High asthma prevalence and associated factors in urban malagasy schoolchildren

Health risks associated with the production and usage of charcoal: a systematic review

Charcoal production and utilisation are linked to various health issues and occupational hazards. However, to our knowledge, no systematic review has primarily focused on the health implications of charcoal production and its use while distinguishing charcoal from other solid fuels such as wood and coal.

OBJECTIVES

This systematic review presents a synthesis of the evidence on the health risks associated with producing and using charcoal across the world.

DESIGN

Systematic review using a systematic narrative synthesis approach.

DATA SOURCES

MEDLINE (through Ovid interface), CINAHL, Embase, Web of Science, PsycINFO, Cochrane Library and SCOPUS, from inception to 26 February 2021.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Peer-reviewed journal articles reporting empirical findings on the associations between charcoal usage/production and health parameters.

DATA EXTRACTION AND SYNTHESIS

Two independent reviewers extracted data and assessed the quality of primary studies.

RESULTS

Our findings showed that charcoal production and usage are linked with specific adverse health outcomes, including respiratory diseases (n=21), cardiorespiratory and neurological diseases (n=1), cancer (n=3), DNA damage (n=3), carbon monoxide (CO) poisoning (n=2), physical injury (n=2), sick house syndrome (n=1), unintentional weight loss and body mass index (BMI) reduction (n=2), increase in blood pressure (n=1) and CO death (n=1). Among the included articles that reported respiratory diseases (n=21), there was one case of asthma and tuberculosis and two cases of chronic obstructive pulmonary disease.

CONCLUSIONS

This review links charcoal production/usage and some associated human health risks. These include respiratory diseases and other non-respiratory illnesses such as sick-building syndrome, cardiovascular diseases, DNA damage, CO poisoning and death, unintentional weight loss and BMI reduction, and physical injuries.

The Burden of Childhood Asthma by Age Group, 1990-2019: A Systematic Analysis of Global Burden of Disease 2019 Data

BACKGROUND

Asthma is a common respiratory disease in children. We aimed to update information about the incidence and mortality and disability-adjusted life years (DALYs) of childhood asthma and provide evidence-based recommendations for childhood asthma prevention.

METHODS

Data were obtained from the Global Burden of Disease (GBD) study, which was conducted from 1990 to 2019 in 204 countries. First, we estimated incidence, mortality and DALY rates of childhood asthma using a Bayesian meta-regression model. Second, we analyzed the relationship between the sociodemographic index (SDI) and DALYs in different age groups. Third, we studied changes in trends of the age-standardized DALY rate between 1990 and 2019 based on age group, SDI, and risk factors.

RESULTS

Globally, the number of deaths due to childhood asthma and the incidence and DALY rates were 12.9 thousand (95% UI 10.6 to 15.7), 22 million (95% UI 15 to 31), and 5.1 million (95% UI 3.4 to 7.5) in 2019, decreasing by 65.1% (95% UI 47.6 to 72.4), 5.3% (95% UI 2.6 to 8.8) and 30% (95% UI 18 to 41) from those in 1990, respectively. With the exception of high-SDI regions, the age-standardized DALY rate in all age groups in all SDI regions declined. In 2019, the age-standardized DALY rate in 1- to 4-year-old individuals was highest in low-SDI regions and that of 5- to 19-year-old individuals was highest in high-SDI regions. In contrast to low-SDI regions, individuals in high-SDI regions had a higher risk of DALYs due to asthma, except in those aged 1 to 4 years. A high body mass index (BMI) was a stronger risk factor than occupational asthmagens for childhood asthma.

CONCLUSION

Our findings provide insight into asthma prevention and treatment through the identification of key factors related to childhood asthma. Based on the data available, different risk factors according to age group and region/country suggest different prevention strategies, which is key for preventing childhood asthma.

Environmental Health Research in Africa: Important Progress and Promising Opportunities

