Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “AFRICA”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources
PubMed1993

The geographical inequalities in mortality in Africa.

This paper reviews the progress that has been made in studies on geographic differentials of mortality in Africa. In general, there is very little known about adult mortality in many Third World countries, and the contributions of geographers have been limited in this area. In many African countries, enormous problems in studies on mortality were encountered due to incomplete and unreliable information. Differential levels of mortality are reported in different regions of the African continent and even within each country. Higher childhood mortality rates are recorded in West and Central Africa when compared with East and Southern Africa; relatively low rates are reported in the Magreb and the lowest in the small island territories. However, the role of geographic and environmental factors at both regional and urban levels are least exploited. Hence, many analyses of mortality in Africa have concentrated more on formal statistical materials and not on the realities of the existing ecological and environmental situation. The paper calls on geographers to exploit ways of utilizing the enormous clinic-based data in the continent. However, even more can be accomplished when geographers conduct interdisciplinary research on mortality in Africa.

Adult↗
PubMed2004

Microsatellite DNA polymorphism and heterozygosity in the malaria vector mosquito Anopheles funestus (Diptera: Culicidae) in east and southern Africa.

There has been an increase in malaria cases in southern African countries in recent years due to the presence of populations of Anopheles funestus that are resistant to the pyrethroid class of insecticides. Since A. funestus is one of the major African malaria vectors, knowledge of its genetic structure will benefit control strategies, such as the management of insecticide resistance, by allowing predictions to be made of possible spread of the resistance. This study uses microsatellite DNA markers to analyze samples from five countries in east (Kenya and Uganda), central (Malawi) and southern (South Africa and Mozambique) Africa. There were deviations from Hardy-Weinberg expectations for some loci in all population samples but this was probably due to the presence of null alleles. High levels of genetic diversity were observed (mean alleles per locus = 6.5-10; unbiased H=0.23-0.89). Low differentiation was observed between Kenya and Uganda (average F(ST)=0.002, R(ST)=0.0001) and between Mozambique and South Africa (F(ST)=0.0004, R(ST)=0.02), contrary to high differentiation among the central and southern Africa samples (average F(ST)=0.023, R(ST)=0.027). High differentiation was measured across the region (mean F(ST)=0.04, R(ST)=0.08), east versus Malawi (F(ST)=0.067, R(ST)=0.089) or southern Africa populations (F(ST)=0.068, R(ST)=0.15). A test of isolation by distance along the east-central-south transect gave evidence (R(2)=0.50, P<0.001) that geographic distance limits gene flow in A. funestus.

Africa↗
PubMed2006

Assessment of Internet-based tele-medicine in Africa (the RAFT project).

The objectives of this paper on the Réseau Afrique Francophone de Télémédecine (RAFT) project are the evaluation of feasibility, potential, problems and risks of an Internet-based tele-medicine network in developing countries of Africa. The RAFT project was started in Western African countries 5 years ago and has now extended to other regions of Africa as well (i.e. Madagascar, Rwanda). A project for the development of a national tele-medicine network in Mali was initiated in 2001, extended to Mauritania in 2002 and to Morocco in 2003. By 2006, a total of nine countries are connected. The entire technical infrastructure is based on Internet technologies for medical distance learning and tele-consultations. The results are a tele-medicine network that has been in productive use for over 5 years and has enabled various collaboration channels, including North-to-South (from Europe to Africa), South-to-South (within Africa), and South-to-North (from Africa to Europe) distance learning and tele-consultations, plus many personal exchanges between the participating hospitals and Universities. It has also unveiled a set of potential problems: (a) the limited importance of North-to-South collaborations when there are major differences in the available resources or the socio-cultural contexts between the collaborating parties; (b) the risk of an induced digital divide if the periphery of the health system in developing countries is not involved in the development of the network; and (c) the need for the development of local medical content management skills. Particularly point (c) is improved through the collaboration between the various countries as professionals from the medical and the computer science field are sharing courses and resources. Personal exchanges between partners in the project are frequent, and several persons received an education at one of the partner Universities. As conclusion, we can say that the identified risks have to be taken into account when designing large-scale tele-medicine projects in developing countries. These problems can be mitigated by fostering South-South collaboration channels, by the use of satellite-based Internet connectivity in remote areas, the appreciation of local knowledge and its publication on-line. The availability of such an infrastructure also facilitates the development of other projects, courses, and local content creation.

