Browsing by Subject "Southern Africa"
Now showing 1 - 20 of 29
Results Per Page
Sort Options
- ItemOpen AccessA comparison of rapid bioassessment protocols used in 2 regions with Mediterranean climates, the Iberian Peninsula and South Africa(2006) BONADA, NÚRIA; DALLAS, HELEN; RIERADEVALL, MARIA; PRAT, NARCÍS; DAY, JENNYAbstract. The ability of 2 Rapid Bioassessment Protocols (RBPs) to assess stream water quality was compared in 2 Mediterranean-climate regions. The most commonly used RBPs in South Africa (SAprotocol) and the Iberian Peninsula (IB-protocol) are both multihabitat, field-based methods that use macroinvertebrates. Both methods use preassigned sensitivity weightings to calculate metrics and biotic indices. The SA- and IB-protocols differ with respect to sampling equipment (mesh size: 1000 lm vs 250-300 lm, respectively), segregation of habitats (substrate vs flow-type), and sampling and sorting procedures (variable time and intensity). Sampling was undertaken at 6 sites in South Africa and 5 sites in the Iberian Peninsula. Forty-four and 51 macroinvertebrate families were recorded in South Africa and the Iberian Peninsula, respectively; 77.3% of South African families and 74.5% of Iberian Peninsula families were found using both protocols. Estimates of community similarity compared between the 2 protocols were .60% similar among sites in South Africa and .54% similar among sites in the Iberian Peninsula (Bray-Curtis similarity), and no significant differences were found between protocols (Multiresponse Permutation Procedure). Ordination based on Non-metric Multidimensional Scaling grouped macroinvertebrate samples on the basis of site rather than protocol. Biotic indices generated with the 2 protocols at each site did not differ. Thus, both RBPs produced equivalent results, and both were able to distinguish between biotic communities (mountain streams vs foothills) and detect water-quality impairment, regardless of differences in sampling equipment, segregation of habitats, and sampling and sorting procedures. Our results indicate that sampling a single habitat may be sufficient for assessing water quality, but a multihabitat approach to sampling is recommended where intrinsic variability of macroinvertebrate assemblages is high (e.g., in undisturbed sites in regions with Mediterranean climates). The RBP of choice should depend on whether the objective is routine biomonitoring of water quality or autecological or faunistic studies.
- ItemOpen AccessAccess to assistive technology in two Southern African countries(BioMed Central, 2018-10-19) Matter, Rebecca A; Eide, Arne HBackground Millions of people in Southern Africa are deprived of basic human rights such as the right to education and work because of the large and growing unmet demand for assistive technologies (AT). Evidence is needed to better characterize the lack of AT access. Methods This study serves to identify the sociodemographic factors that are associated with access to AT in two countries in Southern Africa, Botswana and Swaziland. To achieve this aim, logistics regression was applied to a subset of variables from two Living Conditions Studies, nationally representative surveys that were conducted in Southern Africa (2014 and 2010). Results In Botswana, 44% of people who needed AT did not receive it, while in Swaziland the unmet need was 67%. Among the sociodemographic variables tested, the type of disability was the most important factor in determining AT access in both countries. The likelihood of AT access was highest in both countries for those who had mobility limitations (i.e., difficulty walking/climbing stairs) [Botswana: 6.4 odds ratio (OR) = 6.4., 95% confidence internal (CI) (3.6–11.3); Swaziland: OR = 3.2, CI (1.4–7.3)], in comparison to those with non-mobility types of disabilities. Conclusions These findings provide support for governments and other stakeholders in the AT sector to prioritize AT to address the large unmet demand, and expand the range of AT products provided so that people with hearing, seeing, self-care, communication and cognition difficulties have equal access to AT as those with mobility impairments. A step toward achieving these aims is to inventory AT product types that are commonly covered through the public sector in each country, and identify common gaps (e.g., daily living aids). Advancing the AT sector as a whole within Southern Africa will require large scale qualitative studies that achieve a comprehensive understanding of the bottlenecks in regional AT supply, procurement, and delivery systems.
