scholarly journals Immunogenicity of Novel DosR Regulon-Encoded Candidate Antigens of Mycobacterium tuberculosis in Three High-Burden Populations in Africa

2009 ◽  
Vol 16 (8) ◽  
pp. 1203-1212 ◽  
Author(s):  
Gillian F. Black ◽  
Bonnie A. Thiel ◽  
Martin O. Ota ◽  
Shreemanta K. Parida ◽  
Richard Adegbola ◽  
...  

ABSTRACT Increasing knowledge about DosR regulon-encoded proteins has led us to produce novel Mycobacterium tuberculosis antigens for immunogenicity testing in human populations in three countries in Africa to which tuberculosis (TB) is endemic. A total of 131 tuberculin skin test-positive and/or ESAT-6/CFP10-positive, human immunodeficiency virus-negative adult household contacts of active pulmonary TB cases from South Africa (n = 56), The Gambia (n = 26), and Uganda (n = 49) were tested for gamma interferon responses to 7 classical and 51 DosR regulon-encoded M. tuberculosis recombinant protein antigens. ESAT-6/CFP10 fusion protein evoked responses in >75% of study participants in all three countries. Of the DosR regulon-encoded antigens tested, Rv1733c was the most commonly recognized by participants from both South Africa and Uganda and the third most commonly recognized antigen in The Gambia. The four most frequently recognized DosR regulon-encoded antigens in Uganda (Rv1733c, Rv0081, Rv1735c, and Rv1737c) included the three most immunogenic antigens in South Africa. In contrast, Rv3131 induced the highest percentage of responders in Gambian contacts (38%), compared to only 3.4% of Ugandan contacts and no South African contacts. Appreciable percentages of TB contacts with a high likelihood of latent M. tuberculosis infection responded to several novel DosR regulon-encoded M. tuberculosis proteins. In addition to significant similarities in antigen recognition profiles between the three African population groups, there were also disparities, which may stem from genetic differences between both pathogen and host populations. Our findings have implications for the selection of potential TB vaccine candidates and for determining biosignatures of latent M. tuberculosis infection, active TB disease, and protective immunity.

2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Camilla E. Le Roux ◽  
Sucari S.C. Vlok

Extra-pulmonary tuberculosis (EPTB), caused by Mycobacterium tuberculosis, is the leading cause of communicable disease-related deaths in people with human immunodeficiency virus (HIV) worldwide and in South Africa. Mycobacterium tuberculosis disseminates haematogenously from an active primary lung focus and may affect extra-pulmonary sites in up to 15% of patients. Extra-pulmonary TB may present with a normal chest radiograph, which often causes a significant diagnostic dilemma. This review describes the main sites of involvement in EPTB, which is illustrated by local imaging examples.


2012 ◽  
Vol 9 (72) ◽  
pp. 1544-1554 ◽  
Author(s):  
Leigh F. Johnson ◽  
Timothy B. Hallett ◽  
Thomas M. Rehle ◽  
Rob E. Dorrington

This study aims to assess trends in human immunodeficiency virus (HIV) incidence in South Africa, and to assess the extent to which prevention and treatment programmes have reduced HIV incidence. Two models of the South African HIV epidemic, the STI (sexually transmitted infection)–HIV Interaction model and the ASSA2003 AIDS and Demographic model, were adapted. Both models were fitted to age-specific HIV prevalence data from antenatal clinic surveys and household surveys, using a Bayesian approach. Both models suggest that HIV incidence in 15–49 year olds declined significantly between the start of 2000 and the start of 2008: by 27 per cent (95% CI: 21–32%) in the STI–HIV model and by 31 per cent (95% CI: 23–39%) in the ASSA2003 model, when expressed as a percentage of incidence rates in 2000. By 2008, the percentage reduction in incidence owing to increased condom use was 37 per cent (95% CI: 34–41%) in the STI–HIV model and 23 per cent (95% CI: 14–34%) in the ASSA2003 model. Both models also estimated a small reduction in incidence owing to antiretroviral treatment by 2008. Increased condom use therefore appears to be the most significant factor explaining the recent South African HIV incidence decline.


