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PubMed2001

High-resolution analysis of human Y-chromosome variation shows a sharp discontinuity and limited gene flow between northwestern Africa and the Iberian Peninsula.

In the present study we have analyzed 44 Y-chromosome biallelic polymorphisms in population samples from northwestern (NW) Africa and the Iberian Peninsula, which allowed us to place each chromosome unequivocally in a phylogenetic tree based on >150 polymorphisms. The most striking results are that contemporary NW African and Iberian populations were found to have originated from distinctly different patrilineages and that the Strait of Gibraltar seems to have acted as a strong (although not complete) barrier to gene flow. In NW African populations, an Upper Paleolithic colonization that probably had its origin in eastern Africa contributed 75% of the current gene pool. In comparison, approximately 78% of contemporary Iberian Y chromosomes originated in an Upper Paleolithic expansion from western Asia, along the northern rim of the Mediterranean basin. Smaller contributions to these gene pools (constituting 13% of Y chromosomes in NW Africa and 10% of Y chromosomes in Iberia) came from the Middle East during the Neolithic and, during subsequent gene flow, from Sub-Saharan to NW Africa. Finally, bidirectional gene flow across the Strait of Gibraltar has been detected: the genetic contribution of European Y chromosomes to the NW African gene pool is estimated at 4%, and NW African populations may have contributed 7% of Iberian Y chromosomes. The Islamic rule of Spain, which began in a.d. 711 and lasted almost 8 centuries, left only a minor contribution to the current Iberian Y-chromosome pool. The high-resolution analysis of the Y chromosome allows us to separate successive migratory components and to precisely quantify each historical layer.

Africa South of the Sahara↗
PubMed2003

African tick bite fever in travelers to rural sub-Equatorial Africa.

To estimate the incidence of, identify risk factors for, and describe the clinical presentation of travel-associated African tick bite fever (ATBF), a rapidly emerging disease in travel medicine, we prospectively studied a cohort of 940 travelers to rural sub-Equatorial Africa. Diagnosis was based on suicide polymerase chain reaction and the detection of specific antibodies to Rickettia africae in serum samples by multiple-antigen microimmunofluorescence assay, Western blotting, and cross-adsorption assays. Thirty-eight travelers, 4.0% of the cohort and 26.6% of those reporting flulike symptoms, had ATBF diagnosed. More than 80% of the patients had fever, headache, and/or myalgia, whereas specific clinical features such as inoculation eschars, lymphadenitis, cutaneous rash, and aphthous stomatitis were seen in < or = 50% of patients. Game hunting, travel to southern Africa, and travel during November through April were found to be independent risk factors. Our study suggests that ATBF is not uncommon in travelers to rural sub-Saharan Africa and that many cases have a nonspecific presentation.

Africa↗
PubMed2004

HIV type 1 circulating recombinant form CRF09_cpx from west Africa combines subtypes A, F, G, and may share ancestors with CRF02_AG and Z321.

Two HIV-1 intersubtype recombinant forms are circulating widely in populations and have become important strains in the pandemic: CRF01_AE in Southeast Asia and CRF02_AG in West and West Central Africa, respectively. Several other circulating recombinant forms (CRF) have also been identified, but with fewer numbers of infections and/or more limited geographic spread. Here we expand knowledge of HIV-1 CRF using clinical samples, principally from West Africa, that were difficult to classify by partial genome sequencing. DNA was extracted from primary patient peripheral blood mononuclear cells (PBMC). The virtually complete HIV-1 genome was amplified by polymerase chain reaction (PCR) and directly sequenced. Additional strains were characterized by partial envelope sequencing. Phylogenetic analysis was used to identify and map intersubtype recombination breakpoints. Four virtually complete genome sequences and two partial envelope sequences represent CRF09_cpx, a newly identified complex recombinant HIV-1 whose principal focus seems to be in West Africa. This recombinant includes segments of subtypes A, F, G, and unclassified genetic material. It shares unique unclassified regions with the early Zaire strain Z321. There are similarities in structure, but considerable genetic distances, between CRF09_cpx and CRF02_AG IbNG. In conclusion, it is possible that this CRF shared common ancestors with both Z321 and CRF02_AG in the course of the pandemic, perhaps arising by recombination between earlier forms of these strains. Although newly identified, at least one infection with CRF09_cpx has already occurred outside of Africa.