- ItemOpen AccessAmiodarone-induced thyroid dysfunction(2005) Ross, Ian Louis; Marshall, David; Okreglicki, Andrzej; Isaacs, Sedick; Levitt, Naomi SharleneBackground. Little is known about the frequency of thyroid dysfunction (TD) associated with amiodarone therapy in southern Africa. Objectives. To determine the incidence of TD in a cohort of patients initiated on amiodarone therapy at a cardiac clinic in Cape Town, South Africa, believed to be an iodine-replete area. Patients. Pharmacy records were used to obtain the names of patients who received amiodarone between November 1999 and December 2002. Results. The sample size was 194, but data analysis was limited to the 163 patients for whom there were complete data. The mean age ± standard deviation (SD) was 59.0 ± 15.0 years (range 22 - 89 years). There were 67 female and 96 male patients. The indications for amiodarone therapy were supraventricular tachycardias (N = 102, 62.6%), ventricular tachycardia (N = 55, 33.7%), and prophylaxis against tachycardias (N = 3, 1.8%). The indication was uncertain in 3 patients (1.8%). The median duration of amiodarone treatment was 679.0 days (quartile deviation (QD) 1 172 days, range 3 - 6 425 days) in the whole cohort. The median duration of amiodarone therapy until new TD was 943 days (QD 1 185 days), significantly longer than in patients who remained euthyroid (547 days, QD 1 135 days) (P = 0.05). There were 45 new TD cases (27.6%): 11 patients (6.7%) were thyrotoxic, 1(0.6%) transient thyrotoxicosis, 1 (0.6%) subclinical hyperthyroidism, 13 (8.0%) had subclinical hypothyroidism, 12 (7.4%) hypothyroidism and 7 (4.3%) had minor changes in thyroid function. Conclusions. We found a high incidence of new-onset TD, similar to the highest rates reported internationally. Local factors responsible for this need to be investigated.
- ItemOpen AccessAtypical pneumonia in adults in southern Africa(South African Academy of Family Physicians, 2012) Dlamini, S K; Mendelson, MThe true incidence of Legionella pneumophilia, Mycoplasma pneumoniae, Chlamydophila pneumoniae and Coxiella burnetti, the so-called atypical pathogens that cause adult community-acquired pneumonia in southern Africa, is unknown. Although there are a lack of community-based studies, hospital-based studies suggest that the incidence may be as high as 30% in patients admitted to, but not requiring, an intensive care unit. A lack of specific clinical features that differentiate atypical pathogens, plus the lack of reliable, simple diagnostics, compound the uncertainty regarding the contribution of atypical pathogens to the sum total of community-acquired pneumonia in southern Africa. Without reliable diagnostic tests, macrolide or azalide antibiotics are widely used for in-patients with pneumonia, potentially fuelling the rise of antibiotic resistance to macrolides in other bacteria.
- ItemOpen AccessDiversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant’s foot tubers(2016) Maurin, Olivier; Muasya, A Muthama; Catalan, Pilar; Shongwe, Eugene Z; Viruel, Juan; Wilkin, Paul; van der Bank, MichelleAbstract Background Dioscorea is a widely distributed and highly diversified genus in tropical regions where it is represented by ten main clades, one of which diversified exclusively in Africa. In southern Africa it is characterised by a distinct group of species with a pachycaul or “elephant’s foot” structure that is partially to fully exposed above the substrate. In contrast to African representatives of the genus from other clades, occurring mainly in forest or woodland, the pachycaul taxa and their southern African relatives occur in diverse habitats ranging from woodland to open vegetation. Here we investigate patterns of diversification in the African clade, time of transition from forest to more open habitat, and morphological traits associated with each habitat and evaluate if such transitions have led to modification of reproductive organs and mode of dispersal. Results The Africa clade originated in the Oligocene and comprises four subclades. The Dioscorea buchananii subclade (southeastern tropical Africa and South Africa) is sister to the East African subclade, which is respectively sister to the recently evolved sister South African (e. g., Cape and Pachycaul) subclades. The Cape and Pachycaul subclades diversified in the east of the Cape Peninsula in the mid Miocene, in an area with complex geomorphology and climate, where the fynbos, thicket, succulent karoo and forest biomes meet. Conclusions Diversification out of forest is associated with major shifts in morphology of the perennial tuber (specifically an increase in size and orientation which presumably led them to become pachycaul) and rotation of stem (from twining to non-twining). The iconic elephant's foot morphology, observed in grasslands and thicket biomes, where its corky bark may offer protection against fire and herbivory, evolved since mid Miocene. A shift in pollination trait is observed within the forest, but entry into open habitat does not show association with reproductive morphology, except in the seed wing, which has switched from winged all round the seed margin to just at the base or at the apex of it, or has been even replaced by an elaiosome.