Africa↗
PubMed2006

Manifestations of affective disturbance in sub-Saharan Africa: key themes.

BACKGROUND: Affective disorder, once seen as rare in sub-Saharan Africa, is now viewed as more common. There are however challenges in assessing rates of depression, exploring manifestations of depression, and understanding risk factors for depression, especially those related to gender. AIM: To identify key themes and new directions for research on affective disorder in sub-Saharan Africa, with particular reference to gender issues. METHODS: Interpretive review of selected literature, and theoretical analysis. RESULTS: There are gender differences in manifestations and rates of depression in sub-Saharan Africa, and there are forms of presentation (largely somatic, based on interpersonal relationships, or spiritual in nature) which may obscure the detection of depression. Studies are consistent however that when depressive symptoms are sought and are present, these are reasonably easy to elicit. LIMITATIONS: This was not a systematic review, and the substantial grey literature from sub-Saharan Africa was not reviewed. For many countries, there are no data available. CONCLUSIONS: Affective disorder, when properly sought for through both qualitative and quantitative methods, has been found to be common in sub-Saharan Africa. There is a paucity of research on interventions with affective disorder in this region.

Adult↗
PubMedDate not supplied

Mapping and estimating the population at risk from lymphatic filariasis in Africa.

Lymphatic filariasis remains a major public health problem in Africa and is 1 of the World Health Organization's 6 diseases targeted for global eradication. However, no detailed maps of the geographical distribution of this disease exist, making it difficult to target control activities and quantify the population at risk. We hypothesized that the distribution lymphatic filariasis is governed by climate. The climate at sites in Africa where surveys for lymphatic filariasis had taken place was characterized using computerized climate surfaces. Logistic regression analysis of the climate variables predicted with 76% accuracy whether sites had microfilaraemic patients or not. We used the logistic equation in a geographical information system to map risk of lymphatic filariasis infection across Africa, which compared favourably with expert opinion. Further validation with a quasi-independent data set showed that the model predicted correctly 88% of infected sites. A similar procedure was used to map risk of microfilaraemia in Egypt, where the dominant vector species differs from those in sub-Saharan Africa. By overlaying risk maps on a 1990 population grid, and adjusting for recent population increases, we estimate that around 420 million people will be exposed to this infection in Africa in the year 2000. This approach could be used to produce a sampling frame, based on estimated risk of microfilaraemia, for conducting filariasis surveys in countries that lack accurate distribution maps and thus save on costs.

Africa↗
PubMed2002

The spread and effect of HIV-1 infection in sub-Saharan Africa.

Africa is the continent most severely affected by the global HIV-1 epidemic, with east and southern Africa in general more severely affected than west and central Africa. Differences in the spread of the epidemic can be accounted for by a complex interplay of sexual behaviour and biological factors that affect the probability of HIV-1 transmission per sex act. Sexual behaviour patterns are determined by cultural and socioeconomic contexts. In sub-Saharan Africa, some traditions and socioeconomic developments have contributed to the extensive spread of HIV-1 infection, including the subordinate position of women, impoverishment and decline of social services, rapid urbanisation and modernisation, and wars and conflicts. Populations in many parts of Africa are becoming trapped in a vicious circle as the HIV-1 epidemic leads to high mortality rates in young and economically productive age groups, and thus leads to further impoverishment. Interventions to control HIV-1 should not only target individuals, but also aim to change those aspects of cultural and socioeconomic context that increase the vulnerability to HIV-1 of people and communities.

Adolescent↗
PubMed2003

Antifolate antimalarial resistance in southeast Africa: a population-based analysis.

