Acute Myocardial Infarction in Sub-Saharan Africa: The Need for Data

Background

Trends in the prevalence of acute myocardial infarction in sub-Saharan Africa have not been well described, despite growing recognition of the increasing burden of cardiovascular disease in low- and middle-income countries. The aim of this systematic review was to describe the prevalence of acute myocardial infarction in sub-Saharan Africa.

Methods

We searched PubMed, EMBASE, Global Health Archive, CINAHL, and Web of Science, and conducted reference and citation analyses. Inclusion criteria were: observational studies, studies that reported incidence or prevalence of acute myocardial infarction, studies conducted in sub-Saharan Africa, and studies that defined acute myocardial infarction by EKG changes or elevation of cardiac biomarkers. Studies conducted prior to 1992 were excluded. Two independent reviewers analyzed titles and abstracts, full-texts, and references and citations. These reviewers also performed quality assessment and data extraction. Quality assessment was conducted with a validated scale for observational studies.

Findings

Of 2292 records retrieved, seven studies met all inclusion criteria. These studies included a total of 92,378 participants from highly heterogeneous study populations in five different countries. Methodological quality assessment demonstrated scores ranging from 3 to 7 points (on an 8-point scale). Prevalence of acute myocardial infarction ranged from 0.1 to 10.4% among the included studies.

Interpretation

There is insufficient population-based data describing the prevalence of acute myocardial infarction in sub-Saharan Africa. Well-designed registries and surveillance studies that capture the broad and diverse population with acute myocardial infarction in sub-Saharan Africa using common diagnostic criteria are critical in order to guide prevention and treatment strategies.

Registration

Registered in International Prospective Register of Systematic Reviews (PROSPERO) Database #CRD42012003161.     

Use of Medical Services and Medicines Attributable to Diabetes in Sub-Saharan Africa

Background

Although the large majority of persons with diabetes and other non-communicable diseases (NCDs) lives and dies in low- and middle-income countries, the prevention and treatment of diabetes and other NCDs is widely neglected in these areas. A contributing reason may be that, unlike the impacts of acute and communicable diseases, the demands on resources imposed by diabetes is not superficially obvious, and studies capable of detecting these impacts have not be done.

Methods

To ascertain recent use of medical services and medicines and other information about the impact of ill-health, we in 2008–2009 conducted structured, personal interviews with 1,780 persons with diagnosed diabetes (DMs) and 1,770 matched comparison subjects (MCs) without diabetes in Cameroon, Mali, Tanzania and South Africa. We sampled DMs from diabetes registries and, in Cameroon and South Africa, from attendees at outpatient diabetes clinics. To recruit MCs, we asked subjects with diabetes to identify five persons living nearest to them who were of the same sex and approximate age. We estimated diabetes impact on medical services use by calculating ratios and differences between DMs and MCs, testing for statistical significance using two-stage multivariable hurdle models.

Findings

DMs consumed 12.95 times more days of inpatient treatment, 7.54 times more outpatient visits, and 5.61 times more medications than MCs (all p<0.001). DMs used an estimated 3.44 inpatient days per person per year, made 10.72 outpatient visits per person per year (excluding traditional healers), and were taking an average of 2.49 prescribed medicines when interviewed.

Conclusions

In Sub-Saharan Africa, the relative incremental use of medical care and medicines associated with diagnosed diabetes is much greater than in industrialized countries and in China. Published calculations of the health-system impact of diabetes in Africa are dramatic underestimates. Although non-communicable diseases like diabetes are commonly thought to be minor problems for health systems and patients in Africa, our data demonstrate the opposite.     

