Characterising sources of PM2·5 exposure for school children with asthma: a personal exposure study across six cities in sub-Saharan Africa.

BACKGROUND: Air pollution is the second largest risk to health in Africa, and children with asthma are particularly susceptible to its effects. Yet, there is a scarcity of air pollution exposure data from cities in sub-Saharan Africa. We aimed to identify potential exposure reduction strategies for school children with asthma living in urban areas in sub-Saharan Africa. METHODS: This personal exposure study was part of the Achieving Control of Asthma in Children in Africa (ACACIA) project. Personal exposure to particulate matter (PM) was monitored in school children in six cities in sub-Saharan Africa (Blantyre, Malawi; Durban, South Africa; Harare, Zimbabwe; Kumasi, Ghana; Lagos, Nigeria; and Moshi, Tanzania). Participants were selected if they were aged 12-16 years and had symptoms of asthma. Monitoring was conducted between June 21, and Nov 26, 2021, from Monday morning (approximately 1000 h) to Friday morning (approximately 1000 h), by use of a bespoke backpack with a small air pollution monitoring unit with an inbuilt Global Positioning System (GPS) data logger. Children filled in a questionnaire detailing potential sources of air pollution during monitoring and exposures were tagged into three different microenvironments (school, commute, and home) with GPS coordinates. Mixed-effects models were used to identify the most important determinants of children's PM2·5 (PM <2·5 µm in diameter) exposure. FINDINGS: 330 children were recruited across 43 schools; of these, 297 had valid monitoring data, and 1109 days of valid data were analysed. Only 227 (20%) of 1109 days monitored were lower than the current WHO 24 h PM2·5 exposure health guideline of 15 µg/m3. Children in Blantyre had the highest PM2·5 exposure (median 41·8 µg/m3), whereas children in Durban (16·0 µg/m3) and Kumasi (17·9 µg/m3) recorded the lowest exposures. Children had significantly higher PM2·5 exposures at school than at home in Kumasi (median 19·6 µg/m3vs 14·2 µg/m3), Lagos (32·0 µg/m3vs 18·0 µg/m3), and Moshi (33·1 µg/m3vs 23·6 µg/m3), while children in the other three cities monitored had significantly higher PM2·5 exposures at home and while commuting than at school (median 48·0 µg/m3 and 43·2 µg/m3vs 32·3 µg/m3 in Blantyre, 20·9 µg/m3 and 16·3 µg/m3vs 11·9 µg/m3 in Durban, and 22·7 µg/m3 and 25·4 µg/m3vs 16·4 µg/m3 in Harare). The mixed-effects model highlighted the following determinants for higher PM2·5 exposure: presence of smokers at home (23·0% higher exposure, 95% CI 10·8-36·4), use of coal or wood for cooking (27·1%, 3·9-56·3), and kerosene lamps for lighting (30·2%, 9·1-55·2). By contrast, 37·2% (95% CI 22·9-48·2) lower PM2·5 exposures were found for children who went to schools with paved grounds compared with those whose school grounds were covered with loose dirt. INTERPRETATION: Our study suggests that the most effective changes to reduce PM2·5 exposures in these cities would be to provide paving in school grounds, increase the use of clean fuel for cooking and light in homes, and discourage smoking within homes. The most efficient way to improve air quality in these cities would require tailored interventions to prioritise different exposure-reduction policies in different cities. FUNDING: UK National Institute for Health and Care Research.

Silicosis, tuberculosis and silica exposure among artisanal and small-scale miners: A systematic review and modelling paper.

An estimated 44 million artisanal and small-scale miners (ASM), largely based in developing economies, face significant occupational risks for respiratory diseases which have not been reviewed. We therefore aimed to review studies that describe silicosis and tuberculosis prevalence and respirable crystalline silica (RCS) exposures among ASM and use background evidence to better understand the relationship between exposures and disease outcomes. We searched PubMed, Web of Science, Scopus and Embase for studies published before the 24th March 2023. Our primary outcome of interest was silicosis or tuberculosis among ASM. Secondary outcomes included measurements of respirable dust or silica, spirometry and prevalence of respiratory symptoms. A systematic review and narrative synthesis was performed and risk of bias assessed using the Joanna Briggs Prevalence Critical Appraisal Tool. Logistic and Poisson regression models with predefined parameters were used to estimate silicosis prevalence and tuberculosis incidence at different distributions of cumulative silica exposure. We identified 18 eligible studies that included 29,562 miners from 13 distinct populations in 10 countries. Silicosis prevalence ranged from 11 to 37%, despite four of five studies reporting an average median duration of mining of <6 years. Tuberculosis prevalence was high; microbiologically confirmed disease ranged from 1.8 to 6.1% and clinical disease 3.0 to 17%. Average RCS intensity was very high (range 0.19-89.5 mg/m3) and respiratory symptoms were common. Our modelling demonstrated decreases in cumulative RCS are associated with reductions in silicosis and tuberculosis, with greater reductions at higher mean exposures. Despite potential selection and measurement bias, prevalence of silicosis and tuberculosis were high in the studies identified in this review. Our modelling demonstrated the greatest respiratory health benefits of reducing RCS are in those with highest exposures. ASM face a high occupational respiratory disease burden which can be reduced by low-cost and effective reductions in RCS.

