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At least 307 records · Page 17Linked to original sources
PubMed2005

Modelling malaria risk in East Africa at high-spatial resolution.

OBJECTIVES: Malaria risk maps have re-emerged as an important tool for appropriately targeting the limited resources available for malaria control. In Sub-Saharan Africa empirically derived maps using standardized criteria are few and this paper considers the development of a model of malaria risk for East Africa. METHODS: Statistical techniques were applied to high spatial resolution remotely sensed, human settlement and land-use data to predict the intensity of malaria transmission as defined according to the childhood parasite ratio (PR) in East Africa. Discriminant analysis was used to train environmental and human settlement predictor variables to distinguish between four classes of PR risk shown to relate to disease outcomes in the region. RESULTS: Independent empirical estimates of the PR were identified from Kenya, Tanzania and Uganda (n = 330). Surrogate markers of climate recorded on-board earth orbiting satellites, population settlement, elevation and water bodies all contributed significantly to the predictive models of malaria transmission intensity in the sub-region. The accuracy of the model was increased by stratifying East Africa into two ecological zones. In addition, the inclusion of urbanization as a predictor of malaria prevalence, whilst reducing formal accuracy statistics, nevertheless improved the consistency of the predictive map with expert opinion malaria maps. The overall accuracy achieved with ecological zone and urban stratification was 62% with surrogates of precipitation and temperature being among the most discriminating predictors of the PR. CONCLUSIONS: It is possible to achieve a high degree of predictive accuracy for Plasmodium falciparum parasite prevalence in East Africa using high-spatial resolution environmental data. However, discrepancies were evident from mapped outputs from the models which were largely due to poor coverage of malaria training data and the comparable spatial resolution of predictor data. These deficiencies will only be addressed by more random, intensive small areas studies of empirical estimates of PR.

Animals↗
PubMed2006

Estimation of the sexual transmission of HIV in Kenya and Uganda on the trans-Africa highway: the continuing role for prevention in high risk groups.

OBJECTIVE: To explore the effect of transactional sex on the trans-Africa highway from Mombasa-Kampala in contributing to the HIV epidemic and the impact that an effective prevention intervention could have. METHODS: Variables for input into a simple model of HIV prevention, AVERT, were derived from a study of hot spots of transactional sex on the trans-Africa highway. Diaries were completed by a sample of sex workers at selected sites of transactional sex for a period of 28 consecutive days. Key information elicited included numbers, types and occupations of clients, numbers of liaisons, sexual acts in each liaison, and condom use. 857 diaries were distributed and 578 received and usable in 30 sites. A sexual patterning matrix was completed by 202 truckers at the Malaba border point as part of a health seeking behaviour survey. Two methods were employed to estimate female sex worker (FSW) numbers on the highway. FSW focus group discussions (FGDs) at 15 sites were carried out and included questioning on the number of sex workers at the site. As most transactional sex on the highway is centred on bars and lodgings, a patron census and survey of 1007 bars and lodgings was carried out which included questions on the presence and proportions of FSWs among the clientele. RESULTS: There are an estimated 8000 FSWs on the trans-Africa highway from Mombasa to Kampala. Annual numbers of different sexual partners per FSW were 129, annual numbers of sexual acts per FSW were 634, percentage of sexual acts protected by condom use was 77.7%. Using these input data an estimated 3200-4148 new HIV infections occur on this portion of the trans-Africa highway in 1 year. Having a 90% condom use programme in place could prevent almost two thirds of these infections and cumulative incidence would decline from 1.29% to 0.42%. CONCLUSIONS: In generalised epidemics there has been a debate as to the place of targeted interventions. In the current east African epidemic we show that a targeted intervention could have significant impact in averting HIV infections related to the trans-Africa highway.

Condoms↗
PubMed2002

The application of geographical information systems to important public health problems in Africa.