BACKGROUND: Sulfadoxine-pyrimethamine was first introduced for treatment of malaria in Africa during the early 1980s for cases when chloroquine treatment failed, and has since become the first-line treatment in many countries. Resistance to sulfadoxine-pyrimethamine is now increasing, especially in southeast Africa. METHODS: We characterised genetic change in dhfr and dhps genes in the Plasmodium falciparum population of KwaZulu-Natal, South Africa, during 1995-99, a period of rapid deterioration of the effectiveness of sulfadoxine-pyrimethamine. We assessed the evolutionary origin of the resistance by analysing polymorphic microsatellite repeats in the flanking region of the dhfr and dhps genes, which show whether resistance alleles originated through shared or independent ancestral mutation events. We then assessed the current extent of dispersal of dhfr and dhps resistance alleles by doing the same analysis in P falciparum sampled from communities in the Kilimanjaro region of northern Tanzania in 2001. FINDINGS: The large genetic change during 1995-99 in KwaZulu-Natal, South Africa, in both the health facility and the wider community surveys, was at the dhps locus, apparently because resistance at dhfr was established before 1995. The allelic determinants of resistance in this province share a common evolutionary origin with those found in Kilimanjaro, Tanzania, even though the two sites are 4000 km apart. INTERPRETATION: Three resistant dhfr alleles, and one resistant dhps allele, each derived from independent ancestral lineages, have been driven through through southeast Africa. The movement by the dhfr alleles (pyrimethamine resistance) preceded that of the dhps allele (sulfadoxine resistance). Our findings emphasise that gene flow rather than new mutations has been the most common originator of resistance in African countries.

Adult↗
PubMed2003

Molecular epidemiology of canid rabies in Zimbabwe and South Africa.

The epidemiology of rabies in southern Africa is complex, due to a large number of vector species and the presence of at least two distinct biotypes of the virus. Our objective was to contribute to the understanding of the epidemiology of rabies in the southern African subcontinent by studying the genetic relationship of 89 rabies virus isolates from this region. In this study, we have focused on an analysis of viruses that cycle in canid host species (canid biotype) throughout South Africa and Zimbabwe. By phylogenetic analysis of the cytoplasmic domain of the glycoprotein and the non-coding G-L intergenic region, all the southern African canid viruses were found to be closely related and no apparent general distinction could be made between them. Although there was a minor degree of phylogenetic branching, with certain branches associated with cycles defined by species, location and time, the phylogenetic pattern indicated that canid rabies in southern Africa is derived from a single virus lineage, which has spread opportunistically within whatever canid host population is ecologically capable of sustaining prolonged cycles. This molecular epidemiological study presents the first comprehensive comparison of rabies viruses from South Africa and Zimbabwe and has demonstrated the need for multinational approaches towards the control of this important zoonotic disease in Africa.

Animals↗
PubMed2003

Rotavirus strains circulating in Africa during 1996-1999: emergence of G9 strains and P[6] strains.

Rotavirus infection is associated with 150000-200000 deaths annually in Africa. Although the withdrawal of the RotaShield vaccine has been a major setback in rotavirus vaccine development, new vaccine candidates are under development and approaching phase II and III trials. Before these trials could be conducted in Africa, a comprehensive survey of the circulating VP7 serotypes and VP4 genotypes is required. During the past 3 years, over 3000 rotavirus-positive specimens from several African countries have been analysed. RT-PCR techniques for the VP7 and VP4 genotypes and by monoclonal antibodies to the VP6 subgroup and VP7 serotype have been performed. Almost 75% of the strains were typed by the VP7 monoclonal antibodies or RT-PCR. VP4 genotyping was done in approximately half of these strains. The predominant strains circulating across Africa during 1996-1999 were P[6]G1 and P[6]G3 strains. Geographic differences were noted and West Africa displayed the most diverse strains with G3/8 and G1/3 "mosaic" viruses occurring commonly. G9 strains were identified in several countries indicating that the strain is emerging in Africa too. G9 was the predominant strain in certain countries during 1999. The circulating types observed will have implications for the new rotavirus vaccine candidates.

