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PubMed1992

Workmens' compensation and byssinosis in South Africa: a review of 32 cases.

Byssinosis has been compensable in the Republic of South Africa (RSA) since 1973. The legal and administrative provisions for byssinosis compensation are reviewed. A series of 32 cases of presumed byssinosis was submitted to the compensation authorities by the authors. Identical reports were submitted to an independent medical panel. The findings and outcomes in these cases are presented and compared. Seventeen of the 32 claims initially received compensation and four were subsequently accepted following appeals. Analysis of the medical basis of decision making indicated that seven claims were refused and at least four had their awards reduced as a consequence of inconsistent decisions. Arguable decisions resulted in five claims being refused and one award being reduced. Our experience illustrates problems inherent in the compensation system in South Africa. Initiation of a claim is expensive relative to wages in the industry, and awards are low since they are linked to wages (mean $60.47 per week). Processing of a claim took a mean of 13.8 months, while appeals for refusal to compensate took a further 29.8 months. It is argued that consensus medical definitions of compensable occupational disease should be used routinely and that provision must be made to facilitate entry of claimants into the compensation system.

Adult↗
PubMedDate not supplied

The Martin-Bell syndrome in South Africa.

A national screening programme was introduced in 1980 when the first cases with the Martin-Bell syndrome were diagnosed in South Africa. This survey includes patients from all the major population groups in South Africa. One thousand patients, who include 354 relatives of 21 index cases, were investigated cytogenetically. About 75% of the 354 relatives were either affected males or obligate or possible carriers. The segregation pattern of the fragile site was investigated in 271 offspring of 58 carrier women. At least 30% of the carriers were mildly mentally retarded with most expressing the fragile site. Various other investigations, such as measurements of testes, speech, verbal and IQ evaluations and hormone studies were done on several affected males. No fragile site could be demonstrated in 57 unselected autistic children. The results of this programme show that this syndrome is a common cause of mental retardation and that prevention of mental retardation is possible if all the involved families could be identified.

Adolescent↗
PubMed1990

Studies of ancient crania from northern Africa.

Historical sources and archaeological data predict significant population variability in mid-Holocene northern Africa. Multivariate analyses of crania demonstrate wide variation but also suggest an indigenous craniometric pattern common to both late dynastic northern Egypt and the coastal Maghreb region. Both tropical African and European metric phenotypes, as well intermediate patterns, are found in mid-Holocene Maghreb sites. Early southern predynastic Egyptian crania show tropical African affinities, displaying craniometric trends that differ notably from the coastal northern African pattern. The various craniofacial patterns discernible in northern Africa are attributable to the agents of microevolution and migration.

Africa, Northern↗
PubMed1991

Cerumen phenotypes in certain populations of Eurasia and Africa.

Cerumen polymorphism was studied in several populations of Eurasia and Africa. The frequencies of dry cerumen were shown to be high in Mongoloid populations and low among Europoids. Intermediate frequencies were found among peoples of subequatorial Africa. Special attention is paid to the potential for using this marker in population and anthropological studies.

Adolescent↗
PubMed1993

Taxonomic affinity of the early Homo cranium from Swartkrans, South Africa.

A quantitative analysis that employs randomization methods and distance statistics has been undertaken in an attempt to clarify the taxonomic affinities of the partial Homo cranium (SK 847) from Member 1 of the Swartkrans Formation. Although SK 847 has been argued to represent early H. erectus, exact randomization tests reveal that the magnitude of differences between it and two crania that have been attributed to that taxon (KNM-ER 3733 and KNM-WT 15000) is highly unlikely to be encountered in a modern human sample drawn from eastern and southern Africa. Some of the variables that differentiate SK 847 from the two early H. erectus crania (e.g., nasal breadth, frontal breadth, mastoid process size) have been considered to be relevant characters in the definition of that taxon. Just as the significant differences between SK 847 and the two early H. erectus crania make attribution of the Swartkrans specimen to that taxon unlikely, the linkage of SK 847 to KNM-ER 1813, and especially Stw 53, suggests that the Swartkrans cranium may have its closest affinity with H. habilis sensu lato. Differences from KNM-ER 1813, however, hint that the South African fossils may represent a species of early Homo that has not been sampled in the Plio-Pleistocene of eastern Africa. The similarity of SK 847 and Stw 53 may support faunal evidence which suggests that Sterkfontein Member 5 and Swartkrans Member 1 are of similar geochronological age.

Analysis of Variance↗
PubMed1989

Current aspects of high blood pressure research in Africa.