2001 ◽  
Vol 69 (10) ◽  
pp. 6554-6557 ◽  
Author(s):  
Johan Vekemans ◽  
Christian Lienhardt ◽  
Jackson S. Sillah ◽  
Jeremy G. Wheeler ◽  
George P. Lahai ◽  
...  

ABSTRACT The Mycobacterium tuberculosis antigen ESAT-6 has been proposed for tuberculosis immunodiagnosis. In The Gambia, 30% of community controls produced gamma interferon (IFN-γ) in response to ESAT-6. Increased proportions of responders and intensities of responses were found in household contacts. Responses that were initially low in tuberculosis patients increased after treatment. An ESAT-6 IFN-γ assay will be of limited use in the diagnosis of tuberculosis in countries where tuberculosis is endemic. Its role in contact tracing should be evaluated further.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244420
Author(s):  
Tenielle Schmidt ◽  
Allanise Cloete ◽  
Adlai Davids ◽  
Lehlogonolo Makola ◽  
Nokubonga Zondi ◽  
...  

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is a new strain of virus in the Coronavirus family that has not been previously identified. Since SARS-CoV-2 is a new virus, everyone is at risk of catching the Coronavirus disease 2019 (Covid-19). No one has immunity to the virus. Despite this, misconceptions about specific groups of people who are immune to Covid-19 emerged with the onset of the pandemic. This paper explores South African communities’ misconceptions about who is most vulnerable to Covid-19. A rapid qualitative assessment was conducted remotely in Gauteng, KwaZulu-Natal and the Western Cape provinces of South Africa. Recruitment of study participants took place through established relationships with civil society organizations and contacts made by researchers. In total, 60 key informant interviews and one focus group discussion was conducted. Atlas.ti.8 Windows was used to facilitate qualitative data analysis. The qualitative data was coded, and thematic analysis used to identify themes. The results show a high level of awareness and knowledge of the transmission and prevention of SARS-CoV-2. Qualitative data revealed that there is awareness of elderly people and those with immunocompromised conditions being more vulnerable to catching Covid-19. However, misconceptions of being protected against the virus or having low or no risk were also evident in the data. We found that false information circulated on social media not only instigated confusion, fear and panic, but also contributed to the construction of misconceptions, othering and stigmatizing responses to Covid-19. The study findings bring attention to the importance of developing communication materials adapted to specific communities to help reduce misconceptions, othering and stigmatization around Covid-19.


2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Martin Ziegler ◽  
Margit H. Simon ◽  
Ian R. Hall ◽  
Stephen Barker ◽  
Chris Stringer ◽  
...  

Abstract The development of modernity in early human populations has been linked to pulsed phases of technological and behavioural innovation within the Middle Stone Age of South Africa. However, the trigger for these intermittent pulses of technological innovation is an enigma. Here we show that, contrary to some previous studies, the occurrence of innovation was tightly linked to abrupt climate change. Major innovational pulses occurred at times when South African climate changed rapidly towards more humid conditions, while northern sub-Saharan Africa experienced widespread droughts, as the Northern Hemisphere entered phases of extreme cooling. These millennial-scale teleconnections resulted from the bipolar seesaw behaviour of the Atlantic Ocean related to changes in the ocean circulation. These conditions led to humid pulses in South Africa and potentially to the creation of favourable environmental conditions. This strongly implies that innovational pulses of early modern human behaviour were climatically influenced and linked to the adoption of refugia.