Adult↗
PubMedDate not supplied

Cultural practices contributing to the transmission of human immunodeficiency virus in Africa.

Differences between the epidemiology of AIDS cases in Africa and that in Western societies have prompted speculation regarding risk factors that may be unique to Africa. Because of the age and sex distribution of AIDS cases in Africa, emphasis has been placed on sexual transmission of human immunodeficiency virus (HIV). Factors thought to influence this sexual transmission include (1) promiscuity, with a high prevalence of sexually transmitted disease; (2) sexual practices that have been associated with increased risk of transmission of AIDS virus (homosexuality and anal intercourse); and (3) cultural practices that are possibly connected with increased virus transmission (female "circumcision" and infibulation). Other nonsexual cultural practices that do not fit the age distribution pattern of AIDS but may expose individuals to HIV include (1) practices resulting in exposure to blood (medicinal bloodletting, rituals establishing "blood brotherhood," and possibly ritual and medicinal enemas); (2) practices involving the use of shared instruments (injection of medicines, ritual scarification, group circumcision, genital tatooing, and shaving of body hair); and (3) contact with nonhuman primates. At the current time promiscuity seems to be the most important cultural factor contributing to the transmission of HIV in Africa.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Antenatal syphilis in sub-Saharan Africa: missed opportunities for mortality reduction.

PURPOSE: Between 4-15% of pregnant women are believed to be infected with syphilis in sub-Saharan Africa. Active infection with syphilis in pregnant women results in foetal or infant death or disability for 50-80% of affected pregnancies, and is a major cause of adult morbidity as well. Antenatal syphilis screening is cheap and effective; however, it is often poorly implemented in countries with high syphilis risk. This study sought to estimate the missed opportunities for antenatal syphilis screening in sub-Saharan Africa. METHODS: Survey data were collected from 22 ministries of health in sub-Saharan Africa, complemented by data from published sources and key informants. Informants described their country's policies and experience with antenatal syphilis screening and estimated their national syphilis screening rates. FINDINGS: Seventy-three percent of women are reported by WHO to receive antenatal care in the study countries. Of women in antenatal care, 38% were estimated by survey respondents to be screened for syphilis. Costs and the organization of services were the principal reported obstacles to screening. With syphilis seroprevalence estimated at 8.3%, approximately 1 640 000 pregnant women with syphilis are undetected annually, including 1 030 000 women who attend antenatal care. DISCUSSION: Syphilis testing and treatment is a cost-effective intervention that deserves much greater attention, particularly in sub-Saharan Africa and other countries where syphilis infection is high.

Africa South of the Sahara↗
PubMedDate not supplied

Current status of reproductive behaviour in Africa.

The current annual population growth rate of 3.2% in Africa will double the population by the year 2025. The majority of this population is below 15 years of age, and Africa concurrently also has the highest incidence of infertility in the world. Sexual behaviour, which has been poorly studied in Africa, has a direct impact on reproductive health [including fertility, infertility and sexually transmitted diseases (STDs)]. The multiple cultures and religions which characterize the African continent also affect reproductive health. Factors that have a significant effect on reproductive health in Africa include greater prevalence of extramarital/commercial sexual activity, polygamy, lower prevalence of contraceptives, reliance on traditional practices, high incidence of STDs and teenage pregnancies. High risk reproductive behaviours are predominantly displayed by adolescents, and the prevalence of STDs, including HIV (human immunodeficiency virus), is very high in this group. Pregnancy-related complications are the major cause of health-related problems in 15-19 year old girls. Maternal mortality rates in most countries remain high. Literacy rates affect these behaviours. It is apparent that changing the sexual behaviour of adolescents is one way of reversing the adverse trends, such as STD transmission, unwanted pregnancy and poor general reproductive health.

