire was used to explore symptoms of asthma–rhinitis–eczema. We calculated the prevalence and 95% CIs for each of the symptoms and compared them with the ISAAC results. We conducted bivariate and multivariate analysis using logistic regression to identify possible risk factors for recent wheeze, rhinitis and eczema.

Results

A total of 2380 adolescents aged between 13 and 14 years were evaluated. The prevalence of doctor diagnosis for asthma, rhinitis and eczema was 3.4%, 8.5% and 2.2%, respectively. Compared with ISAAC results, we found a lower prevalence of wheeze and eczema symptoms: wheeze ever (37.6% vs 12.7%), recent wheeze (17.8% vs 6.5%), asthma ever (6.9% vs 4.6%), recent rush (22.4% vs 13.9%) and eczema ever (11.7% vs 3.6%). The prevalence of rhinitis symptoms in the GAN study was higher than the ISAAC results: nose symptoms in the past 12 months (36.6% vs 45.8%) and nose and eye symptoms in the past 12 months (23.1% vs 27.9). Significant associations were observed between symptoms of asthma–rhinitis–eczema and sex, race/ethnicity, smoking habit, physical exercise and sedentary activities.

Conclusions

In the last two decades, the prevalence of asthma and eczema symptoms in adolescent population in the city of Quito has significantly declined; however, the prevalence of rhinitis symptoms has increased. The reduction in asthma symptoms could be related to better managing the disease and changes in local environmental risk factors in the last years. Further studies must be conducted in the country to evaluate the change in trends in asthma and other related allergic diseases.

Factors Associated with Suboptimal Control of Asthma among Adult Asthma Patients: A Cross-sectional Study

Introduction:

Asthma is a major public health problem that negatively impacts patients, families, and the community. Identifying risk factors for poor asthma control may greatly enhance the establishment of more effective treatment of asthma. The level of asthma control and risk factors for poor asthma control is relatively unknown in Ethiopia.

Methods:

A cross-sectional study was conducted on 150 adult asthma patients at the Outpatient Department (OPD) chest clinic of Jimma Medical Center (JMC), from February 15 –March 20, 2019. The Statistical Package for Social Science (SPSS) 21.0 was used for data analysis. Multivariate logistic regression was conducted to analyze the potential associated factors of suboptimal control of asthma.

Results and Discussion:

Of 150 adults diagnosed with asthma recruited in this study, 81 [54.0%] of them were females, and the mean age of the patients was 41.1 ± 12.4 years. Inhaled corticosteroid (ICS) plus short-acting beta-agonist (SABA) (64, 42.7%) was the most frequently used anti-asthmatic medication. Over one-fourth (26.0%) (95% CI, 19.2-33.8) of study participants had suboptimal asthma control. On multivariate logistic regression, being an urban dweller (AOR=3.70, p=0.025) and not applying proper inhalation technique (AOR=16.23, p=0.022) were increased the risk of suboptimal asthma control, while non-prescription anti-asthmatic drugs taking habit (AOR=0.25, p=0.010) reduces the odds of having suboptimal asthma control.

Conclusion:

Suboptimal asthma control is high among adult asthma patients. Being an urban dweller and not applying proper inhalation techniques were increased the likelihood of suboptimal asthma control, while non-prescription anti-asthmatic drugs taking habits had lower odds of suboptimal asthma control. The authors recommend large sample size studies on the comparative status of asthma control using prescription versus non-prescription anti-asthmatic medication.

Impact of early life geohelminths on wheeze, asthma and atopy in Ecuadorian children at 8 years

BACKGROUND

Early-life exposures to geohelminths may protect against development of wheeze/asthma and atopy.

OBJECTIVE

To study the effect of maternal geohelminths and infections in children during the first 5 years on atopy, wheeze/asthma and airways reactivity/inflammation at 8 years.

METHODS

Birth cohort of 2404 neonates followed to 8 years in rural Ecuador. Data on wheeze/asthma were collected by questionnaire and atopy by skin prick test (SPT) reactivity to 9 allergens. We measured airways reactivity to bronchodilator, fractional exhaled nitric oxide (FeNO) and nasal eosinophilia. Stool samples were examined for geohelminths by microscopy.

