Chronic respiratory disease observatory for Africa (CHEST-Africa): study protocol for the prevalence, determinants and economic impacts of asthma and COPD in Africa.

INTRODUCTION: Contemporary data on the burden of chronic respiratory diseases in sub-Saharan Africa is limited. More so, their economic burden is not well described. This study aims to establish a chronic respiratory disease observatory for Africa. Specific study aims are (1) to describe the prevalence and determinants of asthma with a target to screen up to 4000 children and adolescents across four African cities; (2) to determine the prevalence and determinants of chronic obstructive pulmonary disease (COPD) with a target to screen up to 3000 adults (≥18 years) across five African cities; (3) to describe the disease burden by assessing the frequency and severity of symptoms and exacerbations, medication use, emergency healthcare utilisation and hospitalisation; and (4) to assess the economic burden and affordability of the medicines for these diseases. METHODS AND ANALYSIS: Surveys will be conducted in schools to identify children and adolescents with asthma using the Global Asthma Network screening questionnaire in Ghana, Nigeria, the Democratic Republic of Congo, and Uganda. Community surveys will be conducted among adults using an adapted version of the Burden of Obstructive Lung Disease Questionnaire to identify persons with COPD symptoms in Nigeria, Burkina Faso, Mozambique, Rwanda, and Sierra Leone. Fractional exhaled nitric oxide and pre-bronchodilator and post-bronchodilator spirometry will be done for children with asthma or asthma symptoms and for all adult participants. Children and adults with respiratory symptoms or diagnoses will complete the health economic questionnaires. Statistical analysis will involve descriptive and analytical statistics to determine outcomes. ETHICS AND DISSEMINATION: Ethical approval has been obtained from participating institutions. This study's results will inform deliberations at the United Nations General Assembly high-level meeting on non-communicable diseases in 2025. The results will be shared through academic conferences and journals and communicated to the schools and the communities.

Global herpes zoster burden in adults with asthma: a systematic review and meta-analysis.

BACKGROUND: Asthma is a common respiratory disease, which may be associated with an increased risk of herpes zoster (HZ), often a debilitating disease associated with severe pain. This is the first systematic review with the objective of summarising evidence on HZ burden in adults with asthma. METHODS: A global systematic literature review and meta-analysis was conducted (MEDLINE and Embase, 2003-2024) on HZ burden (incidence, risk and complications) in adults (≥18 years) with asthma. RESULTS: There were 19 studies included on HZ outcomes in adults with asthma. Pooled HZ incidence per 1000 person-years was 5.71 (95% CI 4.68-6.96) in adults aged ≥18 years (4.20 (95% CI 3.09-5.70) in those aged <60 years versus 10.33 (95% CI 9.17-11.64) in those aged ≥60 years). The pooled rate ratio for developing HZ was 1.23 (95% CI 1.11-1.35) in those aged ≥18 years and 1.36 (95% CI 1.15-1.61) in those aged ≥50 years. The risk of HZ was higher in people with asthma using systemic corticosteroids, long-acting ß-agonists plus inhaled corticosteroids and "add-on therapy". Asthma was also associated with an increased risk of post-herpetic neuralgia (OR 1.21, 95% CI 1.06-1.37) and HZ ophthalmicus (OR 1.9, 95% CI 1.1-3.2). Differences in study design, setting, case definitions and follow-up durations led to heterogeneity. CONCLUSIONS: This systematic literature review and meta-analysis found that adults with asthma have an increased risk of HZ, with higher risks in older age groups and in those on certain treatments, such as oral corticosteroids. HZ vaccines are available for adults, including those with comorbidities such as asthma, and can be considered as part of integrated respiratory care.

Availability, cost and affordability of essential medicines for chronic respiratory diseases in low-income and middle-income countries: a cross-sectional study.

Contemporary data on the availability, cost and affordability of essential medicines for chronic respiratory diseases (CRDs) across low-income and middle-income countries (LMICs) are missing, despite most people with CRDs living in LMICs. Cross-sectional data for seven CRD medicines in pharmacies, healthcare facilities and central medicine stores were collected from 60 LMICs in 2022-2023. Medicines for symptomatic relief were widely available and affordable, while preventative treatments varied widely in cost, were less available and largely unaffordable. There is an urgent need to address these issues if the Sustainable Development Goal 3 is to be achieved for people with asthma by 2030.

Household Air Pollution Interventions to Improve Health in Low- and Middle-Income Countries: An Official American Thoracic Society Research Statement.

Background: An estimated 3 billion people, largely in low- and middle-income countries, rely on unclean fuels for cooking, heating, and lighting to meet household energy needs. The resulting exposure to household air pollution (HAP) is a leading cause of pneumonia, chronic lung disease, and other adverse health effects. In the last decade, randomized controlled trials of clean cooking interventions to reduce HAP have been conducted. We aim to provide guidance on how to interpret the findings of these trials and how they should inform policy makers and practitioners.Methods: We assembled a multidisciplinary working group of international researchers, public health practitioners, and policymakers with expertise in household air pollution from within academia, the American Thoracic Society, funders, nongovernmental organizations, and global organizations, including the World Bank and the World Health Organization. We performed a literature search, convened four sessions via web conference, and developed consensus conclusions and recommendations via the Delphi method.Results: The committee reached consensus on 14 conclusions and recommendations. Although some trials using cleaner-burning biomass stoves or cleaner-cooking fuels have reduced HAP exposure, the committee was divided (with 55% saying no and 45% saying yes) on whether the studied interventions improved measured health outcomes.Conclusions: HAP is associated with adverse health effects in observational studies. However, it remains unclear which household energy interventions reduce exposure, improve health, can be scaled, and are sustainable. Researchers should engage with policy makers and practitioners working to scale cleaner energy solutions to understand and address their information needs.

