B cell, CD8 + T cell and gamma delta T cell infiltration alters alveolar immune cell homeostasis in HIV-infected Malawian adults

Background: HIV infection is associated with increased risk to lower respiratory tract infections (LRTI). However, the impact of HIV infection on immune cell populations in the lung is not well defined. We sought to comprehensively characterise the impact of HIV infection on immune cell populations in the lung. Methods: Twenty HIV-uninfected controls and 17 HIV-1 infected ART-naïve adults were recruited from Queen Elizabeth Central Hospital, Malawi. Immunophenotyping of lymphocyte and myeloid cell populations was done on bronchoalveolar lavage fluid and peripheral blood cells. Results: We found that the numbers of CD8 + T cells, B cells and gamma delta T cells were higher in BAL fluid of HIV-infected adults compared to HIV-uninfected controls (all p<0.05). In contrast, there was no difference in the numbers of alveolar CD4 + T cells in HIV-infected adults compared to HIV-uninfected controls (p=0.7065). Intermediate monocytes were the predominant monocyte subset in BAL fluid (HIV-, 63%; HIV+ 81%), while the numbers of classical monocytes was lower in HIV-infected individuals compared to HIV-uninfected adults (1 × 10 5 vs. 2.8 × 10 5 cells/100ml of BAL fluid, p=0.0001). The proportions of alveolar macrophages and myeloid dendritic cells was lower in HIV-infected adults compared to HIV-uninfected controls (all p<0.05). Conclusions: Chronic HIV infection is associated with broad alteration of immune cell populations in the lung, but does not lead to massive depletion of alveolar CD4 + T cells. Disruption of alveolar immune cell homeostasis likely explains in part the susceptibility for LRTIs in HIV-infected adults.

Airway CD8+CD161++TCRvα7.2+ T Cell Depletion During Untreated HIV Infection Targets CD103 Expressing Cells

HIV-infected adults are at an increased risk to lower respiratory tract infections (LRTIs). CD8⁺CD161⁺⁺TCRvα7.2⁺ T cells are an innate-like T cell subset that are thought to play an important role in early defense against pathogens in the respiratory tract. HIV infection leads to irreversible depletion of these cells in peripheral blood, however, its impact on this subset in the human airway is still unclear. Here, we show presence of CD103 expressing CD8⁺CD161⁺⁺TCRvα7.2⁺ T cells in the airway that exhibited a distinct cytokine functional profile compared to their CD103^- airway counterparts and those from peripheral blood. These CD103 expressing airway CD8⁺CD161⁺⁺TCRvα7.2⁺ T cells were selectively depleted in untreated HIV-infected adults compared to healthy controls. Their frequency was positively correlated with frequency of airway CD4⁺ T cells. Furthermore, the frequency of airway CD8⁺CD161⁺⁺TCRvα7.2⁺ T cells was also inversely correlated with HIV plasma viral load, while suppressive antiretroviral therapy (ART) resulted in restoration of airway CD8⁺CD161⁺⁺TCRvα7.2⁺ T cells. Our findings show that CD103 expressing airway CD8⁺CD161⁺⁺TCRvα7.2⁺ T cells are functionally distinct and are preferentially depleted during untreated asymptomatic HIV infection. Depletion of CD103 expressing airway CD8⁺CD161⁺⁺TCRvα7.2⁺ T cells, at a major portal of pathogen entry, could partly contribute to the increased propensity for opportunistic LRTIs observed in untreated HIV-infected adults.

Intracellular survival of Streptococcus pneumoniae in human alveolar macrophages is augmented with HIV infection

People Living with HIV (PLHIV) are at an increased risk of pneumococcal pneumonia than HIV-uninfected adults, but the reasons for this are still not well understood. We investigated whether alveolar macrophages (AM) mediated control of pneumococcal infection is impaired in PLHIV compared to HIV-uninfected adults. We assessed anti-bactericidal activity against Streptococcus pneumoniae of primary human AM obtained from PLHIV and HIV-uninfected adults. We found that pneumococcus survived intracellularly in AMs at least 24 hours post ex vivo infection, and this was more frequent in PLHIV than HIV-uninfected adults. Corroborating these findings, in vivo evidence showed that PLHIV had a higher propensity for harboring S. pneumoniae within their AMs than HIV-uninfected adults. Moreover, bacterial intracellular survival in AMs was associated with extracellular propagation of pneumococcal infection. Our data suggest that failure of AMs to eliminate S. pneumoniae intracellularly could contribute to the increased risk of pneumococcal pneumonia in PLHIV.