- ItemOpen AccessDiversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant’s foot tubers(BioMed Central, 2016-11-08) Maurin, Olivier; Muasya, A. M; Catalan, Pilar; Shongwe, Eugene Z; Viruel, Juan; Wilkin, Paul; van der Bank, MichelleBackground: Dioscorea is a widely distributed and highly diversified genus in tropical regions where it is represented by ten main clades, one of which diversified exclusively in Africa. In southern Africa it is characterised by a distinct group of species with a pachycaul or “elephant’s foot” structure that is partially to fully exposed above the substrate. In contrast to African representatives of the genus from other clades, occurring mainly in forest or woodland, the pachycaul taxa and their southern African relatives occur in diverse habitats ranging from woodland to open vegetation. Here we investigate patterns of diversification in the African clade, time of transition from forest to more open habitat, and morphological traits associated with each habitat and evaluate if such transitions have led to modification of reproductive organs and mode of dispersal. Results: The Africa clade originated in the Oligocene and comprises four subclades. The Dioscorea buchananii subclade (southeastern tropical Africa and South Africa) is sister to the East African subclade, which is respectively sister to the recently evolved sister South African (e. g., Cape and Pachycaul) subclades. The Cape and Pachycaul subclades diversified in the east of the Cape Peninsula in the mid Miocene, in an area with complex geomorphology and climate, where the fynbos, thicket, succulent karoo and forest biomes meet. Conclusions: Diversification out of forest is associated with major shifts in morphology of the perennial tuber (specifically an increase in size and orientation which presumably led them to become pachycaul) and rotation of stem (from twining to non-twining). The iconic elephant's foot morphology, observed in grasslands and thicket biomes, where its corky bark may offer protection against fire and herbivory, evolved since mid Miocene. A shift in pollination trait is observed within the forest, but entry into open habitat does not show association with reproductive morphology, except in the seed wing, which has switched from winged all round the seed margin to just at the base or at the apex of it, or has been even replaced by an elaiosome.
- ItemOpen AccessDrivers of HIV-1 drug resistance to non-nucleoside reverse-transcriptase inhibitors (NNRTIs) in nine southern African countries: a modelling study(2021-10-07) Riou, Julien; Dupont, Carole; Bertagnolio, Silvia; Gupta, Ravindra K.; Kouyos, Roger D.; Egger, Matthias; L. Althaus, ChristianIntroduction The rise of HIV-1 drug resistance to non-nucleoside reverse-transcriptase inhibitors (NNRTI) threatens antiretroviral therapy's long-term success (ART). NNRTIs will remain an essential drug for the management of HIV-1 due to safety concerns associated with integrase inhibitors. We fitted a dynamic transmission model to historical data from 2000 to 2018 in nine countries of southern Africa to understand the mechanisms that have shaped the HIV-1 epidemic and the rise of pretreatment NNRTI resistance. Methods We included data on HIV-1 prevalence, ART coverage, HIV-related mortality, and survey data on pretreatment NNRTI resistance from nine southern Africa countries from a systematic review, UNAIDS and World Bank. Using a Bayesian hierarchical framework, we developed a dynamic transmission model linking data on the HIV-1 epidemic to survey data on NNRTI drug resistance in each country. We estimated the proportion of resistance attributable to unregulated, off-programme use of ART. We examined each national ART programme's vulnerability to NNRTI resistance by defining a fragility index: the ratio of the rate of NNRTI resistance emergence during first-line ART over the rate of switching to second-line ART. We explored associations between fragility and characteristics of the health system of each country. Results The model reliably described the dynamics of the HIV-1 epidemic and NNRTI resistance in each country. Predicted levels of resistance in 2018 ranged between 3.3% (95% credible interval 1.9–7.1) in Mozambique and 25.3% (17.9–33.8) in Eswatini. The proportion of pretreatment NNRTI resistance attributable to unregulated antiretroviral use ranged from 6% (2–14) in Eswatini to 64% (26–85) in Mozambique. The fragility index was low in Botswana (0.01; 0.0–0.11) but high in Namibia (0.48; 0.16–10.17), Eswatini (0.64; 0.23–11.8) and South Africa (1.21; 0.83–9.84). The combination of high fragility of ART programmes and high ART coverage levels was associated with a sharp increase in pretreatment NNRTI resistance. Conclusions This comparison of nine countries shows that pretreatment NNRTI resistance can be controlled despite high ART coverage levels. This was the case in Botswana, Mozambique, and Zambia, most likely because of better HIV care delivery, including rapid switching to second-line ART of patients failing first-line ART.