Neglected Fungal Diseases in Sub-Saharan Africa: A Call to Action

Despite the considerable morbidity and mortality associated with fungal diseases in sub-Saharan Africa, it is notable that these diseases have been omitted from an expanded list of neglected tropical diseases. Inextricably tied together with HIV/AIDS and tuberculosis in sub-Saharan Africa, important fungal diseases such as cryptococcal meningitis and Pneumocystis jirovecii pneumonia (PCP) manifest as relatively common and deadly AIDS-defining opportunistic infections, often masked by and comorbid with tuberculosis. Others, such as mycetoma, which manifest as a debilitating and deforming illness primarily affecting rural adults, directly affect the socioeconomic productivity of rural communities. Lack of adequate diagnostic tests makes identifying the true disease burden due to fungal diseases difficult. To highlight the devastating impact of fungal diseases on the health and socioeconomic circumstances of sub-Saharan Africa’s poorest people and to increase the profile of efforts to control and prevent these diseases, we propose that the following fungal diseases be added to the list of neglected tropical diseases: cryptococcal meningitis, PCP, mycetoma, histoplasmosis, sporotrichosis, and blastomycosis. By outlining the prevalence, distribution, and disease burden of these fungal diseases in sub-Saharan Africa in this review, we hope to provide information to prioritize strategies for detection, control, and prevention of the neglected fungal diseases.     

Salt Reduction Interventions in Sub-Saharan Africa: A Systematic Review

Background

Salt intake is associated with hypertension, the leading risk factor for cardiovascular disease. To promote population-level salt reduction, the World Health Organization recommends intervention around three core pillars: Reformulation of processed foods, consumer awareness, and environmental changes to increase availability and affordability of healthy food. This review investigates salt reduction interventions implemented and evaluated in sub-Saharan Africa (SSA).

Methods

MEDLINE and google scholar electronic databases were searched for articles meeting inclusion criteria. Studies that reported evaluation results of a salt intervention in SSA were identified. Titles and abstracts were screened, and articles selected for full-text review. Quality of included articles was assessed, and a narrative synthesis of the findings undertaken. PROSPERO registration number CRD42015019055.

Results

Seven studies representing four countries—South Africa, Nigeria, Ghana, and Tanzania—were included. Two examined product reformulation, one in hypertensive patients and the other in normotensive volunteers. Four examined consumer awareness interventions, including individualised counselling and advisory health sessions delivered to whole villages. One study used an environmental approach by offering discounts on healthy food purchases. All the interventions resulted in at least one significantly improved outcome measure including reduction in systolic blood pressure (BP), 24 hour urinary sodium excretion, or mean arterial BP.

Conclusions

More high quality studies on salt reduction interventions in the region are needed, particularly focused on consumer awareness and education in urban populations given the context of rapid urbanisation; and essentially, targeting product reformulation and environmental change, for greater promise for propagation across a vast, diverse continent.     

Climate Change and Health in Sub-Saharan Africa: A Case-Based Perspective

Over the coming decades, sub-Saharan Africa will face profound stresses and challenges from global climate change. Many of these will manifest as adverse health outcomes. This article uses a series of five hypothetical cases to review the climate impacts on the health and well-being of individuals and populations in sub-Saharan Africa. This approach fosters insights into the human dimensions of the risks to health, their interaction with local human ecology, and awareness of the diverse health ramifications of external environmental changes. Each case illustrates the health impact resulting from a specific environmental or social consequence of climate change, including impacts on agriculture and food security, droughts, floods, malaria, and population displacement. Whereas the article focuses on discrete manifestations of climate change, individuals will, in practice, face multiple stresses from climate change (i.e., floods and malaria) concomitant with other non-climate stressors (i.e., HIV/AIDS, globalization, etc.). These multiple sources of vulnerability must be considered when designing climate change and socioeconomic development interventions.     

Identifying and Targeting Mortality Disparities: A Framework for Sub-Saharan Africa Using Adult Mortality Data from South Africa

Background

Health inequities in developing countries are difficult to eradicate because of limited resources. The neglect of adult mortality in Sub-Saharan Africa (SSA) is a particular concern. Advances in data availability, software and analytic methods have created opportunities to address this challenge and tailor interventions to small areas. This study demonstrates how a generic framework can be applied to guide policy interventions to reduce adult mortality in high risk areas. The framework, therefore, incorporates the spatial clustering of adult mortality, estimates the impact of a range of determinants and quantifies the impact of their removal to ensure optimal returns on scarce resources.

Methods

Data from a national cross-sectional survey in 2007 were used to illustrate the use of the generic framework for SSA and elsewhere. Adult mortality proportions were analyzed at four administrative levels and spatial analyses were used to identify areas with significant excess mortality. An ecological approach was then used to assess the relationship between mortality “hotspots” and various determinants. Population attributable fractions were calculated to quantify the reduction in mortality as a result of targeted removal of high-impact determinants.

