Asthma in South African adolescents: a time trend and risk factor analysis over two decades

Prevalence of asthma and allergic rhinitis in children exposed to pets: a meta-analysis

PURPOSE

Pet exposure has always been controversial with childhood asthma and allergic rhinitis. We aimed to understand the prevalence of asthma and allergic rhinitis in children exposed to pets by meta-analysis.

METHODS

We searched articles published from Jan 1, 2012 to Dec 31, 2022 in the Embase, PubMed, Cochrane Library, and Web of Science databases. We included a cross-sectional study that reported the prevalence of asthma and allergic rhinitis in children exposed to pets. Furthermore, we performed subgroup analyses according to pet type and age.

RESULTS

In 14 selected studies, the meta-analysis results showed that the pooled prevalence of asthma in children exposed to pets was 19.0% (95% CI 13.3-24.7%), and the pooled prevalence of allergic rhinitis in children exposed to pets was 25.5% (95% CI 12.4-38.5%). The prevalence of asthma in children exposed to cats and dogs was 16.4% (95% CI 9.9-22.8%) and 12.5% (95% CI 8.7-16.2%), respectively. The prevalence of allergic rhinitis was 24.9% (95% CI 2.9-47.0%) and 24.1% (95% CI 2.6-45.6%), respectively. The prevalence of asthma in pet-exposed children was 17.1% (95% CI 12.3-22.0%) in the adolescence group (> 10 years) and 26.3% (95% CI 12.2-40.3%) in the childhood group (0-10 years). The prevalence of allergic rhinitis was 8.6% (95% CI 7.2-10.0%) in the adolescence group and 46.3% (95% CI 44.0-48.6%) in the childhood age group.

CONCLUSIONS

The prevalence of asthma and allergic rhinitis in children exposed to pets is different. Exposure to pet cats is more prone to illness, and younger children are more susceptible to disease than older children.

Maternal exposure to pyrethroid insecticides during pregnancy and respiratory allergy symptoms among children participating in the Venda Health Examination of Mothers, Babies and their Environment (VHEMBE)

BACKGROUND

Pyrethroid insecticides use for indoor residual spraying (IRS) in malaria-endemic areas results in high levels of exposure to local populations. Pyrethroids may cause asthma and respiratory allergies but no prior study has investigated this question in an IRS area.

METHODS

We measured maternal urinary concentrations of pyrethroid metabolites (cis-DBCA, cis-DCCA, trans-DCCA, 3-PBA) in samples collected at delivery from 751 mothers participating in the Venda Health Examination of Mothers, Babies, and their Environment (VHEMBE), a birth cohort study based in Limpopo, South Africa. At 3.5-year and 5-year follow-up visits, caregivers of 647 and 620 children, respectively, were queried about children's respiratory allergy symptoms based on validated instruments. We applied marginal structural models for repeated outcomes to estimate associations between biomarker concentrations and asthma diagnosis as well as respiratory allergy symptoms at ages 3.5 and 5 years.

RESULTS

We found that a10-fold increase in maternal urinary cis-DCCA, trans-DCCA and 3-PBA concentrations were associated with more than a doubling in the risk of doctor-diagnosed asthma (cis-DCCA: RR = 2.1, 95% CI = 1.3, 3.3; trans-DCCA: RR = 2.1, 95% CI = 1.1, 3.9; 3-PBA: RR = 2.4, 95% CI = 1.0, 5.8) and an about 80% increase in the risk of wheezing or whistling in the chest (cis-DCCA: RR = 1.8, 95% CI = 1.1, 3.0; trans-DCCA: RR = 1.7, 95% CI = 1.1, 2.6; 3-PBA: RR = 1.8, 95% CI = 1.0, 3.3) and suspected asthma (cis-DCCA: RR = 1.8, 95% CI = 1.1, 3.1; trans-DCCA: RR = 1.8, 95% CI = 1.1, 2.8). We also observed that higher concentrations of cis-DBCA and 3-PBA were related to increases in the risks of dry cough at night (RR = 3.5, 95% CI = 1.3, 9.5) and seasonal rhinoconjunctivitis (RR = 2.0, 95% CI = 1.1, 3.9), respectively.

CONCLUSION

Maternal exposure to pyrethroids may increase the risk of asthma and other respiratory allergy symptoms among preschool children from an IRS area.

