Browsing by Author "Sibongile Walaza"

Now showing 1 - 14 of 14
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    A retrospective observational cohort study of the effect of antenatal influenza vaccination on birth outcomes in Cape Town South Africa 20152016
    Meredith McMorrow; Liza Rossi; Susan Meiring; Katherine Bishop; Sibongile Walaza; Orienka Hellferscee; Florette Treurnicht; Cheryl Cohen; E et al
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    Association of HIV Exposure and HIV Infection With Inhospital Mortality Among Hospitalized Infants 1 Year of Age South Africa 20162018
    Nicole Wolter; Sibongile Walaza; C von Mollendorf; Anne Von Gottberg; S Tempia; M McMorrow; Jocelyn Moyes; Florette Treurnicht; Orienka Hellferscee; Malefu Moleleki; Mvuyo Makhasi; N Baute; Cheryl Cohen
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    Coronavirus Host Genomics Study: South Africa (COVIGen-SA)
    (2022-10-06) Andrew K. May; Heather Seymour; Harriet Etheredge; Heather Maher; Marta C. Nunes; ShabirA.Madhi; SimisoM. Sokhela; W. D. FrancoisVenter; Neil Martinson; Firdaus Nabeemeeah; Cheryl Cohen; Jocelyn Moyes; Sibongile Walaza; Stefano Tempia; Jackie Kleynhans; Anne von Gottberg; Jeremy Nel; Halima Dawood; Ebrahim Variava; Stephen Tollman; Kathleen Kahn; KobusHerbst; EmilyB.Wong; CarolineT.Tiemessen; Alex van Blydenstein; Lyle Murray; Michelle Venter; June Fabian; Miche´le Ramsay
    However, continental Africans are yet to be adequately represented in such studies despite the importance of genetic factors in understanding Africa’s response to the pandemic. We describe the development of a research resource for coronavirus host genomics studies in South Africa known as COVIGen-SA—a multicollaborator strategic partnership designed to provide harmonised demographic, clinical, and genetic information specific to Black South Africans with COVID-19. Over 2,000 participants have been recruited to date. Preliminary results on 1,354 SARS-CoV-2 positive participants from four participating studies showed that 64.7% were female, 333 had severe disease, and 329 were people living with HIV. *rough this resource, we aim to provide insights into host genetic factors relevant to African-ancestry populations, using both genome-wide association testing and targeted sequencing of important genomic loci. *is project will promote and enhance partnerships, build skills, and develop resources needed to address the COVID-19 burden and associated risk factors in South African communities.
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    Detection of Victoria lineage influenza B viruses with K162 and N163 deletions in the hemagglutinin gene South Africa 2018
    Orienka Hellferscee; Florette Treurnicht; Lucinda Gaelejwe; aLEXANDRA mOERDYK; Gary Reubenson; Meredith McMorrow; Stefano Tempia; Johanna McAnerney; Sibongile Walaza; Nicole Wolter; Anne Von Gottberg; Cheryl Cohen
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    Difference in mortality among individuals admitted to hospital with COVID19 during the first and second waves in South Africa a cohort study
    Waasila jassat; Caroline Mudara; Lovelyn Ozougwu; Stefano Tempia; Lucille Blumberg; E et al; Anne Von Gottberg; Jinal Bhiman; Cheryl Cohen; Sibongile Walaza
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    Epidemiology of Pertussis in Individuals of All Ages Hospitalized With Respiratory Illness in South Africa January 2013December 2018
    Nicole Wolter; Cheryl Cohen; Stefano Tempia; Sibongile Walaza; Fahima Moosa; Mignonette Du Plessis; Meredith L McMorrow; Florette Treurnicht; Orienka Hellferscee; Halima Dawood; Ebrahim Variava; Anne Von Gottberg
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    Genomic characterization of Bordetella pertussis in South Africa 20152019
    Fahima Moosa; Mignonette Du Plessis; M.R Weigand; Y Peng; D Mogale; L de Gouveia; Martha Nunes; Shabir Madhi; E et al; Gary Reubenson; Cheryl Cohen; Sibongile Walaza; Anne Von Gottberg; Nicole Wolter
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    Household Transmission of Severe Acute Respiratory Syndrome Coronavirus 2 From Adult Index Cases With and Without Human Immunodeficiency Virus in South Africa 20202021 A CaseAscertained Prospective Observational Household Transmission Study
    (OXFORD UNIV PRESS INC) Jacoba Kleynhans; Sibongile Walaza; Neil Martinson; M Neti; Anne Von Gottberg; Jinal Bhiman; D Toi; D G Amoako; A Buys; Nicole Wolter; Limakatso Lebina; Lucia Maloma; Stefano Tempia; Cheryl Cohen; E et al
