Browsing by Author "Victor, Tommie C"

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    Drug-associated adverse events and their relationship with outcomes in patients receiving treatment for extensively drug-resistant tuberculosis in South Africa
    (Public Library of Science, 2013) Shean, Karen; Streicher, Elizabeth; Pieterson, Elize; Symons, Greg; van Zyl Smit, Richard; Theron, Grant; Lehloenya, Rannakoe; Padanilam, Xavier; Wilcox, Paul; Victor, Tommie C; van Helden Paul; Groubusch Martin; Warren, Robin; Badri, Motasim; Dheda, Keertan
    BACKGROUND: Treatment-related outcomes in patients with extensively drug-resistant tuberculosis (XDR-TB) are poor. However, data about the type, frequency and severity of presumed drug-associated adverse events (AEs) and their association with treatment-related outcomes in patients with XDR-TB are scarce. METHODS: Case records of 115 South-African XDR-TB patients were retrospectively reviewed by a trained researcher. AEs were estimated and graded according to severity [grade 0 = none; grade 1-2 = mild to moderate; and grade 3-5 = severe (drug stopped, life-threatening or death)]. FINDINGS: 161 AEs were experienced by 67/115(58%) patients: 23/67(34%) required modification of treatment, the offending drug was discontinued in 19/67(28%), reactions were life-threatening in 2/67(3.0%), and 6/67(9.0%) died. ∼50% of the patients were still on treatment at the time of data capture. Sputum culture-conversion was less likely in those with severe (grade 3-5) vs. grade 0-2 AEs [2/27(7%) vs. 24/88(27%); p = 0.02]. The type, frequency and severity of AEs was similar in HIV-infected and uninfected patients. Capreomycin, which was empirically administered in most cases, was withdrawn in 14/104(14%) patients, implicated in (14/34) 41% of the total drug withdrawals, and was associated with all 6 deaths in the severe AE group (renal failure in five patients and hypokalemia in one patient). CONCLUSION: Drug-associated AEs occur commonly with XDR-TB treatment, are often severe, frequently interrupt therapy, and negatively impact on culture conversion outcomes. These preliminary data inform on the need for standardised strategies (including pre-treatment counselling, early detection, monitoring, and follow-up) and less toxic drugs to optimally manage patients with XDR-TB.
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    Population Structure of Mixed Mycobacterium tuberculosis Infection Is Strain Genotype and Culture Medium Dependent
    (Public Library of Science, 2013) Hanekom, Madeleine; Streicher, Elizabeth M; Van de Berg, Doreen; Cox, Helen; McDermid, Cheryl; Bosman, Marlein; van Pittius, Nicolaas C Gey; Victor, Tommie C; Kidd, Martin; van Soolingen, Dick
    BACKGROUND: Molecular genotyping methods have shown infection with more than one Mycobacterium tuberculosis strain genotype in a single sputum culture, indicating mixed infection. Aim This study aimed to develop a PCR-based genotyping tool to determine the population structure of M. tuberculosis strain genotypes in primary Mycobacterial Growth Indicator Tubes (MGIT) and Löwenstein-Jensen (LJ) cultures to identify mixed infections and to establish whether the growth media influenced the recovery of certain strain genotypes. Method A convenience sample of 206 paired MGIT and LJ M. tuberculosis cultures from pulmonary tuberculosis patients resident in Khayelitsha, South Africa were genotyped using an in-house PCR-based method to detect defined M. tuberculosis strain genotypes. RESULTS: The sensitivity and specificity of the PCR-based method for detecting Beijing, Haarlem, S-family, and LAM genotypes was 100%, and 75% and 50% for detecting the Low Copy Clade, respectively. Thirty-one (15%) of the 206 cases showed the presence of more than one M. tuberculosis strain genotype. Strains of the Beijing and Haarlem genotypes were significantly more associated with a mixed infection (on both media) when compared to infections with a single strain (Beijing MGIT p = 0.02; LJ, p<0.01) and (Haarlem: MGIT p<0.01; LJ, p = 0.01). Strains with the Beijing genotype were less likely to be with "other genotype" strains (p<0.01) while LAM, Haarlem, S-family and LCC occurred independently with the Beijing genotype. CONCLUSION: The PCR-based method was able to identify mixed infection in at least 15% of the cases. LJ media was more sensitive in detecting mixed infections than MGIT media, implying that the growth characteristics of M. tuberculosis on different media may influence our ability to detect mixed infections. The Beijing and Haarlem genotypes were more likely to occur in a mixed infection than any of the other genotypes tested suggesting pathogen-pathogen compatibility.