Browsing by Author "Lopes, Tatum"

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    Assessment of the association of plant- based diets with cardiovascular disease risk profile in Africa: a systematic review and meta-analysis protocol
    (BMJ Publishing, 2020-06) Lopes, Tatum; Zemlin, Annalise E.; Erasmus, Rajiv T.; Faber, Mieke; Kengne, Andre P.
    Introduction Cardiovascular disease (CVD) is currently the leading cause of death worldwide. In Africa where infectious diseases are still the leading cause of death, the contribution of non-communicable diseases led by CVDs has significantly increased in recent years. The rise of CVDs in Africa is attributed at least in part to the adoption of sedentary behaviours and unhealthy eating habits, which are linked with urbanisation and westernisation of cultures. Dietary attributes associated with CVD risk have been less investigated in Africa. However, evidence from developed nations has reported a protective effect of healthy dietary patterns such as plant-based diets (PBDs) on cardiometabolic health. The current protocol is for a review aiming to assess existing evidence on the association of PBDs with CVD risk profile in African populations. Methods and analysis This protocol was developed following the 2015 guidelines of the Preferred Reporting Items for Systematic Review and Meta-analysis Protocols. We will conduct a comprehensive search of the literature for published studies on PBDs in relation to CVD risk profile in African populations. Observational studies published between January 1990 and December 2019 will be screened. A search strategy using keywords and medical subject headings terms will be applied across multiple scientific databases including PubMed-Medline, Scopus and EBSCOhost and the African Journals Online platform. Manual searches of reference lists from relevant articles will be performed. Citations will be traced using the ISI Web of Science to further identify eligible studies. Grey literature will also be screened for relevant abstracts from conference proceedings, and experts in the field will be contacted where appropriate. Two investigators will independently screen all the titles and abstracts to determine which records are eligible for full-text review. Subsequently, two investigators will review the eligible full text using the selection criteria. A third investigator will be consulted to resolve any discrepancies. Data will be extracted from studies that are eligible for the review. Meta-analysis will be performed for studies with similar or comparable methods and reported outcome measures. This will be performed overall, and by major study-level characteristics. Heterogeneity in the estimates across studies will be assessed and quantified with the use of Cochrane Q and I2 statistics, respectively. Publication biases will be investigated through funnel plots and Egger test of bias. Relevant sensitivity analyses will be performed to confirm the robustness of the findings
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    Prevalence and risks of Hepatitis E virus infection in blood donors from the Western Cape, South Africa
    (Stellenbosch : Stellenbosch University, 2016-03) Lopes, Tatum; Andersson, Monique I.; Preiser, Wolfgang; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Pathology. Medical Virology.
    ENGLISH ABSTRACT: Hepatitis E virus (HEV) is an important cause of enterically transmitted acute hepatitis worldwide and is a locally acquired disease in both developing and developed nations. Different genotypes in these two regions display the different characteristics of this interesting infection. HEV is classified into four major genotypes and it can present as two contrasting clinical entities. HEV genotypes 1 (HEV1) and 2 (HEV 2) are related to waterborne transmission and poor sanitation. Whereas genotypes 3 (HEV3) and 4 (HEV4) are associated with zoonotic transmission mainly through pigs, wild boar and deer. HEV infections in Africa are thought to be caused by HEV1 and HEV2. The seroprevalence of HEV has been described in Southern Africa, but all more than 10 years ago when assays were not well developed. South Africa has three HEV reports, describing a hospital outbreak, and the seroprevalence in specific communities of South Africa. The seroprevalence from these studies ranged from 2% to 10.7% however no genotyping was done. Researchers have reported evidence of direct and indirect transfusion-transmitted HEV infection being a potential risk to recipients of blood transfusions. Asymptomatic HEV infections in blood donors increase the likelihood that blood or blood products are contaminated with HEV viral particles. Hence, there is a greater chance of infecting high-risk recipient groups with compromised immune systems. Therefore, the main aim of this study was to determine the prevalence of past and active HEV infection in blood donors from the Western Cape. We also investigated which risk factors are associated with infection. Our study population consisted of 10,250 blood donors that were tested as two sub-studies. For study group 1 we recruited 250 donors to complete an HEV risk questionnaire. Thereafter these donors were tested using an indirect Wantai ELISA (Fortress Diagnostics) for anti-HEV IgG detection. Statistical analysis was done to determine which demographics and risk factors were associated with past HEV infection. In addition, to this, their plasma donations were pooled, prior to extraction and amplified with an in-house real-time reverse-transcriptase quantitative polymerase chain reaction (RT-qPCR) to detect HEV RNA. The 10,000 blood donors of study group 2 were tested as individual donations using a commercial Procleix HEV nucleic acid testing (NAT) assay to qualitatively detect HEV RNA by transcription-mediated amplification (TMA). Thereafter repeat-reactive donations were quantified using our in-house real-time RT-qPCR. The total anti-HEV IgG seroprevalence of our study was found to be 42.4% in blood donors (study group 1). Risk analysis revealed that eating turkey (p=0.001) and organ meat (p=0.026) and canoeing (p=0.017) were significantly associated with past HEV infection. Whereas direct contact with rabbits (p=0.045) or chickens (p=0.020) were statistically significantly different means of HEV exposure associated with HEV3 and HEV4. Furthermore, we found that the total HEV RNA prevalence was 0.009% (1/10,250). Studies are needed to further assess the risk of HEV blood-borne transmission and to understand the epidemiology of HEV in our setting.