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    Human respiratory syncytial virus diversity and epidemiology among patients hospitalized with severe respiratory illness in South Africa, 2012–2015
    (2015) Ziyaad Valley-Omar; Stefano Tempia; Orienka Hellferscee; Sibongile Walaza; Ebrahim Variava6; Halima Dawood; Kathleen Kahn; Meredith McMorrow; Marthi Pretorius; Senzo Mtshali; Ernest Mamorobela; Nicole Wolter; Marietjie Venter; Anne von Gottberg; Cheryl Cohen; Florette K. Treurnicht
    Background: We aimed to describe the prevalence of human respiratory syncytial virus (HRSV) and evaluate associations between HRSV subgroups and/or genotypes and epidemiologic characteristics and clinical outcomes in patients hospitalized with severe respiratory illness (SRI). Methods: Between January 2012 and December 2015, we enrolled patients of all ages admitted to two South African hospitals with SRI in prospective hospital-based syndromic surveillance. We collected respiratory specimens and clinical and epidemiological data. Unconditional random effect multivariable logistic regression was used to assess factors associated with HRSV infection. Results: HRSV was detected in 11.2% (772/6908) of enrolled patients of which 47.0% (363/772) were under the age of 6 months. There were no differences in clinical outcomes of HRSV subgroup A-infected patients compared with HRSV subgroup B-infected patients but among patients aged <5 years, children with HRSV subgroup A were more likely be coinfected with Streptococcus pneumoniae (23/208 11.0% vs. 2/90, 2.0%; adjusted odds ratio 5.7). No significant associations of HRSV A genotypes NA1 and ON1 with specific clinical outcomes were observed. Conclusions: While HRSV subgroup and genotype dominance shifted between seasons, we showed similar genotype diversity as noted worldwide. We found no association between clinical outcomes and HRSV subgroups or genotypes.
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    Mortality in children aged <5 years with severe acute respiratory illness in a high HIVprevalence urban and rural areas of South Africa, 2009–2013
    (2021-08-12) Oluwatosin A Ayeni; Sibongile Walaza; Stefano Tempia; Michelle Groome; Kathleen Kahn; Shabir A Madhi; Adam L Cohen; Jocelyn Moyes; Marietjie Venter; Marthi Pretorius; Florette Treurnicht; Orienka Hellferscee; Anne von Gottberg; Nicole Wolter; Cheryl Cohen
    Background: Severe acute respiratory illness (SARI) is an important cause of mortality in young children, especially in children living with HIV infection. Disparities in SARI death in children aged <5 years exist in urban and rural areas. Objective: To compare the factors associated with in-hospital death among children aged <5 years hospitalized with SARI in an urban vs. a rural setting in South Africa from 2009-2013. Methods: Data were collected from hospitalized children with SARI in one urban and two rural sentinel surveillance hospitals. Nasopharyngeal aspirates were tested for ten respiratory viruses and blood for pneumococcal DNA using polymerase chain reaction. We used multivariable logistic regression to identify patient and clinical characteristics associated with in-hospital death. Results: From 2009 through 2013, 5,297 children aged <5 years with SARI-associated hospital admission were enrolled; 3,811 (72%) in the urban and 1,486 (28%) in the rural hospitals. In-hospital case-fatality proportion (CFP) was higher in the rural hospitals (6.9%) than the urban hospital (1.3%, p<0.001), and among HIV-infected than the HIV-uninfected children (9.6% vs. 1.6%, p<0.001). In the urban hospital, HIV infection (odds ratio (OR):11.4, 95% confidence interval (CI):5.4-24.1) and presence of any other underlying illness (OR: 3.0, 95% CI: 1.0-9.2) were the only factors independently associated with death. In the rural hospitals, HIV infection (OR: 4.1, 95% CI: 2.3-7.1) and age <1 year (OR: 3.7, 95% CI: 1.9-7.2) were independently associated with death, whereas duration of hospitalization ≥5 days (OR: 0.5, 95% CI: 0.3-0.8) and any respiratory virus detection (OR: 0.4, 95% CI: 0.3-0.8) were negatively associated with death. Conclusion: We found that the case-fatality proportion was substantially higher among children admitted to rural hospitals and HIV infected children with SARI in South Africa. While efforts to prevent and treat HIV infections in children may reduce SARI deaths, further efforts to address health care inequality in rural populations are needed.