RESULTS

1933 (80.4%) children were evaluated at 8 years. Geohelminths were detected in 45.8% of mothers and 45.5% of children to 5 years. Frequencies of outcomes at 8 years were as follows: wheeze (6.6%), asthma between 5 and 8 years (7.9%), SPT (14.7%), airways reactivity (10%) and elevated FeNO (10.3%) and nasal eosinophilia (9.2%). Any maternal geohelminth was associated with reduced SPT prevalence (OR 0.72). Childhood Trichuris trichiura infections during the first 5 years were associated with reduced wheeze (OR 0.57) but greater parasite burdens with Ascaris lumbricoides at 5 years were associated with increased wheeze (OR 2.83) and asthma (OR 2.60). Associations between maternal geohelminths and wheeze/asthma were modified by atopy. Parasite-specific effects on wheeze/asthma and airways reactivity and inflammation were observed in non-atopic children.

CONCLUSIONS

Our data provide novel evidence for persistent effects of in utero geohelminth exposures on childhood atopy but highlight the complex nature of the relationship between geohelminths and the airways. Registered as an observational study (ISRCTN41239086).

The effects of indoor and outdoor air pollution on the prevalence of adults' respiratory diseases in four Chinese cities: a comparison between 2017-2018 and 1993-1996

Background

Over the past decades, both ambient and household air pollution have changed in several aspects, including the emission sources and the concentrations of pollutants, in many Chinese cities. It is unknown whether these changes are associated with changes in health conditions, especially given changes in other factors due to rapid economic growth.

Methods

Two cross-sectional surveys were conducted in two periods spanning more than twenty years (1993–1996 vs. 2017–2018) in four Chinese cities of Chongqing, Wuhan, Lanzhou, and Guangzhou. Data were collected regarding adults’ respiratory disease, smoking status, education, occupation, and household characteristics. Ambient air pollution data were obtained for each study. We first used logistic regression models to construct the district-specific adjusted disease prevalences. In the second stage, first-difference regression models were employed to examine whether the change in respiratory diseases prevalences was associated with the change in outdoor air pollution and indoor air pollution surrogates.

Results

A total of 7,557 and 9,974 households were participating in Period 1 (1993–1996) and Period 2 (2017–2018), respectively. Compared to Period 1, we found substantial reductions in the ambient air pollution concentrations, and a suggestive improvement in cooking-related indoor air pollution in Period 2. We observed decreases in the district-specific covariate-adjusted prevalences of both asthma and chronic bronchitis among participants, with an average reduction of 3.6% (range: 0.0% to 24.3%). From Period 1 to Period 2, one percent decrease in the proportion of cooking with coal was associated with a 19.0% (95% CI, 0.96–37.04%) decrease in the prevalence of males’ chronic bronchitis and a 1.86% (0.69–3.04%) increase in the prevalence of females’ asthma. Little evidence was observed regarding the potential health benefits associated with the decreases in ambient air pollution levels.

Conclusions

The substantial reduction in household use of coal for cooking might be an important contributor to the decrease in adults’ respiratory disease prevalence from 1993–1996 to 2017–2019 in four Chinese cities. Changes in this indoor air pollution source, along with other risk factors for respiratory diseases, may have masked respiratory health benefits associated with reductions in outdoor air pollution levels.

Allergic symptoms in association with naturalness, greenness, and greyness: A cross-sectional study in schoolchildren in the Alps

BACKGROUND

Greenness may protect from or contribute to allergy risk by influencing air pollution and human-microbe interactions. However, existing research on the issue is heterogeneous and produced conflicting results. Less in known about the effects of greyness. This study investigated the association between different characteristics of residential and school environment and allergic symptoms in schoolchildren.

