Assessing Marginal Effects of Non-Pharmaceutical Interventions on the Transmission of SARS-CoV-2 across Africa: A Hybrid Modeling Study.

Since 2019, a new strain of coronavirus has challenged global health systems. Due its fragile healthcare systems, Africa was predicted to be the most affected continent. However, past experiences of African countries with epidemics and other factors, including actions taken by governments, have contributed to reducing the spread of SARS-CoV-2. This study aims to assess the marginal impact of non-pharmaceutical interventions in fifteen African countries during the pre-vaccination period. To describe the transmission dynamics and control of SARS-CoV-2 spread, an extended time-dependent SEIR model was used. The transmission rate of each infectious stage was obtained using a logistic model with NPI intensity as a covariate. The results revealed that the effects of NPIs varied between countries. Overall, restrictive measures related to assembly had, in most countries, the largest reducing effects on the pre-symptomatic and mild transmission, while the transmission by severe individuals is influenced by privacy measures (more than 10%). Countries should develop efficient alternatives to assembly restrictions to preserve the economic sector. This involves, e.g. training in digital tools and strengthening digital infrastructures.

Assessing the Impact of Vaccination on the Dynamics of COVID-19 in Africa: A Mathematical Modeling Study.

Several effective COVID-19 vaccines are administered to combat the COVID-19 pandemic globally. In most African countries, there is a comparatively limited deployment of vaccination programs. In this work, we develop a mathematical compartmental model to assess the impact of vaccination programs on curtailing the burden of COVID-19 in eight African countries considering SARS-CoV-2 cumulative case data for each country for the third wave of the COVID-19 pandemic. The model stratifies the total population into two subgroups based on individual vaccination status. We use the detection and death rates ratios between vaccinated and unvaccinated individuals to quantify the vaccine's effectiveness in reducing new COVID-19 infections and death, respectively. Additionally, we perform a numerical sensitivity analysis to assess the combined impact of vaccination and reduction in the SARS-CoV-2 transmission due to control measures on the control reproduction number (Rc). Our results reveal that on average, at least 60% of the population in each considered African country should be vaccinated to curtail the pandemic (lower the Rc below one). Moreover, lower values of Rc are possible even when there is a low (10%) or moderate (30%) reduction in the SARS-CoV-2 transmission rate due to NPIs. Combining vaccination programs with various levels of reduction in the transmission rate due to NPI aids in curtailing the pandemic. Additionally, this study shows that vaccination significantly reduces the severity of the disease and death rates despite low efficacy against COVID-19 infections. The African governments need to design vaccination strategies that increase vaccine uptake, such as an incentive-based approach.

Traditional knowledge on herbal drinks among indigenous communities in Azad Jammu and Kashmir, Pakistan.

BACKGROUND: Traditional knowledge about the use of medicinal plants for herbal drinks (HDs) is not well documented in the Azad Kashmir region despite their widespread use. This study highlights the taxonomic diversity and traditional knowledge on medicinal plants used for HDs while examining the diversity of diseases treated with HDs in the study area. METHODS: Individual discussions were conducted with 255 informants (84 women and 171 men). Data gathered included (i) informant age and gender, (ii) HD species and respective plant parts used, (iii) health disorders treated, and (iv) mode of preparation and utilizations. Quantitative ethnobotanical indices including relative frequency of citation (RFC), informant consensus factor (ICF), and use value (UV) were used for data analyses. RESULTS: Altogether, 73 medicinal plants belonging to 40 families and 66 genera were reported to be used in HD preparations, with Asteraceae being the richest family. The average number of HD species cited was 9.09 ± 0.17 per informant and did not vary either by age or gender. In addition, men and women, and adults and the young used the same pool of species (dissimilarity nearly zero). The most used plant parts were leaves (20.00%), roots (17.25%), and fruits (16.47%). Based on UV, the top five most used species were Valeriana jatamansi, Isodon rugosus, Onopordum acanthium, Acacia nilotica, and Viola canescens; and the UV was similar among gender and age categories too. The most utilized herbal preparation forms included decoctions, infusions, and tea. One hundred and eleven diseases grouped into 13 ailment categories were reported to be cured using HDs. The main category of disease treated with HDs was gastrointestinal (GIT) disorders (RFC = 17.43%). Relatively few species were used by a large proportion of informants for each category of ailment (ICF ≥ 0.60). Only one species was used for "glandular disorders" and "eye diseases" (ICF = 1). A novelty of about 22% (16 species) was recorded for HD species in the present work. CONCLUSION: The diversity of medicinal plant species used as HDs and the associated traditional knowledge are of considerable value to the indigenous communities of the Azad Kashmir region. Therefore, there is a need for conservation and preservation of medicinal HD species as well as the wealth of indigenous knowledge. The conservation effort should be high for species in the ailments categories glandular disorders and eye diseases. The therapeutic uses of HDs have provided basic data for further research focused on phytochemical and pharmacological studies and conservation of the most important species.