- ItemOpen AccessEffect of initial antiretroviral regime on virological suppression in children in a Southern African urban population: a retrospective record review(2019) Gaibee, Zeenaat; Le Roux, David MBackground Since 2010, adult studies and clinical concerns about stavudine (d4T) toxicity had led to the phasing out of d4T from many antiretroviral treatment (ART) guidelines globally with substitution by abacavir. Recent studies, within Southern Africa, however have shown poorer virological suppression with abacavir (ABC) compared to d4T at their respective centres. Methods A retrospective study of HIV-positive children, who had been initiated on ART from 2005 to 2017, was conducted at an ART unit at New Somerset hospital, Western Cape, South Africa. Data was extracted from clinical notes and electronic medical records and virological suppression reviewed in those started on ABC and d4T based regimes. Results A total of 672 children were included in the study with a median age of 8.9 months (interquartile range (IQR) 4.1- 24.1 months) in the d4T based group and 11 months (IQR 3.5 - 29.9 months) in the ABC group. 64 of the 437 patients in the d4T containing group were transferred out, 15 reported to have died, and 49 were lost to follow up within the first 6months on treatment. Of the 181 ABC containing regimen group, 1 was transferred out to another care facility, 1 reported death within 6months of treatment and 2 children were lost to follow up. There was a noted increased risk of being virologically unsuppressed at 6months while taking ABC containing regimen compared to a d4T containing regimen. . The relative risk of being virologically unsuppressed at 6 months while taking abacavir/lopinavir (LPV/r) was 1.39 (95% confidence interval 1.03 to 1.88, p=0.04) compared to stavudine/LPV/r. The relative risk of being virologically unsuppressed at 6 months while taking abacavir/efavirenz (EFV) was 1.82 (95% confidence interval 0.98 to 3.37, p=0.054) compared to stavudine/EFV. Conclusion Our analysis again raises concerns about virological suppression in the abacavir era of paediatric ART, compared to the previous stavudine era, particularly in combination with LPV/r in the younger, more vulnerable children. Whether this is because of intrinsic properties of the different medications or is a marker of the evolving complexity of the South African ART rollout, may never be resolved. However, this is of concern as abacavir and LPV/r appear to be entrenched as first-line paediatric ART in a setting where attrition is high, many children are lost to follow up and virologic surveillance is not always optimal. Clinicians need to optimize retention strategies, especially of young infants, to ensure that children are retained in care, have viral load testing timeously, so that those virologically unsuppressed can be detected and treated early and appropriately.
- ItemOpen AccessEvaluating the value of e-business in small and medium-sized enterprises: a model and analysis in Southern Africa(2019) Tsumake, Meduduetso; Kyobe, MichaelThe implementation of electronic business (e-business) in organisations has led to a major improvement in business performance in both developed and developing countries. This improvement as well as market forces have put pressure on Small and Medium-sized Enterprises (SMEs) to adopt e-business. However, the e-business models adopted by SMEs are often abstruse and poorly represented, which leads to time consumption and miscommunication between the stakeholders involved, the business operations and Information Technology (IT) functions. These unclear e-business models make it difficult to evaluate its value. This research examines the elements necessary for this e-business value creation and draws from different disciplines and theories to create a comprehensive model for e-business evaluation in Southern African SMEs. Most studies done on e-business in Southern Africa have been found to be on challenges of technology, a lack of resources such as financial and user capabilities and challenges in business processes. Some gaps in the e-business literature have been found to exist on issues of alignment of business mission and strategy, entrepreneurial drive and management capabilities. The study adopted Gerbner’s theory of communication exchange for the data collection strategy and process, which posits that by studying the events of the communication exchange, one can infer about the state of the systems engaged in the exchange and their relationships. Consequently quantitative website content analysis of 100 Southern African SMEs was conducted to determine their e-business value. The results revealed that an SME that comprises of a properly aligned business mission and strategy, business processes that are enabled by e-business, an entrepreneurship orientation, management capabilities and employees as well as technology integration will achieve ebusiness value. This was seen by a positive influence of 68% on e-business value from these elements. Conversely 32% of this influence is from external elements, and future studies could explore more elements that influence e-business value. Also, a small employee size was found to not be a hindrance of e-business value. Lastly, overall infrastructural e-readiness is the same in Botswana and South Africa, which refutes claims that e-readiness is higher in South Africa than the rest of the Southern African countries. However, SMEs in Botswana lag behind when it comes to technological aspects such as technology equipment, successfully integrating their systems within the businesses; and their IT in their entire businesses and networks, forming technology interdependencies of processes with external businesses, and using online means to transfer information to clients/customers. The developed model (EBVE model) could help (1) stakeholders investigate, communicate and make appropriate decisions and (2) aid SMEs to successfully integrate e-business in their business processes and practices.