METHODS

The present cross-sectional survey was undertaken in 2004/2005 among 1251 schoolchildren (8-12 years old) in several alpine valleys in Austria and Italy. Children's mothers completed a questionnaire that asked about allergic symptoms (International Study of Asthma and Allergies in Childhood questionnaire), sociodemographic information, lifestyle, perinatal data, and housing conditions. We constructed four aggregate outcome variables: current asthma symptoms, ever asthma symptoms, ever allergic rhinitis (AR) symptoms, and ever eczema symptoms. We employed well-known greenness and greyness exposure indicators (Normalized Difference Vegetation Index, tree canopy cover, agricultural cover, imperviousness cover, and industrial cover), as well as an alternative naturalness index (Distance to Nature, D2N). Adjusted logistic regressions were used to explore associations between each exposure-outcome pair. Air pollution (NO₂), traffic noise and time spent outdoors were tested as potential mediators in causal mediation analysis.

RESULTS

Decrease in naturalness in a 500-m buffer around the home was associated with higher prevalence of AR symptoms. Associations with asthma symptoms were in the same direction but marginally significant. Residential NDVI and tree cover were marginally associated with lower prevalence of asthma and AR symptoms. Having a domestic garden was associated with lower prevalence of asthma symptoms. School greenness in a 100-m buffer was associated with lower prevalence of AR symptoms. Residential greyness was associated with higher prevalence of AR and asthma symptoms. We observed stronger associations for greenness and greyness in non-movers and in children without a family history of allergies. Mediation by NO₂ and time spent outdoors was present in some of the exposure-outcome pairs.

CONCLUSIONS

Schoolchildren residing in places with lower naturalness and higher greyness may be more likely to have allergic rhinitis and possibly asthma. Considering more comprehensive indicators than greenness and greyness and conducting research in children without a family history of allergic diseases may be key to better understanding who can profit from natural landscapes.

Frequency of asthma exacerbation in children during the coronavirus disease pandemic with strict mitigative countermeasures

BACKGROUND

Strict countermeasures for coronavirus disease (COVID-19) were undertaken in China without knowing their influence on asthma.

OBJECTIVE

To investigate the associations between the frequencies of asthma exacerbations and respiratory infections and air pollutants before and during the COVID-19 pandemic, which were direct consequences of countermeasures undertaken for the pandemic.

METHODS

Asthma exacerbations and respiratory infections among hospitalized children in the permanent population of Guangzhou City, China, from February to June 2016-2019 (before the pandemic) to February to June 2020 (during the pandemic) were collected in this cross-sectional study in Guangzhou.

RESULTS

The number of asthma exacerbation cases per month documented in the Guangzhou Women and Children's Hospital before (median: 13.5; range: 0-48) and during (median: 20; range: 0-34) the mitigative response to the COVID-19 pandemic was similar. The frequency of severe asthma exacerbation cases per month decreased, whereas that of mild asthma exacerbation cases per year increased (p = .004). The number of patients hospitalized with infectious respiratory diseases decreased from 146 (range: 90-172) per month before the pandemic to 42 (range: 33-57) per month during the pandemic (p = .004). Most pathogens and air pollutants decreased during the COVID-19 pandemic. The frequency of severe asthma exacerbations positively correlated to that of respiratory infections in children, but did not correlate to air pollutants.

CONCLUSION

Strict countermeasures undertaken for the pandemic were associated with a decreased the frequency of infectious respiratory diseases and severe asthma exacerbations among urban children.

Huanglong Antitussive Granule Relieves Acute Asthma Through Regulating Pulmonary Lipid Homeostasis