Results

Overall adult mortality rate was 145 per 10,000. Spatial disaggregation identified a highly non-random pattern and 67 significant high risk local municipalities were identified. The most prominent determinants of adult mortality included HIV antenatal sero-prevalence, low SES and lack of formal marital union status. The removal of the most attributable factors, based on local area prevalence, suggest that overall adult mortality could be potentially reduced by ∼90 deaths per 10,000.

Conclusions

The innovative use of secondary data and advanced epidemiological techniques can be combined in a generic framework to identify and map mortality to the lowest administration level. The identification of high risk mortality determinants allows health authorities to tailor interventions at local level. This approach can be replicated elsewhere.     

Thrombohemorrhagic Response to Noradrenaline Following Heterologous Blood Transfusion: A Preliminary Report

Normal rats are extremely tolerant to heterologous blood transfusion; however, after subcutaneous injection of noradrenaline, they lose this tolerance and respond with severe thrombohemorrhagic reactions both at the site of injection and in internal organs, particularly the kidney.In histological structure, the topical and general manifestations of this thrombohemorrhagic response are virtually identical with those of the local and general Sanarelli-Shwartzman phenomenon, respectively.Among the blood specimens tested, those of the dog, cat, rabbit, guinea pig, chicken and man were most effective in inducing this type of noradrenaline hypersensitivity. The blood of the duck and hamster as well as homologous rat blood proved to be virtually or completely inefficacious.The possible theoretical and clinical implications of a noradrenaline test for potential blood-borne thrombohemorrhagic factors are briefly discussed.     

A Bundle of Services Increased Ascertainment of Tuberculosis among HIV-Infected Individuals Enrolled in a HIV Cohort in Rural Sub-Saharan Africa

Objectives

To report on trends of tuberculosis ascertainment among HIV patients in a rural HIV cohort in Tanzania, and assessing the impact of a bundle of services implemented in December 2012, consisting of three components:(i)integration of HIV and tuberculosis services; (ii)GeneXpert for tuberculosis diagnosis; and (iii)electronic data collection.

Design

Retrospective cohort study of patients enrolled in the Kilombero Ulanga Antiretroviral Cohort (KIULARCO), Tanzania.)

Methods

HIV patients without prior history of tuberculosis enrolled in the KIULARCO cohort between 2005 and 2013 were included.Cox proportional hazard models were used to estimate rates and predictors of tuberculosis ascertainment

Results

Of 7114 HIV positive patients enrolled, 5123(72%) had no history of tuberculosis. Of these, 66% were female, median age was 38 years, median baseline CD4+ cell count was 243 cells/µl, and 43% had WHO clinical stage 3 or 4. During follow-up, 421 incident tuberculosis cases were notified with an estimated incidence of 3.6 per 100 person-years(p-y)[95% confidence interval(CI)3.26-3.97]. The incidence rate varied over time and increased significantly from 2.96 to 43.98 cases per 100 p-y after the introduction of the bundle of services in December 2012. Four independent predictors of tuberculosis ascertainment were identified:poor clinical condition at baseline (Hazard Ratio (HR) 3.89, 95% CI 2.87-5.28), WHO clinical stage 3 or 4 (HR 2.48, 95% CI 1.88-3.26), being antiretroviralnaïve (HR 2.97, 95% CI 2.25-3.94), and registration in 2013(HR 6.07, 95% CI 4.39-8.38).

Conclusion

The integration of tuberculosis and HIV services together with comprehensive electronic data collection and use of GeneXpert increased dramatically the ascertainment of tuberculosis in this rural African HIV cohort.     

A new pilot plant scale acetifier designed for vinegar production in Sub-Saharan Africa

A novel thermotolerant strain Acetobacter senegalensis sp. nov. (CWBI-B418^T) isolated in Senegal from mango fruit, previously freeze-dried and conserved at 4 °C under vacuum packaging was successfully rehydrated into an acetifying medium. It was used as an inoculum culture and then applied into a new pilot plant scale acetifier (300 L) for vinegar production. This latter was specifically designed to produce a high volume and quality of vinegar in Sub-Saharan Africa at fermentation temperature of 35 °C. Several semi-continuous cycles of acetic acid fermentations were carried out. The behaviour of substrate and product concentrations, population of bacteria into the reactor was analysed as well as the evolution of acidity, acetification rates and stoichiometric yields. Operation with this novel bioreactor allowed achieving 8% (v/v) of acetic acid concentration at 35 °C.     