Adolescent↗
PubMed2000

Status of a health care quality review programme in South Africa.

This paper provides an overview of an accreditation programme for health care facilities in South Africa. It traces the origin of COHSASA (The Council for Health Service Accreditation of Southern Africa) which began as a pilot programme in 1992, to its current status as the only accreditation body in the country. There are brief descriptions of its structure, how it is governed, and how standards were developed and organized. The authors sketch a background of the unique sociopolitical context and legal developments within which the programme operates in South Africa and how the programme is contributing towards the new government's intention to provide equitable and quality health care to all its citizens. There is an outline of the principles on which the COHSASA programme is based and the structure and process of the programme. The programme incorporates an integrated, multi-disciplinary, continuous quality improvement approach with special emphasis on capacity building of hospital staff when necessary. The paper refers to groundbreaking research in Kwa-Zulu Natal where the impact of accreditation is being measured in a randomized control trial. It points to the benefits of accreditation being perceived in both public and private sectors of health care in South Africa and outlines some of the results of the program's implementation.

Accreditation↗
PubMed2004

Genome scans of DNA variability in humans reveal evidence for selective sweeps outside of Africa.

The last 50,000-150,000 years of human history have been characterized by rapid demographic expansions and the colonization of novel environments outside of sub-Saharan Africa. Mass migrations outside the ancestral species range likely entailed many new selection pressures, suggesting that genetic adaptation to local environmental conditions may have been more prevalent in colonizing populations outside of sub-Saharan Africa. Here we report a test of this hypothesis using genome-wide patterns of DNA polymorphism. We conducted a multilocus scan of microsatellite variability to identify regions of the human genome that may have been subject to continent-specific hitchhiking events. Using published polymorphism data for a total of 624 autosomal loci in multiple populations of humans, we used coalescent simulations to identify candidate loci for geographically restricted selective sweeps. We identified a total of 13 loci that appeared as outliers in replicated population comparisons involving different reference samples for Africa. A disproportionate number of these loci exhibited reduced levels of relative variability in non-African populations alone, suggesting that recent episodes of positive selection have been more prevalent outside of sub-Saharan Africa.

Africa↗
PubMed1995

Predictive factors of severity of spondyloarthropathy in North Africa.

Both genetic and environmental factors probably influence the severity of Spondyloarthropathies. Hip involvement, which may be used as a marker of disease severity, is more frequent in spondyloarthropathies developed in North Africa. The objective of this study was determine the predisposing factors of hip involvement in spondyloarthropathy in North Africa. Patients fulfilled the Amor or European Spondyloarthropathy Study Group (ESSG) criteria of spondyloarthropathy. The study was retrospective, cross-sectional, multicentre and carried out in North Africa. The data collected were demographic data, socio-cultural factors and clinical presentation at onset. The risk of hip involvement with regard to disease duration was estimated using Kaplan-Meier's method. The predictive value of each variable with regard to time to hip involvement was evaluated using a uni- and then a multivariate Cox proportional hazard model. Five hundred and eighteen patients were included. The risk of hip involvement was estimated at 39+/-3% after 10 yr disease duration. The factors picked up by the multivariate analysis were: diagnostic delay less than 7 yr, age at onset below 24 yr and a combination of 'lower social class' and 'no refrigerator at home'. This study confirms the high prevalence of hip involvement during the course of spondyloarthropathy in North Africa and suggests a role of environmental factors in its appearance.

Adult↗
PubMed1999

Bloodborne viruses in forensic medical practice in South Africa.