Background: Asthma is a respiratory disease with chronic airway inflammatory, and individuals with asthma exacerbations is one of the most frequent causes of hospitalization. Huanglong antitussive granule (HL Granule), a Chinese proprietary herbal medicine, has been proved to be effective in the clinical treatment of pulmonary disease. This study is devoted to the pharmacodynamics of HL Granule in acute asthma and the possible mechanism from the perspective of lipidomics. Methods: Mice were divided into four groups, control group, acute asthma model group, HL Granule treatment and montelukast sodium treatment group. Acute asthma was induced by ovalbumin (OVA). Histopathology, pulmonary function and enzyme linked immunosorbent assay (ELISA) were used to validated model and effect of HL Granule. Lipids were detected by ultra-high-performance liquid chromatography coupled to hybrid Quadrupole-Exactive Orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap MS) and identified by MS-DAIL and built-in Lipidblast database. Differentially expressed lipids recalled in HL Granule treatment group were extracted for heatmap, enrichment analysis and correlation analysis. Results: HL Granule was effective in decreasing airway hyperresponsiveness (AHR), airway inflammatory and the levels of IL-4 and IL-5. A total of 304 and 167 lipids were identified in positive and negative ion mode, respectively. Among these, 104 and 73 lipids were reserved in HL Granule group (FDR < 0.05), including acylcarnitine (ACar), fatty acid (FA), lysophosphatidylcholine (LPC), phosphatidylcholine (PC), lysophosphatidylethanolamine (LPE), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylinositol (PI), phosphatidylserine (PS), diglyceride (DG), triglyceride (TG), sphingomyelin (SM) and ceramide (Cer). Furthermore, 118 and 273 correlations among 47 and 96 lipids in the positive and negative were observed, with ether-linked phosphatidylethanolamine (PEe) and phosphatidylcholine (PCe) (FDR < 0.001, Spearman correlation coefficient r ² > 0.75). Conclusion: HL Granule might improve pulmonary lipid homeostasis and could be used as an alternative or supplementary therapy in clinical for the treatment of asthma.

Anxiety disorders and asthma among adolescents in Uganda: role of early-life exposures

The reasons for the positive association between anxiety disorders and asthma are unknown. We investigated the possible role of shared exposures in early life. We conducted a case-control study among adolescents (age 12-17 years) with and without asthma in urban Uganda, as part of a larger asthma case-control study. Anxiety disorders were diagnosed by psychiatric clinical officers. We focused on generalised anxiety disorder (GAD), panic disorder and social anxiety disorder. Asthma was doctor-diagnosed by study clinicians. We used questionnaires to collect data on early-life exposures. The data were analysed using multiple logistic regression. We enrolled 162 adolescents; 73 of them had asthma. Adolescents with asthma were more likely to have any of the three anxiety disorders studied (46.6%) than adolescents without asthma (21.4%) (adjusted OR (aOR) 2.68, 95% CI 1.30-5.53). The association was strong for GAD (aOR 4.49, 95% CI 1.48-13.56) and panic disorder (aOR 5.43, 95% CI 2.11-14.02), but not for social anxiety disorder. The early-life risk factors associated with anxiety disorders among adolescents were similar to asthma risk factors previously published, including urban residence at birth (aOR 3.42, 95% CI 1.29-9.09) and during most of the first 5 years of life (aOR 2.87, 95% CI 1.07-7.66), father's tertiary education (aOR 2.09, 95% CI 1.00-4.37), and adolescent's history of other allergy-related diseases (aOR 4.64, 95% CI 1.66-13.00). We confirm a positive association between anxiety disorders and asthma among adolescents in urban Uganda. The early-life risk factors associated with anxiety disorders among adolescents were similar to those for asthma in the same age group, suggesting shared underlying environmental exposures.

External Environmental Pollution as a Risk Factor for Asthma

Air pollution is a worrisome risk factor for global morbidity and mortality and plays a special role in many respiratory conditions. It contributes to around 8 million deaths/year, with outdoor exposure being responsible for more than 4.2 million deaths throughout the world, while more than 3.8 million die from situations related to indoor pollution. Pollutant agents induce several respiratory symptoms. In addition, there is a clear interference in numerous asthma outcomes, such as incidence, prevalence, hospital admission, visits to emergency departments, mortality, and asthma attacks, among others. The particulate matter group of pollutants includes coarse particles/PM₁₀, fine particles/PM_2.5, and ultrafine particles/PM_0.1. The gaseous components include ground-level ozone, nitrogen dioxide, sulfur dioxide, and carbon monoxide. The timing, load, and route of allergen exposure are other items affecting allergic disease phenotypes. The complex interaction between pollutant exposures and human host factors has an implication in the development and rise of asthma as a public health problem. However, there are hiatuses in the understanding of the pathways in this disease. The routes through which pollutants induce asthma are multiple, and include the epigenetic changes that occur in the respiratory tract microbiome, oxidative stress, and immune dysregulation. In addition, the expansion of the modern Westernized lifestyle, which is characterized by intense urbanization and more time spent indoors, resulted in greater exposure to polluted air. Another point to consider is the different role of the environment according to age groups. Children growing up in economically disadvantaged neighborhoods suffer more important negative health impacts. This narrative review highlights the principal polluting agents, their sources of emission, epidemiological findings, and mechanistic evidence that links environmental exposures to asthma.