The World Health Organization in 2016 estimated that over 20% of the global disease burden and deaths were attributed to modifiable environmental factors. However, data clearly characterizing the impact of environmental exposures and health endpoints in African populations is limited. To describe recent progress and identify important research gaps, we reviewed literature on environmental health research in African populations over the last decade, as well as research incorporating both genomic and environmental factors. We queried PubMed for peer-reviewed research articles, reviews, or books examining environmental exposures and health outcomes in human populations in Africa. Searches utilized medical subheading (MeSH) terms for environmental exposure categories listed in the March 2018 US National Report on Human Exposure to Environmental Chemicals, which includes chemicals with worldwide distributions. Our search strategy retrieved 540 relevant publications, with studies evaluating health impacts of ambient air pollution (n=105), indoor air pollution (n = 166), heavy metals (n = 130), pesticides (n = 95), dietary mold (n = 61), indoor mold (n = 9), per- and polyfluoroalkyl substances (PFASs, n = 0), electronic waste (n = 9), environmental phenols (n = 4), flame retardants (n = 8), and phthalates (n = 3), where publications could belong to more than one exposure category. Only 23 publications characterized both environmental and genomic risk factors. Cardiovascular and respiratory health endpoints impacted by air pollution were comparable to observations in other countries. Air pollution exposures unique to Africa and some other resource limited settings were dust and specific occupational exposures. Literature describing harmful health effects of metals, pesticides, and dietary mold represented a context unique to Africa. Studies of exposures to phthalates, PFASs, phenols, and flame retardants were very limited. These results underscore the need for further focus on current and emerging environmental and chemical health risks as well as better integration of genomic and environmental factors in African research studies. Environmental exposures with distinct routes of exposure, unique co-exposures and co-morbidities, combined with the extensive genomic diversity in Africa may lead to the identification of novel mechanisms underlying complex disease and promising potential for translation to global public health.

Risk factors for asthma among schoolchildren who participated in a case-control study in urban Uganda

Data on asthma aetiology in Africa are scarce. We investigated the risk factors for asthma among schoolchildren (5–17 years) in urban Uganda. We conducted a case-control study, among 555 cases and 1115 controls. Asthma was diagnosed by study clinicians. The main risk factors for asthma were tertiary education for fathers (adjusted OR (95% CI); 2.32 (1.71–3.16)) and mothers (1.85 (1.38–2.48)); area of residence at birth, with children born in a small town or in the city having an increased asthma risk compared to schoolchildren born in rural areas (2.16 (1.60–2.92)) and (2.79 (1.79–4.35)), respectively; father’s and mother’s history of asthma; children’s own allergic conditions; atopy; and cooking on gas/electricity. In conclusion, asthma was associated with a strong rural-town-city risk gradient, higher parental socio-economic status and urbanicity. This work provides the basis for future studies to identify specific environmental/lifestyle factors responsible for increasing asthma risk among children in urban areas in LMICs.

Asthma is a chronic disease of the airways that leads to breathing difficulty and sometimes death: the condition affects about 235 million people worldwide, especially children. Scientists still do not know exactly what causes asthma, but studies in Europe and North America suggest that individuals born or raised in rural areas are less likely to be affected. However, few studies have examined asthma in African countries, where urbanization is often quickly increasing. Examining the factors associated with the disease as more people move to cities may provide new clues about how asthma emerges, and how to prevent it.

To this end, Mpairwe et al. conducted a study with over 1,670 schoolchildren in Uganda. Those born or raised in rural areas were least likely to have asthma, but the risk doubled among children from small towns, and tripled in those born or who grew up in the city. Children whose parents had a higher education and socioeconomic status had the highest asthma risk, but more work is required to understand why this is the case.

The study by Mpairwe et al. is the first step towards identifying environmental and lifestyle factors associated with increased asthma risk in Africa. Further studies may help scientists to understand how beginning life in a more urban area plays a role in the development of the disease.

Roles of Heat Shock Proteins in Apoptosis, Oxidative Stress, Human Inflammatory Diseases, and Cancer

Heat shock proteins (HSPs) play cytoprotective activities under pathological conditions through the initiation of protein folding, repair, refolding of misfolded peptides, and possible degradation of irreparable proteins. Excessive apoptosis, resulting from increased reactive oxygen species (ROS) cellular levels and subsequent amplified inflammatory reactions, is well known in the pathogenesis and progression of several human inflammatory diseases (HIDs) and cancer. Under normal physiological conditions, ROS levels and inflammatory reactions are kept in check for the cellular benefits of fighting off infectious agents through antioxidant mechanisms; however, this balance can be disrupted under pathological conditions, thus leading to oxidative stress and massive cellular destruction. Therefore, it becomes apparent that the interplay between oxidant-apoptosis-inflammation is critical in the dysfunction of the antioxidant system and, most importantly, in the progression of HIDs. Hence, there is a need to maintain careful balance between the oxidant-antioxidant inflammatory status in the human body. HSPs are known to modulate the effects of inflammation cascades leading to the endogenous generation of ROS and intrinsic apoptosis through inhibition of pro-inflammatory factors, thereby playing crucial roles in the pathogenesis of HIDs and cancer. We propose that careful induction of HSPs in HIDs and cancer, especially prior to inflammation, will provide good therapeutics in the management and treatment of HIDs and cancer.

