Browsing by Author "Abayomi, A."

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    The HIV/AIDS epidemic in South Africa : convergence with tuberculosis, socioecological vulnerability, and climate change patterns
    (Health & Medical Publishing Group, 2014-08) Abayomi, A.; Cowan, M. N.
    Recent assessment reports suggest that climate change patterns are threatening social and ecological vulnerability and resilience, with the strong potential of negatively affecting human health. Persons living with HIV/AIDS (PLWHA) have weakened physiological responses and are immunologically vulnerable to pathogens and stressors in their environment, putting them at a health disadvantage in climate-based rising temperatures, water scarcity, air pollution, potential water- and vector-borne disease outbreaks, and habitat redistributions. These climatic aberrations may lead to increased surface drying and decreased availability of arable land, threatening food/nutrition security and sanitary water practices. Coupled with HIV/AIDS, climate change threatens ecological biodiversity via a larger-scale socioeconomic recourse to natural resources. Corresponding human and environmental activity shape conditions conducive to exacerbating high rates of HIV/AIDS. In South Africa, this epidemic is forming a ‘syndemic’ with tuberculosis (TB), which has come to include multidrug-resistant TB (MDR-TB) and extremely drug-resistant TB (XDR-TB) strains. Because of high convergence rates, one epidemic cannot be addressed without understanding the other. Concurrent climate change mitigation and adaptation strategies are becoming increasingly important to curb changes that negatively affect the biospheres on which civilisation is ultimately dependent – from an agricultural, a developmental, and especially a health standpoint. Mitigation strategies such as reducing carbon emissions are essential, but may be only partially effective in slowing the rate of surface warming. However, global climate assessments assert that these are not sufficient to halt climate change patterns. The roles of regionally specific climate research, socioecologically sustainable industrialisation paths for developing countries, and adoption of health system strengthening strategies are therefore vital.
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    Incidence of Haemolytic Disease of the Newborn in Harare, Zimbabwe
    (2008) Mandisodza, A. R.; Mangoyi, G.; Musekiwa, Z.; Mvere, D.; Abayomi, A.
    Background: Haemolytic Disease of Newborn is responsible for a number of neonatal deaths and complications worldwide. Its incidence in Zimbabwe is not clearly understood. Objective: To find out incidence of Haemolytic Disease of Newborn in Harare and ability to identify antibodies associated with HDN. Methods: A retrospective cross sectional study at the Parirenyatwa Group of Hospitals and National Blood Service, Zimbabwe (NBSZ). We studied 22493 infants at Parirenyatwa Hospital during the 1995-1997 and 2002-2003 periods. The main outcome measures were ABO and Rh blood group results, Direct Antiglobulin Test and Maternal Antibody Screening and Identification Results were obtained from the NBSZ. Results: One hundred and ninety-one (0,85%) infants had Haemolytic Disease of Newborn. One hundred and sixty-three (85.34 %) of these were due to anti-AB, twenty five (13.09%) were due to anti-D and three (1.57%) due to anti-Kell. Incidence of Haemolytic Disease of Newborn during 1995-1997 and 2002-2003, were 0.93% and 0.64 %, respectively (p = 0.014). ABO Haemolytic Disease of Newborn showed a statistically significant difference during the two periods (p=0.003). Rhesus Haemolytic Disease of Newborn showed no statistically significant difference during same periods (p=0.317). Conclusion: The incidence of Haemolytic Disease of Newborn at Parirenyatwa Hospital is comparable with that found in other countries. It is recommended that K antigen be included in the pretransfusion testing to avoid anti-K related Haemolytic Disease of Newborn.
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    Incidence of Hodgkin lymphoma in HIV-positive and HIV-negative patients at a tertiary hospital in South Africa (2005 - 2016) and comparison with other African countries
    (Health & Medical Publishing Group, 2018-06-26) Naidoo, N.; Abayomi, A.; Locketz, C.; Musaigwa, F.; Grewal, R.
    Background. Hodgkin lymphoma (HL) is the most common non-AIDS-defining cancer in HIV-positive patients. Studies on South African (SA) populations have described the prevalence as 7 - 17% of all lymphomas, 8 - 27% of head and neck lymphomas, 9% of lymph node biopsies and 4% of HIV-related malignancies. Objectives. To describe the incidence of HL at our centre between 2005 and 2016 by year, gender, HIV status, histological subclassification and bone marrow involvement, and compare these findings with similar SA and African studies. Methods. This was a retrospective study of all incident HL cases diagnosed in the Department of Pathology, National Health Laboratory Service, Tygerberg Academic Hospital, Cape Town. Follow-up, relapsed and referral cases were excluded. A positive diagnosis of HL was confirmed by either lymph node or bone marrow biopsy and was based on morphological and immunohistochemical findings in accordance with the World Health Organization classification. Results. There were 303 incident cases of HL diagnosed. The incidence increased from 2005 to 2011, with a spike in cases in 2008 and a subsequent decline overall after 2011. The highest proportion of cases was in the 25 - 49-year-old age category (51.1%). There were 77 HIV-positive patients (25.4%), of whom 53 (68.8%) had CD4+ counts <500 cells/µL. In keeping with other African studies, the main subtypes were nodular sclerosis HL (49.8%) and mixed-cellularity HL (23.1%). Bone marrow biopsy following lymph node diagnosis of HL confirmed involvement in 23.7% of patients. Conclusions. Absolute numbers of cases of HL at our centre have increased since the roll-out of antiretroviral therapy (ART) to the public sector. The recent change in policy to make ART available to all HIV-positive patients independent of CD4+ count suggests that patients will survive longer and are therefore at increased risk of developing HL. We anticipate that numbers of HL cases will increase or remain high in the coming years, and we need to prepare for this.
