Access to Risk Mitigating Weather Forecasts and Changes in Farming Operations in East and West Africa: Evidence from a Baseline Survey

BackgroundThe HIV-1 epidemic in sub-Saharan Africa is heterogeneous with diverse unevenly distributed subtypes and regional differences in prevalence. Subtype-specific differences in disease progression rate and transmission efficiency have been reported, but the underlying biological mechanisms have not been fully characterized. Here, we tested the hypothesis that the subtypes prevalent in the East Africa, where adult prevalence rate is higher, have lower viral replication capacity (VRC) than their West African counterparts where adult prevalence rates are lower.ResultsGag-protease sequencing was performed on 213 and 160 antiretroviral-naïve chronically infected participants from West and East Africa respectively and bioinformatic tools were used to infer subtypes and recombination patterns. VRC of patient-derived gag-protease chimeric viruses from West (n = 178) and East (n = 114) Africa were determined using a green fluorescent protein reporter-based cell assay. Subtype and regional differences in VRC and amino acid variants impacting VRC were identified by statistical methods. CRF02_AG (65%, n = 139), other recombinants (14%, n = 30) and pure subtypes (21%, n = 44) were identified in West Africa. Subtypes A1 (64%, n = 103), D (22%, n = 35), or recombinants (14%, n = 22) were identified in East Africa. Viruses from West Africa had significantly higher VRC compared to those from East Africa (p < 0.0001), with subtype-specific differences found among strains within West and East Africa (p < 0.0001). Recombination patterns showed a preference for subtypes D, G or J rather than subtype A in the p6 region of gag, with evidence that subtype-specific differences in this region impact VRC. Furthermore, the Gag A83V polymorphism was associated with reduced VRC in CRF02_AG. HLA-A*23:01 (p = 0.0014) and HLA-C*07:01 (p = 0.002) were associated with lower VRC in subtype A infected individuals from East Africa.ConclusionsAlthough prevalent viruses from West Africa displayed higher VRC than those from East Africa consistent with the hypothesis that lower VRC is associated with higher population prevalence, the predominant CRF02_AG strain in West Africa displayed higher VRC than other prevalent strains suggesting that VRC alone does not explain population prevalence. The study identified viral and host genetic determinants of virus replication capacity for HIV-1 CRF02_AG and subtype A respectively, which may have relevance for vaccine strategies.

Our aim in this chapter is to provide an updated and concise description of the diversity of fertility decline patterns among countries1 in sub- Saharan Africa drawing on the latest series of fertility estimates that take into account many different data sources and that are harmonized with other demographic components (United Nations 2015d). We focus on the level of fertility prior to the start of fertility decline the time period of the fertility transition and the estimated pace of decline. We also explore the implications of different fertility decline patterns for future fertility and population projections in the region. We draw on the distinct patterns of fertility decline among countries worldwide that are advanced in (or have completed) their first fertility transition to construct probabilistic fertility and population projections for sub-Saharan African countries. The illustrative comparisons of projections highlight the demographic impact if future fertility decline in sub-Saharan countries were to accelerate and follow the rapid pace of decline already experienced by a diverse group of countries. (excerpt)

This research has two main goals: (i) to examine fertility desires (number of children) in sub-Saharan Africa: levels as compared to other major regions and recent trends; and (ii) to assess the extent to which fertility decline in sub-Saharan Africa is contingent on decline in fertility desires (singly and in combination with other reproductive changes).

To identify which British residents travelling abroad are at greatest risk of malaria infection, and to determine the efficacy of malaria chemoprophylaxis for preventing P falciparum infections in tropical Africa. Prospective cohort study (case-base linkage) with routine national surveillance systems. Denominators (base population) were obtained from monitoring a random sample of returning British travellers with the international passenger survey. Numerators (cases) were obtained from reports of malaria infections in British residents, through the Malaria Reference Laboratory network. International passenger survey conducted at passport control of international airports in Britain. Malaria reports received nationally were collated centrally in London. 2948 British residents (0.2%) returning to Britain in 1987 randomly selected and questioned and 1052 British residents with microscopically confirmed malaria infections in 1987, whose case reports were reviewed and on whom additional data were collected by postal survey. Annual incidence subdivided by categories of risk. Chemoprophylactic efficacy for east and west Africa by principal regimens and compliance. Annual rates of reported infection per 100,000 travellers to Oceania were 4100; to west and east Africa were 375 and 172 respectively; to Latin America, the Far East, and the Middle East were 12, 2, and 1 respectively. Immigrants visiting friends and relatives in Ghana and Nigeria were at greatest risk (1303 and 952 per 100,000 respectively) in west Africa. Business travellers to Kenya experienced the highest attack rates in east Africa (465 per 100,000). Age-sex specific attack rates varied by region. No prophylaxis was reported to have been used by 23% of British visitors to west Africa, 17% to east Africa, 46% to central or southern Africa, and 58% visiting south Asia. The efficacy of chloroquine plus proguanil against P falciparum infection was 73% and 54% in west and east Africa respectively. Lower values were obtained for chloroquine alone and proguanil alone. The efficacy of Maloprim (pyrimethamine-dapsone) was 61% in west Africa, but only 9% in east Africa. Visitors to west Africa who did not comply with their chemoprophylactic regimen were at a 2.5-fold higher risk of infection than fully compliant users. Non-compliant visitors to east Africa had similar rates of infection as non-drug users. In 1987 chloroquine plus proguanil was the preferred chemoprophylactic regimen for P falciparum infection in Africa; antimalarial drugs must be taken regularly to be effective.