- ItemOpen AccessExploring the environmental drivers of waterfowl movement in arid landscapes using first-passage time analysis(2016) Henry, Dominic A W; Ament, Judith M; Cumming, Graeme SBackgroundThe movement patterns of many southern African waterfowl are typified by nomadism, which is thought to be a response to unpredictable changes in resource distributions. Nomadism and the related movement choices that waterfowl make in arid environments are, however, poorly understood. Tracking multiple individuals across wide spatiotemporal gradients offers one approach to elucidating the cues and mechanisms underpinning movement decisions. We used first-passage time (FPT) to analyse high spatial and temporal resolution telemetry data for Red-billed Teal and Egyptian Geese across a 1500km geographical gradient between 2008 and 2014. We tested the importance of several environmental variables in structuring movement patterns, focusing on two competing hypotheses: (1) whether movements are driven by resource conditions during the current period of habitat occupation (reactive movement hypothesis), or (2) whether movements are structured by shifts in the magnitude and direction of environmental variables at locations prior to occupation (prescient movement hypothesis).ResultsAn increase in rainfall at a 32day lag (i.e., prior to wetland occupancy), along with tagging site, were significant predictors of FPT in both waterfowl species. There was a positive relationship between NDVI and FPT for Egyptian Geese during this 32day period; the relationship was negative for Red-billed Teal. Consistent with findings for migratory grazing geese, Egyptian Geese prioritised food quality over food biomass. Red-billed Teal showed few immediate responses to wetland filling, contrary to what one would predict for a dabbling duck, suggesting high dietary flexibility. Our results were consistent with the prescient movement hypothesis.ConclusionsUsing FPT analysis we showed that the proximate drivers of southern African waterfowl movement are the dynamics of rainfall and primary productivity. Waterfowl appeared to be able to perceive and respond to temporal shifts in resource conditions prior to habitat patch occupation. This in turn suggests that their movements in semi-arid landscapes may be underpinned by intimate knowledge of the local environment; waterfowl pursue a complex behavioural strategy, locating suitable habitat patches proactively, rather than acting as passive respondents.
- ItemOpen AccessGeochemistry of the Sabie River Basalt Formation in the central Lebombo, Karoo Igneous Province(1988) Sweeney, Russell James; Sweeney, Russell James; Erlank, Tony; Duncan, Andy; Erlank, Tony; Duncan, AndyThe Sabie River Basalt Formation is a group of tholeiitic basaltic rocks erupted ca 190 Ma ago in the eastern zone of the Karoo Igneous Province of southern Africa. It is traceable over a distance of 700 km from Zululand, northwards along the Lebombo monocline into the Transvaal and south-east Zimbabwe. An abrupt compositional change in this formation occurs about halfway down its length in the vicinity of the Sabie and Komati Rivers: basalts to the north are known to be enriched in certain incompatible elements relative to basalts in the south, which are comparable in geochemistry to most basaltic rocks in the southern part of the Karoo Igneous Province. New data obtained in this work include 134 major and trace element whole-rock analyses, some 400 analyses of constituent minerals, 38 ⁸⁷Sr/⁸⁶Sr ratio determinations, 19 ¹⁴³Nd/¹⁴⁴Nd ratio determinations, 16 common Pb determinations and 12 oxygen isotope analyses. The "normal" (N) and "enriched" basaltic rocks are distinguished by differences in the concentrations of Ti, P, Zr, Nb, Y, La, Ce and Nd (high field strength elements). Broadly these differences are substantiated by K, Rb, Ba and Sr, but with much more overlap. The "enriched" group of basaltic rocks has been further subdivided into a low-Fe "enriched" (LFE) group and a high-Fe "enriched" group (HFE). The LFE-group basalts, which predominate at the base of the stratigraphic sections, are considered to be equivalent to basalts occurring in the N. Lebombo. In the central Lebombo N-group basalts predominate in the mid- and upper portions of the sections and HFE-group basalt occurs near the top of each section. Interbedding of all basalt groups occurs in the Sabie River section at the northern end of the study area, while the N- and HFE-group basalts are interbedded in the Crocodile and Komati River sections further to the south. The decrease in LFE-group basalt abundance southwards is accompanied by an increase in N-group basalt abundance. HFE-group basalts appear to be unique to the central Lebombo area of the Karoo Igneous Province and are volumetrically less significant than N- or LFE-group basalts. Petrogenetic models involving closed-system fractional crystallization; coupled assimilation (of granitic crust) fractional crystallization; replenished, tapped and fractionated magma chambers and partial melting are examined. Granitic crustal contamination appears to have been significant only in some samples of the N group where assimilation of granitic material has proceeded in a bulk fashion described by an AFC model. RTF models are dynamically more realistic than closed-system fractional