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    Modulation of LPS-induced CD4+ T-cell activation and apoptosis by antioxidants in untreated asymptomatic HIV infected participants : an in vitro study
    (Hindawi Publishing Corporation, 2013-11) Wanjiku, Samuel Mburu; Marnewick, J. L.; Abayomi, A.; Ipp, H.
    Persistent immune activation characterises HIV infection and is associated with depletion of CD4+ T-cells and increased risk of disease progression. Early loss of gutmucosal integrity results in the translocation of microbial products such as lipopolysaccharide (LPS) into the systemic circulation. This is an important source of on-going immune stimulation.The purpose of this study was to determine levels of CD4+ T-cell activation (%CD25 expression) and apoptosis (% annexin V/7-AAD) in asymptomatic, untreated HIV infection at baseline and after stimulation with LPS and incubation with or without vitamin C and N-acetylcysteine. LPS induced a significant (𝑃�� < 0.03) increase in %CD25 expression, annexin V, and 7-AAD in HIV positive individuals. NAC in combination with vitamin C, significantly (𝑃�� = 0.0018) reduced activation and early apoptosis of CD4+ T-cells to a greater degree than with either antioxidant alone. Certain combinations of antioxidants could be important in reducing the harmful effects of chronic immune activation and thereby limit CD4+ T-cell depletion. Importantly, we showed that CD4+ T-cells of the HIV positive group responded better to a combination of the antioxidants at this stage than those of the controls.Therefore, appropriate intervention at this asymptomatic stage could rescue the cells before repetitive activation results in the death of CD4+ T-cells.
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    Performance of the panleucogating protocol for CD4+ T cell enumeration in an HIV dedicated laboratory facility in Barbados
    (2008) Sippy-Chatrani, N.; Marshall, S.; Branch, S.; Carmichael-Simmons, K.; Landis, R. C.; Abayomi, A.
    Objective: To compare the Panleucogating (PLG) protocol with the routinely used four-color protocol for CD4+ T cell count enumeration. Design and Methods: One hundred fifty-three blood samples were randomly selected from samples received at the National HIV Laboratory for routine immunological monitoring. Samples were prepared using Coulter CYTO-STAT® tetraCHROME monoclonal antibodies and FlowCARE™ PLG CD4 reagent for four-color and PLG, respectively, and analyzed on the Beckman Coulter EPICS XL flow cytometer. The PLG protocol used a sequential gating strategy where CD4+ T cells were identified using side scatter properties of cells and CD45 staining. The four-color protocol used CD45 and CD3 to identify CD4+ T cells. Results: Absolute CD4+ T cell counts and percentages ranged from 4 to 1,285 cells/μL and 0.9 to 46.7%, respectively. Linear regression analyses revealed good correlation of PLG with the four-color protocol (absolute counts, R2 = 0.95; percentages, R2 = 0.98) over the entire range including the clinically relevant range. Bland Altman statistics revealed no bias for CD4 counts <500 cells/μL and a slight underestimation by PLG for counts >500 cells/μL (Bias = -32.7 cells/μL; 95% agreement limits = -151.3- +86.0). CD4+ T cell percentages were the similar over the entire range (Bias = 0.6%; 95% agreement limits = -1.97 ± 3.18). Conclusions: PLG is an accurate method for enumerating CD4+ T cells and has resulted in major cost savings to the Government of Barbados. This has implications for the sustainability of the National HIV containment program in Barbados and the other resource limited Caribbean countries. The PLG technique is now being routinely used in Barbados. © 2008 Clinical Cytometry Society.
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    The human immunodeficiency virus epidemic: A race against time for millions and the role of flow cytometry. A Caribbean and resource-constrained country perspective
    (2007) Abayomi, A.
    There is a race against time for millions in the world today. Both the technology and the manpower are currently available to deliver the services that are required to meet the needs of the 40 million people currently living with HIV/AIDS, but at what price? The reality is therefore that we are a long shot away from this realization. What are the facts and why have we not achieved even the simplest deadlines set by the World Health Organization (WHO)? Are these objectives realistic? What role does hard science have to play in the search for cost-effective solutions and futuristic effective options? To stem this unrelenting epidemic and convert the natural history of the disorder in those already living with the virus into one of chronicity, rather than one characterized by a dehumanizing and stigmatized death, requires a global commitment at all levels. This discussion examines the reality and offers a snapshot of capacity and experiences in the developing world. Crucially it looks at the immediate and long term role of flow cytometry in the expanded care and treatment programs for developing nations. © 2007 Clinical Cytometry Society.
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    Wireless networks for surveillance, data capture and data management in the human immunodeficiency virus epidemic care and treatment programmes.
    (2006) Abayomi, A.; Goodridge, W.; Asika, O.
    Biomedical and demographic data capture and the subsequent management of such information are critical factors in the implementation of any level of healthcare prevention and treatment program. The developing world is seriously handicapped by lack of infrastructure to acquire such data let alone manipulate the information banks for projections, forecasting and priority project planning. With this in mind we set about to use the recent proliferation of wireless cellular networks and easily accessible Personal Digital Assistants (PDA), to devise a means of collecting such data even from the most remote primary healthcare facility. Our priority is aimed at initially at providing a support technology for the HIV expanded program. This technology can be implemented in the absence of computerization and regular power supply. Utilizing a PDA to capture patient data (demographic, clinical and laboratory parameters), the healthcare giver can use a wireless link between the PDA and a cellular phone to transfer the data to a central medical data base. These can then become permanent and secure data banks for future use by health providers, either at the same location or at other health facility that have authorized access to the data bank. It also affords a platform for integrating reference labs into the network as well as the opportunity to disseminate continuing medical educational material. The network can also be adapted to electronic remote consultations and eventually its data banks can be assimilated into protocols of artificial intelligence and data mining.