Asthma in developing worlds

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.

The Role of Macrophages in the Development of Acute and Chronic Inflammatory Lung Diseases

Macrophages play an important role in the innate and adaptive immune responses of organ systems, including the lungs, to particles and pathogens. Cumulative results show that macrophages contribute to the development and progression of acute or chronic inflammatory responses through the secretion of inflammatory cytokines/chemokines and the activation of transcription factors in the pathogenesis of inflammatory lung diseases, such as acute lung injury (ALI), acute respiratory distress syndrome (ARDS), ARDS related to COVID-19 (coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)), allergic asthma, chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF). This review summarizes the functions of macrophages and their associated underlying mechanisms in the development of ALI, ARDS, COVID-19-related ARDS, allergic asthma, COPD, and IPF and briefly introduces the acute and chronic experimental animal models. Thus, this review suggests an effective therapeutic approach that focuses on the regulation of macrophage function in the context of inflammatory lung diseases.

Delivery and adherence with inhaled therapy in asthma

The benefits of inhaled medication for the treatment of respiratory diseases are immense. Inhalers are unquestionably the most important medical devices for the treatment of asthma and in Europe today there are more than 230 different device and drug combinations of inhaled therapies many of which are available for the treatment of asthma. They are designed to alleviate the symptoms of asthma by controlling inflammation and minimising exacerbations and are intended to be simple enough to operate by all patients regardless of their age and education. However, it is still a huge challenge for patients to use their inhaler correctly and consistently and achieving asthma control continues to be an elusive goal for most patients worldwide. The reality is that despite advances in the diagnosis of asthma, the availability of comprehensive asthma management guidelines and potent asthma medications combined with efficient delivery systems, uncontrolled disease is still linked to substantial morbidity and mortality. Despite the enormous benefits of delivering topically acting medication directly to the site of disease in the lungs adherence to treatment still remains one of the biggest challenges in asthma control. This current review looks at why patients have difficulty in using their inhalers and why adherence is so poor and how this may be improved through the use of innovation in inhaler design.

Association between Caesarean Delivery and Childhood Asthma in India and Vietnam

BACKGROUND

While there is evidence of an association between caesarean birth and increased asthma in children in high-income countries, it is unknown whether this association exists in low-to-middle-income countries (LMICs). We investigated whether children born through caesarean in India and Vietnam are at increased risk of caregiver-reported asthma by 8 years of age.

METHODS

Data from an ongoing multi-national longitudinal cohort study (the Young Lives Study) in two LMICs (India n = 2026; Vietnam n = 2000) were used. Caregiver questionnaires captured information on caregiver-reported long-term respiratory problems such as asthma or wheeze at age 8 years, birth mode and a range of sociodemographic factors. Multivariable logistic regression models using propensity score adjustment were used to explore birth mode and asthma at age 8 years adjusted for a range of known confounders.

RESULTS

Children delivered by caesarean in India (odds ratio (OR) 2.6, 95% confidence interval (CI) 1.3, 5.4) and Vietnam (OR 2.0, 95% CI 1.2, 3.3) had greater odds of asthma at age 8 years, after adjustment for other risk factors including wealth, liveborn parity, low birthweight, geographic location, cooking fuel used, livestock ownership, household size, housing quality and parental smoking.

CONCLUSIONS

The study suggests that caesarean birth may be associated with an increased risk of childhood asthma in India and Vietnam. The underlying mechanisms of this finding need to be further elucidated.

Distribution and etiology of chronic respiratory diseases in primary healthcare departments in Cape Verde

BACKGROUND AND OBJECTIVE

Data on chronic respiratory diseases (CRD) are scarce or unavailable in most African countries. We aimed to determine the prevalence of CRD and associated risk factors in Cape Verde, at the primary healthcare level.

METHODS

In the frame of the Global Alliance Against Chronic Respiratory Diseases, a cross-sectional study was carried out in October 2006 in 3256 outpatients (2142 women) (median age of 30 years) seeking care at primary healthcare departments, through a standardized interview questionnaire during two weeks.

RESULTS

The prevalence of emphysema, tuberculosis, chronic bronchitis, rhinoconjunctivitis and asthma were 0.7%, 2%, 4.5%, 12.3% and 6.2%, respectively. Current smoking was associated with emphysema (OR: 3.36; 95% CI: 0.97-11.40) and tuberculosis (OR: 2.14; 95% CI: 1.07-4.30), ever exposed to a dusty workplace with chronic bronchitis (OR: 2.20; CI 95%: 1.50-3.21) and rhinoconjunctivitis (OR: 1.56; CI 95%: 1.23-1.98) and cooking or heating using an open fire with asthma (OR: 1.59; CI 95%: 1.16-2.19). The estimates of attributable risks percent indicated that, in the sample, a noticeable part of CRD could be attributed to active smoking, exposure to dust and biomass. Results varied according to gender, particularly regarding current smoking which was more important for men.