B cell, CD8 + T cell and gamma delta T cell infiltration alters alveolar immune cell homeostasis in HIV-infected Malawian adults

Background: HIV infection is associated with increased risk to lower respiratory tract infections (LRTI). However, the impact of HIV infection on immune cell populations in the lung is not well defined. We sought to comprehensively characterise the impact of HIV infection on immune cell populations in the lung. Methods: Twenty HIV-uninfected controls and 17 HIV-1 infected ART-naïve adults were recruited from Queen Elizabeth Central Hospital, Malawi. Immunophenotyping of lymphocyte and myeloid cell populations was done on bronchoalveolar lavage fluid and peripheral blood cells. Results: We found that the numbers of CD8 + T cells, B cells and gamma delta T cells were higher in BAL fluid of HIV-infected adults compared to HIV-uninfected controls (all p<0.05). In contrast, there was no difference in the numbers of alveolar CD4 + T cells in HIV-infected adults compared to HIV-uninfected controls (p=0.7065). Intermediate monocytes were the predominant monocyte subset in BAL fluid (HIV-, 63%; HIV+ 81%), while the numbers of classical monocytes was lower in HIV-infected individuals compared to HIV-uninfected adults (1 × 10 5 vs. 2.8 × 10 5 cells/100ml of BAL fluid, p=0.0001). The proportions of alveolar macrophages and myeloid dendritic cells was lower in HIV-infected adults compared to HIV-uninfected controls (all p<0.05). Conclusions: Chronic HIV infection is associated with broad alteration of immune cell populations in the lung, but does not lead to massive depletion of alveolar CD4 + T cells. Disruption of alveolar immune cell homeostasis likely explains in part the susceptibility for LRTIs in HIV-infected adults.

B cell, CD8 + T cell and gamma delta T cell lymphocytic alveolitis alters alveolar immune cell homeostasis in HIV-infected Malawian adults

Background: HIV infection is associated with increased risk to lower respiratory tract infections (LRTI). However, the impact of HIV infection on immune cell populations in the lung is not well defined. We sought to comprehensively characterise the impact of HIV infection on immune cell populations in the lung. Methods: Twenty HIV-uninfected controls and 17 HIV-1 infected ART-naïve adults were recruited from Queen Elizabeth Central Hospital, Malawi. Immunophenotyping of lymphocyte and myeloid cell populations was done on bronchoalveolar lavage fluid and peripheral blood cells. Results: We found that the numbers of CD8 + T cells, B cells and gamma delta T cells were higher in BAL fluid of HIV-infected adults compared to HIV-uninfected controls (all p<0.05). In contrast, there was no difference in the numbers of alveolar CD4 + T cells in HIV-infected adults compared to HIV-uninfected controls (p=0.7065). Intermediate monocytes were the predominant monocyte subset in BAL fluid (HIV-, 63%; HIV+ 81%), while the numbers of classical monocytes was lower in HIV-infected individuals compared to HIV-uninfected adults (p=0.0006). The proportions of alveolar macrophages and myeloid dendritic cells was lower in HIV-infected adults compared to HIV-uninfected controls (all p<0.05). Conclusions: Chronic HIV infection is associated with broad alteration of immune cell populations in the lung, but does not lead to massive depletion of alveolar CD4 + T cells. Disruption of alveolar immune cell homeostasis likely explains in part the susceptibility for LRTIs in HIV-infected adults.

Energy Logistic Regression and Survival Model: Case Study of Russian Exports

The importance of environmental sustainability is becoming more and more obvious, so the rationale behind long-term usage of solely non-renewable energy sources appeared questionable. This study aims to identify, using Kaplan-Meier survival analysis and logistic regressions, the main determinants that affect the duration of Russian non-renewable energy exports to different regions of the world. Data were retrieved from the databanks of the World Development Indicators (WDI), World Integrated Trade Solution (WITS), and the French Centre for Prospective studies and International Information (CEPII). The obtained results point to the fact that approximately 52% of energy products survive beyond their first year of trading, nearly 38% survive beyond the second year, and almost 18% survive to the twelfth year. The survival of Russian non-renewable energy exports differs depending on the region, and the affecting factors are of different importance. The duration of Russian non-renewable energy exports is significantly linked to Russia's GDP, Total export, and Initial export values. A decline in Russia's GDP by 1% is associated with an increasing probability of a spell ending by 2.9% on average, in turn growing Total export and Initial export values positively linked with the duration of non-renewable energy exports from Russia. These findings may have practical relevance for strategic actions aimed at approaching both energy security and environmental sustainability.