Measuring urbanicity as a risk factor for childhood wheeze in a transitional area of coastal ecuador: a cross-sectional analysis

Background

The urbanisation process has been associated with increases in asthma prevalence, an observation supported largely by studies comparing urban with rural populations. The nature of this association remains poorly understood, likely because of the limitations of the urban–rural approach to understand what a multidimensional process is.

Objective

This study explored the relationship between the urbanisation process and asthma prevalence using a multidimensional and quantitative measure of urbanicity.

Methods

A cross-sectional analysis was conducted in 1843 children living in areas with diverse levels of urbanisation in the district of Quinindé, Ecuador in 2013–2015. Categorical principal components analysis was used to generate an urbanicity score derived from 18 indicators measured at census ward level based on data from the national census in 2010. Indicators represent demographic, socioeconomic, built environment and geographical dimensions of the urbanisation process. Geographical information system analysis was used to allocate observations and urban characteristics to census wards. Logistic random effects regression models were used to identify associations between urbanicity score, urban indicators and three widely used definitions for asthma.

Results

The prevalence of wheeze ever, current wheeze and doctor diagnosis of asthma was 33.3%, 13% and 6.9%, respectively. The urbanicity score ranged 0–10. Positive significant associations were observed between the urbanicity score and wheeze ever (adjusted OR=1.033, 95% CI 1.01 to 1.07, p=0.05) and doctor diagnosis (adjusted OR=1.06, 95% CI 1.02 to 1.1, p=0.001). For each point of increase in urbanicity score, the prevalence of wheeze ever and doctor diagnosis of asthma increased by 3.3% and 6%, respectively. Variables related to socioeconomic and geographical dimensions of the urbanisation process were associated with greater prevalence of wheeze/asthma outcomes.

Conclusions

Even small increases in urbanicity are associated with a higher prevalence of asthma in an area undergoing the urban transition. The use of a multidimensional urbanicity indicator has greater explanatory power than the widely used urban–rural dichotomy to improve our understanding of how the process of urbanisation affects the risk of asthma.

The impact of baseline incidence rates on burden of disease assessment of air pollution and onset childhood asthma: analysis of data from the contiguous United States

PURPOSE

Burden of disease (BoD) assessments typically rely on national-level incidence rates for the health outcomes of interest. The impact of using a constant national-level incidence rate, versus a more granular spatially varying rate, remains unknown and understudied in the literature. There has been an increasing number of publications estimating the BoD of childhood asthma attributable to air pollution, as emerging evidence demonstrates that traffic-related air pollution (TRAP) leads to onset of the disease. In this study, we estimated the burden of incident childhood asthma cases which may be attributable to nitrogen dioxide (NO₂), a criteria pollutant and a good marker of TRAP, in the contiguous United States. We used both a national-level and newly generated state-specific asthma incidence rates and compared results from the two approaches.

METHODS

We estimated incident childhood asthma cases which may be attributable to NO₂ using standard BoD assessment methods. We combined child (<18 years) counts with 2010 NO₂ exposures at the census block level, concentration-response function, and state-specific asthma incidence rates. NO₂ concentrations were obtained from a previously validated land-use regression model. We sourced the concentration-response function from a meta-analysis on TRAP and risk of childhood asthma. We estimated incidence rates using raw data collected in the 2006-2010 Behavioral Risk Factor Surveillance System and Asthma Call-back Surveys. We stratified the estimated BoD by urban versus rural status and by median household income, explored trends in BoD across 48 states and the District of Columbia, and compared our results with a published BoD analysis which used a constant national-level incidence rate across all states.

