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PubMed2001

Phylogeography and conservation of impala and greater kudu.

The phylogeography of the bush habituated African bovid species impala (Aepyceros melampus) and greater kudu (Tragelaphus strepsiceros) is investigated using mitochondrial DNA (mtDNA) markers. Combined analysis of individual lineages, relationships and population genetics suggest a colonization process from Southern Africa toward Eastern regions in the greater kudu. Results are less clear for the impala, although remaining consistent with a similar pattern of historical dispersion. The study reveals a similar pattern, that is a marked divergence of lineages from South-western Africa relative to other regions. This pattern is opposed to previously published findings in other African bovid species. In the impala, the genetically isolated region is consistent with morphology because it is recognized as the subspecies A. m. petersi, the black-faced impala. In contrast, the similar split of South-western mitochondrial lineages was not expected in the greater kudu on the basis of morphology. Both species show a significant population genetic differentiation. Beyond their phylogeographical value, our results should raise conservation concerns about South-western populations of both species. The black-faced impala is categorized as vulnerable and our data show indications of hybridization with common impala A. m. melampus. The previously unrecognized genetic status of the South-western kudus could also imply conservation regulations.

Africa, Eastern↗

PubMed2003

Species identification within the Anopheles funestus group of malaria vectors in Cameroon and evidence for a new species.

Anopheles funestus is a major vector of malaria in Africa. It belongs to a group of sibling species that can be identified morphologically only at certain stages of their development. A diagnostic polymerase chain reaction (PCR)-based tool made it possible to differentiate five species of the group. The assay seems to be applicable over all their distribution area for four of these species: An. funestus, An. leesoni, An. parensis, and An. vaneedenip. The fifth species, An. rivulorum, is the second most abundant species of the group and can be mistaken at its adult stage for the major vector of malaria An. funestus. Molecular and morphologic observations of specimens identified as An. rivulorum from Cameroon and South Africa showed that they belong to two different taxa. The species identified in Cameroon, and named here An. rivulorum-like, might extend to western Africa and central Africa. The species-specific PCR assay is supplemented by a primer specific to An. rivulorum-like and thus makes it possible to differentiate the five species of the An. funestus group and the newly defined taxon.

Animals↗

PubMed1989

Laboratory diagnosis of the first cases of HIV-2 infection in Canada.

Until recently the geographic distribution of infection due to human immunodeficiency virus type 2 (HIV-2) had excluded North America. We report the first two cases of such infection in Canada. Both people came from endemic areas of western Africa and were asymptomatic. The results of a commercial enzyme immunoassay specific for HIV-1 antibody were positive in both cases, but those of the Western blot technique were indeterminate. The Western blot technique specific for HIV-2 antibody and the indirect fluorescent antibody test were used to verify the presence of HIV-2 antibody.

Adult↗

PubMedDate not supplied

Type D retrovirus markers in healthy Africans from Guinea.

Sixteen matching sera and DNA samples from healthy African blood donors living in rural areas of Guinea were analysed for the presence of type D retrovirus markers. Screening for the antibodies against structural proteins of Mason-Pfizer monkey virus (M-PMV) was carried out by Western blot with a purified M-PMV as an antigen. Eight out of 16 sera samples were found to contain antibodies against at least two gag gene-coded proteins, and three of these were weakly positive against env gene-coded protein. Using PCR amplification and Southern hybridization, we detected M-PMV-like gag sequences in 11 out of 16 samples and env-related sequences in 8 out of 16 samples. Six DNAs were found to contain both M-PMV gag- and env-related sequences. Restriction endonuclease analysis of the PCR-amplified gag sequences from two individuals and direct DNA sequencing analysis of the amplimers confirmed their M-PMV-like origin. Detection of antibodies and M-PMV-related sequences in blood donors from Guinea, but not in French or Algerian blood donors, indicated exogenous SRV infection in humans from certain geographic areas of Western Africa.

Adolescent↗

PubMed2002

Phylogeny of Acridocarpus-Brachylophon (Malpighiaceae): implications for tertiary tropical floras and Afroasian biogeography.

