1834 research outputs found
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The role of eddies in the diving behaviour of female southern elephant seals
No full textAs the Antarctic Circumpolar Current crosses the South-West Indian Ocean Ridge, it creates an extensive eddy field characterised by high sea level anomaly variability. We investigated the diving behaviour of female southern elephant seals from Marion Island during their post-moult migrations in relation to this eddy field in order to determine its role in the animals’ at-sea dispersal. Most seals dived within the region significantly more often than predicted by chance, and these dives were generally shallower and shorter than dives outside the eddy field. Mixed effects models estimated reductions of 44.33 ± 3.00 m (maximum depth) and 6.37 ± 0.10 min (dive duration) as a result of diving within the region, along with low between-seal variability (maximum depth: 5.5 % and dive duration: 8.4 %). U-shaped dives increased in frequency inside the eddy field, whereas W-shaped dives with multiple vertical movements decreased. Results suggest that Marion Island’s adult female elephant seals’ dives are characterised by lowered cost-of-transport when they encounter the eddy field during the start and end of their post-moult migrations. This might result from changes in buoyancy associated with varying body condition upon leaving and returning to the island. Our results do not suggest that the eddy field is a vital foraging ground for Marion Island’s southern elephant seals. However, because seals preferentially travel through this area and likely forage opportunistically while minimising transport costs, we hypothesise that climate-mediated changes in the nature or position of this region may alter the seals’ at-sea dispersal patterns.National Research Foundation (South Africa
Achieving universal health coverage in South Africa through a district health system approach: conflicting ideologies of health care provision
No full textBACKGROUND: Universal Health Coverage (UHC) has emerged as a major goal for health care delivery in the post-2015 development agenda. It is viewed as a solution to health care needs in low and middle countries with growing enthusiasm at both national and global levels. Throughout the world, however, the paths of countries to UHC have differed. South Africa is currently reforming its health system with UHC through developing a national health insurance (NHI) program. This will be practically achieved through a decentralized approach, the district health system, the main vehicle for delivering services since democracy.
METHODS: We utilize a review of relevant documents, conducted between September 2014 and December 2015 of district health systems (DHS) and UHC and their ideological underpinnings, to explore the opportunities and challenges, of the district health system in achieving UHC in South Africa.
RESULTS: Review of data from the NHI pilot districts suggests that as South Africa embarks on reforms toward UHC, there is a need for a minimal universal coverage and emphasis on district particularity and positive discrimination so as to bridge health inequities. The disparities across districts in relation to health profiles/demographics, health delivery performance, management of health institutions or district management capacity, income levels/socio-economic status and social determinants of health, compliance with quality standards and above all the burden of disease can only be minimised through positive discrimination by paying more attention to underserved and disadavantaged communities.
CONCLUSIONS: We conclude that in South Africa the DHS is pivotal to health reform and UHC may be best achieved through minimal universal coverage with positive discrimination to ensure disparities across districts in relation to disease burden, human resources, financing and investment, administration and management capacity, service readiness and availability and the health access inequalities are consciously implicated. Yet ideological and practical issues make its achievement problematic.National Research Foundation (South Africa
Reevaluating cumulative HIV-1 viral load as a prognostic predictor: predicting opportunistic infection incidence and mortality in a Ugandan cohort
No full textRecent studies have evaluated cumulative human immunodeficiency virus type 1 (HIV-1) viral load (cVL) for predicting disease outcomes, with discrepant results. We reviewed the disparate methodological approaches taken and evaluated the prognostic utility of cVL in a resource-limited setting. Using data on the Infectious Diseases Institute (Makerere University, Kampala, Uganda) cohort, who initiated antiretroviral therapy in 2004–2005 and were followed up for 9 years, we calculated patients' time-updated cVL by summing the area under their viral load curves on either a linear scale (cVL1) or a logarithmic scale (cVL2). Using Cox proportional hazards models, we evaluated both metrics as predictors of incident opportunistic infections and mortality. Among 489 patients analyzed, neither cVL measure was a statistically significant predictor of opportunistic infection risk. In contrast, cVL2 (but not cVL1) was a statistically significant predictor of mortality, with each log10 increase corresponding to a 1.63-fold (95% confidence interval: 1.02, 2.60) elevation in mortality risk when cVL2 was accumulated from baseline. However, whether cVL is predictive or not hinges on difficult choices surrounding the cVL metric and statistical model employed. Previous studies may have suffered from confounding bias due to their focus on cVL1, which strongly correlates with other variables. Further methodological development is needed to illuminate whether the inconsistent predictive utility of cVL arises from causal relationships or from statistical artifacts.National Research Foundation (South Africa
Antimicrobial susceptibility profiles of Escherichia coli and Klebsiella pneumoniae isolated from outpatients in urban and rural districts of Uganda
No full textBackground: Antimicrobial resistance is a global public health concern contributing to increased morbidity and mortality particularly in low-income countries. Studies on commensal bacteria are important as they reflect the state of antimicrobial susceptibility patterns in populations. However, susceptibility data on potentially pathogenic commensal bacteria from individuals in communities are still limited. The aim of this cross-sectional study was to determine the susceptibility profiles of Escherichia coli and Klebsiella species isolated from clients attending outpatient clinics in Kampala (urban district) and two rural districts of Uganda, Kayunga and Mpigi. Factors associated with such carriage are also reported.