Despite a broadening consensus about the effectiveness of intermittent preventive treatment (IPTp) in preventing the adverse outcomes of malaria during pregnancy, policy change to IPTp was initially limited to East Africa. In West Africa, where the policy change process for the prevention of malaria during pregnancy started much later, IPTp has been taken up swiftly. To describe the factors that contributed to the rapid adoption of policies to prevent malaria during pregnancy in West Africa. Several factors appear to have accelerated the process: (1) recognition of the extent of the problem of malaria during pregnancy and its adverse consequences; (2) a clear, evidence-based program strategy strongly articulated by an important multilateral organization (World Health Organization); (3) subregionally generated evidence to support the proposed strategy; (4) a subregional forum for dissemination of data and discussion regarding the proposed policy changes; (5) widespread availability of the proposed intervention drug (sulfadoxine-pyrimethamine); (6) technical support from reputable and respected institutions in drafting new policies and planning for implementation; (7) donor support for pilot experiences in integrating proposed policy change into a package of preventive services; and (8) financial support for scaling up the proposed interventions.

BackgroundIn sub-Saharan Africa (SSA), Plasmodium falciparum causes most of the malaria cases. Despite its crucial roles in disease severity and drug resistance, comprehensive data on Plasmodium falciparum genetic diversity and multiplicity of infection (MOI) are sparse in SSA. This study summarizes available information on genetic diversity and MOI, focusing on key markers (msp-1, msp-2, glurp, and microsatellites). The systematic review aimed to evaluate their influence on malaria transmission dynamics and offer insights for enhancing malaria control measures in SSA.MethodsThe review was conducted following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Two reviewers conducted article screening, assessed the risk of bias (RoB), and performed data abstraction. Meta-analysis was performed using the random-effects model in STATA version 17.ResultsThe review included 52 articles: 39 cross-sectional studies and 13 Randomized Controlled Trial (RCT)/cohort studies, involving 11,640 genotyped parasite isolates from 23 SSA countries. The overall pooled mean expected heterozygosity was 0.65 (95% CI: 0.51–0.78). Regionally, values varied: East (0.58), Central (0.84), Southern (0.74), and West Africa (0.69). Overall pooled allele frequencies of msp-1 alleles K1, MAD20, and RO33 were 61%, 44%, and 40%, respectively, while msp-2 I/C 3D7 and FC27 alleles were 61% and 55%. Central Africa reported higher frequencies (K1: 74%, MAD20: 51%, RO33: 48%) than East Africa (K1: 46%, MAD20: 42%, RO33: 31%). For msp-2, East Africa had 60% and 55% for I/C 3D7 and FC27 alleles, while West Africa had 62% and 50%, respectively. The pooled allele frequency for glurp was 66%. The overall pooled mean MOI was 2.09 (95% CI: 1.88–2.30), with regional variations: East (2.05), Central (2.37), Southern (2.16), and West Africa (1.96). The overall prevalence of polyclonal Plasmodium falciparum infections was 63% (95% CI: 56–70), with regional prevalences as follows: East (62%), West (61%), Central (65%), and South Africa (71%).ConclusionThe study shows substantial regional variation in Plasmodium falciparum parasite genetic diversity and MOI in SSA. These findings suggest a need for malaria control strategies and surveillance efforts considering regional-specific factors underlying Plasmodium falciparum infection.