crystallization models and explain increases in incompatible elements with decreasing MgO in the LFE and HFE groups. Variations in the N group, however, require varying degrees of partial melting of a N-type source to be explained fully. RTF models may explain the absence of any stratigraphic correlations of element abundances in the three groups. The HFE group may be related to an uncontaminated N-type parent composition by a combination of continued fractional crystallization from an N-group parent composition and varying degrees of partial melting of an N-type source. The only petrogenetic process by which the N and LFE groups may be related is different degrees of partial melting. However, this demands a source composition which has no resemblance on trace element and isotopic grounds, to observed mantle xenolith compositions. The preferred model is one in which the LFE group is derived from old sub-cratonic mantle similar to garnet-bearing "cold" peridotite xenoliths and the N group from a source similar in composition to estimates of primitive mantle. The existence of two types of mantle derived continental flood basalt magmas occurs in other Mesozoic basalt provinces in "southern" Gondwanaland (e.g. Kirwanveggan of Antarctica, Etendeka of Namibia and the Parana Basin of South America). It is suggested that there is a geographical association of LFE-type basalts with Archaean crust (or Archaean crust re-worked in low temperature - high pressure events) and N-type basalts with post-Archaean crust (or Archaean crust re-worked in high temperature - low pressure events). This model suggests the derivation of the LFE group, from old sub-cratonic lithospheric mantle relatively enriched in incompatible elements and the N group being derived from more recently accreted and less enriched lithospheric mantle underlying younger crustal terraines.
- ItemOpen AccessHistories of forced sex and health outcomes among Southern African lesbian and bisexual women: a cross-sectional study(BioMed Central Ltd, 2015) Sandfort, Theo; Frazer, M; Matebeni, Zethu; Reddy, Vasu; Southey-Swartz, Ian; Southern African Lesbian and Bisexual Women Research TeamBACKGROUND: Experiences of forced sex have been shown to be prevalent in Southern Africa. Negative outcomes of forced sex have been documented in general populations of women and men and include alcohol abuse, drug use, mental health problems, mental distress, sexual health problems and poor overall health. This study is the first to examine experiences of forced sex and associated health problems among lesbian and bisexual women in Southern Africa. METHODS: This study is based on data collected as part of a collaborative endeavor involving various Southern African community-based organizations. Lesbian and bisexual women in four Southern African countries participated in a cross-sectional survey, for a total study sample of 591. RESULTS: Nearly one-third of participants had been forced to have sex at some time in their lives. Thirty-one percent of all women reported to have experienced forced sex at least once in their life: 14.9% reported forced sex by men only; 6.6% reported forced sex by women only; 9.6% had had forced sexual experiences with both men and women. Participants experienced forced sex by men as more serious than forced sex by women; forced sex by women was more likely to involve intimate partners compared to forced sex by men. Participants who experienced forced sex by men were more likely to report drug problems, mental distress and lower sense of belonging. Forced sex by women was associated with drinking problems and mental distress. Having experienced forced sex by both men and women was associated with lower sense of belonging to the LGBT community, drug use problem and mental distress. CONCLUSIONS: The findings indicate that forced sex among Southern African women is a serious issue that needs further exploration. Clinicians should be made aware of the prevalence and possible consequences of forced sex among lesbian and bisexual women. Policies and community interventions should be designed to address this problem.
- ItemOpen AccessHIV type 1 subtype C gag and nef diversity in Southern Africa.(Mary Ann Liebert, 2007) Bredell, Helba; Martin, Darren P; Van Harmelen Joanne; Varsani, Arvind; Sheppard, Haynes W; Donovan, R; Gray, C; HIVNET028 Study Team; Williamson, CSeveral HIV-1 subtype C-specific gag- and/or nef-based vaccines are currently intended for clinical trial in southern Africa. Here we provide sequences of 64 gag and 45 nef genes sampled in Malawi, Zambia, Zimbabwe, and South Africa and assess the degree of southern African HIV-1 diversity that will confront these vaccines. Whereas reasonable phylogenetic evidence exists for geographical clustering of subtype C gag and nef sequences from various other parts of the world, there is little evidence of similar population founder effects in the southern African epidemic. The entire breadth of subtype C diversity is represented in the southern African genes suggesting there may be no advantage in producing region- or country-specific subtype C vaccines. We do not, however, find much evidence of intersubtype recombination in the Southern African genes, implying that the likelihood of vaccine failure due to the emergence of intersubtype recombinants is probably low.