Digital health in the era of COVID-19: Reshaping the next generation of healthcare.

COVID-19 is one of the most deadly diseases to have stricken us in recent decades. In the fight against this disease, governments and stakeholders require all the assistance they can get from various systems, including digital health interventions. Digital health technologies are supporting the tracking of the COVID-19 outbreak, diagnosing patients, expediting the process of finding potential medicines and vaccines, and disinfecting the environment, The establishment of electronic medical and health records, computerized clinical decision support systems, telemedicine, and mobile health have shown the potential to strengthen the healthcare system. Recently, these technologies have aided the health sector in a variety of ways, including prevention, early diagnosis, treatment adherence, medication safety, care coordination, documentation, data management, outbreak tracking, and pandemic surveillance. On the other hand, implementation of such technologies has questions of cost, compatibility with existing systems, disruption in patient-provider interactions, and sustainability, calling for more evidence on clinical utility and economic evaluations to help shape the next generation of healthcare. This paper argues how digital health interventions assist in the fight against COVID-19 and their opportunities, implications, and limitations.

Post tuberculosis chronic lung disease in tuberculosis HIV coinfected and non-HIV individuals in Sub-Saharan Africa: A systematic review and meta-analysis.

Background: Post tuberculosis (TB) sequelae are faced by many individuals who survive TB. The most common of all is post-TB chronic lung disease (CLD) and pulmonary impairment. We reviewed studies that estimated the prevalence of post-TB CLD in patients with TB only and those with TB-HIV coinfection. Methods: Searched Google scholar, PubMed, African journals online, Embase, and Cochrane Central Register of Clinical Trials from the year 2000 to 01 March 2022 for all designs of studies that examined the impact of post on lung impairment or damage. The protocol was registered in PROSPERO, ID: chronic respiratory disease 42022304628. Results: Three hundred and thirty-six studies were identified and five studies were identified through other sources, four were finally in the meta-analysis with a total of 4382 enrolled participants. All the studies had a low risk of bias; The prevalence of CLD between the TB HIV coinfection and those with TB only was of no statistical significance between the three of the four studies - new statement: the prevalence of CLD in the TB-HIV coinfected group when compared to the group of participants with TB only was not statistically significant in the study. This was seen in three of the four studies. One study was in favor of the high prevalence of CLD in HIV coinfection participants (relative risk [RR] = 0.75 [0.61-0.89] with 95% confidence interval [0.61-0.89]). Conclusions: Post-TB lung disease is still a burden that needs advocation and an increase of awareness is necessary from the health-care level to the communities and societies, especially in regions of high prevalence. Development of guidelines for health-care workers to aid the management of individuals, multi-disciplinary advocacy is necessary for those whom prevention is not too late.

Early empiric anti-Mycobacterium tuberculosis therapy for sepsis in sub-Saharan Africa: a protocol of a randomised clinical trial.

INTRODUCTION: Sub-Saharan Africa shoulders the highest burden of global sepsis and associated mortality. In high HIV and tuberculosis (TB) prevalent settings such as sub-Saharan Africa, TB is the leading cause of sepsis. However, anti-TB therapy is often delayed and may not achieve adequate blood concentrations in patients with sepsis. Accordingly, this multisite randomised clinical trial aims to determine whether immediate and/or increased dose anti-TB therapy improves 28-day mortality for participants with HIV and sepsis in Tanzania or Uganda. METHODS AND ANALYSIS: This is a phase 3, multisite, open-label, randomised controlled clinical 2×2 factorial superiority trial of (1) immediate initiation of anti-TB therapy and (2) sepsis-specific dose anti-TB therapy in addition to standard of care antibacterials for adults with HIV and sepsis admitted to hospital in Tanzania or Uganda. The primary endpoint is 28-day mortality. A sample size of 436 participants will provide 80% power for testing each of the main effects of timing and dose on 28-day mortality with a two-sided significance level of 5%. The expected main effect for absolute risk reduction is 13% and the expected OR for risk reduction is 1.58. ETHICS AND DISSEMINATION: This clinical trial will determine the optimal content, dosing and timing of antimicrobial therapy for sepsis in high HIV and TB prevalent settings. The study is funded by the National Institutes of Health in the US. Institutional review board approval was conferred by the University of Virginia, the Tanzania National Institute for Medical Research, and the Uganda National Council for Science and Technology. Study results will be published in peer-reviewed journals and in the popular press of Tanzania and Uganda. We will also present our findings to the Community Advisory Boards that we convened during study preparation. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov (NCT04618198).