Prevalence of Mycoplasma pneumoniae Infection in Malagasy Children

BACKGROUND

Childhood community-acquired pneumonia is a leading cause of childhood morbidity in low-income countries. The etiologic agents are usually Staphylococcus aureus, Streptococcus pneumoniae and Mycoplasma pneumoniae. M. pneumoniae was recognized as a cofactor in asthmatic disease. High asthma prevalence was reported in Madagascar. Our aim was to clarify the prevalence of M. pneumoniae infection in this country and its relationship with asthma.

METHODS

A prospective study was conducted in 351 children (from 2 to 16 years of age) from January 2012 to December 2014. According to the clinical symptoms, children were enrolled in 3 groups: "control group" (CG, n = 106), "asthma group" (n = 129) and "pneumonia group" (n = 116). The IgG and IgM M. pneumoniae status was evaluated by an enzyme-linked immunosorbent assay. Clinical signs of infection, socioeconomic data and antimicrobial treatment were recorded.

RESULTS

The overall prevalence of M. pneumoniae infection was 18.2%. The multivariate analysis demonstrated that M. pneumoniae infection was significantly more frequent in the CG [pneumonia group vs. CG: odds ratio = 0.45 (0.21-0.91), P = 0.037 and asthma group vs. CG: odds ratio = 0.39 (0.18-0.87), P = 0.021]. The C-reactive protein value was significantly higher in children with M. pneumonia-positive serology (85 vs. 61 mg/L, P = 0.03). Of note, 99 (41%) children received antibiotics before attending.

CONCLUSIONS

We report a prevalence of 18.2% for M. pneumoniae infection in children in Madagascar. The prevalence of M. pneumoniae infection was higher in the control patients than in asthmatic ones.

Evidence of an overweight/obesity transition among school-aged children and youth in Sub-Saharan Africa: a systematic review

BACKGROUND

Prevalence of childhood overweight/obesity has increased considerably in recent years. The transition to higher rates of overweight/obesity has been well documented in high income countries; however, consistent or representative data from lower income countries is scarce. It is therefore pertinent to assess if rates of overweight/obesity are also increasing in lower income countries, to inform public health efforts.

OBJECTIVE

This systematic review aimed to investigate the evidence for an overweight/obesity transition occurring in school-aged children and youth in Sub Saharan Africa.

METHODS

Studies were identified by searching the MEDLINE, Embase, Africa Index Medicus, Global Health, Geobase, and EPPI-Centre electronic databases. Studies that used subjective or objective metrics to assess body composition in apparently healthy or population-based samples of children and youth aged 5 to 17 years were included.

RESULTS

A total of 283 articles met the inclusion criteria, and of these, 68 were used for quantitative synthesis. The four regions (West, Central, East, and South) of Sub Saharan Africa were well represented, though only 11 (3.9%) studies were nationally representative. Quantitative synthesis revealed a trend towards increasing proportions of overweight/obesity over time in school-aged children in this region, as well as a persistent problem of underweight. Weighted averages of overweight/obesity and obesity for the entire time period captured were 10.6% and 2.5% respectively. Body composition measures were found to be higher in girls than boys, and higher in urban living and higher socioeconomic status children compared to rural populations or those of lower socioeconomic status.

CONCLUSIONS

This review provides evidence for an overweight/obesity transition in school-aged children in Sub Saharan Africa. The findings of this review serve to describe the region with respect to the growing concern of childhood overweight/obesity, highlight research gaps, and inform interventions.

PROSPERO REGISTRATION NUMBER

CRD42013004399.

An estimate of asthma prevalence in Africa: a systematic analysis

Aim

To estimate and compare asthma prevalence in Africa in 1990, 2000, and 2010 in order to provide information that will help inform the planning of the public health response to the disease.

Methods

We conducted a systematic search of Medline, EMBASE, and Global Health for studies on asthma published between 1990 and 2012. We included cross-sectional population based studies providing numerical estimates on the prevalence of asthma. We calculated weighted mean prevalence and applied an epidemiological model linking age with the prevalence of asthma. The UN population figures for Africa for 1990, 2000, and 2010 were used to estimate the cases of asthma, each for the respective year.