RESULTS

The overall mean (min-max) NO₂ concentration(s) was 13.2 (1.5-58.3) ug/m³ and was highest in urbanized areas. The estimated national aggregate asthma incidence rate was 11.6 per 1000 at-risk children and ranged from 4.3 (Montana) to 17.7 (District of Columbia) per 1000 at-risk children. The 17 states that did not have data to estimate an incidence rate were assigned the national aggregate asthma incidence rate. Using the state-specific incidence rates, we estimated a total of 134,166 (95% confidence interval: 75,177-193,327) childhood asthma incident cases attributable to NO₂, accounting for 17.6% of all childhood asthma incident cases. Using the national-level incidence rate, we estimated a total of 141,931 (95% confidence interval: 119,222-163,505) incident cases attributable to NO₂, accounting for 17.9% of all childhood asthma incident cases. Using the state-specific incidence rates therefore reduced the attributable number of cases by 7,765 (5.5% relative reduction), compared with estimates using the national-level incidence rate. Across states, the change in the attributable number of cases ranged from -64.1% (Montana) to +33.8% (Texas). California had the largest absolute decrease (-6,190) in attributable cases, whereas Texas had the largest increase (+3,615). Stratifying by socioeconomic status and urban versus rural status produced new trends compared with the previously published BoD analysis showing high heterogeneity across the states.

CONCLUSIONS

We estimated new state-specific asthma incidence rates for the contiguous United States. Using state-specific incidence rates versus a constant national incidence rate resulted in a small change in the NO₂ attributable BoD at the national level, but had a more prominent impact at the state level.

Effect of maternal sleep, physical activity and screen time during pregnancy on the risk of childhood respiratory allergies: a sex-specific study

BACKGROUND

Early life exposure in the uterus had a long-term effect on children's health. As the prevalence of allergies is increasing with a remarkable sex difference, very few studies have traced back to their early origins. We sought to investigate if maternal behavioral exposure, herein sleep, physical activity, and screen time during pregnancy is associated with childhood respiratory allergies. The sex difference would be examined.

METHODS

Six thousand two hundred thirty-six mother-child pairs from Shanghai Children Allergy Study (SCAS) were enrolled, The International Study of Asthma and Allergies in Childhood questionnaire was adopted to evaluate respiratory allergic diseases.

RESULTS

14.6, 16.2, and 21.0% of children had asthma, wheeze, and allergic rhinitis, respectively. Maternal short sleep duration, lack of physical activity, and too much screen exposure during pregnancy could increase the risk of childhood respiratory allergies, however, the significance was found only in males. Moreover, a dose-response trend was clearly shown, any two of the three combined could increase the risk (OR,1.921; 95% CI,1.217-3.033), and the coexistence of all three further amplified the risk (OR,2.412; 95% CI,1.489-3.906). The findings can be verified in allergen test subgroup and each single type of respiratory allergies in most cases.

CONCLUSIONS

Maternal unhealthy behaviors during pregnancy could increase the risk of childhood respiratory allergies with a dose-response pattern. Males were more susceptible to the association. The identification of modifiable maternal risk behaviors lies in the emphasis of intervention in early life to face up increasing childhood allergies.

Air pollution and family related determinants of asthma onset and persistent wheezing in children: nationwide case-control study

OBJECTIVE

To identify risk factors (air pollution and family related) for the onset of asthma and persistent wheezing in children.

DESIGN

Nationwide case-control study.

SETTING

Denmark.

PARTICIPANTS

All Danish children born from 1997 to 2014 and followed for asthma onset and persistent wheezing from age 1 year to 15 years.

MAIN OUTCOME MEASURE

Onset of asthma and persistent wheezing.

RESULTS

A higher incidence of asthma was found in children of parents with asthma (adjusted hazard ratio 2.29 (95% confidence interval 2.22 to 2.35) and mothers who smoked during pregnancy (1.20, 1.18 to 1.22), whereas a lower incidence was found in children of parents with high educational attainment (0.72, 0.69 to 0.75) and high incomes (0.85, 0.81 to 0.89). Exposure to particulate matter ≤2.5 µm (PM_2.5) and ≤10 µm (PM₁₀) and nitrate was associated with an increased risk of asthma and persistent wheezing, with hazard ratios per 5 µg/m³ increase in pollutant concentrations 1.05 (1.03 to 1.07) for PM_2.5, 1.04 (1.02 to 1.06) for PM₁₀, and 1.04 (1.03 to 1.04) for nitrogen dioxide. Only the positive association of PM_2.5 with asthma and persistent wheezing remained robust across the different models and in sensitivity analyses.