2018 ◽  
Vol 19 (1) ◽  
Author(s):  
Nathan Geffen ◽  
Alex Welte

We review key mathematical models of the South African human immunodeficiency virus (HIV) epidemic from the early 1990s onwards. In our descriptions, we sometimes differentiate between the concepts of a model world and its mathematical or computational implementation. The model world is the conceptual realm in which we explicitly declare the rules – usually some simplification of ‘real world’ processes as we understand them. Computing details of informative scenarios in these model worlds is a task requiring specialist knowledge, but all other aspects of the modelling process, from describing the model world to identifying the scenarios and interpreting model outputs, should be understandable to anyone with an interest in the epidemic.


2020 ◽  
Vol 17 (3) ◽  
pp. 433-444
Author(s):  
Amanuel Isak Tewolde

Many scholars and South African politicians characterize the widespread anti-foreigner sentiment and violence in South Africa as dislike against migrants and refugees of African origin which they named ‘Afro-phobia’. Drawing on online newspaper reports and academic sources, this paper rejects the Afro-phobia thesis and argues that other non-African migrants such as Asians (Pakistanis, Indians, Bangladeshis and Chinese) are also on the receiving end of xenophobia in post-apartheid South Africa. I contend that any ‘outsider’ (White, Asian or Black African) who lives and trades in South African townships and informal settlements is scapegoated and attacked. I term this phenomenon ‘colour-blind xenophobia’. By proposing this analytical framework and integrating two theoretical perspectives — proximity-based ‘Realistic Conflict Theory (RCT)’ and Neocosmos’ exclusivist citizenship model — I contend that xenophobia in South Africa targets those who are in close proximity to disadvantaged Black South Africans and who are deemed outsiders (e.g., Asian, African even White residents and traders) and reject arguments that describe xenophobia in South Africa as targeting Black African refugees and migrants.


2016 ◽  
Vol 13 (3) ◽  
pp. 359-376 ◽  
Author(s):  
Tiffany L Green ◽  
Amos C Peters

Much of the existing evidence for the healthy immigrant advantage comes from developed countries. We investigate whether an immigrant health advantage exists in South Africa, an important emerging economy.  Using the 2001 South African Census, this study examines differences in child mortality between native-born South African and immigrant blacks.  We find that accounting for region of origin is critical: immigrants from southern Africa are more likely to experience higher lifetime child mortality compared to the native-born population.  Further, immigrants from outside of southern Africa are less likely than both groups to experience child deaths.  Finally, in contrast to patterns observed in developed countries, we detect a strong relationship between schooling and child mortality among black immigrants.


2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Andrea Hill ◽  
Sylvia Poss

The paper addresses the question of reparation in post-apartheid South Africa. The central hypothesis of the paper is that in South Africa current traumas or losses, such as the 2008 xenophobic attacks, may activate a ‘shared unconscious phantasy’ of irreparable damage inflicted by apartheid on the collective psyche of the South African nation which could block constructive engagement and healing. A brief couple therapy intervention by a white therapist with a black couple is used as a ‘microcosm’ to explore this question. The impact of an extreme current loss, when earlier losses have been sustained, is explored. Additionally, the impact of racial difference on the transference and countertransference between the therapist and the couple is explored to illustrate factors complicating the productive grieving and working through of the depressive position towards reparation.


Derrida Today ◽  
2010 ◽  
Vol 3 (1) ◽  
pp. 21-36
Author(s):  
Grant Farred

‘The Final “Thank You”’ uses the work of Jacques Derrida and Friedrich Nietzsche to think the occasion of the 1995 rugby World Cup, hosted by the newly democratic South Africa. This paper deploys Nietzsche's Zarathustra to critique how a figure such as Nelson Mandela is understood as a ‘Superman’ or an ‘Overhuman’ in the moment of political transition. The philosophical focus of the paper, however, turns on the ‘thank yous’ exchanged by the white South African rugby captain, François Pienaar, and the black president at the event of the Springbok victory. It is the value, and the proximity and negation, of the ‘thank yous’ – the relation of one to the other – that constitutes the core of the article. 1


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