Decision letter: Admixture into and within sub-Saharan Africa

Women account for over half of persons living with HIV/AIDS globally. We examined geographic variation in all-cause mortality after antiretroviral therapy (ART) for women living with HIV (WLWH) worldwide. We pooled data from WLWH at least 18 years initiating ART 2000-2014 within COHERE (Europe) and IeDEA regions (East Africa, West Africa, South Africa, North America, Latin America/Caribbean). Mortality rates were calculated at 0-3, 3-6, 6-12, 12-24 and 24-48 months after ART, and mortality rate ratios were compared with European rates with piecewise exponential parametric survival models based on Poisson regression. One hundred ninety thousand, one hundred and seventy-five WLWH (16% Europe, 47% East Africa, 13% West Africa, 19% South Africa, 1% South America, 3% North America and 2% Central America/Caribbean) were included. The highest death rates occurred 0-3 months after ART [1.51 (95% CI 1.25-1.82) per 100 person-years in Europe, 12.45 (11.30-13.73), 14.03 (13.12-15.02) and 9.44 (8.80-10.11) in East, West and South Africa, and 1.53 (0.97-2.43), 7.83 (5.44-11.27) and 17.02 (14.62-19.81) in North, South America and Central America/Caribbean, respectively] and declined thereafter. Mortality in Europe was the lowest, with regional differences greatest in the first 3 months and smaller at longer ART durations [adjusted rate ratios 24-48 months after ART: 3.63 (95% CI 3.04-4.33), 5.61 (4.84-6.51) and 3.47 (2.97-4.06) for East, West and South Africa; 2.86 (2.26-3.62), 2.42 (1.65-3.55) and 2.50 (1.92-3.26) for North, South America and Central America/Caribbean, respectively]. Global variations in short-term and long-term mortality among WLWH initiating ART may inform context-specific interventions.

The spatial and temporal cloud coverage derived by CloudSat, CERES, ISCCP satellite observations and their relationship with GPCP and TRMM precipitation in West, East and South of Africa were analyzed in this study. CloudSat, CERES and ISCCP show that the high spatial cloud coverage is more frequent in equatorial regions mainly due to more strong convection than other regions. CloudSat shows a low temporal cloud coverage than CERES and ISCCP which are close. Only ISCCP was used to investigate seasonal and temporal variability of different cloud types. The stratocumulus, altostratus, and cirrus clouds are the low, middle and high cloud types with high cloud coverage during JJA, JJA, MAM in West of Africa, during SON, JJA, MAM in East of Africa, and during SON, DJF, DJF in South of Africa respectively . The correlation between cloud coverage and precipitation dataset generally shows a low positive correlation in East of Africa probably due to GPCP and TRMM observations biases whereas a high positive correlation in West and South of Africa. Only middle clouds level in East of Africa, both low and middle in West of Africa show negative correlation with precipitation, whereas all cloud types level in South of Africa show a positive correlation with precipitation.

Disease, we have argued, influenced patterns of colonization, especially in West Africa, the Americas, and Australia (Chapter 2). In turn, imperial transport routes facilitated the spread of certain diseases, such as bubonic plague. This chapter expands our discussion of environmentally related diseases by focusing on trypanosomiasis, carried by tsetse fly, in East and Central Africa. Unlike plague, this disease of humans and livestock was endemic and restricted to particular ecological zones in Africa. But as in the case of plague, the changing incidence of trypanosomiasis was at least in part related to imperialism and colonial intrusion in Africa. Coastal East Africa presented some of the same barriers to colonization as West Africa. Portugal maintained a foothold in South-East Africa for centuries, and its agents expanded briefly onto the Zimbabwean plateau in the seventeenth century, but could not command the interior. Had these early incursions been more successful, southern Africa may have been colonized from the north, rather than by the Dutch and British from the south. Parts of East Africa were a source of slaves and ivory in the eighteenth and early nineteenth centuries. The trading routes, commanded by Arab and Swahili African networks, as well as Afro-Portuguese further south, were linked with the Middle East and the Indian Ocean. In the early decades of the nineteenth century, slave-holding expanded within enclaves of East Africa, such as the clove plantations of Zanzibar. When Britain attempted to abolish the slave trade in the early nineteenth century, and policed the West African coast, East and Central African sources briefly became more important for the Atlantic slave trade. African slaves from these areas were taken to Latin America and the Spanish Caribbean. Britain did not have the same intensity of contact with East Africa as with West and southern Africa until the late nineteenth century. There was no major natural resource that commanded a market in Europe and British traders had limited involvement in these slave markets. But between the 1880s and 1910s, most of East and Central Africa was taken under colonial rule, sometimes initially as protectorates: by Britain in Kenya and Uganda; Germany in Tanzania; Rhodes’s British South Africa Company in Zimbabwe, Zambia, and Malawi; and by King Leopold of Belgium in the Congo.