Living with Asthma in Low- and Middle-Income Countries in the Six WHO Regions.

Living with AsthmaAsthma is a highly prevalent disease. Although most people with asthma can be treated effectively with certain inhaled medicines, accessing affordable care near their homes is a challenge for many people in low- and middle-income countries. We present stories from six men, women, and children living with asthma in such countries.

Household air pollution and risk of pulmonary tuberculosis in HIV-Infected adults.

BACKGROUND: In low- and middle-income countries countries, millions of deaths occur annually from household air pollution (HAP), pulmonary tuberculosis (PTB), and HIV-infection. However, it is unknown whether HAP influences PTB risk among people living with HIV-infection. METHODS: We conducted a case-control study among 1,277 HIV-infected adults in Bukavu, eastern Democratic Republic of Congo (February 2018 - March 2019). Cases had current or recent (<5y) PTB (positive sputum smear or Xpert MTB/RIF), controls had no PTB. Daily and lifetime HAP exposure were assessed by questionnaire and, in a random sub-sample (n=270), by 24-hour measurements of personal carbon monoxide (CO) at home. We used multivariable logistic regression to examine the associations between HAP and PTB. RESULTS: We recruited 435 cases and 842 controls (median age 41 years, [IQR] 33-50; 76% female). Cases were more likely to be female than male (63% vs 37%). Participants reporting cooking for >3h/day and ≥2 times/day and ≥5 days/week were more likely to have PTB (aOR 1·36; 95%CI 1·06-1·75) than those spending less time in the kitchen. Time-weighted average 24h personal CO exposure was related dose-dependently with the likelihood of having PTB, with aOR 4·64 (95%CI 1·1-20·7) for the highest quintile [12·3-76·2 ppm] compared to the lowest quintile [0·1-1·9 ppm]. CONCLUSION: Time spent cooking and personal CO exposure were independently associated with increased risk of PTB among people living with HIV. Considering the high burden of TB-HIV coinfection in the region, effective interventions are required to decrease HAP exposure caused by cooking with biomass among people living with HIV, especially women.

Prevalence of chronic cough, its risk factors and population attributable risk in the Burden of Obstructive Lung Disease (BOLD) study: a multinational cross-sectional study.

Background: Chronic cough is a common respiratory symptom with an impact on daily activities and quality of life. Global prevalence data are scarce and derive mainly from European and Asian countries and studies with outcomes other than chronic cough. In this study, we aimed to estimate the prevalence of chronic cough across a large number of study sites as well as to identify its main risk factors using a standardised protocol and definition. Methods: We analysed cross-sectional data from 33,983 adults (≥40 years), recruited between Jan 2, 2003 and Dec 26, 2016, in 41 sites (34 countries) from the Burden of Obstructive Lung Disease (BOLD) study. We estimated the prevalence of chronic cough for each site accounting for sampling design. To identify risk factors, we conducted multivariable logistic regression analysis within each site and then pooled estimates using random-effects meta-analysis. We also calculated the population attributable risk (PAR) associated with each of the identifed risk factors. Findings: The prevalence of chronic cough varied from 3% in India (rural Pune) to 24% in the United States of America (Lexington,KY). Chronic cough was more common among females, both current and passive smokers, those working in a dusty job, those with a history of tuberculosis, those who were obese, those with a low level of education and those with hypertension or airflow limitation. The most influential risk factors were current smoking and working in a dusty job. Interpretation: Our findings suggested that the prevalence of chronic cough varies widely across sites in different world regions. Cigarette smoking and exposure to dust in the workplace are its major risk factors. Funding: Wellcome Trust.

Screening for post-TB lung disease at TB treatment completion: Are symptoms sufficient?

Pulmonary TB survivors face a high burden of post-TB lung disease (PTLD) after TB treatment completion. In this secondary data analysis we investigate the performance of parameters measured at TB treatment completion in predicting morbidity over the subsequent year, to inform programmatic approaches to PTLD screening in low-resource settings. Cohort data from urban Blantyre, Malawi were used to construct regression models for five morbidity outcomes (chronic respiratory symptoms or functional limitation, ongoing health seeking, spirometry decline, self-reported financial impact of TB disease, and death) in the year after PTB treatment, using three modelling approaches: logistic regression; penalised regression with pre-selected predictors; elastic net penalised regression using the full parent dataset. Predictors included demographic, clinical, symptom, spirometry and chest x-ray variables. The predictive performance of models were examined using the area under the receiver-operator curve (ROC AUC) values. Key predictors were identified, and their positive and negative predictive values (NPV) determined. The presence of respiratory symptoms at TB treatment completion was the strongest predictor of morbidity outcomes. TB survivors reporting breathlessness had higher odds of spirometry decline (aOR 20.5, 95%CI:3-199.1), health seeking (aOR 10.2, 2.4-50), and symptoms or functional limitation at 1-year (aOR 16.7, 3.3-133.4). Those reporting activity limitation were more likely to report symptoms or functional limitation at 1-year (aOR 4.2, 1.8-10.3), or severe financial impact of TB disease (aOR2.3, 1.0-5.0). Models were not significantly improved by including spirometry or imaging parameters. ROC AUCs were between 0.65-0.77 for the morbidity outcomes. Activity limitation at treatment completion had a NPV value of 78-98% for adverse outcomes. Our data suggest that whilst challenging to predict the development of post-TB morbidity, the use of symptom screening tools at TB treatment completion to prioritise post-TB care should be explored. We identified little benefit from the additional use of spirometry or CXR imaging.