Molecular bacterial load assay versus culture for monitoring treatment response in adults with tuberculosis.

The lack of rapid, sensitive, and deployable tuberculosis diagnostic tools is hampering the early diagnosis of tuberculosis and early detection of treatment failures. The conventional sputum smear microscopy or Xpert MTB/RIF assay cannot distinguish between alive and dead bacilli and the culture method delays providing results. Tuberculosis molecular bacterial load assay is a reverse transcriptase real-time quantitative polymerase chain reaction that quantifies viable tuberculosis bacillary load as a marker of treatment response for patients on anti-tuberculosis therapy. However, results are not synthesized enough to inform its comparative advantage to tuberculosis culture technique which is yet the gold standard of care. With this review, we searched electronic databases, including PubMed, Embase, and Web of Science, from March 2011 up to February 2021 for clinical trials or prospective cohort studies that compared tuberculosis molecular bacterial load assay with tuberculosis culture in adults. We included eight studies that meet the inclusion criteria. Tuberculosis molecular bacterial load assay surpasses culture in monitoring patients with tuberculosis during the first few weeks of anti-tuberculosis treatment. It is more desirable over culture for its shorter time to results, almost zero rates of contamination, need for less expertise on the method, early rate of decline, lower running cost, and reproducibility. Its rapid and specific tuberculosis treatment monitoring competency benefits patients and healthcare providers to monitor changes of bacillary load among isolates with drug-susceptible or resistance to anti-tuberculosis regimens. Despite of the high installing cost of the tuberculosis molecular bacterial load assay method, molecular expertise, and a well-equipped laboratory, tuberculosis molecular bacterial load assay is a cost-effective method with comparison to culture in operational running. To achieve maximum utility in high tuberculosis burden settings, an intensive initial investment in nucleic acid extraction and polymerase chain reaction equipment, training in procedures, and streamlining laboratory supply procurement systems are crucial. More evidence is needed to demonstrate the potential large-scale and sustainable use of tuberculosis molecular bacterial load assay over culture in resource-constrained settings.

COVID-19 and Health Sector Development Plans in Africa: The Impact on Maternal and Child Health Outcomes in Uganda.

INTRODUCTION: Health Sector Development Plans (HSDPs) aim to accelerate movement towards achieving sustainable development goals for health, reducing inequalities, and ending poverty. Reproductive, maternal, newborn and child health (RMNCH) services are vulnerable to economic imbalances, including health insecurity, unmet need for healthcare, and low health expenditure. The same vulnerability influences the potential of a country to combat global outbreaks such as the COVID-19. We aimed to provide some important insights into the impacts of COVID-19 on RMNCH indicators and outcomes of the HSDP in Uganda. METHODS: We conducted a descriptive study of secondary data obtained from the Ugandan government-led portals, supplemented by analyses of relevant articles published up to 06 May 2021 and deposited in PubMed. RESULTS: Through synthesizing actionable and relevant evidence, we realized that RMNCH in Uganda is highly affected by the COVID-19 pandemic and the lockdown measures. The impact was across immunization, antenatal, sexual and reproductive health, emergency and obstetric, and postnatal care services. There was a decline sharply by 9.6% for under-five vitamin A coverage, 9% for DPT3HibHeb3 coverage, 6.8% for measles vaccination coverage, 6% for isoniazid preventive therapy coverage, and 3% for facility-based deliveries. Maternal and under-five deaths increased by 7.6% and 4%, respectively. Outreaches were rarely conducted in the lockdown period. CONCLUSION: The COVID-19 pandemic has created a multitude of questions regarding the optimal policies to mitigate the disease while minimizing the unintended detrimental consequences of RMNCH. The lockdown restrictions threatened to reverse the progress made on the national HSDP for RMNCH. In Uganda, where young women are vulnerable to early marriage, unintended pregnancies, and unsafe abortion, access to RMNCH services should continue regardless of the COVID-19 status in the country. We urge that Uganda and other African countries should build resilient and sustainable health systems that can withstand emerging diseases like the COVID-19.