Health care workers are at risk of exposure to bloodborne viruses including human immunodeficiency virus types 1 and 2 (HIV-1 and -2), hepatitis B virus (HBV) and hepatitis C virus (HCV). However, limited data is available regarding these risks to forensic medical personnel who are exposed daily to large numbers of severely traumatized bodies in South Africa, a country that has an existing and growing HIV epidemic and a high HBV seroprevalence. Because no specific prescriptions ensuring occupational safety in this regard exist for forensic medical personnel in South Africa, the prevalence of bloodborne viruses within this setting must be determined. Blood was taken randomly from 263 bodies examined at the Medicolegal Laboratory in Pretoria. Serologic tests to detect antibodies to HIV, HCV, and human T-cell lymphotropic virus types I and II (HTLV-I and -II) and to detect the presence of HBV surface antigen (HBsAg) were performed and positive results confirmed using conventional serologic assays. Serologic tests detected at least one of the four bloodborne viruses in 21% of cases. The overall seroprevalence for HIV-1/2 was 11%, rising to 19% in the sexually active reproductive age group (15 - 49 years). The HBsAg prevalence overall was 8%, rising to 9% in sexually active reproductive individuals. There was a low overall HCV seroprevalence of 1% and an even lower HTLV-I/II seroprevalence of 0.01%. Forensic medical personnel in South Africa are therefore at risk of exposure to bloodborne viral pathogens in, on average, 1 of 5 bodies autopsied. This risk is compounded by the high daily workload, traumatized state of many of the bodies, and adverse working conditions. It is imperative that occupational health safety guidelines be created for the forensic medicine discipline and crime scene attendants in South Africa.

Adolescent↗
PubMed1989

Strategies for developing innovative programs in international medical education. A viewpoint from Africa.

Postgraduate medical education is an important factor in Africa's present emphasis on health care as a basis for socioeconomic development. Such education must be relevant to the realities of health problems in Africa. The priority of most African governments is training in traditional health care management and in fields related to community- and problem-based medicine. Presently, opportunities for such training exist in only seven centers throughout Africa. A model health care system, offered by most national governments, is described. This system, which includes district, provincial, and central levels of care, delivers over 80% of health services, and it is within such a system that nationals returning from postgraduate medical education abroad will function. Problems currently associated with these systems are the shortages of expertise in the areas of management, logistics, informatics, and resources mobilization, as well as the generally low literacy of the community. Africa also needs more teachers in the basic sciences, further development of biomedical research, courses in continuing education, particularly for field workers in isolated areas, short courses on investigative techniques, and goal-oriented research aimed at solving public health problems in the student's country.

Africa↗
PubMed1999

Reversal in mortality trends: evidence from the Agincourt field site, South Africa, 1992-1995.

OBJECTIVE: To examine changes in mortality in rural South Africa over the period 1992-1995 by age, sex and cause of death. DESIGN: As with much of sub-Saharan Africa, South Africa lacks effective vital registration and information on mortality is lacking. The Agincourt demographic and health surveillance system was established to inform health policy and practice with regard to rural subdistrict populations. METHODS: Prospective community-based study involving annual update of a household census with enquiry into all birth, death and migration events. All reported deaths (n = 1001) are the subject of a verbal autopsy. RESULTS: An increasing trend in overall mortality relative to general population growth in the study area is apparent. There is evidence for a reversal in the previously declining trend in mortality among women 20-44 years. A comparison of 1992-1993 with 1994-1995 shows that most of the increase in mortality is concentrated in the younger adult (20-49 year) age group. AIDS and related diseases, particularly tuberculosis, appear primarily responsible. Injuries and violence (especially homicide) and circulatory disease are important, under-recognized causes of death, although their levels have remained constant over the period. CONCLUSIONS: Mortality from AIDS and related diseases appears responsible for the probable reversal in mortality emerging in South Africa's rural northeast. Findings carry implications for the emerging system of decentralized health care.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Male circumcision and risk of HIV infection in sub-Saharan Africa: a systematic review and meta-analysis.