Hypertension in Africa represents a challenge and an opportunity. As the two epidemics of infection and malnutrition are increasingly brought under control, increasing morbidity and mortality from hypertension have been documented and offer a challenge for prevention. Heterogeneity within and between African populations offers opportunities for detecting clues to the etiology and pathogenesis of hypertension. For example, populations in urban areas have already shown a greater prevalence of obesity, hypertension, and hypertensive heart and kidney disease than those in rural areas. The generally better lipid profiles in African blacks compared with whites is associated not only with low rates of coronary heart disease, but also with low prevalences of hypertensive retinopathy, despite substantial prevalences of hypertension in African blacks. Areas of Africa with a natural abundance of salt, such as Gambia and Senegal, tend to have indigenes with less tendency to retain a salt load than those from areas that are traditionally salt poor.

Africa↗
PubMed1997

A study of the genetic diversity of Mycobacterium tuberculosis isolated from patients in the eastern province of South Africa using random amplified polymorphic DNA profiling.

This population genetics study was done to determine the degree of genetic diversity amongst clinical isolates of Mycobacterium tuberculosis in one of the largest provinces of South Africa. Three hundred and fifty-nine individual cultures were obtained from single patients over a nine-month period. Bacterial DNA was extracted and amplified with two arbitrary ten-mer primers, using the random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) technique. RAPD markers were separated by agarose gel electrophoresis, visualised with ethidium bromide, and then analysed for similarity using the GelCompar programme. The isolates were seen to fall into two major population groups. A high degree of genetic diversity was seen, with a total of 350 unique strains occurring amongst the 359 isolates. The majority of drug-resistant isolates grouped together in the smaller population group. The genetic data were also correlated with geographical locality. It was found that a slight preponderance of isolates that grouped together closely, vis. that were either genetically identical or very similar (similarity index of approximately 97%), were from areas that were considered to be geographically distant. Antibiotic resistance patterns were also examined, revealing a total of 16 different resistance profiles among the 68 drug-resistant isolates. RAPD-PCR has proved to be a cost- and time-effective technique, suitable for such a large-scale population genetics study. It has provided useful information on the genetic diversity of an organism which is responsible for an increasing amount of morbidity and mortality in South Africa's second-largest province.

DNA Fingerprinting↗
PubMed1980

Space-time clustering of Burkitt's lymphoma in East Africa: analysis of recent data and a new look at old data.

Forty cases of Burkitts' lymphoma (BL) in North Mara, Tanzania, with onset between 1971 and 1977, were analysed for evidence of space-time clustering. Previous analyses in East Africa had produced conflicting results. The Knox method used in those analyses dichotomizes the space and time scales and does not take into account the degree of closeness. The Mantel method, a generalization of Knox's, does permit closeness between pairs of cases to enter into computations. To see whether this method could clarify matters, previously reported data sets from West Nile, Uganda and North Mara were reanalysed. Unexplained differences were found between West Nile and North Mara with respect to age, sex and temporal distributions of BL, and between the eastern and western parts of North Mara with respect to incidence. In West Nile between 1961 and 1965, there was clustering. All of the Mantel analyses and a few of the Knox analyses were highly significant (p less than 0.0025). Since 1966, evidence of clustering is weak. In North Mara, there was no statistical evidence of space-time clustering between 1971 and 1977, as there was none between 1964 and 1970. The conflicting results in East Africa are compatible with a model involving several factors which "move about", or with a single factor which is sporadic in some areas but constant in others. Alternatively, artifactual biases or coincidence may have created or wiped out the appearance of clustering. Results of space-time clustering analyses permit little discrimination between infectious and non-infectious etiologic hypotheses. Either one type or both may be operating.

Adolescent↗
PubMed1988

Drug regulation in South Africa.

South Africa has a population of approximately 30 million people. The country has a mixture of advanced industrial and rural economies, but the medicine control system is consistent with similar systems established in the major industrial countries of Western Europe and North America. Because most of South Africa's population lives in conditions more closely akin to the developing world than to the Western nations, it is important to examine whether the country is optimally served by this drug regulation model and to define critically the strengths and limitations of the established system. The conclusions might be relevant for other countries at a comparable stage of development.

Drug Industry↗
PubMed1990

Polymerase chain reaction for studies of mother to child transmission of HIV1 in Africa.

The feasibility and implications of the use of the polymerase chain reaction (PCR) assay in studies of HIV1 mother to child transmission in Africa were investigated. Uncultured leukocyte blood cells (PBL) obtained in Brazzaville (Congo) from newborns and infants (mean age = 27 weeks) of infected mothers were tested. HIV1 DNA sequences were identified in the PBL of six of eight newborns and 14 of 23 babies born to HIV1-positive mothers. In addition two of four babies, who at birth had been seropositive and subsequently were seronegative, were HIV1 DNA positive by PCR. This study demonstrates directly, therefore, a high rate of HIV1 transmission in Africa; it also indicates that PCR should be used for such epidemiological studies.

