Browsing by Author "Coetzee, Gerrit"

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    The chemoprophylaxis of meningococcal disease in the Cape Town City Council area : an evaluation of programme efficacy
    (1994) Girdler-Brown, Brendan Vaughan; Coetzee, Nicol; Coetzee, Gerrit
    This dissertation reports the findings of a study which was carried out in the Cape Town City Council area, in order to establish whether the offering of rifampicin to household contacts, of patients with meningococcal disease, resulted in protection of those contacts against developing the disease during a 32 week follow up period. The study took the form of a retrospective follow up of 3 350 household contacts of 412 cases notified over a 4-year period (mid 1988-mid 1992). It was found that the offering of rifampicin to the household contacts resulted in an odds ratio of not developing meningococcal disease over the 32-week follow up period of 14, 17 (SD = 12, 34). Although there was a tendency for contacts who were not offered rifampicin to have been younger, and of male gender, when compared to those who were offered prophylaxis, these demographic differences were not statistically significant at the 0,05 level. Furthermore, three out of the four male second cases, all in the younger age group, were in fact offered prophylaxis. It seems desirable that prophylaxis should be given as soon as possible. It is concluded, therefore, that the offering of rifampicin to household contacts of patients with meningococcal disease, living under the prevailing social circumstances in the Western Cape, has protective benefit for those contacts. It is likely that the chemoprophylaxis programme prevented up to 88 cases of meningococcal disease over the study period of four years, as well as preventing 8 deaths from this disease, in the CCC population.
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    Epidemic levels of drug resistant tuberculosis (MDR and XDR-TB) in a high HIV prevalence setting in Khayelitsha, South Africa
    (Public Library of Science, 2010) Cox, Helen S; McDermid, Cheryl; Azevedo, Virginia; Muller, Odelia; Coetzee, David; Simpson, John; Barnard, Marinus; Coetzee, Gerrit; van Cutsem, Gilles; Goemaere, Eric
    BACKGROUND: Although multidrug-resistant tuberculosis (MDR-TB) is emerging as a significant threat to tuberculosis control in high HIV prevalence countries such as South Africa, limited data is available on the burden of drug resistant tuberculosis and any association with HIV in such settings. We conducted a community-based representative survey to assess the MDR-TB burden in Khayelitsha, an urban township in South Africa with high HIV and TB prevalence. METHODOLOGY/PRINCIPAL FINDINGS: A cross-sectional survey was conducted among adult clinic attendees suspected for pulmonary tuberculosis in two large primary care clinics, together constituting 50% of the tuberculosis burden in Khayelitsha. Drug susceptibility testing (DST) for isoniazid and rifampicin was conducted using a line probe assay on positive sputum cultures, and with culture-based DST for first and second-line drugs. Between May and November 2008, culture positive pulmonary tuberculosis was diagnosed in 271 new and 264 previously treated tuberculosis suspects (sample enriched with previously treated cases). Among those with known HIV status, 55% and 71% were HIV infected respectively. MDR-TB was diagnosed in 3.3% and 7.7% of new and previously treated cases. These figures equate to an estimated case notification rate for MDR-TB of 51/100,000/year, with new cases constituting 55% of the estimated MDR-TB burden. HIV infection was not significantly associated with rifampicin resistance in multivariate analyses. Conclusions/Significance There is an extremely high burden of MDR-TB in this setting, most likely representing ongoing transmission. These data highlight the need to diagnose drug resistance among all TB cases, and for innovative models of case detection and treatment for MDR-TB, in order to interrupt transmission and control this emerging epidemic.
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    A subset of circulating blood mycobacteria-specific CD4 T cells can predict the time to Mycobacterium tuberculosis sputum culture conversion
    (Public Library of Science, 2014) Riou, Catherine; Gray, Clive M; Lugongolo, Masixole; Gwala, Thabisile; Kiravu, Agano; Deniso, Pamela; Stewart-Isherwood, Lynsey; Omar, Shaheed Vally; Grobusch, Martin P; Coetzee, Gerrit
    We investigated 18 HIV-negative patients with MDR-TB for M. tuberculosis (Mtb)- and PPD-specific CD4 T cell responses and followed them over 6 months of drug therapy. Twelve of these patients were sputum culture (SC) positive and six patients were SC negative upon enrollment. Our aim was to identify a subset of mycobacteria-specific CD4 T cells that would predict time to culture conversion. The total frequency of mycobacteria-specific CD4 T cells at baseline could not distinguish patients showing positive or negative SC. However, a greater proportion of late-differentiated (LD) Mtb- and PPD-specific memory CD4 T cells was found in SC positive patients than in those who were SC negative (p = 0.004 and p = 0.0012, respectively). Similarly, a higher co-expression of HLA-DR + Ki67 + on Mtb- and PPD-specific CD4 T cells could also discriminate between sputum SC positive versus SC negative (p = 0.004 and p = 0.001, respectively). Receiver operating characteristic (ROC) analysis revealed that baseline levels of Ki67 + HLA-DR + Mtb- and PPD-specific CD4 T cells were predictive of the time to sputum culture conversion, with area-under-the-curve of 0.8 (p = 0.027). Upon treatment, there was a significant decline of these Ki67 + HLA-DR + T cell populations in the first 2 months, with a progressive increase in mycobacteria-specific polyfunctional IFNγ + IL2 + TNFα + CD4 T cells over 6 months. Thus, a subset of activated and proliferating mycobacterial-specific CD4 T cells (Ki67 + HLA-DR + ) may provide a valuable marker in peripheral blood that predicts time to sputum culture conversion in TB patients at the start of treatment.