Over-the-counter use of short-acting beta-2 agonists: a systematic review

BACKGROUND

The widespread use of short-acting beta-2 agonists (SABA) as an as-needed treatment for asthma is well-established. However, excessive use of SABA has been linked to undesirable outcomes such as increased risk of asthma attacks, exacerbations, and even death. The availability of SABA as an over-the-counter (OTC) medication has contributed to their overuse, leading to undertreated asthma and reduced access to asthma education.

OBJECTIVE

This systematic review aimed to summarize the prevalence, characteristic features of, and factors contributing to over-the-counter SABA purchase or overuse.

METHODS

The databases searched included PubMed, Scopus, Springer Link, Google Scholar, CINAHL, and APA PsycArticles. Original research articles reporting the prevalence, characteristics features, and factors regarding over-the-counter SABA use, available as full text, published in English language between the year 2000 and April 2023 were included in this review. Commentaries, letters to editor, review articles, qualitative studies, clinical trials, and conference proceedings were excluded. Data extraction was followed by a review of the quality of studies included and data were then synthesized for meaningful findings. This systematic review had been registered in the PROSPERO with registration number CRD42023421007.

RESULTS

A total of 18 articles were included. The prevalence range of OTC SABA users in populations were 1.4% to 39.6% and SABA over-users among OTC users were 14% to 66.4%. Factors mostly associated with this behavior were moderate-severe asthma, and less use of preventers. On top of that, not understanding the risk of SABA overuse was clear in many studies that explored this factor.

CONCLUSION

Over-the-counter purchase and overuse of SABA medication is a common problem, leading to adverse consequences such as uncontrolled asthma and increased healthcare utilization. Addressing these issues requires improved patient education about their conditions and adequate information regarding the potential long-term effects of SABA use by the healthcare providers. Management and education of asthma patients, including regular monitoring and follow-up, can help reduce overuse of SABA medication and prevent negative consequences.

A cross-country qualitative analysis of teachers' perceptions of asthma care in sub-Saharan Africa

Asthma is the most common chronic respiratory disease among school-going adolescents worldwide. However, the burden of severe asthma is highest in Sub-Saharan Africa. This study aimed to explore teachers' perceptions of asthma care across six African countries. We conducted focus group discussions (FGDs) using a semi-structured interview guide. Interviews were audio-recorded, transcribed verbatim and analysed thematically. FGDs were conducted in Kumasi(Ghana), Blantyre (Malawi), Lagos (Nigeria), Durban (South Africa), Kampala (Uganda), and Harare (Zimbabwe) between 01 November 2020 and 30 June 2021. We identified two key themes related to asthma care; barriers to asthma care and suggestions to improve the care of adolescents with asthma. Barriers reported by teachers included a lack of knowledge and skills among themselves, adolescents, and caregivers. In addition, some traditional beliefs of teachers on asthma exacerbated challenges with asthma care in schools. Regarding suggestions, most teachers identified a need for all-inclusive asthma training programmes for teachers, adolescents and caregivers, focusing on acute episodes and mitigating triggers. Utilising teachers with personal experiences with asthma to advocate and support these initiatives was suggested. Further suggestions included the need for annual screening to enable early identification of adolescents with asthma and clarify restrictions on teachers administering asthma medications. Teachers across African schools identify multiple barriers to asthma care. Structured school education programs and annual asthma screening are key to addressing some barriers to care.

Immunogenetics and pharmacogenetics of allergic asthma in Africa

Asthma is a common chronic condition in children and in an African setting is often highly prevalent in urban areas as compared to rural areas. Asthma is a heritable disease and the genetic risk is often exacerbated by unique localised environmental factors. The Global Initiative for Asthma (GINA) recommendation for the control of asthma includes inhaled corticosteroids (ICS) alone or together with short-acting β₂-agonists (SABA) or long-acting β₂-agonists (LABA). While these drugs can relieve asthma symptoms, there is evidence of reduced efficacy in people of African ancestry. Whether this is due to immunogenetics, genomic variability in drug metabolising genes (pharmacogenetics) or genetics of asthma-related traits is not well defined. Pharmacogenetic evidence of first-line asthma drugs in people of African ancestry is lacking and is further compounded by the lack of representative genetic association studies in the continent. In this review, we will discuss the paucity of data related to the pharmacogenetics of asthma drugs in people of African ancestry, mainly drawing from African American data. We will further discuss how this gap can be bridged to improve asthma health outcomes in Africa.