Results: A total of 1448 participants were recruited into the study with 985 yielding organisms of interest from stool or urine samples (one per client). Most growth occurred from stool samples (636/985, 87 %), of which 620/636 (97 %) grew E. coli while 16 (3 %) were Klebsiella pneumoniae. Growth from urine was 349/985 (35 %) of which 310/349 (89 %) were E. coli while 39 (11 %) K. pneumoniae. High rates of antimicrobial resistance were detected among E. coli and Klebsiella isolates combined: sulphamethoxazole/trimethoprim 70 %, amoxicillin/clavulanate 36 %, chloramphenicol 20 %, ciprofloxacin 11 %, gentamicin 11 %, nitrofurantoin 4 %, ceftriaxone 3 %, piperacillin/tazobactam 27 %, cefoxitin 22 %, and cefepime 15 %. Multidrug resistance was noted in 33 % of the isolates. None of the isolates were resistant to imipenem. Overall, isolates from Kampala were more resistant to antimicrobials. Across the three districts combined, isolates producing beta-lactamase enzymes extended spectrum β-lactamase-(ESBL) and AmpC comprised 5.3 and 13.2 %, respectively. Further, medical procedures involving inoculation were independent risk factors [aOR 50.76 (1.80, 1432.90)] while residing in a rural district and use of sulphamethoxazole/trimethoprim 3 months prior to visiting the outpatient clinics were protective against carriage of multidrug resistant isolates. Furthermore, use of gentamicin was protective against AmpC producing isolates while clients attending HIV/AIDs clinics were less likely to carry such isolates. No factor was independently associated with carriage of ESBL-producing isolates.
Conclusion: Antimicrobial resistance is prevalent among E. coli and K.pneumoniae carried in the gut of clients attending outpatient clinics in Kampala and two rural districts in Uganda. This could complicate treatment options for community-acquired infections caused by the Enterobacteriaceae.
Electronic supplementary material: The online version of this article (doi:10.1186/s13104-016-2049-8) contains supplementary material, which is available to authorized usersNational Research Foundation (South Africa
Comparison of Existing Phenotypic and Genotypic Tests for the Detection of NDM and GES Carbapenemase- Producing Enterobacteriaceae.
No full textThe efficient detection and distinction of carbapenem-resistant and carbapenemase-producing Enterobacteriaceae continues to pose a major challenge to clinical microbiology laboratories, particularly in resource-constrained countries. Disc diffusion (DD), micro-broth dilution (BMD), Vitek II, Carba NP test, modified Hodge’s test (MHT) and real-time PCR were evaluated on known carbapenem-resistant and carbapenemase-producing clinical Enterobacteriaceae isolates in terms of their sensitivity and specificity using whole genome sequencing (WGS) as the gold standard. DD with meropenem (MRP), real-time PCR, DD with imipenem (IMP), BMD, Carba NP test, and BMD with IMP had sensitivities of 100%, 97.96%, 97.96%, 97.96%, 95.92%, and 95.92% respectively. Real-time PCR and Carba NP test had the highest specificities (100%) and shortest turnaround times (< 3 hours). DD or BMD using meropenem, followed by Carba NP test and PCR were the best protocols for detecting and confirming CPEs clinically. We recommend the Carba NP test and/or DD specifically for resource-constrained laboratories for detection and control of carbapenemase-producing Enterobacteriaceae.National Research Foundation (South Africa
The use and abuse of police data in protest analysis: South Africa’s incident registration information system (iris)
No full textSouth Africa's Incident Registration Information System (IRIS) is a comprehensive, computerised database maintained by the South African Police Service. In principle, it records all public order policing activity, including all crowd incidents. While IRIS data is, potentially, a unique source for protest event analysis, it should be approached with considerable care. In this article we aim to correct misunderstandings about the data advanced by academics and in the media, and expose its misuse by police chiefs and politicians. In particular, we argue that the incidents that IRIS reports are not protests, although protests can be found in the raw data. This article is based, in part, on records of 156 230 incidents covering the period 1997-2013. We estimate that only about 67 750 of these, 43% of the total, were protests. This may be the largest number of police-recorded protests released anywhere in the world.National Research Foundation (South Africa
The domestication of fire as social-ecological regime shift
No full textSocial-ecological regime shifts involve large, often abrupt, reorganizations in interlinked social and ecological systems. The domestication of fire illustrates how physiological and social changes enabled humans to start actively controlling fire, dramatically reshaping the environment and society itself.National Research Foundation (South Africa
Evidence for interspecific interactions in the ectoparasite infracommunity of a wild mammal
No full textBackground: Co-infection with multiple parasite species is commonly observed in nature and interspecific interactions are likely to occur in parasite infracommunities. Such interactions may affect the distribution of parasites among hosts but also the response of infracommunities to perturbations. However, the response of infracommunities to perturbations has not been well studied experimentally for ectoparasite communities of small mammal hosts.