CONCLUSIONS

Tobacco smoking, exposure to dust at work and using an open fire were important risk factors for CRD. Our results suggest that if actions were taken in order to reduce the aforementioned exposures, an important CRD decrease could be achieved.

Asthma symptoms in rural living Tanzanian children; prevalence and the relation to aerobic fitness and body fat

OBJECTIVE

To determine the prevalence of asthma symptoms in children from a rural district in North-Tanzania, and their relationship to aerobic fitness and body fat.

METHODS

In Manyara region in Tanzania, children (aged 9-10 years) were randomly selected to participate in the present cross-sectional study. Hundred and seventy two participants completed a video questionnaire showing the symptoms and signs of asthma. Lung function was measured by maximum forced expiratory flow-volume curves. Aerobic fitness was estimated from a standardized indirect maximal cycle ergometer test and sum of three skinfolds reflected body fat.

RESULTS

Twenty four per cent reported asthma symptoms last year. Severe wheezing attacks last year were reported in 5% of the participants. Thirty seven per cent of the participants were underweight. Underweight children had significantly lower (P < 0.02) lung function (per cent of predicted). Lower body fat was associated with higher occurrence of asthma symptoms (odds ratio and 95% CI; 0.45 (0.22-0.95; P = 0.04). Aerobic fitness was not associated with asthma symptoms.

CONCLUSIONS

More than every fifth 9-10 year old child from a rural district in North-Tanzania reported asthma symptoms. Lower body fat was associated with higher occurrence of asthma symptoms, but aerobic fitness was not associated with asthma symptoms.

Under-report and underdiagnosis of chronic respiratory diseases in an African country

BACKGROUND

Chronic respiratory diseases (CRD) are greatly underestimated. The aim of this study was to assess the burden associated with reported CRD and chronic obstructive pulmonary disease, as defined on the basis of various standardized criteria, by estimating their point prevalence in a sample of individuals attending the Primary Health Care (PHC) level and Emergency Room (ER) Departments in Cape Verde (CV) archipelago. The second aim of the study was to identify factors related to airways obstruction and reported CRD in this population.

METHODS

A cross-sectional study was carried out in CV during 2 weeks. Outpatients aged more than 20 years seeking care at PHC level and ER answered a standardized questionnaire and were subjected to spirometry, independently of their complaint. Two criteria for airways obstruction were taken into account: forced expiratory volume (FEV(1)) <80% of the predicted value and FEV(1)/forced vital capacity (FVC) ratio <0.70.

RESULTS

A total of 274 individuals with a satisfactory spirometry were included. 22% of the individuals had a FEV(1) < 80%. Individuals older than 46 years had a higher risk of having airways obstruction. Asthma diagnosis (11%) had a clear association with airways obstruction. Smoking was a risk factor for a lower FEV(1). Working in a dust place and cooking using an open fire were both related to chronic bronchitis and asthma diagnosis.

CONCLUSION

Under-report and underdiagnosis of chronic respiratory conditions seem to be a reality in CV just as in other parts of the world. To improve diagnosis, our results reinforce the need of performing a spirometry.

Nxwisen, ntzarrin or ntzo'lin? Mapping children's respiratory symptoms among indigenous populations in Guatemala

Estimating the prevalence of asthma is an epidemiologic challenge, particularly in rural areas of lesser-developed countries characterized by low literacy and poor access to health care. To avoid under or over reporting of symptoms, questionnaires must use terminology familiar to participants and that accurately describes the triad of cough, wheeze and breathlessness characteristic of asthma. In preparation for a large longitudinal cohort study entitled Chronic Respiratory Effects of Early Childhood Exposure to Respirable Particulate Matter (CRECER) that will examine the effects of variable early lifetime woodsmoke exposure on the respiratory health of Mam-speaking children residing in communities in the western highlands of Guatemala, we conducted individual interviews (n=18) and five focus groups (n=46) with indigenous women from 17 of these communities to elicit and define local Mam and Spanish terms for common respiratory symptoms used to describe their own and their children's respiratory symptoms. Focus group participants were also shown an International Study of Asthma and Allergies in Childhood (ISAAC) video of wheezing children and adults. We developed a conceptual framework that can be used as an efficient model for future studies investigating health and/or disease terminology in isolated communities, an integral step in the development of standardized questionnaires. Among this Mam-speaking population, wheeze was best described as nxwisen or ntzarrin, "breathing sounds that are heard in the neck but come from the chest." The variation in understanding of terms between women with and without children with a history of wheeze (such that for those without wheezing children some terms were virtually unrecognized), has important implications for large-scale population surveys within countries and comparative surveys such as ISAAC. It is important to use linguistically and culturally appropriate terminology to describe wheeze in prevalence studies of asthmatic symptoms among relatively isolated communities in lesser-developed countries.