Africa↗
PubMed1993

Two successive outbreaks of SRSV-associated gastroenteritis in South Africa.

Two successive outbreaks of gastroenteritis in South Africa were investigated to identify the aetiological agents. Some patients were involved in both outbreaks. Enteropathogenic bacteria or parasites were not evident in either outbreak. Small round structured viruses (SRSVs) were demonstrated in both outbreaks by direct electron microscopy. SRSV UK3/Hawaii virus was identified by immune electron microscopy as the causative agent in the first outbreak. Using new recombinant Norwalk virus (rNV) immunoassays for antibodies and antigen, Norwalk virus was implicated in the second outbreak. Preexisting antibodies to Norwalk virus were not protective and there was no cross protection between Hawaii and Norwalk viruses. There was no anamnestic response to Norwalk virus following the SRSV UK3/Hawaii outbreak although those affected had preexisting antibodies to Norwalk virus. To our knowledge, this is the first definitive diagnosis of SRSV-associated gastroenteritis in South Africa.

Adult↗
PubMed1994

Hepatitis E seroprevalence in selected individuals in South Africa.

Antibodies to the hepatitis E virus (HEV) were detected by an enzyme immunoassay using synthetic HEV peptides. Positive anti-HEV results were confirmed by a neutralization assay and Western blot analysis. Anti-HEV was detected in 10 of 555 canoeists (1.8%) with regular exposure to sewage-polluted water and in 6 of 227 (2.6%) medical students with minimal exposure. The overall prevalence of 16 per 782 individuals (2.05%) suggests that HEV may be endemic in South Africa. This is confirmed by indications of infection earlier than the third decade of life, and by individuals with anti-HEV who had rarely or never been out of the country. The prevalence data suggest that regular exposure to sewage-polluted water was not a particular risk factor. None of the individuals with anti-HEV had a history of clinical hepatitis E, suggesting sporadic low level subclinical cases of infection. This is in agreement with the absence of reports on clinical cases or outbreaks of hepatitis E in South Africa.

Adult↗
PubMed2005

Full genome analysis of hepatitis B virus genotype E strains from South-Western Africa and Madagascar reveals low genetic variability.

The eight genotypes of hepatitis B virus (HBV), A-H, have a characteristic geographical distribution. The high prevalence of genotype E within a wide expanse of Africa makes it important to characterize this genotype. Although the preS/S region of a large number of genotype E isolates has been sequenced, to date only eight complete genotype E genomes have been published. The aim of this study, therefore, was to sequence and characterize the complete genome of genotype E isolates obtained from geographically distinct regions in Africa, including Namibia, Angola, and Madagascar. The nine newly sequenced genotype E isolates were closely related with an intra-group nucleotide divergence of 1.2%, reflecting their close geographical origin. All genotype E strains have the same characteristics, an in-frame deletion of three nucleotides (one amino acid) in the 5' pre-S1, a signature pattern of amino acids in the pre-S1 region and the serological subtype ayw4. In addition, we have identified another unique attribute of genotype E strains, the introduction of another start codon Met(83) in the pre-S1 region that may result in the translation of an elongated middle hepatitis B surface protein (MHBs).

Adult↗
PubMed2025

Seropositivity to Dengue, Zika, Yellow Fever, and West Nile Viruses in Senegal, West Africa.

West Africa serves as a critical region for the co-circulation of mosquito-borne flaviviruses, which often precipitate sporadic outbreaks. This study investigated the seropositivity to dengue virus serotypes 1-4 (DENV-1-4), Zika virus (ZIKV), yellow fever virus (YFV), and West Nile virus (WNV) in three regions of Senegal: Sindia, Thies, and Kedougou. We retrospectively analyzed 470 serum samples for flavivirus immunoglobulin G (IgG) using a DENV-2 envelope (E) ELISA. Our findings revealed an overall flavivirus seroprevalence of 37.23%. Among the DENV-2 E IgG positive samples, the proportion of subjects with IgG to DENV-1-4, ZIKV, YFV, or WNV NS1 was 57.14%, 12.57%, 80.57%, and 17.14%, respectively, with 66.86% harboring neutralizing antibodies against two or more flaviviruses. We also identified that residents in Sindia (ZIKV, aOR, 9.428; 95% CI: 1.882-47.223 and WNV, aOR, 6.039; 95% CI: 1.855-19.658) and Kedougou (ZIKV, aOR, 7.487; 95% CI: 1.658-33.808 and WNV, aOR, 1.142; 95% CI: 0.412-3.164) were at significant risk for ZIKV and WNV exposure. This study underscores the complexity of flavivirus epidemiology in West Africa and the necessity for enhanced surveillance to inform public health strategies.

Humans↗
PubMed1988

Sperm head structure of a murid rodent from southern Africa: the red veld rat Aethomys chrysophilus.