Methods: In the current study we used experimental perturbations of the ectoparasite infracommunity of sengis from Africa. We suppressed tick recruitment by applying an acaride and monitored the effects on the ectoparasite community.
Results: Our treatment affected the target as well as two non-target species directly. The experimental removal of the dominant tick (Rhipicephalus spp.) resulted in increases in the abundance of chiggers and lice. However, while these effects were short-lived in chiggers, which are questing from the environment, they were long-lasting for lice which spend their entire life-cycle on the host. In addition, the recruitment rates of some ectoparasite species were high and did not always correspond to total burdens observed.
Conclusion: These findings indicate that infracommunity interactions may contribute to patterns of parasite burdens. The divergent responses of species with differing life-history traits suggest that perturbation responses may be affected by parasite life-history and that the ectoparasite infracommunity of sengis may lack resilience to perturbations. The latter observation contrasts with the high resilience reported previously for endoparasite communities and also suggests that anti-parasite treatments can affect the distribution of non-target species.National Research Foundation (South Africa
Characteristics of roost cavities used by Lilian's Lovebird Agapornis lilianae in Liwonde National Park, Malawi
No full textLilian's Lovebird Agapornis lilianae is a non-excavating cavity user of mopane Colophospermum mopane woodlands. We investigated roost characteristics of Lilian's Lovebirds in Liwonde National Park, Malawi. We quantified tree and roost site variables for roost and non-roost trees. Sixty-six roosts were found. Roosts were in large tall mopane trees with a mean diameter at breast height (dbh) of 57.4 ± 1.64 cm, a mean height of 16.5 ± 0.42 m, and with a mean cavity entrance height of 10.0 ± 0.05 m. Non-roost areas had significantly smaller trees (mean dbh = 39.4 ± 1.72 cm). Human disturbance was low in both areas, but browsing of African elephant Loxodonta africana was evident by large areas of stunted mopane woodland recorded in non-roost areas. We recommend that the current Liwonde National Park vegetation map be updated to highlight areas of stunted mopane woodland unsuitable for Lilian's Lovebird roosts. The impact of elephant browsing on large mopane trees should be assessed to understand its impact on the availability of suitable cavities for lovebirds and other tree cavity reliant vertebrate speciesNational Research Foundation (South Africa
Comparative performance of four survey methods for assessing Lilian’s Lovebird abundance in Liwonde National Park, Malawi.
No full textMonitoring abundance of threatened species is important for conservation planning. Lilian’s Lovebird Agapornis lilianae is a near-threatened small parrot found in mopane Colophospermum mopane woodland. Its population has not been investigated in any part of its range. We investigated the abundance and density of the Lilian’s Lovebird in Liwonde National Park, Malawi. Both distance sampling (line and point transects) methods and total counts (waterhole and flyway counts) were applied. The point count method gave very low numbers and was discontinued after the first year. Line transects conducted during the wet season had the highest density estimates of 17 ± 4.8 lovebirds km−2 of mopane woodland. However, number of observations per transect in each year were low. Waterhole counts had the lowest density estimates (10 ± 3.5 lovebirds km−2). Flyway counts gave an intermediate estimate (13 ± 3.0 lovebirds km−2). The total population of Lilian’s Lovebirds in Liwonde National Park is therefore estimated to be about 4 000 individuals. The use of line transect counts at the end of the rainy season is recommended for continued monitoring of Lilian’s Lovebirds abundance in Liwonde National Park.National Research Foundation (South Africa