Publications (10)97.59 Total impact
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Article: Drug-Resistant tuberculosis, KwaZulu-Natal, South Africa, 2001-2007.
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ABSTRACT: In Africa, incidence and prevalence of drug-resistant tuberculosis have been assumed to be low. However, investigation after a 2005 outbreak of extensively drug-resistant tuberculosis in KwaZulu-Natal Province, South Africa, found that the incidence rate for multidrug-resistant tuberculosis in KwaZulu-Natal was among the highest globally and would be higher if case-finding efforts were intensified.Emerging Infectious Diseases 10/2011; 17(10):1913-6. · 6.79 Impact Factor -
Article: Resistance to TB drugs in KwaZulu-Natal: causes and prospects for control
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ABSTRACT: In 2005 there was an outbreak of XDR (extensively drug resistant) TB in Tugela Ferry, which is served by the Church of Scotland Hospital (COSH), in the uMzinyathi District, KwaZulu-Natal, South Africa. An investigation was carried out to determine if XDR TB was occurring elsewhere in the province, and to develop hypotheses for the rise in drug resistance with a view to developing a strategy for the control of MDR (multi-drug resistant) and XDR TB in the province and elsewhere. TB incidence and treatment success rates, for each of the 11 districts in the province, were obtained from the provincial electronic TB register for the years 2002-2007. The results of culture and drug sensitivity tests for the years 2002 to 2007 in each of the districts were compiled and culture taking practices were compared to the number of MDR TB cases. Interviews were conducted with key personnel in affected sites. In 2007, 2799, or 2.3% of 119,218 notified TB cases in the province were multi-drug resistant (MDR), and of these 270 (9.6%) were XDR. The two worst affected districts were uMzinyathi where 226 (4.1%) of 5522 notified TB cases were MDR, and of these 120 (53%) were extensively drug resistant (XDR), and uMkhanyakude where 337 (4.8%) of 6991 notified TB cases were MDR, but of these only four or (1.2%) were XDR. The worst affected medical centre was COSH where 164 or 9.8% of notified TB cases were MDR and of these 99 (60%) were XDR. Very high rates of XDR TB in the province are only found in uMzinyathi district even though MDR TB is common in most other districts. XDR may arisen at COSH because of the early and effective integration of the TB and HIV programmes in overcrowded and poorly ventilated facilities particular to COS.H To control XDR TB better management of both susceptible and resistant forms of TB is needed including treatment supervision, infection control and HIV management.07/2011; -
Article: Tuberculosis among health care workers.
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ABSTRACT: To assess the annual risk for latent tuberculosis infection (LTBI) among health care workers (HCWs), the incidence rate ratio for tuberculosis (TB) among HCWs worldwide, and the population-attributable fraction of TB to exposure of HCWs in their work settings, we reviewed the literature. Stratified pooled estimates for the LTBI rate for countries with low (<50 cases/100,000 population), intermediate (50-100/100,000 population), and high (>100/100,000 population) TB incidence were 3.8% (95% confidence interval [CI] 3.0%-4.6%), 6.9% (95% CI 3.4%-10.3%), and 8.4% (95% CI 2.7%-14.0%), respectively. For TB, estimated incident rate ratios were 2.4 (95% CI 1.2-3.6), 2.4 (95% CI 1.0-3.8), and 3.7 (95% CI 2.9-4.5), respectively. Median estimated population-attributable fraction for TB was as high as 0.4%. HCWs are at higher than average risk for TB. Sound TB infection control measures should be implemented in all health care facilities with patients suspected of having infectious TB.Emerging Infectious Diseases 03/2011; 17(3):488-94. · 6.79 Impact Factor -
Article: Tuberculosis incidence in prisons: a systematic review.
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ABSTRACT: Transmission of tuberculosis (TB) in prisons has been reported worldwide to be much higher than that reported for the corresponding general population. A systematic review has been performed to assess the risk of incident latent tuberculosis infection (LTBI) and TB disease in prisons, as compared to the incidence in the corresponding local general population, and to estimate the fraction of TB in the general population attributable (PAF%) to transmission within prisons. Primary peer-reviewed studies have been searched to assess the incidence of LTBI and/or TB within prisons published until June 2010; both inmates and prison staff were considered. Studies, which were independently screened by two reviewers, were eligible for inclusion if they reported the incidence of LTBI and TB disease in prisons. Available data were collected from 23 studies out of 582 potentially relevant unique citations. Five studies from the US and one from Brazil were available to assess the incidence of LTBI in prisons, while 19 studies were available to assess the incidence of TB. The median estimated annual incidence rate ratio (IRR) for LTBI and TB were 26.4 (interquartile range [IQR]: 13.0-61.8) and 23.0 (IQR: 11.7-36.1), respectively. The median estimated fraction (PAF%) of tuberculosis in the general population attributable to the exposure in prisons for TB was 8.5% (IQR: 1.9%-17.9%) and 6.3% (IQR: 2.7%-17.2%) in high- and middle/low-income countries, respectively. The very high IRR and the substantial population attributable fraction show that much better TB control in prisons could potentially protect prisoners and staff from within-prison spread of TB and would significantly reduce the national burden of TB. Future studies should measure the impact of the conditions in prisons on TB transmission and assess the population attributable risk of prison-to-community spread. Please see later in the article for the Editors' Summary.PLoS Medicine 01/2010; 7(12):e1000381. · 16.27 Impact Factor -
Article: Tuberculosis-associated immune reconstitution inflammatory syndrome: case definitions for use in resource-limited settings.