Services as a Determinant of Botswana's Economic Sustainability

In 2015, the services sector contributed about 58 percent to the gross domestic product (GDP) in Sub-Saharan Africa (SSA), which was a significant increase from the 47.6 percent observed in 2005, and a shift from the mining, agriculture, and manufacturing sector. This increase calls to support services as the catalyst for sustained economic development as indicated by the structural transformation and modernization theories. The main objective of this paper was to examine the relationship between and the impact of services on the economic development in Botswana and make recommendations on how Botswana can apply well-directed policies to improve its services sector and diversify its impact on other sectors and GDP, making it less reliant on mining which is vulnerable to price volatilities. The paper applied econometric modeling and results of the Autoregressive-Distributed Lag (ARDL) Bounds test for cointegration indicate that services and other industries services, agriculture, industry, mining, and investment impact GDP over the short and long run. These variables impacted GDP and converged to equilibrium at the speed of 46.89 percent, with a percent change in services in the short and long run impacting GDP by 0.328 and 0.241 percentages, respectively, and the outcome of the Wald test indicated causality from services to GDP growth. The services sectors have contributed over 40 percent to the country's GDP from 1995 to the present, though the sectors have not gone without challenges with limitations such as limited infrastructure development; poverty and inequality; unemployment of over 20 percent; disease, which has dampened productivity; and lack of proper governance and accountability, which has created a habitat for an increase in cases of corruption in state and private entities. The findings of the study with the lessons learned from other studies with similar findings recommend that the government of Botswana should formulate suitable policies and strategies for services diversification. This is by expanding the market for the sector in areas such as tourism that were impacted by the COVID-19 pandemic, escalating investments by instituting strategies to attract and grow domestic and foreign investments, and improve on management of institutions and resources.

Experimental pneumococcal carriage in people living with HIV in Malawi: the first controlled human infection model in a key at-risk population

Background: As well as suffering a high burden of pneumococcal disease people living with HIV (PLHIV) may contribute to community transmission in sub-Saharan African (sSA) settings. Pneumococcal vaccination is not currently offered to PLHIV in sSA but may prevent disease and reduce transmission. More evidence of vaccine effectiveness against carriage in PLHIV is needed. An Experimental Human Pneumococcal Carriage model (EHPC) has been safely and acceptably used in healthy adults in Malawi to evaluate pneumococcal vaccines against carriage and to identify immune correlates of protection from carriage. This study will establish the same model in PLHIV and will be the first controlled human infection model (CHIM) in this key population. Methods: Healthy participants with and without HIV will be inoculated intranasally with Streptococcus pneumoniae serotype 6B. Sequential cohorts will be challenged with increasing doses to determine the optimal safe challenge dose to establish experimental carriage. Nasal fluid, nasal mucosal, and blood samples will be taken before inoculation and on days 2, 7, 14, and 21 following inoculation to measure pneumococcal carriage density and identify immune correlates of protection from carriage. The vast majority of natural pneumococcal carriage events in PLHIV do not result in invasive disease and no invasive disease is expected in this study. However, robust participant safety monitoring is designed to identify signs of invasive disease early should they develop, and to implement treatment immediately. Participants will complete a Likert-style questionnaire at study-end to establish acceptability. Interpretations: We expect the EHPC model to be safely and acceptably implemented in PLHIV. The CHIM can then be used to accelerate pneumococcal vaccine evaluations in this population, and an evidence-based pneumococcal vaccination policy for PLHIV in sSA.

Impact of macroeconomic indicators and regime change on debt stress in Zambia

This paper quantifies the economic impact of regime changes and macroeconomic indicators on debt stress in Zambia using the Autoregressive Distributed Lag (ARDL) Bounds test. A 1% short run increase in gross domestic products (GDP) increases debt stress by 3.16% and in the subsequent year lowers it by 7.21%; in the long-run the 1% GDP increases lowers debt stress by 22%. In the long-run, a 1% rise in inflation and the lending rate negatively and positively impacted debt stress levels by -1.52% and 3.90%, respectively. Short-run shocks culminated regime change had short-run adverse impact on debt stress by 3.45% in one year and in the subsequent year by -10.35%, with the variables adjusting to long-run equilibrium at a speed of 71.5%. This is the first paper to quantify the empirical effect of macroeconomic indicators and change in Presidents on debt stress, especially in Africa were the problem of the debt trap is perpetuated. The results from the study implies that to deescalate the impact of debt stress on the economy, the electorate should vote in governments that will not fall short on growth driven macroeconomic policies, making it possible for economic sustainability to prevail; and paper seeks to promote good governance and good economic policies as a premise for sustained macroeconomic stability and development.