Wetlands of Sub-Saharan Africa: distribution and contribution of agriculture to livelihoods

Wetlands contribute in diverse ways to the livelihoods of millions of people in Sub-Saharan Africa. In many places they are inextricably linked to cropping and livestock management systems. At the same time, increasing population in conjunction with efforts to increase food security is escalating pressure to expand agriculture within wetlands. The environmental impact of wetland agriculture can, however, have profound social and economic repercussions for people dependent on ecosystem services other than those provided directly by agriculture. Currently, the basis for making decisions about the extent to which wetlands can be sustainably used for agriculture is weak. This paper provides an overview of wetland distribution, type and condition across Sub-Saharan Africa. Findings from an investigation of wetland use conducted in Tanzania are presented. These highlight the reliance of communities on both wetland agriculture and natural resources, and show that the nature of household dependence varies significantly from place to place and as socio-economic status changes. Consequently, incentives to manage wetland resources will differ markedly, not only from one location to another, but also across socio-economic groups within the same community. This complexity highlights the need for critical analysis of the social and economic factors that underpin the dynamics of wetland resource use in the development of sustainable management plans.     

Explaining Adherence Success in Sub-Saharan Africa: An Ethnographic Study

Background

Individuals living with HIV/AIDS in sub-Saharan Africa generally take more than 90% of prescribed doses of antiretroviral therapy (ART). This number exceeds the levels of adherence observed in North America and dispels early scale-up concerns that adherence would be inadequate in settings of extreme poverty. This paper offers an explanation and theoretical model of ART adherence success based on the results of an ethnographic study in three sub-Saharan African countries.

Methods and Findings

Determinants of ART adherence for HIV-infected persons in sub-Saharan Africa were examined with ethnographic research methods. 414 in-person interviews were carried out with 252 persons taking ART, their treatment partners, and health care professionals at HIV treatment sites in Jos, Nigeria; Dar es Salaam, Tanzania; and Mbarara, Uganda. 136 field observations of clinic activities were also conducted. Data were examined using category construction and interpretive approaches to analysis. Findings indicate that individuals taking ART routinely overcome economic obstacles to ART adherence through a number of deliberate strategies aimed at prioritizing adherence: borrowing and “begging” transport funds, making “impossible choices” to allocate resources in favor of treatment, and “doing without.” Prioritization of adherence is accomplished through resources and help made available by treatment partners, other family members and friends, and health care providers. Helpers expect adherence and make their expectations known, creating a responsibility on the part of patients to adhere. Patients adhere to promote good will on the part of helpers, thereby ensuring help will be available when future needs arise.

Conclusion

Adherence success in sub-Saharan Africa can be explained as a means of fulfilling social responsibilities and thus preserving social capital in essential relationships.     

Evaluating Spatial Interaction Models for Regional Mobility in Sub-Saharan Africa

Simple spatial interaction models of human mobility based on physical laws have been used extensively in the social, biological, and physical sciences, and in the study of the human dynamics underlying the spread of disease. Recent analyses of commuting patterns and travel behavior in high-income countries have led to the suggestion that these models are highly generalizable, and as a result, gravity and radiation models have become standard tools for describing population mobility dynamics for infectious disease epidemiology. Communities in Sub-Saharan Africa may not conform to these models, however; physical accessibility, availability of transport, and cost of travel between locations may be variable and severely constrained compared to high-income settings, informal labor movements rather than regular commuting patterns are often the norm, and the rise of mega-cities across the continent has important implications for travel between rural and urban areas. Here, we first review how infectious disease frameworks incorporate human mobility on different spatial scales and use anonymous mobile phone data from nearly 15 million individuals to analyze the spatiotemporal dynamics of the Kenyan population. We find that gravity and radiation models fail in systematic ways to capture human mobility measured by mobile phones; both severely overestimate the spatial spread of travel and perform poorly in rural areas, but each exhibits different characteristic patterns of failure with respect to routes and volumes of travel. Thus, infectious disease frameworks that rely on spatial interaction models are likely to misrepresent population dynamics important for the spread of disease in many African populations.