A major tenet of African Tertiary biogeography posits that lowland rainforest dominated much of Africa in the late Cretaceous and was replaced by xeric vegetation as a response to continental uplift and consequent widespread aridification beginning in the late Paleogene. The aridification of Africa is thought to have been a major factor in the extinction of many African humid-tropical lineages, and in the present-day disparity of species diversity between Africa and other tropical regions. This primarily geologically based model can be tested with independent phylogenetic evidence from widespread African plant groups containing both humid- and xeric-adapted species. We estimated the phylogeny and lineage divergence times within one such angiosperm group, the acridocarpoid clade (Malpighiaceae), with combined ITS, ndhF, and trnL-F data from 15 species that encompass the range of morphological and geographic variation within the group. Dispersal-vicariance analysis and divergence-time estimates suggest that the basal acridocarpoid divergence occurred between African and Southeast Asian lineages approximately 50 million years ago (mya), perhaps after a southward ancestral retreat from high-latitude tropical forests in response to intermittent Eocene cooling. Dispersion of Aeridocarpus from Africa to Madagascar is inferred between approximately 50 and 35 mya, when lowland humid tropical forest was nearly continuous between these landmasses. A single dispersal event within Acridocarpus is inferred from western Africa to eastern Africa between approximately 23 and 17 mya, coincident with the widespread replacement of humid forests by savannas in eastern Africa. Although the spread of xeric environments resulted in the extinction of many African plant groups, our data suggest that for others it provided an opportunity for further diversification.

Africa↗

PubMed2002

Chronic poisoning by hydrogen cyanide in cassava and its prevention in Africa and Latin America.

Africa produces more than 30 million tons of cassava on about 5 million hectares (6 tons per hectare). Approximately 80% of the root production and 70% of the harvested area are from Western Africa. Recent reports suggest that the ingestion of poorly processed cassava roots is associated with the incidence of an ataxic neuropathy (konzo) in African countries. When cassava-based diets are not supplemented with good sources of protein and iodine, goiter and rickets are also prevalent. In certain countries of Africa where the rate of ataxic neuropathy is high, the incidence of thyroid disorders is also high. Persons consuming poorly processed cassava in large quantities are susceptible to neuropathologies caused by cyanide. Cyanide detoxification in the body is impaired by protein deficiency. When properly processed, the root of cassava is safe and cheap as a major dietary energy source for humans and domestic animals; however, a cassava-based diet will lack sufficient protein and will be particularly deficient for the growth and development of children unless it is supplemented by protein from animal, including fish, or legume sources. Cassava leaves, if they are appropriately cooked, can be a useful source of some nutrients.

Acute Disease↗

PubMed2000

Re-emergence of Chikungunya and O'nyong-nyong viruses: evidence for distinct geographical lineages and distant evolutionary relationships.

Chikungunya (CHIK) virus is a member of the genus Alphavirus in the family TOGAVIRIDAE: Serologically, it is most closely related to o'nyong-nyong (ONN) virus and is a member of the Semliki Forest antigenic complex. CHIK virus is believed to be enzootic throughout much of Africa and historical evidence indicates that it spread to other parts of the world from this origin. Strains from Africa and Asia are reported to differ biologically, indicating that distinct lineages may exist. To examine the relatedness of CHIK and ONN viruses using genetic data, we conducted phylogenetic studies on isolates obtained throughout Africa and Southeast Asia. Analyses revealed that ONN virus is indeed distinct from CHIK viruses, and these viruses probably diverged thousands of years ago. Two distinct CHIK virus lineages were delineated, one containing all isolates from western Africa and the second comprising all southern and East African strains, as well as isolates from Asia. Phylogenetic trees corroborated historical evidence that CHIK virus originated in Africa and subsequently was introduced into Asia. Within the eastern Africa and southern Africa/Asia lineage, Asian strains grouped together in a genotype distinct from the African groups. These different geographical genotypes exhibit differences in their transmission cycles: in Asia, the virus appears to be maintained in an urban cycle with Aedes aegypti mosquito vectors, while CHIK virus transmission in Africa involves a sylvatic cycle, primarily with AE: furcifer and AE: africanus mosquitoes.

Aedes↗

PubMedDate not supplied

[BCG vaccination and development of an innovative vaccine for preventing vertical HIV transmission in Africa].

"Families First Africa" is an international project whose main objective is to develop a pediatric vaccine that protects infants against HIV transmission during breast feeding. The vaccine being developed consists of HIV peptides matching HLA genotypes of the Western Africa population and will be administered in association with BCG vaccine which acts as a strong adjuvant. An alternative strategy is to administer a recombinant BCG vaccine with HIV gene fragments which codify for the same peptides.