Prevalence, severity and risk factors for asthma in school-going adolescents in KwaZulu Natal, South Africa

BACKGROUND

Asthma remains highly prevalent, with more severe symptoms in low-income to middle-income countries (LMICs) compared with high-income countries. Identifying risk factors for severe asthma symptoms can assist with improving outcomes. We aimed to determine the prevalence, severity and risk factors for asthma in adolescents in an LMIC.

METHODS

A cross-sectional survey using the Global Asthma Network written and video questionnaires was conducted in adolescents aged 13 and 14 from randomly selected schools in Durban, South Africa, between May 2019 and June 2021.

RESULTS

A total of 3957 adolescents (51.9% female) were included. The prevalence of lifetime, current and severe asthma was 24.6%, 13.7% and 9.1%, respectively. Of those with current and severe asthma symptoms; 38.9% (n=211/543) and 40.7% (n=147/361) had doctor-diagnosed asthma; of these, 72.0% (n=152/211) and 70.7% (n=104/147), respectively, reported using inhaled medication in the last 12 months. Short-acting beta agonists (80.4%) were more commonly used than inhaled corticosteroids (13.7%). Severe asthma was associated with: fee-paying school quintile (adjusted OR (CI)): 1.78 (1.27 to 2.48), overweight (1.60 (1.15 to 2.22)), exposure to traffic pollution (1.42 (1.11 to 1.82)), tobacco smoking (2.06 (1.15 to 3.68)), rhinoconjunctivitis (3.62 (2.80 to 4.67)) and eczema (2.24 (1.59 to 3.14)), all p<0.01.

CONCLUSION

Asthma prevalence in this population (13.7%) is higher than the global average (10.4%). Although common, severe asthma symptoms are underdiagnosed and associated with atopy, environmental and lifestyle factors. Equitable access to affordable essential controller inhaled medicines addressing the disproportionate burden of asthma is needed in this setting.

Challenges in the diagnosis of asthma in children, what are the solutions? A scoping review of 3 countries in sub Saharan Africa

Background

Asthma is the commonest chronic respiratory tract disease in children. In low-income countries, challenges exist in asthma diagnosis. In surveys done in children, the prevalence of ‘asthma’ defined by symptoms is high compared to ‘doctor diagnosed asthma’. The questions answered by this review are (i) What challenges have been experienced in the diagnosis of asthma in children? (ii) What solutions will address these challenges?

Methods

The Arksey and O’Malley’s framework for scoping reviews was used for the study methodology, while the PRISMA-ScR checklist guided the reporting process. Electronic databases: PubMed Central, EMBASE and Google Scholar were searched. Primary quantitative and qualitative studies and reviews from 2010 to 2021, from Nigeria, South Africa and Uganda written in English or translated to English, which answered the study questions were included. The author, title, country, study type, methods, purpose, findings and references were captured onto a predefined data collection table. The ‘Preview, Question, Read, Summarise’ system was used and a narrative report was used to summarise the findings.

Results

A total of 28 studies were included. The causes of under-diagnosis of asthma include lack of community knowledge and perception of asthma, poor accessibility to health care, strained health systems, lack of diagnostic tests including spirometry, low levels of knowledge among health-care workers and lack of or non-implementation of asthma guidelines. Strategies to improve asthma diagnosis will include community and school based education programmes, revision of asthma diagnostic terms, guideline development and implementation and health systems strengthening.

Conclusion

This scoping review provides research evidence for policy makers and health-workers involved in the care of asthmatic children on challenges faced in asthma diagnosis and strategies to improve asthma diagnosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02170-y.

Parental Education Moderates the Relation between Physical Activity, Dietary Patterns and Atopic Diseases in Adolescents

Background: Atopic diseases, particularly asthma, eczema, and rhinitis, are among the most common chronic diseases in childhood, with several factors implicated in their pathogenesis. Our study examined the role of parental education in the association between diet, physical activity, and atopy in adolescents. Methods: 1934 adolescents (47.5% boys) aged 13−14 years old reported information about their diet and physical activity and their parents reported their highest educational level. The moderating role of parental education level (primary/secondary vs. tertiary) in the relation between lifestyle patterns and atopic diseases was examined with logistic regression analyses. Results: High consumption of dairy products was inversely associated to adolescents’ asthma and rhinitis symptoms overall, but this relation was almost 50% stronger for the adolescents with high parental education level background. The same pattern of reduction of the odds was noticed also regarding the association among the high intake of fruits, vegetables, pulses, with all three atopic diseases and the adherence to a physically active lifestyle only with current asthma and eczema (all p < 0.05). Conclusion: Adolescents who are physically active and consume a higher intake of fruits, vegetables, and pulses and a lower intake of fast-food and sweets, and their parents/guardians having higher education, are less likely to have any current symptoms of asthma, eczema, and rhinitis than the ones who have low educated parents.