The morphology of spermatozoa from the red veld rat, Aethomys chrysophilus, of Southern Africa is described; two very different types were found, which came from animals from two separate, as-yet-undescribed, species. In individuals from South Africa the sperm head had a somewhat disc-shaped nucleus and a large acrosome with a huge apical segment that, during epididymal transit, changed in form from initially projecting anteriorly to a highly complex structure that was flexed caudad and lay alongside part of the rest of the sperm head. In addition, the chromatin generally appeared to be not fully condensed. Spermatozoa from animals collected in Malawi were very different in morphology and had a head with a typical apical hook, a perforatorium, fully condensed chromatin, and a 4-micron-long ventral spur. Its sperm tail was also significantly longer. The time of divergence of these two groups of animals from a common ancestor is not known, but the present results show that a considerable morphological change in the sperm nucleus, acrosome, and subacrosomal space can evolve even between two, presumably closely related, species.

Acrosome↗
PubMed2007

When to start supplementary iron to prevent iron deficiency in early childhood in sub-Saharan Africa setting.

BACKGROUND: To study the efficacy of oral ferrous fumarate, an inexpensive, readily available preparation on iron deficiency in infants in Africa. PROCEDURE: Four months old (group 1, n = 252) and 6-18 months old (group 2, n = 360) healthy infants attending four primary health care centers (PHC) for vaccination/well-child visits in Benin were studied. Ninety-six pregnant women (PW) over 36 weeks gestational age attending the same PHC during the study period were also studied. Infants were offered 2 months supplementation with oral powdered generic ferrous fumarate (GFF), that is, 5 mg/kg/day of elemental iron, given twice and were reevaluated 2 months later for hematological indices. The prevalence of anemia and iron deficiency among pregnant women was assessed using hematological indices and transferrin saturation. RESULTS: The prevalence of anemia was 42.0%, 61.9%, and 37.5% in groups 1, 2, and PW, respectively. All anemic PW were iron deficient. Hemoglobin level shifted towards high values after supplementation. In addition, 24 infants from group 1 whose mothers interrupted the treatment, showed a significant decrease in hemoglobin level values, and similar improvement after two additional months of supplementation. CONCLUSION: Programs to prevent iron deficiency in Africa should utilize inexpensive preparations, start during pregnancy, continue in infants at 3 months of age and address problems of noncompliance.

Administration, Oral↗
PubMed1991

Behavioural and biological determinants of fertility transition in sub-Saharan Africa.

In the transition from high to low fertility, different biological and behavioural proximate determinants play roles of varying importance in mediating the change. In most regions of the world, the practice of contraception has come to play the major role, so much so that there is a close relationship worldwide between the level of practice of contraception and the level of fertility. In sub-Saharan Africa, the prevalence of contraceptive practice is low, and fertility levels are exceptionally high for recorded levels of contraceptive practice, even where levels of contraceptive practice are comparable to other regions. The discrepancies are explained to a very large extent by differences between Africa and other regions in other proximate determinants--notably exposure to the risk of pregnancy, and abstinence after delivery. It would seem that transition in African countries will follow one of two patterns that are different to the pattern of transition observed in all other regions. First, fertility may rise before it declines, due to abandonment of traditional fertility regulation for some time prior to the eventual adoption of contraceptive practice. Second, the prevalence of contraceptive practice may rise for a time before there is an observable decline in fertility, because at the same time that contraception is adopted, traditional regulation of fertility is being abandoned, offsetting any effect on fertility. Kenya is an example of the first pattern, while Botswana, Ghana, and Zimbabwe are probably examples of the second.

Africa↗
PubMed1997

The complete coding sequence of hepatitis C virus genotype 5a, the predominant genotype in South Africa.

Hepatitis C virus (HCV) genotype 5a is the predominant genotype in southern Africa with a high prevalence amongst infected blood donors from areas in South Africa. We have determined the nucleotide sequence corresponding to the complete coding region of an HCV isolate, EUH1480, previously classified as genotype 5a, from an Edinburgh haemophiliac. The sequence contained a single open reading frame (ORF) coding for a polyprotein of 3014 amino acids. Comparison with the polyprotein sequences from other HCV genotypes, where the ORF varies from 3008 to 3037 amino acids, showed the observed variation in size was due to differences in lengths of the envelope 2 and the nonstructural 5A proteins. The sequence divergence of HCV genotype 5 ranged from 29.4% nucleotide differences (24.91% amino acid differences) compared with genotype 1c to 32.5% nucleotide differences (30.3% amino acid differences) compared with 2a. Phylogenetic analysis of the available full length nucleotide sequences showed EUH1480 to form a branch distinct from the other HCV types, confirming the classification of type 5a as a separate genotype.

Amino Acid Sequence↗