- ItemOpen AccessInfluence of the Madden–Julian Oscillation on Southern African Summer Rainfall(2007) Pohl, B; Richard, Y; Fauchereau, NComposite maps of outgoing longwave radiation (OLR) anomalies over the Madden-Julian oscillation (MJO) cycle show marked intraseasonal fluctuations over southern Africa (south of 15°S). Large-scale convective clusters are seen to propagate eastward and then northward over the continent, mainly between 10° and 20°S. The corresponding response of the rainfall field presents the alternation, over the cycle, of dry and humid phases, which are both significant. Moisture flux anomalies indicate an intraseasonal modulation of the midtropospheric easterly flow over the Congo basin at 700 hPa; these fluctuations are coupled to meridional flux anomalies that extend from the tropical to the subtropical austral latitudes, and favor occurrences of wet or dry conditions over the domain. Though statistically significant, the influence of the MJO on southern Africa is however not homogeneous spatially, and only the tropical areas exhibit sharp periodicities in the 30-60-day period range. The OLR dipole observed in previous studies at the interannual and synoptic time scales between the hinterland parts of southern Africa and the southwestern Indian Ocean in the north of Madagascar is investigated next, as it also shows strong fluctuations at the intraseasonal time scale. The study points out that the dipole is partly influenced by the MJO, though the strongest periodicities are found for slightly longer periods (35-80 days) than those typically associated with the oscillation. The forcing of the MJO on the OLR dipole, though significant, remains thus partial.
- ItemOpen AccessInterannual memory effects for spring NDVI in semi-arid South Africa(2008) Richard, Yves; Martiny, Nadège; Fauchereau, Nicolas; Reason, Chris; Rouault, Mathieu; Vigaud, Nicolas; Tracol, YannAlmost 20 years of Normalized Difference Vegetative Index (NDVI) and precipitation (PPT) data are analysed to better understand the interannual memory effects on vegetation dynamics observed at regional scales in Southern Africa (SA). The study focuses on a semi-arid region (25°S–31°S; 21°E–26°E) during the austral early summer (September–December). The memory effects are examined using simple statistical approaches (linear correlations and regressions) which require the definition of an early summer vegetation predictand (December NDVI minus September NDVI) and a consistent set of potential predictors (rainfall amount, number of rainy days, rainfall intensity, NDVI and Rain-Use-Efficiency) considered with 4 to 15-month time-lag. An analysis over six SA sub-regions, corresponding to the six major land-cover types of the area reveals two distinct memory effects. A “negative” memory effect (with both rainfall and vegetation) is detected at 7 to 10-month time-lag while a “positive” memory effect (with vegetation only) is observed at 12 to 14-month time-lag. These results suggest that interannual memory effects in early summer vegetation dynamics of semi-arid South Africa may preferably be driven by biological rather than hydrological mechanisms.
- ItemOpen AccessMaking the invisible visible: a systematic review of sexual minority women’s health in Southern Africa(BioMed Central, 2016) Muller, Alexandra; Hughes, Tonda LBackground: Over the past two decades research on sexual and gender minority (lesbian, gay, bisexual and transgender; LGBT) health has highlighted substantial health disparities based on sexual orientation and gender identity in many parts of the world. We systematically reviewed the literature on sexual minority women’s (SMW) health in Southern Africa, with the objective of identifying existing evidence and pointing out knowledge gaps around the health of this vulnerable group in this region. Methods: A systematic review of publications in English, French, Portuguese or German, indexed in PubMed or MEDLINE between the years 2000 and 2015, following PRISMA guidelines. Additional studies were identified by searching bibliographies of identified studies. Search terms included (Lesbian OR bisexual OR “women who have sex with women”), (HIV OR depression OR “substance use” OR “substance abuse” OR “mental health” OR suicide OR anxiety OR cancer), and geographical specification. All empirical studies that used quantitative or qualitative methods, which contributed to evidence for SMW’s health in one, a few or all of the countries, were included. Theoretical and review articles were excluded. Data were extracted independently by 2 researchers using predefined data fields, which included a risk of bias/quality assessment. Results: Of 315 hits, 9 articles were selected for review and a further 6 were identified through bibliography searches. Most studies were conducted with small sample sizes in South Africa and focused on sexual health. SMW included in the studies were racially and socio-economically heterogeneous. Studies focused predominately on young populations, and highlighted substance use and violence as key health issues for SMW in Southern Africa. Conclusions: Although there are large gaps in the literature, the review highlighted substantial sexual-orientationrelated health disparities among women in Southern Africa. The findings have important implications for public health policy and research, highlighting the lack of population-level evidence on the one hand, and the impact of criminalizing laws around homosexuality on the other hand.
