Zar H.J.,University of Cape Town |
Madhi S.A.,South African National Institute for Communicable Diseases |
Madhi S.A.,University of Witwatersrand |
Aston S.J.,Malawi Liverpool Wellcome Trust Clinical Research Programme
Thorax | Year: 2013
Pneumonia remains the leading cause of childhood mortality and the most common reason for adult hospitalisation in low and middle income countries, despite advances in preventative and management strategies. In the last decade, pneumonia mortality in children has fallen to approximately 1.3 million cases in 2011, with most deaths occurring in low income countries. Important recent advances include more widespread implementation of protein-polysaccharide conjugate vaccines against Haemophilus influenzae type B and Streptococcus pneumoniae, implementation of case-management algorithms and better prevention and treatment of HIV. Determining the aetiology of pneumonia is challenging in the absence of reliable diagnostic tests. High uptake of new bacterial conjugate vaccines may impact on pneumonia burden, aetiology and empiric therapy but implementation in immunisation programmes in many low and middle income countries remains an obstacle. Widespread implementation of currently effective preventative and management strategies for pneumonia remains challenging in many low and middle income countries.
Moxon C.A.,Malawi Liverpool Wellcome Trust Clinical Research Programme |
Grau G.E.,University of Sydney
British Journal of Haematology | Year: 2011
Residence in the human erythrocyte is essential for the lifecycle of all Plasmodium that infect man. It is also the phase of the life cycle that causes disease. Although the red blood cell (RBC) is a highly specialized cell for its function of carrying oxygen to and carbon dioxide away from tissues, it is devoid of organelles and lacks any cellular machinery to synthesize new protein. Therefore in order to be able to survive and multiply within the RBC membrane the parasite needs to make many modifications to the infected RBC (iRBC). Plasmodium falciparum (P. falciparum) also expresses parasite-derived proteins on the surface of the iRBC that enable the parasite to cytoadhere to endothelial and other intravascular cells. These RBC modifications are at the root of malaria pathogenesis and, in this ancient disease of man, have formed the epicentre of a genetic 'battle' between parasite and host. This review discusses some of the critical modifications of the RBC by the parasite and some of the consequences of these adaptations on disease in the human host, with an emphasis on advances in understanding of the pathogenesis of severe and cerebral malaria (CM) from recent research. © 2011 Blackwell Publishing Ltd.
MacPherson E.E.,Malawi Liverpool Wellcome Trust Clinical Research Programme
Journal of the International AIDS Society | Year: 2012
In Southern Malawi, the fishing industry is highly gendered, with men carrying out the fishing and women processing, drying and selling the fish. Research has shown that individuals living in fishing communities in low-income countries are particularly vulnerable to HIV infection. One of the key drivers of HIV in fishing communities is transactional sex. In the fishing industry this takes the form of "fish-for-sex" networks where female fish traders exchange sex with fishermen for access to or more favourable prices of fish. By controlling the means of production, the power dynamics in these exchanges favour men and can make it more difficult for women to negotiate safe sex. Qualitative methods were used to collect data on gendered drivers of transactional sex in the fishing community and how different groups perceive HIV risk in these transactions. Observation, focus group discussions and semi-structured interviews were undertaken with members of the fishing communities, including men and women directly and indirectly involved in fishing. In fishing communities transactional sex was prevalent across a spectrum ranging from gift giving within relationships, to sex for fish exchanges, to sex worker encounters. Power differences between couples in transactional sexual encounters shape individual's abilities to negotiate condom use (with women being at a particularly disadvantaged negotiating position). The context and motivations for transactional sex varied and was mediated by economic need and social position both of men and women. Female fish traders new to the industry and boat crew members who travelled for work and experienced difficult living conditions often engaged in transactional sex. Transactional sex is common in Malawian fishing communities, with women particularly vulnerable in negotiations because of existing gendered power structures. Although knowledge and understanding of the HIV risk associated with transactional sex was common, this did not appear to result in the adoption of risk reduction strategies. This suggests that specially targeted strategies to increase women's economic empowerment and tackle the structural drivers of women's HIV risk could be important in fishing communities.
Burgess P.I.,Malawi Liverpool Wellcome Trust Clinical Research Programme
Diabetic medicine : a journal of the British Diabetic Association | Year: 2013
To summarize findings from studies reporting the prevalence and incidence of diabetic retinopathy and diabetic maculopathy in African countries in light of the rising prevalence of diabetes mellitus. Using a predefined search strategy, we systematically searched MEDLINE, EMBASE, Science Citation index and Conference Proceedings Citation index, African Index Medicus and the grey literature database 'OpenSIGLE' for studies published between January 1990 and February 2011. Included studies reported prevalence or incidence of diabetic retinopathy or diabetic maculopathy of subjects with diabetes resident in African countries. Sixty-two studies from 21 countries were included: three population-based surveys; two cohort studies; five case-control studies; 32 diabetes clinic-based, nine eye clinic-based and 11 other hospital-based surveys. Included studies varied considerably in terms of patient selection, method of assessing the eye and retinopathy classification. In population-based studies, the reported prevalence range in patients with diabetes for diabetic retinopathy was 30.2 to 31.6%, proliferative diabetic retinopathy 0.9 to 1.3%, and any maculopathy 1.2 to 4.5%. In diabetes clinic-based surveys, the reported prevalence range for diabetic retinopathy was 7.0 to 62.4%, proliferative diabetic retinopathy 0 to 6.9%, and any maculopathy 1.2 to 31.1%. No obvious association between prevalence and income level of the country was detected. Large, community-based cross-sectional and cohort studies are needed to investigate rates and determinants of prevalence of diabetic retinopathy, incidence and progression in Africa. Consensus is needed on the most appropriate methods of identification and classification of retinopathy for research and clinical practice. Estimates of prevalence of diabetic retinopathy, proliferative diabetic retinopathy and maculopathy are comparable with recent European and American studies. © 2012 The Authors. Diabetic Medicine © 2012 Diabetes UK.
Rylance J.,Malawi Liverpool Wellcome Trust Clinical Research Programme |
Rylance J.,International Health Group |
Pai M.,McGill University |
Lienhardt C.,WHO |
Garner P.,International Health Group
The Lancet Infectious Diseases | Year: 2010
Reliable and relevant research can help to improve tuberculosis control worldwide. In recent years, various organisations have assessed research needs and proposed priorities for tuberculosis. We summarise existing priority statements and assess the rigour of the methods used to generate them. We found 33 documents that specifically outline priorities in tuberculosis research. The top priority areas were drug development (28 articles), diagnosis and diagnostic tests (27), epidemiology (20), health services research (16), basic research (13), and vaccine development and use (13). The most focused questions were on the treatment and prevention of multidrug-resistant tuberculosis in people co-infected with HIV. Methods used to identify these priorities were varied. Improvements can be made to ensure the process is more rigorous and transparent, and to use existing research or systematic reviews more often. WHO, Stop TB Partnership, and other organisations could adopt an incremental process of priority development, building on the existing knowledge base. © 2010 Elsevier Ltd.