AIDS Vaccines↗

PubMed2005

Addressing the paediatric HIV epidemic: a perspective from the Western Cape Region of South Africa.

In the Western Cape province of South Africa, a prevention of mother-to-child-transmission (PMTCT) intervention programme, based on short-course nevirapine, achieved universal coverage in 2003. Despite this programme, an estimated 1,400-1,650 HIV-infected children were born in the province in that year. These crude estimates suggest that there are many children in the province who need medical care. Several strategies could collectively reduce the size of the paediatric epidemic and improve the outcome of HIV-infected children in the region, including intensification of the existing PMTCT programme and provision of antiretroviral therapy (ART) for children with moderate or severe disease. Progress towards implementing these interventions is discussed. Future challenges include understanding the factors that favour long-term survival of children on highly active antiretroviral therapy in resource-limited settings, identifying appropriate treatment for the metabolic complications of ART, and the provision of adolescent services for long-term survivors. Developments over the next few years will determine whether these challenges can be met.

Adolescent↗

PubMed2002

Disadvantaged black and coloured infants in two urban communities in the Western Cape, South Africa differ in micronutrient status.

OBJECTIVES: To determine the nutritional and health status of urban infants in two disadvantaged communities in the Western Cape, South Africa with special reference to micronutrient status. The results of this study will serve to plan an intervention study in these communities in the same age group. DESIGN: Cross-sectional study. SETTING: Two disadvantaged urban black and 'coloured' communities in the Western Cape, South Africa. SUBJECTS: Sixty infants aged 6-12 months from each community. OUTCOME MEASURES: Dietary intake, anthropometric measurements, micronutrient status and psychomotor development. RESULTS: Stunting and underweight were more prevalent in coloured infants (18% and 7%, respectively) than in black infants (8% and 2%, respectively). Anaemia (haemoglobin (Hb) < 11 g dl(-1) was prevalent in 64% of coloured and 83% of black infants. Iron-deficiency anaemia (Hb < 11 g dl(-1) and ferritin < 10 ng ml(-1) was found in 32% of coloured infants and in 46% of black infants. Zinc deficiency was prevalent in 35% and 33% of the coloured and black infants, respectively. Marginal vitamin A deficiency (serum retinol < 20 microg dl(-1) was observed in 23% of black infants compared with 2% of coloured infants. Of black infants, 43% and of coloured infants 6% were deficient in two or more micronutrients. Six per cent of coloured infants had C-reactive protein concentrations above 5 mg l(-1) compared with 38% of the black infants. The dietary intake of micronutrients was in general lower in black infants than in coloured infants. The overall psychomotor development, assessed by the Denver Developmental Screening Test, was different between the two groups. The coloured infants scored higher in three out of the four categories as well as in their overall score. CONCLUSIONS: This study shows that information on stunting and wasting only in urban disadvantaged infants is not sufficient to make recommendations about specific community intervention programmes. Information on the micronutrient status, independent of wasting and stunting, is necessary to design nutrition programmes for different communities. The study also showed a substantially higher prevalence of micronutrient deficiencies among black infants.

Black or African American↗

PubMed1999

Tick-borne relapsing fever imported from West Africa: diagnosis by quantitative buffy coat analysis and in vitro culture of Borrelia crocidurae.

West African tick-borne relapsing fever (TBRF) is difficult to diagnose due to the low number of spirochetes in the bloodstream of patients. Previously, the causative microorganism, Borrelia crocidurae, had never been cultured in vitro. TBRF was rapidly diagnosed for two patients returning from western Africa with fever of unknown origin by quantitative buffy coat (QBC) analysis. Diagnosis was confirmed by intraperitoneal inoculation of blood specimens from patients into laboratory mice. In vitro experiments showed that QBC analysis may be as much as 100-fold more sensitive than thick smear. Spirochetes were also cultured from blood samples from both patients in modified Kelly's medium and were identified as B. crocidurae by partial sequencing of the PCR-amplified rrs gene.

Acridine Orange↗

PubMed1976

Blood and serum protein groups of the dama of South-West Africa.

The phenotype and gene frequencies of the following polymorphisms are given for the blood samples taken from 448 adults of the South-West African Dama Negro tribe: ABO (with sub-groups), MN, Rh, K, Hp, Gc, Gm(1,2,b), InV(1). The frequencies are discussed in comparison with other African samples and a multivariate comparison between series from south-western Africa is conducted. The Dama prove to be relatively independent.