Geopolitical risks for Egypt wheat supply and trade

Introduction

Since 2005, Russia has established a stable position in Egypt's wheat imports, and after 2016, it became the largest global wheat exporter. The shift in Russian grain production has visibly affected wheat export destinations in favor of developing countries. This paper identifies the main determinants of wheat trade in Egypt concerning the primary risks associated with the war in Ukraine.

Methods

The paper utilizes time series analysis, index analysis, and an econometric model to define the statistical relationship between the quantity of wheat imported into Egypt and population development, wheat price, and wheat production.

Results

Despite increasing wheat production growth rates (1.9% p.a. over 2000–2020) and a growing population (2.01% p.a.), Egypt is unable to reduce its import dependence below 50% of total consumption. Undernourishment in Egypt remains at 5.2%–5.4% of the population. The econometric model shows that variables describing the evolution of production, population, and prices are statistically significant in relation to wheat imports. Egypt's wheat imports continue to increase even with rising prices, which is typical for developing countries. The war in Ukraine and associated commodity price increases have far-reaching implications for Africa's food security and supply systems.

Discussion

Egypt's vulnerability to external influences, such as climate change, migration, rising commodity prices, and population growth, exacerbates the situation. Most African countries, including Egypt, struggle with the economic and social impacts of the COVID-19 pandemic. They also face rising food and energy prices, conflicts between the world's largest food producers, and increasing poverty rates. The research findings confirm that Egypt is among the highly vulnerable countries due to the war in Ukraine and the disruption of agricultural supply chains.

Spatially resolved single-cell atlas unveils a distinct cellular signature of fatal lung COVID-19 in a Malawian population

Postmortem single-cell studies have transformed understanding of lower respiratory tract diseases (LRTDs), including coronavirus disease 2019 (COVID-19), but there are minimal data from African settings where HIV, malaria and other environmental exposures may affect disease pathobiology and treatment targets. In this study, we used histology and high-dimensional imaging to characterize fatal lung disease in Malawian adults with (n = 9) and without (n = 7) COVID-19, and we generated single-cell transcriptomics data from lung, blood and nasal cells. Data integration with other cohorts showed a conserved COVID-19 histopathological signature, driven by contrasting immune and inflammatory mechanisms: in US, European and Asian cohorts, by type I/III interferon (IFN) responses, particularly in blood-derived monocytes, and in the Malawian cohort, by response to IFN-γ in lung-resident macrophages. HIV status had minimal impact on histology or immunopathology. Our study provides a data resource and highlights the importance of studying the cellular mechanisms of disease in underrepresented populations, indicating shared and distinct targets for treatment.

Estimating pneumococcal carriage dynamics in adults living with HIV in a mature infant pneumococcal conjugate vaccine programme in Malawi, a modelling study

BACKGROUND

Adults living with human immunodeficiency virus (ALWHIV) receiving antiretroviral therapy (ART) exhibit higher pneumococcal carriage prevalence than adults without HIV (HIV-). To assess factors influencing high pneumococcal carriage in ALWHIV, we estimated pneumococcal carriage acquisition and clearance rates in a high transmission and disease-burdened setting at least 10 years after introducing infant PCV13 in routine immunisation.

METHODS

We collected longitudinal nasopharyngeal swabs from individuals aged 18-45 in Blantyre, Malawi. The study group included both HIV- individuals and those living with HIV, categorised based on ART duration as either exceeding 1 year (ART > 1y) or less than 3 months (ART < 3 m). Samples were collected at baseline and then weekly for 16 visits. To detect pneumococcal carriage, we used classical culture microbiology, and to determine pneumococcal serotypes, we used latex agglutination. We modelled trajectories of serotype colonisation using multi-state Markov models to capture pneumococcal carriage dynamics, adjusting for age, sex, number of under 5 year old (< 5y) children, social economic status (SES), and seasonality.

RESULTS

We enrolled 195 adults, 65 adults in each of the study groups. 51.8% were females, 25.6% lived with more than one child under 5 years old, and 41.6% lived in low socioeconomic areas. The median age was 33 years (IQR 25-37 years). The baseline pneumococcal carriage prevalence of all serotypes was 31.3%, with non-PCV13 serotypes (NVT) at 26.2% and PCV13 serotypes (VT) at 5.1%. In a multivariate longitudinal analysis, pneumococcal carriage acquisition was higher in females than males (hazard ratio [HR], NVT [1.53]; VT [1.96]). It was also higher in low than high SES (NVT [1.38]; VT [2.06]), in adults living with 2 + than 1 child < 5y (VT [1.78]), and in ALWHIV on ART > 1y than HIV- adults (NVT [1.43]). Moreover, ALWHIV on ART > 1y cleared pneumococci slower than HIV- adults ([0.65]). Residual VT 19F and 3 were highly acquired, although NVT remained dominant.