Africa is generally held to be in crisis, and the quality of life for the majority of the continent's inhabitants has been declining in both relative and absolute terms. In addition, the majority of the world's disease burden is realised in Africa. Geographical information systems (GIS) technology, therefore, is a tool of great inherent potential for health research and management in Africa. The spatial modelling capacity offered by GIS is directly applicable to understanding the spatial variation of disease, and its relationship to environmental factors and the health care system. Whilst there have been numerous critiques of the application of GIS technology to developed world health problems it has been less clear whether the technology is both applicable and sustainable in an African setting. If the potential for GIS to contribute to health research and planning in Africa is to be properly evaluated then the technology must be applicable to the most pressing health problems in the continent. We briefly outline the work undertaken in HIV, malaria and tuberculosis (diseases of significant public health impact and contrasting modes of transmission), outline GIS trends relevant to Africa and describe some of the obstacles to the sustainable implementation of GIS. We discuss types of viable GIS applications and conclude with a discussion of the types of African health problems of particular relevance to the application of GIS.

Journal Article↗
PubMed2006

Managing health professional migration from sub-Saharan Africa to Canada: a stakeholder inquiry into policy options.

BACKGROUND: Canada is a major recipient of foreign-trained health professionals, notably physicians from South Africa and other sub-Saharan African countries. Nurse migration from these countries, while comparatively small, is rising. African countries, meanwhile, have a critical shortage of professionals and a disproportionate burden of disease. What policy options could Canada pursue that balanced the right to health of Africans losing their health workers with the right of these workers to seek migration to countries such as Canada? METHODS: We interviewed a small sample of émigré South African physicians (n = 7) and a larger purposive sample of representatives of Canadian federal, provincial, regional and health professional departments/organizations (n = 25); conducted a policy colloquium with stakeholder organizations (n = 21); and undertook new analyses of secondary data to determine recent trends in health human resource flows between sub-Saharan Africa and Canada. RESULTS: Flows from sub-Saharan Africa to Canada have increased since the early 1990s, although they may now have peaked for physicians from South Africa. Reasons given for this flow are consistent with other studies of push/pull factors. Of 8 different policy options presented to study participants, only one received unanimous strong support (increasing domestic self-sufficiency), one other received strong support (increased health system strengthening in source country), two others mixed support (voluntary codes on ethical recruitment, bilateral or multilateral agreements to manage flows) and four others little support or complete rejection (increased training of auxiliary health workers in Africa ineligible for licensing in Canada, bonding, reparation payments for training-cost losses and restrictions on immigration of health professionals from critically underserved countries). CONCLUSION: Reducing pull factors by improving domestic supply and reducing push factors by strengthening source country health systems have the greatest policy traction in Canada. The latter, however, is not perceived as presently high on Canadian stakeholder organizations' policy agendas, although support for it could grow if it is promoted. Canada is not seen as "actively' recruiting" ("poaching") health workers from developing countries. Recent changes in immigration policy, ongoing advertising in southern African journals and promotion of migration by private agencies, however, blurs the distinction between active and passive recruitment.

Journal Article↗
PubMed1999

Tick-borne rickettiosis in Guadeloupe, the French West Indies: isolation of Rickettsia africae from Amblyomma variegatum ticks and serosurvey in humans, cattle, and goats.

Twenty-seven rickettsiae were isolated and/or detected from 100 Amblyomma variegatum ticks collected on Guadeloupe in the French West Indies. In this study, the polymerase chain reaction procedure appeared to be more sensitive in detecting rickettsiae in ticks than the shell-vial technique. Sequencing a portion of the outer membrane protein A-encoding gene showed that these rickettsiae appeared to be identical to Rickettsia africae, a member of the spotted fever group rickettsiae recently described as an agent of African tick-bite fever occurring in sub-Sahelian Africa. A high seroprevalence of antibodies to R. africae was demonstrated among mammals, particularly humans, cattle, and goats. These results and a recently reported case of an infection due to R. africae on Guadeloupe demonstrate that R. africae is present on this island. Although this disease has been underdiagnosed there, it may be frequent and may exist on other Caribbean islands where A. variegatum has propagated dramatically over recent years.

Adolescent↗
PubMed2003

Recruiting foreign doctors to South Africa: difficulties and dilemmas.