Africa↗
PubMed2004

HIV prevention in Africa: programs and populations served by non-governmental organizations.

The AIDS epidemic in Africa remains an urgent health crisis. Non-governmental organizations (NGOs) in Africa play a critical role in the delivery of HIV prevention services and assistance to persons living with AIDS. African NGOs are conducting numerous HIV prevention programs with several at-risk populations, yet their efforts have only rarely been systematically documented. To address this gap in the literature, the authors surveyed one NGO in each of 29 African countries regarding their HIV prevention activities and populations served. This report provides details concerning HIV prevention activities across the continent and describes in detail innovative programs from Togo and South Africa. NGOs in the present sample operate with modest budgets and small staff sizes, yet conduct programs that reach large segments of their communities. NGOs were most likely to report community-level interventions such as peer-education or community outreach. Faced with an epidemic where the main transmission occurs via heterosexual activity, African NGOs were most likely to direct their attention to the general public and to youth. NGOs in Africa are struggling to implement sustainable, cost-effective programs with few resources. Strengthening the infrastructure and capacity of these key agencies is crucial to fighting the AIDS epidemic in Africa.

Africa↗
PubMed2005

Ethiopia: between Sub-Saharan Africa and western Eurasia.

Ethiopia is central to population genetic studies investigating the out of Africa expansion of modern humans, as shown by Y chromosome and mtDNA studies. To address the level of genetic differentiation within Ethiopia, and its relationship to Sub-Saharan Africa and Eurasia, we studied an 8 kb segment of the X-chromosome from 72 chromosomes from the Amhara, Oromo and Ethiopian Jews, and compared these results with 804 chromosomes from Middle Eastern, African, Asian and European populations, and 22 newly typed Saharawi. Within Ethiopia the two largest ethnic groups, the Amhara and Oromo, were not found to be statistically distinct, based on an exact test of haplotype frequencies. The Ethiopian Jews appear as an admixed population, possibly of Jewish origin, though the data remain equivocal. There is evidence of a close relationship between Ethiopian and Yemenite Jews, likely a result of indirect gene flow. Within an African and Eurasian context, the distribution of alleles of a variable T(n) repeat, and the spread of haplotypes containing Africa-specific alleles, provide evidence of a genetic continuity from Sub-Saharan Africa to the Near East, and furthermore suggest that a bottleneck occurred in Ethiopia associated with an out of Africa expansion. Ethiopian genetic heterogeneity, as evidenced by principal component analysis of haplotype frequencies, most likely resulted from periods of subsequent admixture. While these results are from the analysis of one locus, we feel that in association with data from other marker systems they add a complementary perspective on the history of Ethiopia.

Africa↗
PubMed1998

Genetic evidence for a Paleolithic human population expansion in Africa.

Human populations have undergone dramatic expansions in size, but other than the growth associated with agriculture, the dates and magnitudes of those expansions have never been resolved. Here, we introduce two new statistical tests for population expansion, which use variation at a number of unlinked genetic markers to study the demographic histories of natural populations. By analyzing genetic variation in various aboriginal populations from throughout the world, we show highly significant evidence for a major human population expansion in Africa, but no evidence of expansion outside of Africa. The inferred African expansion is estimated to have occurred between 49,000 and 640,000 years ago, certainly before the Neolithic expansions, and probably before the splitting of African and non-African populations. In showing a significant difference between African and non-African populations, our analysis supports the unique role of Africa in human evolutionary history, as has been suggested by most other genetic work. In addition, the missing signal in non-African populations may be the result of a population bottleneck associated with the emergence of these populations from Africa, as postulated in the "Out of Africa" model of modern human origins.

Africa↗
PubMed2002

Prevalence of household food poverty in South Africa: results from a large, nationally representative survey.