- ItemOpen AccessMitral valve replacement for rheumatic heart disease in Southern Africa(BioMed Central Ltd, 2013) Zilla, Peter; Koshy, J; Brink, J; Human, PBackground: Threshold countries like South Africa provide cardiac surgery to a largely indigent population with rheumatic heart disease. Although repairs are a preferred treatment modality many rheumatic mitral valves can only be replaced. In view of significantly improved primary health care and broad access of the indigent population to communication technology we revisited the efficacy of mitral valve replacement (MVR) at the interface of the developing and developed world. Methods: A cohort of 280 patients (mean age 40.7±13.7y/range 12-80y/median 41y; 76.4% female) with rheumatic heart disease (21% MR; 11% MS; 68% mixed) undergoing mitral valve replacement (MVR) (88.2% mechanical versus 11.8% tissue valves) was analyzed.
- ItemOpen AccessModel selection for the dynamics of southern African hake resources(1988) Punt, A E; Butterworth, Doug S
- ItemOpen AccessPublic health implications of changing patterns of recruitment into the South African mining industry, 1973–2012: a database analysis(2018) Ehrlich, Rodney; Montgomery, Alex; Akugizibwe, Paula; Gonsalves, GreggAbstract Background The triple epidemic of silicosis, tuberculosis and HIV infection among migrant miners from South Africa and neighbouring countries who have worked in the South African mining industry is currently the target of regional and international control efforts. These initiatives are hampered by a lack of information on this population. Methods This study analysed the major South African mining recruitment database for the period 1973 to 2012 by calendar intervals and demographic and occupational characteristics. Changes in area of recruitment were mapped using a geographic information system. Results The database contained over 10 million contracts, reducible to 1.64 million individuals. Major trends relevant to health projection were a decline in gold mining employment, the major source of silicosis; increasing recruitment of female miners; and shifts in recruitment from foreign to South African miners, from the Eastern to the Northwestern parts of South Africa, and from company employees to contractors. Conclusions These changes portend further externalisation of the burden of mining lung disease to home communities, as miners, particularly from the gold sector, leave the industry. The implications for health, surveillance and health services of the growing number of miners hired as contractors need further research, as does the health experience of female miners. Overall, the information in this report can be used for projection of disease burden and direction of compensation, screening and treatment services for the ex-miner population throughout Southern Africa.
- ItemOpen AccessPublic health implications of changing patterns of recruitment into the South African mining industry, 1973–2012: a database analysis(BioMed Central, 2017-08-03) Ehrlich, Rodney; Montgomery, Alex; Akugizibwe, Paula; Gonsalves, GreggBackground: The triple epidemic of silicosis, tuberculosis and HIV infection among migrant miners from South Africa and neighbouring countries who have worked in the South African mining industry is currently the target of regional and international control efforts. These initiatives are hampered by a lack of information on this population. Methods: This study analysed the major South African mining recruitment database for the period 1973 to 2012 by calendar intervals and demographic and occupational characteristics. Changes in area of recruitment were mapped using a geographic information system. Results: The database contained over 10 million contracts, reducible to 1.64 million individuals. Major trends relevant to health projection were a decline in gold mining employment, the major source of silicosis; increasing recruitment of female miners; and shifts in recruitment from foreign to South African miners, from the Eastern to the Northwestern parts of South Africa, and from company employees to contractors. Conclusions: These changes portend further externalisation of the burden of mining lung disease to home communities, as miners, particularly from the gold sector, leave the industry. The implications for health, surveillance and health services of the growing number of miners hired as contractors need further research, as does the health experience of female miners. Overall, the information in this report can be used for projection of disease burden and direction of compensation, screening and treatment services for the ex-miner population throughout Southern Africa.