Pharmacodynamic biomarkers for quantifying the mycobacterial effect of high doses of rifampin in patients with rifampin-susceptible pulmonary tuberculosis.

Background: Suboptimal drug exposure in patients with drug-susceptible tuberculosis (DS-TB) can drive treatment failure. Pharmacodynamics (PD) biomarkers such as the plasma TB drug-activity (TDA) assay may guide dose finding studies and predict microbiological outcomes differently than conventional indices. Methods: A study was nested from phase 2b randomized double-blind controlled trial of Tanzanian patients who received a 600 mg, 900 mg, or 1200 mg with a standard dose for DS-TB. Serum at 6 weeks collected over 24-h at 2-h intervals was collected for rifampin area under the concentration-time curve relative to minimum inhibitory concentration (AUC0-24/MIC) or peak concentration and MIC (Cmax/MIC). TDA was the ratio of time-to-positive growth of the patient's Mycobacterium tuberculosis isolates with and without coculture of patient's plasma collected at Cmax. Spearman's rank correlation (r) between PD parameters and culture convention on both liquid and solid culture media. Results: Among 10 patients, 600 mg (3), 900 mg (3), and 1200 mg (4) of rifampin dosages. The mean ± standard deviation (SD) of AUC0-24/MIC for patients on 600 mg was 168 ± 159 mg·h/L, on 900 mg was 169 ± 166 mg·h/L, and on 1200 mg was 308 ± 238 mg·h/L. The mean-TDA (SD) was 2.56 (±0.75), 1.5 (±0.59), and 2.29 (±1.08) for patients on 600 mg, 900 mg, and 1200 mg rifampin doses, respectively. Higher TDA values correlated with faster time to culture convention on both liquid (r = -0.55, P = 0.099) and solid media (r = -0.65, P = 0.04). Conclusions: TDA and rifampin AUC0-24/MIC did not trend as expected with rifampin dose, but TDA better predicted the time to sputum culture conversion. TDA may provide additional discrimination in predicting treatment response for some regimens distinct from plasma exposure relative to MIC or mg/kg dose.

Pyrosequencing for diagnosis of multidrug and extensively drug-resistant tuberculosis: A systemic review and meta-analysis.

BACKGROUND: Multidrug and extensively drug-resistant tuberculosis (M/XDR-TB) pose major threats to global health. Diagnosis accuracy and delay have been the major drivers for the upsurge of M/XDR-TB. Pyrosequencing (PSQ) is a novel, real-time DNA sequencing for rapid detection of mutations associated with M/XDR-TB. We aimed to systematically synthesize the evidence on the diagnostic accuracy of PSQ for M/XDR-TB. METHODS: We conducted an electronic search of PubMed, Embase, Biosis, Web of Science, and Google Scholar up to March 2020. We used the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies) tool to assess the quality of studies, the BRMA (bivariate random-effects meta-analysis) model to synthesize diagnostic accuracies, and the Rev-Man 5.4 software to perform the meta-analyses. We analyzed dichotomous data using the risk ratio (RR) with a 95% confidence interval. PROSPERO Registration ID: CRD42020200817. RESULTS: The analysis included seven studies, with a total sample of 3,165. At 95% confidence interval, the pooled sensitivity and specificity of PSQ were 89.7 (CI: 83.5-93.8) and 97.8 (CI: 94.9-99.1) for Isoniazid, 94.6 (CI: 90.9-96.8) and 98.5 (CI: 96.5-99.3) for Rifampicin, 87.9 (CI: 81.2-92.4) and 98.8 (CI: 97.2-99.5) for Fluoroquinolone, 83.5 (CI: 72.8-90.5) and 99.4 (CI: 98.3-99.8) for Amikacin, 79 (CI: 67-8-87) and 97.9 (CI: 95.5-99) for Capreomycin, and 69.6 (CI: 57-79.8) and 98.2 (CI: 95.9-99.2) for Kanamycin. The overall pooled sensitivity and specificity were 85.8 (CI: 76.7-91.7) and 98.5 (CI: 96.5-99.3), respectively. CONCLUSION: According to the pooled data, PSQ is highly sensitive and specific for detecting M/XDR-TB, both from clinical specimens and culture isolates, and within a shorter turnaround time. We suggest a continued synthesis of the evidence on the cost-effectiveness and technical feasibilities of PSQ in low-income countries context, including sub-Saharan Africa.