OBJECTIVES: Household food insecurity is a major determinant of undernutrition, yet there is little information on its prevalence in the South African population. This paper assesses household food insecurity in South Africa using a quantitative and objective measure, known as food poverty, and provides prevalence estimates by geographic area and socio-economic condition. DESIGN: Secondary data analysis combining two sources: Statistics South Africa's household-based 1995 Income and Expenditure Survey; and the University of Port Elizabeth's Household Subsistence Level series, a nationally-conducted, market-based survey. SETTING: South Africa. SUBJECTS: A nationally representative sample of the entire country - stratified by race, province, and urban and non-urban areas - consisting of 28 704 households. RESULTS: A household is defined to be in food poverty when monthly food spending is less than the cost of a nutritionally adequate very low-cost diet. The prevalence of food poverty in South Africa in 1995 was 43%. Food poverty rates were highest among households headed by Africans, followed by coloureds, Indians and whites. Higher food poverty rates were found with decreasing income, increasing household size, and among households in rural areas or those headed by females. CONCLUSIONS: The widespread nature of household food insecurity in South Africa is documented here. Prevalence rates by geographic and socio-economic breakdown provide the means for targeting of nutritional interventions and for monitoring progress in this field. The corroboration of these findings with both internal validation measures and external sources suggests that food poverty is a useful, objective measure of household food insecurity.

Adult↗
PubMed2006

Responding to the crisis in sub-Saharan Africa: the role of nutrition.

In the chapter dealing with education and health, the report of the influential Commission for Africa prioritises basic health systems, HIV/AIDS, malaria and tuberculosis. In contrast, nutrition is given less than half a page and is reduced to parasite control and micronutrient support. Such neglect of nutrition is hard to understand in the context of increasing hunger and malnutrition across the continent. Sub-Saharan Africa is the only region in the world where the proportion of underweight children has stagnated and the absolute numbers have actually increased in the last decade. It has been pointed out that if current trends continue sub-Saharan Africa will achieve the Millennium Development Goal for child mortality around 2115 - one century after the target date. Quite clearly those concerned with nutrition need to more powerfully advocate the role of nutrition in lifting Africa out of the spiral of poverty. The present paper argues that to achieve this requires an understanding not just of the critical role of nutrition for health and development (both individual and national), but also of how recent global changes are interacting with changes in food production and supply, other determinants of maternal and child health, and the role and capacity of the state to tackle malnutrition in Africa. It concludes by suggesting some responses that nutritionists could now be making.

Africa South of the Sahara↗
PubMed2004

The Levant versus the Horn of Africa: evidence for bidirectional corridors of human migrations.

Paleoanthropological evidence indicates that both the Levantine corridor and the Horn of Africa served, repeatedly, as migratory corridors between Africa and Eurasia. We have begun investigating the roles of these passageways in bidirectional migrations of anatomically modern humans, by analyzing 45 informative biallelic markers as well as 10 microsatellite loci on the nonrecombining region of the Y chromosome (NRY) in 121 and 147 extant males from Oman and northern Egypt, respectively. The present study uncovers three important points concerning these demic movements: (1) The E3b1-M78 and E3b3-M123 lineages, as well as the R1*-M173 lineages, mark gene flow between Egypt and the Levant during the Upper Paleolithic and Mesolithic. (2) In contrast, the Horn of Africa appears to be of minor importance in the human migratory movements between Africa and Eurasia represented by these chromosomes, an observation based on the frequency distributions of E3b*-M35 (no known downstream mutations) and M173. (3) The areal diffusion patterns of G-M201, J-12f2, the derivative M173 haplogroups, and M2 suggest more recent genetic associations between the Middle East and Africa, involving the Levantine corridor and/or Arab slave routes. Affinities to African groups were also evaluated by determining the NRY haplogroup composition in 434 samples from seven sub-Saharan African populations. Oman and Egypt's NRY frequency distributions appear to be much more similar to those of the Middle East than to any sub-Saharan African population, suggesting a much larger Eurasian genetic component. Finally, the overall phylogeographic profile reveals several clinal patterns and genetic partitions that may indicate source, direction, and relative timing of different waves of dispersals and expansions involving these nine populations.