Functional diversity of home gardens and their agrobiodiversity conservation benefits in Benin, West Africa.

BACKGROUND: Understanding the functional diversity of home gardens and their socio-ecological determinants is essential for mainstreaming these agroforestry practices into agrobiodiversity conservation strategies. This paper analyzed functional diversity of home gardens, identified the socio-ecological drivers of functions assigned to them, and assessed the agrobiodiversity benefits of home gardens functions. METHODS: Using data on occurring species in home garden (HG) and functions assigned to each species by the gardeners, the study combined clustering and discriminant canonical analyses to explore the functional diversity of 360 home gardens in Benin, West Africa. Next, multinomial logistic models and chi-square tests were used to analyze the effect of socio-demographic characteristics of gardeners (age, gender, and education level), agro-ecological zones (humid, sub-humid, and semi-arid), and management regime (single and multiple managers) on the possession of a functional type of home gardens. Generalized linear models were used to assess the effect of the functions of home gardens and the determinant factor on their potential in conserving agrobiodiversity. RESULTS: Seven functional groups of home gardens, four with specific functions (food, medicinal, or both food and medicinal) and three with multiple functions (more than two main functions), were found. Women owned most of home gardens with primarily food plant production purpose while men owned most of home gardens with primarily medicinal plant production purposes. Finding also showed that multifunctional home gardens had higher plant species diversity. Specifically, crops and crop wild relatives occurred mainly in home gardens with food function while wild plant species were mostly found in home gardens with mainly medicinal function. CONCLUSIONS: Home gardening is driven by functions beyond food production. These functions are mostly related to direct and extractive values of home gardens. Functions of home gardens were gendered, with women mostly involved in home food gardens, and contribute to maintenance of crops and crop wild relatives while men were mostly home medicinal gardeners and contribute to the maintenance of wild plant species in home gardens. Although multiple functional home gardens were related to higher plant diversity, there was no guarantee for long-term maintenance of plant species in home gardens.

Factors affecting home gardens ownership, diversity and structure: a case study from Benin.

BACKGROUND: Home gardens (HGs) provide perspectives for conservation of plant genetic resources while contributing to improving livelihoods. However, knowledge of local factors shaping their ownership, plant diversity (PD) and structure is still limited especially in West-Africa, where food insecurity is acute. This is critical to ensure effective mainstreaming of HGs into future biodiversity conservation and food production policies. METHODS: Socio-economic and PD data were obtained from individual interviews (n = 470) and gardens inventories (n = 235) spanning humid, sub-humid and semi-arid zones of Benin. Generalised Linear Models, Hierarchical Cluster Analysis, Principal Component Analysis and Simple Correspondence Analysis were performed to examine socio-economic characteristics (age, gender, education level and main economic activity) affecting HGs ownership, and their effect coupled with intrinsic HGs characteristics (size, age) on PD and structure within HGs, across contrasting bio-geographical regions. RESULTS: HG ownership was significantly dependent upon a complex relationship between age, gender and education level of the farmers. The probability to own HG increased with age with an early involvement in home gardening for women. Similarly, with increasing age, it was more likely to find a male owner than a female owner among the uneducated informants and those of primary school. Inversely, it was more likely to find female owner than a male owner among secondary school level or more. PD increased with increasing owner age and size of the HG. Larger and more diversified HGs were found in sub-humid and semi-arid zones while smaller and less diversified HGs were encountered in the humid zone. HGs were multi-layered. Based on the prevailing plant groups, three categories of HG were distinguished: Herb based gardens, Herb and Shrub/Trees based gardens, and Palm and Liana based gardens. Their prevalence was dependent upon bio-geographical zones and HG owner socio-economic characteristics, with herbs based HGs being mainly associated to women. CONCLUSION: Results suggest effects of complex interactions between socio-economic factors on HG ownership, and influence of these effects combined with intrinsic characteristics of HGs on PD. The early involvement of women in home gardening and their particular interest in herbs and shrubs are important assets for future conservation strategies based on HG and food production. Interventions are required to interfere with declining PD in HG across generations to accommodate multiple ecosystem service benefits.