Browsing by Author "Lebina, Limakatso"

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    Comparing rates of mycobacterial clearance in sputum smear-negative and smear-positive adults living with HIV
    (BMC (part of Springer Nature), 2021-05-22) Machowski, Edith E.; Letutu, Matebogo; Lebina, Limakatso; Waja, Ziyaad; Msandiwa, Reginah; Milovanovic, Minja; Gordhan, Bhavna G.; Otwombe, Kennedy; Friedrich, Sven O.; Chaisson, Richard; Diacon, Andreas H.; Kana, Bavesh; Martinson, Neil
    Background: Pulmonary tuberculosis (TB) in people living with HIV (PLH) frequently presents as sputum smearnegative. However, clinical trials of TB in adults often use smear-positive individuals to ensure measurable bacterial responses following initiation of treatment, thereby excluding HIV-infected patients from trials. Methods: In this prospective case cohort study, 118 HIV-seropositive TB patients were assessed prior to initiation of standard four-drug TB therapy and at several time points through 35 days. Sputum bacillary load, as a marker of treatment response, was determined serially by: smear microscopy, Xpert MTB/RIF, liquid culture, and colony counts on agar medium. Results: By all four measures, patients who were baseline smear-positive had higher bacterial loads than those presenting as smear-negative, until day 35. However, most smear-negative PLH had significant bacillary load at enrolment and their mycobacteria were cleared more rapidly than smear-positive patients. Smear-negative patients’ decline in bacillary load, determined by colony counts, was linear to day 7 suggesting measurable bactericidal activity. Moreover, the decrease in bacterial counts was comparable to smear-positive individuals. Increasing cycle threshold values (Ct) on the Xpert assay in smear-positive patients to day 14 implied decreasing bacterial load. Conclusion: Our data suggest that smear-negative PLH can be included in clinical trials of novel treatment regimens as they contain sufficient viable bacteria, but allowances for late exclusions would have to be made in sample size estimations. We also show that increases in Ct in smear-positive patients to day 14 reflect treatment responses and the Xpert MTB/RIF assay could be used as biomarker for early treatment response.
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    Incidence of TB and HIV in prospectively followed household contacts of TB index patients in South Africa
    (PLoS, 2014-04) Van Schalkwyk, Cari; Variava, Ebrahim; Shapiro, Adrienne E.; Rakgokong, Modiehi; Masonoke, Katlego; Lebina, Limakatso; Welte, Alex; Martinson, Neil
    Objective: To report the incidence rates of TB and HIV in household contacts of index patients diagnosed with TB. Design: A prospective cohort study in the Matlosana sub-district of North West Province, South Africa. Methods: Contacts of index TB patients received TB and HIV testing after counseling at their first household visit and were then followed up a year later, in 2010. TB or HIV diagnoses that occurred during the period were determined. Results: For 2,377 household contacts, the overall observed TB incidence rate was 1.3 per 100 person years (95% CI 0.9–1.9/100py) and TB incidence for individuals who were HIV-infected and HIV seronegative at baseline was 5.4/100py (95% CI 2.9–9.0/100py) and 0.7/100py (95% CI 0.3–1.4/100py), respectively. The overall HIV incidence rate was 2.2/100py (95% CI 1.3–8.4/100py). Conclusions: In the year following a household case finding visit when household contacts were tested for TB and HIV, the incidence rate of both active TB and HIV infection was found to be extremely high. Clearly, implementing proven strategies to prevent HIV acquisition and preventing TB transmission and progression to disease remains a priority in settings such as South Africa.