CONCLUSIONS

The disproportionately high point prevalence of pneumococcal carriage in ALWHIV on ART > 1y is likely due to impaired nasopharyngeal clearance, which results in prolonged carriage. Our findings provide baseline estimates for comparing pneumococcal carriage dynamics after implementing new PCV strategies in ALWHIV.

Ensuring food sovereignty and nutritional sustainability in Egypt

Understanding Egypt's dependence on wheat imports is crucial for enhancing food security and economic stability. This study aims to identify the extent of Egypt's wheat import dependency and recommend measures for increasing food self-sufficiency. We employed index analysis and an econometric model to analyze data sourced from the Food and Agriculture Organization (FAO), Observatory of Economic Complexity (OEC), Chicago Mercantile Exchange (CME), World Bank (WB), and Organisation for Economic Co-operation and Development (OECD). Quantitative and qualitative indicators of wheat production and consumption were examined. Key findings include that Egypt's food insecurity levels remain unchanged, and the country faces threats from rising global food prices, low-quality agricultural land, and climate change, which is expected to reduce cereal yields by 6-15 %. Econometric analysis revealed that a 1 % increase in population growth and protein intake results in a 1.09 % and 3.63 % increase in wheat imports, respectively, while a 1 % increase in wheat consumption leads to a 0.87 % decrease in wheat imports. These findings suggest the need for Egypt to diversify its agriculture by adopting less water-intensive crops and improving irrigation efficiency. Future research should explore non-linear models, recent data, and qualitative factors to build on these insights and further inform policy development.

Effect of a mother-baby delivery pack on institutional deliveries: A community intervention trial to address maternal mortality in rural Zambia

OBJECTIVES

To test the effect of providing additional health education during antenatal care (ANC) and a mother-baby delivery pack on institutional deliveries in Monze, Zambia.

SETTING

16 primary health facilities conducting deliveries in the district.

PARTICIPANT

A total of 5000 pregnant women at any gestation and age attending antenatal care (ANC) services in selected health facilities were eligible for enrolment into the study. Out of these, 4,500 (90%) were enrolled into and completed the study. A total of 3,882 (77.6%) were included in the analysis; 12.4% were not included in the analysis due to incomplete data.

INTERVENTION

A three-year study (2012 to 2014) analysing baseline delivery data for 2012 and 2013 followed by a community intervention trial was conducted from January to December 2014. Health facilities on the western side were assigned to the intervention arm; those on the eastern side were in the control. In addition to the health education provided during routine ANC visits, participants in the intervention arm received health education and a mother-baby delivery pack when they arrived at the health facility for delivery. Participants in the control arm continued with routine ANC services.

OUTCOME MEASURES

The primary measure was the number of institutional deliveries in both arms over the one-year period. Secondary measures were utilisation of ANC, post-natal care (PNC) and under-five clinic services. Descriptive statistics (frequencies, proportions, means and standard deviation) were computed to summarise participant characteristics. Chi-square and Independent T-tests were used to make comparisons between the two arms. One way analysis of variance (ANOVA) was used to test the effect of the intervention after one year (p-value<0.05). Analysis was conducted using R-studio statistical software version 4.2.1. The p-value<0.05 was considered significant.

RESULTS

Analysis showed a 15.9% increase in the number of institutional deliveries and a significant difference in the mean number of deliveries between intervention and control arms after one year (F(1,46) = 18.85, p<0.001). Post hoc analysis showed a significant difference in the mean number of deliveries between the intervention and control arms for 2014 (p<0.001). Compared to the control arm, participants in the intervention arm returned earlier for PNC clinic visit, brought their children back and started the under-five clinic visits earlier.

CONCLUSION

These findings provide evidence for the effectiveness of the mother-baby delivery pack and additional health education sessions on increasing institutional deliveries, PNC and under-five children's clinic utilisation in rural Zambia.

TRIAL REGISTRATION

ISRCTN Registry (ISRCTN15439813 DOI 10.1186/ISRCTN15439813); Pan African Clinical Trial Registry (PACTR202212611709509).