ABO Blood-Group System↗

PubMedDate not supplied

[Competition for the promotion of essential generic drugs in Africa].

STATEMENT OF THE PROBLEM: in most sub-Saharan countries, an extensive economic crisis coupled with a low level of existing resources has put most pharmaceuticals beyond the reach of the general public. This situation was worsened by the devaluation of the Franc CFA in 1994. The supply of lowprice drugs and the improvement of rational drug use is now a priority. Unfortunately, essential generic drugs are little known and used in Africa. OBJECTIVE: 1. To improve the knowledge of and confidence in essential and generic drugs among providers, prescribers and consumers, through the participation of the general public in an incentive-based, creative competition; 2. To collect locally-adapted promotional material, to be used in the future promotion of essential and generic drugs in Africa. Design, setting and method: a competition was announced in June 1995, via various networks, in French-speaking Africa: the population was invited to create one or several items promoting essential generic drugs. These items included slogans, posters, songs and short plays. Over 550 entries were received before the deadline (15 October 1995), from 22 countries (mostly Sub-Saharan and French-speaking). The entries included 387 slogans, 94 posters, 22 plays, and various (photos, comic strips, songs, poems). RESULTS: 1. Greater awareness of essential generic drugs in Western Africa, through the publicity given to the competition; 2. Selection of a pool of approximately 200 promotional items, produced by the target populations, to be published in a catalog and distributed in African countries; 3. Insights into popular practices and representations of Western medications, and local re-interpretation of the concept. CONCLUSION: this public competition was effective at achieving three important goals: 1. Dynamic promotion (the competition was the opportunity for school projects, radio talkshows, etc. on generic drugs); 2. Re appropriation of a policy, thanks to a participative approach; 3. Analysis of the population's general comprehension of pharmaceuticals, through analysis of competition entries.

Advertising↗

PubMed2004

MtDNA profile of West Africa Guineans: towards a better understanding of the Senegambia region.

The matrilineal genetic composition of 372 samples from the Republic of Guiné-Bissau (West African coast) was studied using RFLPs and partial sequencing of the mtDNA control and coding region. The majority of the mtDNA lineages of Guineans (94%) belong to West African specific sub-clusters of L0-L3 haplogroups. A new L3 sub-cluster (L3h) that is found in both eastern and western Africa is present at moderately low frequencies in Guinean populations. A non-random distribution of haplogroups U5 in the Fula group, the U6 among the "Brame" linguistic family and M1 in the Balanta-Djola group, suggests a correlation between the genetic and linguistic affiliation of Guinean populations. The presence of M1 in Balanta populations supports the earlier suggestion of their Sudanese origin. Haplogroups U5 and U6, on the other hand, were found to be restricted to populations that are thought to represent the descendants of a southern expansion of Berbers. Particular haplotypes, found almost exclusively in East-African populations, were found in some ethnic groups with an oral tradition claiming Sudanese origin.

Black People↗

PubMed1995

[The Institute of Tropical Ophthalmology of Africa].

The Tropical Ophthalmology Institute of Africa (TOIA) is an integral part of the OCCGE. Located in Bamako since 1953, the TOIA is operated jointly by the member states of the OCCGE, the French Cooperation Ministry, and the WHO for which it serves as a center for the prevention of blindness. In addition to providing eye care for the people of western Africa, the TOIA promotes clinical, epidemiologic, and surgical research and carries out health surveys in function of the needs of the member states of the OCCGE. The major purpose of the TOIA is to training doctors and ophthalmologic nurses as well as for cataract operators and eyeglasses technicians. At the center of a network dedicated to the fight against blindness, the range of action of the TOIA now reaches beyond the borders of the eight states in the OCCGE.

Academies and Institutes↗

PubMed1991

Current status of food-borne parasitic zoonoses in Mediterranean and African regions.