Africa, Eastern↗
PubMed1992

Assessment of epidemiological and HIV/AIDS publications in Africa.

To assess the quantity of epidemiological publications emanating from Africa, three international epidemiology journals were examined. In addition, a separate MEDLINE search was undertaken for 1987 and 1989-1990 to assess AIDS/HIV prevalence and incidence publications. Of 361 general epidemiological articles examined for 1974-1975, 49.3% were from the US, 20.5% from the UK, 11.1% from Europe, 10.2% from the rest of America, 4.4% from Asia, 3.9% from Australasia and 0.06% (only two) from Africa. The overall proportion from the USA declined to 44.0% by 1989-1990; from the UK to 11.1% while from South America and Australasia the proportion remained similar. Striking increases occurred in Europe and to a lesser extent in Asia. By 1989-1990 African articles contributed 3.6% (31) of the total. While over 90% of first authors came from the study region in the US, UK, Europe and Australasia; 85.7% in Asia; 70.8% in South America in 1989-1990, in Africa only 32.2% were authors from their continent. Of the 220 published articles on AIDS/HIV epidemiology 6.8% emanated from Africa in 1987 and 12% of 606 articles in 1989-1990. African scientists were first authors in 46.7% of articles from the continent in 1987 and only 35.5% in 1989 and 1990. In 1987, 60% of the articles were co-authored by overseas scientists of various nationalities while collaborative publications increased to 78.4% in 1989-1990. Only 15% of these articles were published in African Journals. This study stresses the urgent need for improving all aspects of epidemiological research and training in Africa with particular need with respect to AIDS/HIV research capacity.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Current status of polio eradication in Southern Africa.

During the 1990s, poliomyelitis transmission in 11 mainland and island nations of southern Africa appeared relatively low. However, the implementation of specific strategies recommended by the World Health Organization for eradicating polio in southern Africa began only in 1994. In 1995, oral poliovirus vaccine coverage (three doses) among infants was > or = 75% in all but 4 countries. National immunization days (NIDs) to control polio outbreaks were carried out in Namibia in 1994 and 1995. Angola, Botswana, and South Africa carried out subnational NIDs in 1995. All countries in southern Africa except Madagascar planned NIDs in 1996. Epidemiologic surveillance of acute flaccid paralysis (AFP) and laboratory surveillance of wild poliovirus was launched after nationwide training workshops in 7 mainland countries and is planned in the remaining countries by the end of 1996. Analysis of recommended performance indicators of AFP surveillance shows that substantial progress was made during 1994-1995, and the prospects for the certification of polio-free status in southern Africa on target appear good.

Adolescent↗
PubMed2003

Impact of the HIV epidemic in sub-Saharan Africa on the pattern of HIV in the UK.

OBJECTIVE: To describe the epidemiology of HIV infection acquired in Africa and among African communities in the United Kingdom. DESIGN: Descriptive analysis using national HIV and AIDS surveillance data, routine voluntary confidential HIV reporting and unlinked anonymous seroprevalence surveys in the United Kingdom to the end of December 2001. RESULTS: Of all reported HIV infections diagnosed in the United Kingdom by the end of 2001, 21% (9993 of 48,226) were probably acquired in Africa and 90% of these infections were heterosexually acquired. Numbers of diagnoses of HIV infection acquired in Africa have been increasing rapidly, with rises in infections from southeastern and southern Africa predominating recently. Among those living with diagnosed HIV infection in 2000, 23% (4883 of 21,291) were described as black African, 81% of whom lived in London. The proportion living in London has declined over successive prevalence surveys. CONCLUSIONS: Infections acquired in Africa and among Africans are making an increasing contribution to HIV infection in the United Kingdom. Migration, diagnosis of long-standing infection and incident cases are all potential influences, but they are difficult to measure. Improvement in early diagnosis of HIV continues to be an important component of intervention to prevent onward vertical and sexual transmission and to promote access to treatment and care.

Adult↗