Results

Our search returned 790 studies. We retained 45 studies that met our selection criteria. In Africa in 1990, we estimated 34.1 million asthma cases (12.1%; 95% confidence interval [CI] 7.2-16.9) among children <15 years, 64.9 million (11.8%; 95% CI 7.9-15.8) among people aged <45 years, and 74.4 million (11.7%; 95% CI 8.2-15.3) in the total population. In 2000, we estimated 41.3 million cases (12.9%; 95% CI 8.7-17.0) among children <15 years, 82.4 million (12.5%; 95% CI 5.9-19.1) among people aged <45 years, and 94.8 million (12.0%; 95% CI 5.0-18.8) in the total population. This increased to 49.7 million (13.9%; 95% CI 9.6-18.3) among children <15 years, 102.9 million (13.8%; 95% CI 6.2-21.4) among people aged <45 years, and 119.3 million (12.8%; 95% CI 8.2-17.1) in the total population in 2010. There were no significant differences between asthma prevalence in studies which ascertained cases by written and video questionnaires. Crude prevalences of asthma were, however, consistently higher among urban than rural dwellers.

Conclusion

Our findings suggest an increasing prevalence of asthma in Africa over the past two decades. Due to the paucity of data, we believe that the true prevalence of asthma may still be under-estimated. There is a need for national governments in Africa to consider the implications of this increasing disease burden and to investigate the relative importance of underlying risk factors such as rising urbanization and population aging in their policy and health planning responses to this challenge.

Spirometric reference values in urban children in Madagascar: poverty is a risk factor for low lung function

BACKGROUND

Studies about children with respiratory diseases in Africa are impeded by the dearth of reliable data for the vast majority of countries on the continent. This study was conducted to establish representative reference values, therefore allowing a more accurate evaluation of lung function in Malagasy children.

METHODS

One thousand two hundred thirty-six students from three public and five private schools aged 8-12 years were recruited. A total of 1,093 children were healthy, had a valid lung function measurement and were thus deemed evaluable for this study. Lung function data were collected on consecutive days in Antananarivo, Madagascar's capital, using spirometry and a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire.

RESULTS

The lung volumes found were substantially lower compared to Caucasian and African equations. The mean Z-score (Stanojevic) for the forced vital capacity (FVC) found was -1.45 and -0.93 for the forced expiratory volume in 1 sec (FEV1) with significant differences between private and public schools (FVC: P = 0.0023, FEV1: P = 0.0004).

CONCLUSIONS

The equations established for school children in Madagascar's capital Antananarivo showed lung function values were lower than reference values for the same age group seen not only in European, but also in African American and African children. The unique ethnicity of the Malagasy people, which combines Southeast-Asian with substantial African influences, the heavy burden of pollution and poverty may explain these differences.

Factors associated with asthma among under-fives in Mulago hospital, Kampala Uganda: a cross sectional study

BACKGROUND

Asthma is the most common chronic childhood illness, with rapidly increasing prevalence in low-income countries. Among young children, asthma is often under-diagnosed.We investigated the factors associated with asthma among under-fives presenting with acute respiratory symptoms at Mulago hospital, Uganda.

METHODS

A hospital-based cross sectional study of 614 children with cough and/or difficult breathing, and fast breathing, was conducted between August 2011 and June 2012. A questionnaire focusing on clinical history of the child was administered to the caretakers. A physical examination and, laboratory and radiological investigations were done. Asthma was defined according to GINA (Global Initiative for Asthma) guidelines which were modified by excluding the symptom of "chest tightness", spirometry/peak expiratory flow measurements and by adding chest x-ray findings to distinguish asthma from pneumonia. A panel of three paediatricians reviewed the participants' case reports and, guided by the study definitions, made a diagnosis of asthma or other. Multivariable logistic regression analysis was done to determine factors independently associated with asthma.

RESULTS

Of the 614 children, 128 (20.8%) had asthma, 125 (20.4%) bronchiolitis, 167 (27.2%) bacterial pneumonia only, 163 (26.5%) viral pneumonia while 31 (5.1%) had other diagnoses including pulmonary tuberculosis. The majority (71.1%) of children with asthma were aged ≥ 12 months. Factors associated with asthma included maternal asthma (AOR 2.4, 95% CI 1.2, 4.6), a history of allergy in the patient (AOR 2.6, 95% CI 1.2, 5.4,), use of gas for cooking (AOR 3.8, 95% CI 1.2, 13.3), prematurity (AOR 9.3, 95% CI 1.2, 83.3) and high level of education of caretaker (AOR 9.1, 95% CI 1.1, 72.8).

CONCLUSION

Maternal asthma, a history of allergy in the patient, use of gas for cooking, prematurity and high level of education of caretaker were significantly associated with asthma. There is need for studies to explore the role of the above factors in development and exacerbation of childhood asthma to provide information that can be used to design strategies for asthma prevention and control.