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    Role of vaccines in preventing influenza in healthy children
    E Z Sambala; S Cooper; B M Schmidt; Sibongile Walaza; C S Wiysonge
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    The attributable fraction of respiratory syncytial virus among patients of different age with influenza-like illness and severe acute respiratory illness in a high HIV prevalence setting, South Africa, 2012-2016 Running title: The attributable fraction of RSV in South Africa (all ages), South Africa 2012- 2016
    (2022-11-22) Jocelyn Moyes; Stefano Tempia; Sibongile Walaza; Meredith L. McMorrow; Adam L. Cohen; Florette Treurnicht; Orienka Hellferscee; Nicole Wolter; Anne Von Gottberg; Halima Dawood; Ebrahim Variava; Kathleen Kahn; Shabir A. Madhi; Cheryl Cohen
    Introduction The detection of respiratory syncytial virus (RSV) in upper airway samples does not necessarily infer causality of illness. Calculating the attributable fraction (AF) of RSV in clinical syndromes could refine disease burden estimates. Methods Using unconditional logistic regression models, we estimated the AF of RSV-associated influenza-like illness (ILI) and severe-acute respiratory illness (SARI) cases by comparing RSVdetection prevalence among ILI and SARI cases to those of healthy controls in South Africa, 2012-2016. The analysis, stratified by HIV serostatus, was conducted in the age categories <1, 1-4, 5-24, 25-44, 45-64, ≥65 years. Results We included 12,048 individuals: 2,687 controls, 5,449 ILI cases and 5,449 SARI cases. RSVAFs for ILI were significant in <1, 1-4, 5-24, 25-44-year age groups: 84.9%(95% confidence interval (CI) 69.3%-92.6%), 74.6%(95%CI 53.6%-86.0%), 60.8%(95%CI 21.4%-80.5%) and 64.1%(95%CI 14.9%-84.9%), respectively. Similarly, significant RSV-AFs for SARI were 95.3%(95%CI 91.1%-97.5) and 83.4%(95%CI 70.9-90.5) in the <1 and 1-4-year age groups respectively. In HIV-infected persons, RSV was significantly associated with ILI cases versus controls in individuals aged 5-44 years. Conclusion High RSV-AFs in young children confirm RSV detection is associated severe respiratory illness in South African children, specifically infants. These estimates will assist with refining burden estimates and cost effectiveness models
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    The economic burden of RSV-associated illness in children aged < 5 years, South Africa 2011–2016.
    (2022-06-21) Jocelyn Moyes; Stefano Tempia; Sibongile Walaza; Meredith L. McMorrow3; Florette Treurnicht4 Nicole Wolter; Anne von Gottberg; Kathleen Kahn6; Adam L Cohen; Halima Dawood; Ebrahim Variava; Cheryl Cohen
    Introduction Data on the economic burden of RSV-associated illness will inform decisions on the programmatic implementation of maternal vaccines and monoclonal antibodies. We estimated these costs in fine age bands to allow more accurate cost-effectiveness models to account for limited duration of protection conferred by short or long acting interventions. Methods We conducted a costing study at sentinel sites across South Africa to estimate out-of-pocket and indirect costs for RSV-associated mild and severe illness. We collected facility-specific costs for staffing, equipment, services, diagnostic tests and treatment. Using case-based data we calculated a patient day equivalent (PDE) for RSV-associated hospitalisations or clinic visits; the PDE was multiplied by the number of days of care to provide a case-cost to the healthcare system. We estimated the costs in 3-month age intervals in children aged <1 years and as a single group for children aged 1-4 years. We then applied our data to a modified version of the World Health Organization tool for estimating mean annual national cost burden, including medically and non-medically attended RSV-associated illness. Results The estimated mean annual cost of RSV-associated Illness in children aged <5 years was United States dollars ($)137 204 393, of which 81% ($111 742 713) were healthcare system incurred, 6% ($8 881 612) were out of pocket expenses and 13% ($28 225 801) were indirect costs. Thirty-three percent ($45 652 677/$137 204 393) of the total cost in children aged <5 years was in the <3-month age group, of which 52% ($71 654 002) were healthcare system incurred. The costs of non-medically attended cases increased with age from $3 307 218 in the <3-month age group to $8 603 377 in the 9-11-month age group. Conclusion Among children <5 years of age with RSV in South Africa, the highest cost burden was in young infants; therefore, interventions against RSV targeting this age group are important to reduce the health and cost burden of RSV-associated illness.
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    The importation and establishment of community transmission of SARSCoV2 during the first eight weeks of the South African COVID19 epidemic
    Kerrigan McCarthy; Stefano Tempia; T Kufa; J Kleynhans; Nicole Wolter; W jassat; J Ebonwu; Anne Von Gottberg; L Erasmus; M Muchengeti; Sibongile Walaza; G Ntshoe; A Shonhiwa; Pinky Manana; Y Pillay; D Moonasar; T Muthivhi; S Mngemane; K Mlisana; K Chetty