In 2003, the Medical and Dental Professional Board of the Health Professions Council of South Africa again made it possible for foreign-qualified doctors to obtain registration without sitting an examination. This eased the way for eligible non-South African doctors to work in South Africa in order to assist with the current staffing crisis in rural hospitals. This personal view examines the issues and difficulties related to foreign-trained doctors practising in South Africa, such as short-term practice vs long-term commitment; strategies to promote preparation of local doctors for rural hospital practice; the loss of recruited doctors to third-party countries; the principle of distributive justice in international medical training; and defining acceptable standards of training. The conclusions reached are that while doctors from developing countries, especially from neighbouring African nations, have historically brought a wealth of practical experience to South Africa's rural hospitals, there are also mutual benefits in recruiting from doctors trained in developed countries. The guiding principle is to obtain well-trained and experienced doctors who are able to function in a rural hospital until there are sufficient local-trained doctors. While the article focuses specifically on medical staffing in rural South Africa, the principles discussed apply equally to other health-care professionals and other, similar countries.

Journal Article↗
PubMed2000

Financing blood transfusion services in sub-Saharan Africa: a role for user fees?

The provision of a secure and safe blood supply has taken on new importance in sub-Saharan Africa with the onset of the AIDS epidemic. Blood transfusion services capable of providing safe blood are not cheap, however, and there has been some debate on the desirability and sustainability of different financing mechanisms for blood transfusion services. This paper examines patterns of financing blood transfusion in three countries--Côte d'Ivoire, Zimbabwe and Mozambique. It goes on to consider the conceptual options for financing safe blood, and to examine in detail the possible role of user fees for blood transfusion in Africa, developing a simple model of their likely burden to patients based on data from Côte d'Ivoire. The model indicates that, at best, there can only be a limited role for user fees in the financing of safe blood transfusion services, due mainly to the relatively high cost of producing a unit of safe blood. Charging individuals for the blood they receive is likely to be administratively complex and costly, could realistically recover only a fraction of the production costs involved, and is further complicated by the fact that the main recipients of blood transfusion in sub-Saharan Africa are children and pregnant women. If cost-recovery for safe blood is to be attempted, the most viable option appears to be that of charging a collective fee, levied upon all inpatients, not just on those who receive blood. Such a mechanism is not without problems, not least in its failure to offer incentives for more appropriate blood use, and it is still likely to recover only a portion of the costs of producing safe blood. Whether or not cost-recovery is instituted, there will remain an important role for public funding of blood transfusion services, and, by implication, an important role for foreign donor support.

Blood Banks↗
PubMed1991

Notes on the demography of black Africans in South Africa in the early 1980s.

The demography of the black population of South Africa is analyzed and compared with that of blacks in the rest of Sub-Saharan Africa, using data from official sources. "The article is organized into four sections. First, it surveys what is known about mortality and fertility (and family planning). Then it turns to the issue of the population's size, past growth and projected future growth. Finally, the article takes a bold leap into the morass of population distribution, involving forays into migration and urbanization." It is found that "black Africans in South Africa are demographically quite similar to other sub-Saharan populations."

Africa↗
PubMed1997

South Africa says 2.4 million people infected with HIV.

South Africa's Health Ministry said the HIV infection rate had risen to 6% of the population from about 4.6% a year ago. Rose Smuts, Health Ministry AIDS expert, said that the estimated number of people infected with HIV was up to 2.4 million at the end of 1996 from 1.8 million a year earlier. "In 1997, about 90,000 people will progress to [advanced], of whom about 20,000 will be children," she said. Health Minister Nkosazana Zuma released results at the same news conference of the 1996 antenatal HIV survey, which showed that the infection rate among pregnant women attending state clinics rose nearly 35%. Anonymous testing of more than 15,000 pregnant women showed the infection rate up from 10.44% at the end of 1995 to 14.07% in 1996. Infections have almost doubled from 7.5% in 1994. "The sharp increase of 34.8% over the previous year confirms that South Africa is still experiencing a fast growing HIV epidemic," the Health Ministry said in a report. The highest infection rate and a threefold increase were recorded in Northwest Province, near Johannesburg, where positive tests jumped from 8.3% in 1995 to 25.13% in 1996. KwaZulu-Natal, South Africa's most populous province and previously the worst affected, showed a modest increase from 18.23% to 19.9% in 1996. The Western Cape, which includes Cape Town, showed the lowest infection rate of 1.65%, which was unchanged from the previous year. Zuma said that the doubling rate of HIV infection had slowed from 12 months to about 24 months, but she said that the emphasis should remain on the spread of the epidemic, which hits the working population hardest. Smuts said results of the antenatal survey could be extrapolated to a national infection rate of 6%, an 11% infection rate among all adults, and a 10% infection level among men aged 15-45 years.