Lung Function in Preschool Children in Low and Middle Income Countries: An Under-Represented Potential Tool to Strengthen Child Health

BACKGROUND

The burden of respiratory disease is high in low-middle income countries (LMIC). Pulmonary function tests are useful as an objective measure of lung health and to track progression. Spirometry is the commonest test, but its use is limited in preschool children. Other lung function methods have been developed but their use in LMIC has not been well described.

AIM

To review the use of preschool lung function testing in children in LMIC, with particular reference to feasibility and clinical applications.

METHODS

Electronic databases "PubMed", "Scopus"," Web of Science", and "EBSCO host" were searched for publications in low and middle income countries on preschool lung function testing, including spirometry, fractional exhaled nitric oxide (FeNO), oscillometry, interrupter technique, tidal breathing and multiple breath washout (MBW), from 1 January 2011 to 31 January 2022. Papers in English were included and those including only children ≥6 years were excluded.

RESULT

A total of 61 papers from LMIC in Asia, South America, Africa, Eurasia or the Middle East were included. Of these, 40 included spirometry, 7 FeNO, 15 oscillometry, 2 interrupter technique, and 2 tidal breathing. The papers covered test feasibility (19/61), clinical application (46/61) or epidemiological studies (13/61). Lung function testing was successful in preschool children from LMIC. Spirometry was the most technically demanding and success gradually increased with age.

CONCLUSION

Preschool lung function testing is under-represented in LMIC for the burden of respiratory disease. These tests have the potential to strengthen respiratory care in LMIC, however access needs to be improved.

Over-prescription of short-acting β2-agonists for asthma in South Africa: Results from the SABINA III study

Background

Asthma medication prescription trends, including those of short-acting β₂ -agonists (SABAs), are not well documented for South Africa (SA).

Objectives

To describe demographics, disease characteristics and asthma prescription patterns in the SA cohort of the SABA use IN Asthma (SABINA) III study.

Methods

An observational, cross-sectional study conducted at 12 sites across SA. Patients with asthma (aged ≥12 years) were classified by investigator-defined asthma severity, guided by the Global Initiative for Asthma (GINA) 2017 recommendations, and practice type (primary/ specialist care). Data were collected using electronic case report forms.

Results

Overall, 501 patients were analysed - mean (standard deviation) age, 48.4 (16.6) years; 68.3% female - of whom 70.6% and 29.4% were enrolled by primary care physicians and specialists, respectively. Most patients were classified with moderate-to-severe asthma (55.7%; GINA treatment steps 3 - 5), were overweight or obese (70.7%) and reported full healthcare reimbursement (55.5%). Asthma was partly controlled/uncontrolled in 60.3% of patients, with 46.1% experiencing ≥1 severe exacerbations in the 12 months before the study visit. Overall, 74.9% of patients were prescribed ≥3 SABA canisters in the previous 12 months (over-prescription); 56.5% were prescribed ≥10 SABA canisters. Additionally, 27.1% of patients reported purchasing SABA over-the-counter (OTC); among patients with both SABA purchase and prescriptions, 75.4% and 51.5% already received prescriptions for ≥3 and ≥10 SABA canisters, respectively, in the preceding 12 months.

Conclusion

SABA over-prescription and OTC purchase were common in SA, demonstrating an urgent need to align clinical practices with the latest evidence-based recommendations and regulate SABA OTC purchase to improve asthma outcomes.

Study synopsis

What the study adds. This study provides valuable insights into asthma medication prescription patterns, particularly SABAs, across SA. Collection of this real-world data in patients treated in primary and specialty care demonstrates that SABA over-prescription and SABA OTC purchase are common, even in patients with mild asthma. These findings will enable clinicians and policymakers to make targeted changes to optimise asthma outcomes across the country Implications of the findings. SABA over-prescription represents a major public health concern in SA. Healthcare providers and policymakers will need to work together to promote educational initiatives aimed at patients, pharmacists and physicians, align clinical practices with the latest evidence-based recommendations, improve access to affordable medications and regulate SABA purchase without prescription.