OBJECTIVE: To systematically review studies of male circumcision and the risk of HIV-1 infection in men in sub-Saharan Africa, and to summarize the findings in a meta-analysis. DESIGN: A meta-analysis of observational studies. METHODS: A systematic literature review was carried out of studies published up to April 1999 that included circumcision as a risk factor for HIV-1 infection among men in sub-Saharan Africa. A random effects meta-analysis was used to calculate a pooled relative risk (RR) and 95% confidence interval (CI) for all studies combined, and stratified by type of study population. Further analyses were conducted among those studies that adjusted for potential confounding factors. RESULTS: Twenty-seven studies were included. Of these, 21 showed a reduced risk of HIV among circumcised men, being approximately half that in uncircumcised men (crude RR = 0.52, CI 0.40-0.68). In 15 studies that adjusted for potential confounding factors, the association was even stronger (adjusted RR = 0.42, CI 0.34-0.54). The association was stronger among men at high risk of HIV (crude RR = 0.27; adjusted RR = 0.29, CI 0.20-0.41) than among men in general populations (crude RR = 0.93; adjusted RR = 0.56, CI 0.44-0.70). CONCLUSION: Male circumcision is associated with a significantly reduced risk of HIV infection among men in sub-Saharan Africa, particularly those at high risk of HIV. These results suggest that consideration should be given to the acceptability and feasibility of providing safe services for male circumcision as an additional HIV prevention strategy in areas of Africa where men are not traditionally circumcised.

Africa South of the Sahara↗
PubMed2003

Migrants from Sub-Saharan Africa in the Swiss HIV Cohort Study: access to antiretroviral therapy, disease progression and survival.

OBJECTIVE: To examine the proportion of migrants from Sub-Saharan Africa entering the Swiss HIV Cohort Study (SHCS) and to compare these participants with participants from Northwestern Europe for access to antiretroviral therapy, progression to AIDS and survival. DESIGN: Prospective national cohort study of HIV-1-infected adults from seven HIV centres in Switzerland. METHODS: Trends in the proportion of participants from Sub-Saharan Africa were followed in 11 872 HIV-infected adults entering the SHCS from 1984 to 2001. Survival methods were used to compare uptake of antiretroviral therapy, survival and progression to AIDS in the 2684 participants from Sub-Saharan Africa and Northwest Europe enrolled from 1997-2001. RESULTS: There was a steady increase in the proportion of Sub-Saharan African participants over time, reaching 11.9% in 1997-2001. These participants were more likely to be younger, female, to have been infected by heterosexual intercourse and had lower CD4 cell counts at presentation. There were no differences between Sub-Saharan Africans and Northwest Europeans in uptake of triple antiretroviral therapy, progression to AIDS or survival up to 48 months after starting treatment. Tuberculosis was the most frequent AIDS-defining event in Sub-Saharan African patients. CONCLUSIONS: There is no evidence that access to potent antiretroviral therapy is influenced by geographic origin of participants. The prognosis of Sub-Saharan African patients on triple therapy is equivalent to that of Northwest European patients. Future research should address wider issues about access to specialist health services for HIV-infected people from Sub-Saharan Africa.

Acquired Immunodeficiency Syndrome↗
PubMed2004

HIV infection as a cofactor for severe falciparum malaria in adults living in a region of unstable malaria transmission in South Africa.

BACKGROUND: Malaria and HIV are two of the most important diseases facing Africa. It remains uncertain whether HIV-related immunosuppression adversely affects the clinical outcome of malaria. OBJECTIVE: To measure the association between HIV status and outcome from malarial infection in adults living in a region of unstable malaria transmission. DESIGN: Observational cohort study. SETTING: Four community clinics and the Government hospital in Hlabisa district, KwaZulu-Natal, South Africa; a region of high HIV prevalence. METHODS: Consecutive febrile adults were screened for malaria with a rapid antigen test. Those with malaria provided blood spots for HIV testing, a thick blood film for confirmation of malaria and clinical data. Outcome was established following management according to South African government guidelines. RESULTS: Malaria was microscopically confirmed in 613. HIV prevalence was 29.9% (180/613); 110 (18%) had severe/complicated malaria and 28 (4.6%) died. HIV-infected patients were more likely to vomit or be confused and were more likely to be admitted to hospital (P = 0.05). In patients admitted to hospital, HIV infection was associated with severe/complicated malaria [adjusted odds ratio (OR) 2.3; 95% confidence interval (CI), 1.4-3.9] and with death (OR 7.5; 95% CI, 2.2-25.1). Acidosis and coma were also strong independent risk factors for death. CONCLUSION: HIV infection had an unexpectedly large association with the outcome of falciparum malaria in a region of unstable transmission. Both diseases are widespread in Africa and these results add to the body of knowledge suggesting an interaction of significant public health importance between HIV and malaria in Africa.