CONCLUSIONS

The findings of this study suggest that children exposed to higher levels of PM_2.5 are more likely to develop asthma and persistent wheezing than children who are not exposed. Other risk factors associated with these outcomes were parental asthma, parental education, and maternal smoking during pregnancy.

Early-life exposure to air pollution and childhood allergic diseases: an update on the link and its implications

INTRODUCTION

Although mounting evidence has linked environmental factors with childhood allergies, some specific key issues still remain unclear: what is the main environmental factor? what is the critical timing window? And whether these contribute to the development of disease?

AREAS COVERED

This selective review summarizes recent epidemiological studies on the association between early-life exposure to indoor/outdoor air pollution and childhood allergic diseases. A literature search was conducted in the PubMed and Web of Science for peer-reviewed articles published until April 2020. Exposure to the traffic-related air pollutant, NO₂, exposure during pregnancy and early postnatal periods is found to be associated with childhood allergies, and exposure during different trimesters causes different allergic diseases. However, exposure to classical air pollutants (PM₁₀ and SO₂) also contributes to childhood allergy in developing countries. In addition, early-life exposure to indoor renovation and mold/dampness significantly increases the risk of allergy in children. A synergistic effect between indoor and outdoor air pollution is found in the development of allergic diseases.

EXPERT OPINION

Early-life exposure to outdoor air pollution and indoor environmental factors plays an important role in the development of childhood allergic diseases, and the synergy between indoor and outdoor exposures increases allergy risk. The available findings support the hypothesis of the 'fetal origins of childhood allergy,' with new implications for the effective control and early prevention of childhood allergies.

Association of bacterial load in drinking water and allergic diseases in childhood

BACKGROUND

Treatment of drinking water may decrease microbial exposure.

OBJECTIVE

To investigate whether bacterial load in drinking water is associated with altered risk of allergic diseases.

METHODS

We recruited 1,110 schoolchildren aged 6-16 years between 2011 and 2013 in Požega-Slavonia County in Croatia, where we capitalized on a natural experiment whereby individuals receive drinking water through public mains supply or individual wells. We obtained data on microbial content of drinking water for all participants; 585 children were randomly selected for more detailed assessments, including skin prick testing. Since water supply was highly correlated with rural residence, we compared clinical outcomes across four groups (Rural/Individual, Rural/Public, Urban/Individual and Urban/Public). For each child, we derived quantitative index of microbial exposure (bacterial load in the drinking water measured during the child's first year of life).

RESULTS

Cumulative bacterial load in drinking water was higher (median [IQR]: 6390 [4190-9550] vs 0 [0-0]; P < .0001), and lifetime prevalence of allergic diseases was significantly lower among children with individual supply (5.5% vs 2.3%, P = .01; 14.4% vs 6.7%, P < .001; 25.2% vs 15.1%, P < .001; asthma, atopic dermatitis [AD] and rhinitis, respectively). Compared with the reference group (Urban/Public), there was a significant reduction in the risk of ever asthma, AD and rhinitis amongst rural children with individual supply: OR [95% CI]: 0.14 [0.03,0.67], P = .013; 0.20 [0.09,0.43], P < .001; 0.17 [0.10,0.32], P < .001. Protection was also observed in the Rural/Public group, but the effect was consistently highest among Rural/Individual children. In the quantitative analysis, the risk of allergic diseases decreased significantly with increasing bacterial load in drinking water in the first year of life (0.79 [0.70,0.88], P < .001; 0.90 [0.83,0.99], P = .025; 0.80 [0.74,0.86], P < .001; current wheeze, AD and rhinitis).

CONCLUSIONS AND CLINICAL RELEVANCE

High commensal bacterial content in drinking water may protect against allergic diseases.