Africa↗
PubMed1995

[More and more Dutch nationals to South Africa].

"From 1950-1994 almost 62 thousand Dutch nationals left for South Africa. Almost half of them left the Netherlands in the fifties. In the same period, more than 43 thousand Dutch nationals returned to the Netherlands. Fluctuations in external migration with South Africa can be related to political events there.... From the end of 1994, emigration of Dutch nationals to South Africa is now higher than immigration from that country." (SUMMARY IN ENG)

Africa↗
PubMed1982

The biocultural evolution of Khoisan populations of Southern Africa.

The research presented here offers new information on the recent evolution of Khoisan populations of southern Africa through the new study of Holocene skeletons. When combined with subfossil and historical remains, these archeological specimens provide a skeletal record for the last 5000-9000 years of southern African prehistory. Multivariate statistical analyses of cranial measurements were used to determine patterns of morphological variation in the skeletal record with which hypotheses of biocultural evolution were tested. These analyses yielded the following results. First, the traditional distinction between Bushmen ad Hottentots holds for recent inland individuals. Second, there is a suggestion of a morphologically distinct San population living on the coast of South Africa. The idea of a "Strandloper" population suggested by early scholars is here revived. The third results is that there is little evidence of complete population succession on the coast of South Africa,, suggesting that there were to massive population movements associated with the spread of Hottentot pastoralism throughout southern Africa.

Africa, Southern↗
PubMed2002

Opportunistic infections associated with HIV infection in Africa.

HIV-associated infections in sub-Saharan Africa differ markedly in their incidence from those in industrialized countries. Tuberculosis is the commonest cause of morbidity and mortality. Enteric pathogens such as microsporidiosis commonly cause disease as access to safe water is limited. Pneumocystis carinii pneumonia, which is the commonest opportunistic infection in industrialized countries, is uncommon in adults with HIV infection. This remains unexplained because P. carinii pneumonia is common in Black African HIV-infected children. Cytomegalovirus and Mycobacterium avium complex, which only occur in severely immune-suppressed individuals, are seldom found. One reason may be that survival after conversion to AIDS is relatively short in Africa. Patients often die before they develop severe immune suppression. Recently, prophylactic cotrimoxazole treatment was shown to be effective in symptomatic HIV-infected adults in Africa. Tuberculosis preventive therapy is also effective in Africa, at least in the medium term. It is hoped that these two affordable interventions will become available to large numbers of patients identified in voluntary counselling and testing centres.

AIDS Serodiagnosis↗
PubMed2006

Community attitudes towards sexual activity and childbearing by HIV-positive people in South Africa.

While the ability to lead a healthy sexual life and to choose whether and when to have children are well-established features of reproductive health and human rights, issues surrounding sexual activity and childbearing among HIV-infected women and men have received little attention in sub-Saharan Africa. We conducted a semi-structured, cross-sectional survey at 26 primary health care clinics in South Africa to investigate community attitudes towards sexual activity and reproduction by HIV-infected individuals. Of the 843 women interviewed, slightly less than half (43%, n = 361) thought that people living with HIV/AIDS should remain sexually active if they choose, while 13% (n = 113) said they thought that people living with HIV/AIDS should have children if they wished to do so. In multivariate analysis, negative attitudes towards both sexuality and childbearing were persistently associated with not knowing someone infected with HIV (p = 0.001 and 0.043, respectively). These findings suggest that the sexual and reproductive health rights of HIV-infected women and men may be an important target as part of efforts to reduce HIV/AIDS-related stigma. Health policies and services are required to reinforce the reproductive rights of HIV-infected individuals in South Africa and other countries in sub-Saharan Africa where HIV is most prevalent.