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ABSTRACT: The immune reconstitution inflammatory syndrome (IRIS) has emerged as an important early complication of antiretroviral therapy (ART) in resource-limited settings, especially in patients with tuberculosis. However, there are no consensus case definitions for IRIS or tuberculosis-associated IRIS. Moreover, previously proposed case definitions are not readily applicable in settings where laboratory resources are limited. As a result, existing studies on tuberculosis-associated IRIS have used a variety of non-standardised general case definitions. To rectify this problem, around 100 researchers, including microbiologists, immunologists, clinicians, epidemiologists, clinical trialists, and public-health specialists from 16 countries met in Kampala, Uganda, in November, 2006. At this meeting, consensus case definitions for paradoxical tuberculosis-associated IRIS, ART-associated tuberculosis, and unmasking tuberculosis-associated IRIS were derived, which can be used in high-income and resource-limited settings. It is envisaged that these definitions could be used by clinicians and researchers in a variety of settings to promote standardisation and comparability of data.The Lancet Infectious Diseases 08/2008; 8(8):516-23. · 17.39 Impact Factor -
Article: Tuberculosis preventive therapy in the era of HIV infection: overview and research priorities.
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ABSTRACT: The recognition of tuberculosis (TB) as a major cause of morbidity and mortality among human immunodeficiency virus (HIV)-infected persons has led to renewed interest in TB preventive therapy and its incorporation into the essential package of health care for these individuals. Despite convincing data regarding its efficacy, TB preventive therapy has not been widely implemented. Further work is needed to determine how to overcome the barriers to the implementation of such therapy, including how best to exclude the presence of active TB before providing preventive therapy. Such issues as the optimal duration of preventive therapy for and the role of TB preventive therapy in the treatment of individuals receiving antiretroviral therapy remain to be defined. Ongoing research will help to determine how best to use this intervention in the care of HIV-infected persons and in the control of TB on a wider basis.The Journal of Infectious Diseases 09/2007; 196 Suppl 1:S52-62. · 6.41 Impact Factor -
Article: T-cell assays for the diagnosis of latent tuberculosis infection: moving the research agenda forward.
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ABSTRACT: For nearly a century, the tuberculin skin test was the only tool available for the detection of latent tuberculosis infection. A recent breakthrough has been the development of T-cell-based interferon-gamma release assays. Current evidence suggests interferon-gamma release assays have higher specificity than the tuberculin skin test, better correlation with surrogate markers of exposure to Mycobacterium tuberculosis in low-incidence settings, and less cross-reactivity as a result of BCG vaccination compared with the tuberculin skin test. The body of literature supporting the use of interferon-gamma release assays has rapidly expanded. However, several unresolved and unexplained issues remain. To address these issues, a group of experts met in Geneva, Switzerland, in March, 2006, to discuss the research evidence on T-cell-based assays, their clinical usefulness, limitations, and directions for future research, with a specific focus on resource-limited and high HIV prevalence settings. On the basis of 2 days of discussions, a comprehensive research agenda was generated, which will propel the field forward by stimulating focused high-impact research and encourage the investment of resources needed to tackle priority research questions, especially in resource-limited settings. Ultimately, if adequately financed, the research findings will inform appropriate use of novel latent tuberculosis infection diagnostics in global tuberculosis control.The Lancet Infectious Diseases 07/2007; 7(6):428-38. · 17.39 Impact Factor -
Article: Towards universal access to HIV prevention, treatment, care, and support: the role of tuberculosis/HIV collaboration.
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ABSTRACT: Tuberculosis is the oldest of the world's current pandemics and causes 8.9 million new cases and 1.7 million deaths annually. The disease is among the most common causes of morbidity and mortality in people living with HIV. However, tuberculosis is more than just part of the global HIV problem; well-resourced tuberculosis programmes are an important part of the solution to scaling-up towards universal access to comprehensive HIV prevention, diagnosis, care, and support. This article reviews the impact of the interactions between tuberculosis and HIV in resource-limited settings; outlines the recommended programmatic and clinical responses to the dual epidemics, highlighting the role of tuberculosis/HIV collaboration in increasing access to prevention, diagnostic, and treatment services; and reviews progress in the global response to the epidemic of HIV-related tuberculosis.The Lancet Infectious Diseases 09/2006; 6(8):483-95. · 17.39 Impact Factor -
Article: Effects of human immunodeficiency virus infection on recurrence of tuberculosis after rifampin-based treatment: an analytical review.
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ABSTRACT: We reviewed 47 prospective studies of recurrence of pulmonary tuberculosis (TB) after cure to assess the influence of human immunodeficiency virus (HIV) infection and rifampin treatment. Multivariate regression revealed that the recurrence rate for HIV-uninfected persons increased with decreasing duration of therapy: it was 1.4 cases per 100 person-years for recipients of >or=7 months of rifampin therapy and 2.0 and 4.0 cases per 100 person-years for recipients of 5-6 and 2-3 months of rifampin therapy, respectively (trend P=.00014), over a mean follow-up duration of 34 months, at a TB incidence of 250 cases per 100,000 person-years. Relative risks of recurrence associated with HIV infection at these 3 treatment durations were 2.2, 2.1, and 3.4, respectively, with a significant interaction between HIV infection status and treatment duration (P=.025). The recurrence rate increased with the background TB incidence (P=.048), and it decreased over time since completion of treatment in HIV-uninfected but not in HIV-infected patients (overall trend, P=.00008; difference by HIV infection status, P=.025). In countries where HIV infection is endemic, TB recurrence may be reduced by administration of rifampin-based treatment for at least 6 months, in accordance with World Health Organization recommendations.Clinical Infectious Diseases 08/2003; 37(1):101-12. · 9.15 Impact Factor -
Article: Ten best resources in ... tuberculosis control