Epidemiological data on food-borne parasitic zoonoses of Mediterranean and African regions are fragmentary. Several studies indicate that toxoplasmosis frequently occurs in Africa, but the epidemiological patterns in these countries are far from being complete. Serological investigations have been carried out with different methods and the results are not always comparable. Food habits, presence or absence of domestic and/or synanthropic felines, and environmental characteristics (damp or dry areas) seem to influence the prevalence of infection in man from 15 to over 60%. There are few reports on Sarcocystis infection in man, while its presence in domestic and sylvatic animals is well evidenced. Cysticercosis infection in cattle is widespread in Africa with a prevalence ranging from 2 to 50% in relation to breeding and human habits. In European countries of the Mediterranean area the prevalence of infection is below 2%. Cysticercosis infection in swine has almost disappeared in the Mediterranean area, while it is still present in some African countries. Human paragonimiasis is present in Western Africa with a prevalence ranging from 2 to 31%. Heterophyasis in man is present in Egypt, Tunisia, and Middle East. Sylvatic trichinellosis is widespread in Mediterranean (Trichinella sp.3) and African (T. nelsoni, Trichinella T8) regions. Domestic trichinellosis (T. spiralis spiralis) is present in Spain, France, Yugoslavia, Egypt, Gambia, and Nigeria in domestic and/or sylvatic animals. In Africa human trichinellosis is rare, mostly from religious and food habits. Till now very few control projects against food-borne parasitic zoonoses have been developed in Africa.

Africa↗

PubMed1995

Pneumococcal resistance to beta-lactam antibiotics: a global geographic overview.

beta-Lactam resistance in Streptococcus pneumoniae has spread over the entire world. The 10 main foci of resistant organisms are located in the following areas: (1) southwest Europe (Spain, France, Portugal), (2) central-east Europe (Hungary, Roumania, Bulgaria, Turkey) and Israel, (3) northwest Russia, (4) South Africa, (5) Japan and South Korea, (6) Papua-New Guinea, (7) Alaska, (8) southeast North America, (9) southwest North America, and (10) south cone in South America. A comparison of the presumed factors influencing the increase of pneumococcal resistance in these foci with those occurring in low incidence areas, such as central-north Europe, Scandinavia, north and western Africa, or middle-north Mediterranean countries (Italy, Greece) should provide the clues to predict and prevent further spread of resistant pneumococci.

Humans↗

PubMed2004

Estimates of global prevalence of childhood underweight in 1990 and 2015.

CONTEXT: One key target of the United Nations Millennium Development goals is to reduce the prevalence of underweight among children younger than 5 years by half between 1990 and 2015. OBJECTIVE: To estimate trends in childhood underweight by geographic regions of the world. DESIGN, SETTING, AND PARTICIPANTS: Time series study of prevalence of underweight, defined as weight 2 SDs below the mean weight for age of the National Center for Health Statistics and World Health Organization (WHO) reference population. National prevalence rates derived from the WHO Global Database on Child Growth and Malnutrition, which includes data on approximately 31 million children younger than 5 years who participated in 419 national nutritional surveys in 139 countries from 1965 through 2002. MAIN OUTCOME MEASURES: Linear mixed-effects modeling was used to estimate prevalence rates and numbers of underweight children by region in 1990 and 2015 and to calculate the changes (ie, increase or decrease) to these values between 1990 and 2015. RESULTS: Worldwide, underweight prevalence was projected to decline from 26.5% in 1990 to 17.6% in 2015, a change of -34% (95% confidence interval [CI], -43% to -23%). In developed countries, the prevalence was estimated to decrease from 1.6% to 0.9%, a change of -41% (95% CI, -92% to 343%). In developing regions, the prevalence was forecasted to decline from 30.2% to 19.3%, a change of -36% (95% CI, -45% to -26%). In Africa, the prevalence of underweight was forecasted to increase from 24.0% to 26.8%, a change of 12% (95% CI, 8%-16%). In Asia, the prevalence was estimated to decrease from 35.1% to 18.5%, a change of -47% (95% CI, -58% to -34%). Worldwide, the number of underweight children was projected to decline from 163.8 million in 1990 to 113.4 million in 2015, a change of -31% (95% CI, -40% to -20%). Numbers are projected to decrease in all subregions except the subregions of sub-Saharan, Eastern, Middle, and Western Africa, which are expected to experience substantial increases in the number of underweight children. CONCLUSIONS: An overall improvement in the global situation is anticipated; however, neither the world as a whole, nor the developing regions, are expected to achieve the Millennium Development goals. This is largely due to the deteriorating situation in Africa where all subregions, except Northern Africa, are expected to fail to meet the goal.

Body Weight↗