Adult↗
PubMed2002

Lack of evidence for HIV type 1-related SIVcpz infection in captive and wild chimpanzees (Pan troglodytes verus) in West Africa.

Serum from 387 chimpanzees (Pan troglodytes verus), caught in the wild or bred in captivity, was tested for antibody to HIV-1 and HIV-2, using second- and third-generation enzyme immunoassays. Six samples were repeatedly positive; however, only one of these was Western blot positive. Serial sera drawn before and after the Western blot-positive samples were seronegative, and thus we conclude that this sample represented specimen contamination, or mislabeling. Thus, none of the 387 Pan troglodytes verus from West Africa were spontaneously infected with SIVcpz. Chimpanzees are known to be exquisitely susceptible to infection with HIV-1 when experimentally inoculated, and thus our findings suggest that HIV-1-related viruses do not exist in Pan troglodytes verus in the wild. As it has been convincingly shown that SIVcpz exists in wild Pan troglodytes troglodytes in Central Africa, this suggests that HIV-1 arose in Central Africa, but not in West Africa.

Africa, Central↗
PubMed1997

Simian T cell leukemia virus type I from naturally infected feral monkeys from central and west Africa encodes a 91-amino acid p12 (ORF-I) protein as opposed to a 99-amino acid protein encoded by HTLV type I from humans.

A single protein of 12 kDa, p12 is encoded by the HTLV-I genome from both the singly spliced mRNA pX-ORF-I and doubly spliced mRNA pX-rex-ORF-I. While many full-length sequences of HTLV-1 are known, data on the p12 regions of African STLV-I are unavailable. We have undertaken to sequence the p12 gene in STLV-I from Central and West Africa naturally infected primates, and have compared them to known p12 sequences of HTLV-I. Our data on sequence and in vitro transcription-translation analyses indicate that p12 is a 91-amino acid (aa) protein among STLV-I strains from Central and West Africa, in contrast to the 99-aa protein found among HTLV-I strains around the globe. The p12 sequences of STLV-I exhibit a marked genetic variability at the level of both nucleotide and peptide sequences. Hydropathic and helical wheel analyses reveal that 60% of residues in HTLV-I p12 are hydrophobic, in contrast to 55% in STLV-I from Africa. Although HTLV-I and STLV-I show a similar putative antigenic site, a second potential site was located exclusively in STLV-I from Africa. There are differences in the predicted transmembrane domains in p12 between STLV-I and HTLV-I. Furthermore, the secondary structure data according to the Chou and Fasman algorithm predict an alpha-helical domain at the carboxy terminus in HTLV-I, and this domain may be truncated in STLV-I p12. The amino acid sequence of p12 shows two leucine zipper motifs (LZMs) at the amino terminus and in the middle region, respectively. This is the first report describing the size differences in p12 protein between HTLV-I and STLV-I, which may provide insights into pathogenic mechanisms used by HTLV-I and STLV-I.

Africa, Central↗
PubMed2006

Mapping malaria transmission in West and Central Africa.

We have produced maps of Plasmodium falciparum malaria transmission in West and Central Africa using the Mapping Malaria Risk in Africa (MARA) database comprising all malaria prevalence surveys in these regions that could be geolocated. The 1846 malaria surveys analysed were carried out during different seasons, and were reported using different age groupings of the human population. To allow comparison between these, we used the Garki malaria transmission model to convert the malaria prevalence data at each of the 976 locations sampled to a single estimate of transmission intensity E, making use of a seasonality model based on Normalized Difference Vegetation Index (NDVI), temperature and rainfall data. We fitted a Bayesian geostatistical model to E using further environmental covariates and applied Bayesian kriging to obtain smooth maps of E and hence of age-specific prevalence. The product is the first detailed empirical map of variations in malaria transmission intensity that includes Central Africa. It has been validated by expert opinion and in general confirms known patterns of malaria transmission, providing a baseline against which interventions such as insecticide-treated nets programmes and trends in drug resistance can be evaluated. There is considerable geographical variation in the precision of the model estimates and, in some parts of West Africa, the predictions differ substantially from those of other risk maps. The consequent uncertainties indicate zones where further survey data are needed most urgently. Malaria risk maps based on compilations of heterogeneous survey data are highly sensitive to the analytical methodology.