Cassava (Manihot esculenta) is a tropical crop that is grown in Africa, Latin America and Southeast Asia. Cassava was introduced from Latin America into West and East Africa at two independent events. In Uganda a serious threat to cassava's survival is the cassava mosaic disease (CMD). Uganda has had two notable CMD epidemics since the introduction of cassava in the 1850s causing severe losses. SSR markers were used to study the effect of CMD on the genetic diversity in five agroecologies in Uganda with high and low incidence of CMD. Surprisingly, high gene diversity was detected. Most of the diversity was found within populations, while the diversity was very small among agroecological zones and the high and low CMD incidence areas. The high genetic diversity suggests a mechanism by which diversity is maintained by the active involvement of the Ugandan farmer in continuously testing and adopting new genotypes that will serve their diverse needs. However, in spite of the high genetic diversity we found a loss of rare alleles in areas with high CMD incidence. To study the effect of the introgression history on the gene pool the genetic differentiation between East and West Africa was also studied. Genetic similarities were found between the varieties in Uganda and Tanzania in East Africa and Ghana in West Africa. Thus, there is no evidence for a differentiation of the cassava gene pool into a western and an eastern genetic lineage. However, a possible difference in the genetic constitution of the introduced cassava into East and West Africa may have been diminished by germplasm movement.

In this chapter the author adopts a comparative approach to examining longterm trends in female age at marriage and fertility in sub-Saharan Africa with a focus on continental countries having at least 1 million inhabitants. The author’s database on nuptiality includes over 360 censuses and national surveys conducted in these 39 countries since the 1960s. The author analyzes the association between changes in age at first union and the onset of fertility transition examining whether there is a typical pattern of association followed by most countries in the region.

Digitalization is an opportunity for African farmers, as it brings several services and innovative technology closer to them. Nowadays, the digital agriculture ecosystem in Africa involves hundreds of start-ups and projects that work toward innovative and sustainable solutions. However, the government policies that need to create a conducive environment do not always keep pace with the digital ecosystems needs. In this article, we review ICT-related policies and their influence on agriculture in thirteen countries from West Africa and six from East Africa. The review was conducted using a mixed-methods approach. We used MCI and EBA ICT index for quantitative analysis on one hand, and on the other hand the content analysis technique Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was used. The analysis yielded four main conclusions. First, government policies address mainly the areas of infrastructure development, digital finance and access to credit, and data protection. Second, countries with a dedicated ICT for agriculture strategy are scarce in East and West Africa. Third, in-country actions on e-agriculture are scattered with weak coordination and synergy. Fourth, East Africa is farther ahead than West Africa in terms of digital policy enforcement for agriculture on the continent. The findings have implications for policies that are more adapted to farmers’ context and needs.

Climate change is one of the major challenges of agricultural production in many developing countries. It complements some other development challenges like civil unrests, environmental degradation and HIV&amp;AIDS as one of the major obstacles to Africa’s socioeconomic development. African policy makers have now realized the enormity of economic consequences of climate change, and are coming up with mechanisms for reducing vulnerability through adaptive mechanisms. These would reduce the problem of food insecurity since agriculture is the dominant sector in many African countries. Similarly, these efforts are justifiable given that high proportion of the labor force is found in agriculture and other related activities. This paper analysed the impact of sustainable land use on monthly food shortages among farmers in selected African countries. Data used for this study were collected by the CGIAR’s Research Program on Climate Change, Agriculture and Food Security (CCAFS) as baseline survey between late 2010 to early 2011. Five sites were randomly selected from East Africa (Ethiopia, Kenya, Tanzania and Uganda), while in West Africa, five sites were each selected from Burkina Faso, Ghana, Mali, Niger and Senegal. A total of 1398 farm households were sampled from the two sub-regions using structured questionnaire. Data were analysed with descriptive statistics and Negative Binomial (NB) regression model. The results showed that majority of the farmers from Senegal had no formal education, while average numbers of months when farm households were unable to meet households’ food needs were highest in Ethiopia (6.55), Tanzania (5.36) and Ghana (4.44). The results from Negative binomial regression showed that monthly food shortages significantly increased (p&lt;0.05) with exposure to climatic shocks, introduction of new crops, late planting, use of mulching and stopping irrigation. It however reduced significantly (p&lt;0.05) with food cropland owned, vegetable cultivation, fish production, remittance income, access to formal and informal loans, income from renting land, stop planting a variety, improved irrigation and use of integrated crop management. It was concluded that the farmers were adjusting their farming systems in response to climate change and efforts at promoting sustainable farming system will enhance their adaptive capacity and food security given the current climatic changes.

Impact of climate change on malaria in Africa: a combined modelling and observational study