Adolescent↗
PubMed2006

Challenges and opportunities for treatment and research of AIDS-related malignancies in Africa.

PURPOSE OF REVIEW: Following our review of AIDS-associated cancer in developing nations in 2004, we sought to update recent publications and review data on the challenges and opportunities for the treatment and research of AIDS malignancies in Africa. RECENT FINDINGS: It is apparent that the burden of AIDS-related malignancies and other virus-associated tumors is significant and increasing in Africa. Several recent studies report findings on conjunctival squamous cell carcinoma and there is a report that Hodgkin's disease, a non-AIDS-defining neoplasm, is increasing in incidence. International collaborative partnerships dedicated to AIDS malignancies in developing countries are feasible and invaluable for clinical strategies to address this aspect of the pandemic. A departure point is the ongoing work of the East Africa - Case Western Reserve University Collaboration in AIDS malignancies. SUMMARY: The burden of neoplastic complications of HIV infection and endemic virus-associated tumors are assuming increasing significance in Africa. There is a need to develop nonmyelotoxic therapies and approaches that are hypothesis-driven and pathogenesis-based. The scarcity and shortages in this region demand that our scientific and therapeutic strategies are both suitable and pragmatic for testing in this setting. It is also imperative that African investigators lead us in this important endeavor.

Africa↗
PubMed2004

Theory-based HIV risk reduction counseling for sexually transmitted infection clinic patients in Cape Town, South Africa.

BACKGROUND: South Africa has the world's fastest growing AIDS epidemic. There is an urgent need for effective HIV risk reduction interventions in South Africa. OBJECTIVE: The objective of this study was to develop and test the potential efficacy of a brief theory-based HIV prevention counseling intervention for sexually transmitted infection (STI) clinic patients in South Africa. METHOD: STI clinic patients in Cape Town (N=228) were assessed at baseline and randomized to receive either: 1) a single 60-minute session motivational/skills-building HIV risk reduction counseling intervention or 2) a 20-minute HIV information/education session. Participants completed 1- and 3-month follow ups with 80% retention. RESULTS: The 60-minute motivational/skills risk reduction counseling demonstrated significantly greater risk reduction practices, lower rates of unprotected intercourse, and greater likelihood of receiving HIV testing after the intervention. CONCLUSIONS: Brief theory-based HIV prevention counseling may significantly reduce HIV risk behaviors for STI clinic patients in South Africa.

Adult↗
PubMed2006

Coital bleeding and HIV risks among men and women in Cape Town, South Africa.

BACKGROUND: South Africa has one of the world's fastest growing HIV epidemics. Genital bleeding during sexual intercourse may play a role in facilitating HIV transmission in South Africa. PURPOSE: The purpose of this study was to examine the prevalence and sources of coital bleeding among men and women living in a Cape Town South Africa township. METHODS: A purposive sample of 464 men and 531 women completed anonymous street intercept surveys of HIV risk history and sexual behaviors. RESULTS: Thirty-one percent of men and 26% of women had a lifetime history of engaging in sexual intercourse that involved genital bleeding, and 21% of men and 16% of women reported coital bleeding in the previous 3 months. Over 75% of coital bleeding was attributed to menses. Across genders and controlling for demographic, sexual behavior, and life history factors, coital bleeding in the previous 3 months was associated with being an indigenous African, having multiple sexual partners, and higher rates of unprotected intercourse during that time period. People who reported coital bleeding were over 3 times more likely to have been diagnosed with a sexually transmitted infection even after controlling for having had genital ulcers. CONCLUSIONS: Coital bleeding may be common in South Africa. Prevention messages that promote condom use or refraining from sex when there is genital bleeding are therefore needed.

Adolescent↗