Africa, Central↗
PubMed1996

Plant poisonings and mycotoxicoses as constraints in livestock production in east Africa: the southern African experience.

The major plant poisonings and mycotoxicoses of southern Africa are discussed in relation to East Africa. As almost all the plant genera and most species responsible for intoxication in southern Africa are present in East Africa, it is postulated that the same intoxications probably also occur in the latter. There is a necessity to diagnose and control these conditions.

Africa, Eastern↗
PubMedDate not supplied

[Current status of the female condom in Africa].

The female condom was developed in the 1980s. It is a contraceptive device used by women that protects against both pregnancy and sexually-transmitted diseases (STDs) including HIV infection. Two studies have investigated the contraceptive effectiveness of the female condom, and it was found to be as effective as other barrier methods. It has been shown to be effective against STD and HIV transmission in vitro but there is only limited evidence of its efficacy in vivo. No serious local side effects or allergies have been reported and the female condom can be used with any type of lubricant, spermicidal cream or foam. The female condom is the only device other than the male condom that has been shown to prevent HIV transmission. The female condom has been marketed in 13 countries since the summer of 1996. Most of these countries are industrialized and the selling price in these countries is too high for developing countries. Sub-Saharan Africa has very high prevalence rates for HIV infection, at least 30% of the general population in Eastern and Central regions. The epidemic is also spreading fast in some parts of the Western region. In Ivory Coast for example, 12 to 15% of pregnant women are infected. African women are subordinate to men in many aspects of their lives, politically, educationally, socially and sexually. This sexual inequality makes them highly vulnerable to STDs, including HIV, and unwanted pregnancies. This paper reviews 10 of the 15 studies carried out in sub-Saharan African countries between 1990 and 1996 and compiled by the World Health Organization. Recruitment methods, education of subjects, methodology and assessment of acceptability differed between studies. Despite these limitations, most studies concluded that the women who participated in the trials generally found the female condom acceptable. Acceptability was established quicker among prostitutes than among other women and men found the female condom less acceptable than did women. However, the sample size is too small to draw any firm conclusions. Commercial sex workers in the studies reviewed were very interested in this new method because it gave them an additional method of safer protection during sex. However, they were occasionally faced with difficult negotiations with some clients, refusal to use the female condom and sexual violence. Reuse of the device was reported in four studies, but the term reuse is seldom defined. In cases where it was defined, the frequency of reuse, with washing of the device, accounted for no more than 1% of the total number of uses. The acceptability of the female condom among women other than prostitutes faces two obstacles, the reaction of the woman's regular partner and attitudes to the device itself (appearance, difficulties or uneasiness concerning its use). However, some women liked it because it provided dual protection against pregnancy and STDs and sexual pleasure. The moderate level of acceptability to male partners may be overestimated because women whose partners disliked the device would be more likely to discontinue its use. The studies of acceptability reviewed here show that use of the female condom in Africa is realistic and that it provides women with more independent protection. Initial negative perceptions of the device are often replaced with a more positive reaction after several uses. The experience gained with use reduces the technical problems. We need to overcome the stereotypes, simplifications and strong opinions that threaten to damage the acceptance of this new method and efforts to encourage women to adopt it. However, we still require further clinical data on the effectiveness of the female condom at preventing pregnancy and HIV transmission. Availability of the female condom is improving in Africa. Pilot marketing studies were launched in 1996 in Guinea, Zambia, South Africa, followed by Uganda and Tanzania. There are local initiatives in Ivory Coast and Zimbabwe. (ABSTRACT TRUNC

Africa↗