- Title
- IMMUNE RESPONSE TO SPECIFIC MYCOBACTERIUM TUBERCULOSIS ANTIGENS AMONG PARASITE INFECTED SCHOOL CHILDREN IN MTHATHA
- Creator
- NTOMBIZODUMO NXASANA
- Subject
- IMMUNE RESPONSE, MYCOBACTERIUM TUBERCULOSIS ANTIGENS
- Date
- 2015
- Type
- Masters, Msc
- Identifier
- http://hdl.handle.net/11260/2369
- Identifier
- vital:41452
- Description
- Children from low socio-economic communities in the Eastern Cape Province of South Africa and in South Africa at large are frequently infected by intestinal parasites. The parasites are diverse and complex pathogens that include multi-cellular helminths and single-celled protozoa. Because of this diversity, immunity to parasites is more difficult to sustain. Tuberculosis also, remains a problem in South Africa and worldwide. Infection with Mycobacterium tuberculosis can result either in the disease itself or, more commonly, latent infection. A variety of mechanisms that include both humoral and cell mediated immunity achieve host protection against mycobacterial pathogens. Macrophages and cell-mediated immunity are the primary defence mechanisms against mycobacteria. According to the literature, parasitic infections impair the body’s immune response to tuberculosis, but these diseases are not adequately researched in this province. The extent to which the school children of Mthatha are infected with intestinal parasites and latent tuberculosis, or even how their immune systems respond to these infections have not been investigated. Therefore, the immune response of school children, both of those infected and those not infected with parasites, to specific Mycobacterium tuberculosis antigens was evaluated. The present study used two study design methods: firstly, a descriptive cross-sectional design for the prevalence rates of intestinal parasites and, secondly, a case-control study for comparison of interferon gamma and T-helper 1 and T-helper 2 cytokines in parasite infected and non-parasite infected participants. A total of 137 school children participated in the survey and all were analyzed for parasites. Due to the high cost of the reagent kits, only 75 participants were included in the case-control study. Data collection methods: i) for the prevalence of intestinal parasites, formalin ethyl acetate sedimentation technique was used to process stool specimens, ii) for immune response to Mycobacterium tuberculosis antigens (measurement of interferon gamma for latent tuberculosis),the QuantiFeron TB Gold In-Tube assay was used, and iii) for the quantification of Th1 and Th2 cytokines, the Bio-Plex Pro assay was used. Out of 137 school children analyzed, 66.4% (91/137) were positive for parasites (ova and cysts). The most prevalent parasite was the pathogenic helminth, Ascaris lumbricoides at 21.9% (30/137), followed by Trichuris trichiura at 8.8%. The pathogenic protozoa, Giardia lamblia and Blastocystis hominis were both at 2.9% (4/137). The non-pathogenic protozoa, Entamoeba coli and Endolimax nana had high prevalence rates at 32.1% (44/137) and 29.2% (40/137) respectively. Associations between parasitic infections and sociodemographics showed a significant difference in participants whose parents had a low level of education and those who were unemployed (P = 0.004; P = 0.005 respectively). Out of 75 participants analyzed for tuberculosis, 53.3% (40/75) were positive. In conclusion, the present study demonstrates high prevalence rates of parasitic as well as latent tuberculosis infections in Mthatha. The study also showed that intestinal parasites, especially helminths, interfere with immune responses to TB by down-regulating Th1 response leading to reduced production of interferon gamma, a cytokine that mediates protection against TB.
- Format
- Publisher
- Walter Sisulu University
- Language
- English
- Rights
- Walter Sisulu University
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WSU Department of Medicine
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