Over the past several years, new diagnostic techniques have been developed to allow for the rapid detection of multidrug resistant tuberculosis. The GenoType.sup.R .sup.MTBDRplus test is a ...deoxyribonucleic acid (DNA) strip assay which uses polymerase chain reaction (PCR) and hybridization to detect genetic mutations in the genes that confer isoniazid (INH) and rifampn (RIF) resistance. This assay has demonstrated good performance and a rapid time to results, making this a promising tool to accelerate MDR-TB diagnosis and improve MDR-TB control. Validation of rapid tests for MDR-TB detection in different settings is needed to ensure acceptable performance, particularly in Asia, which has the largest number of MDR-TB cases in the world but only one previous report, in Vietnam, about the performance of the GenoType.sup.R .sup.MDRplus assay. Thailand is ranked 18.sup.th .sup.of 22 "high-burden" TB countries in the world, and there is evidence to suggest that rates of MDR-TB are increasing in Thailand. We compared the performance of the GenoType.sup.R .sup.MTBDRplus assay to Mycobacterial Growth Indicator Tube for Antimycobacterial Susceptibility Testing (MGIT AST) for detection INH resistance, RIF resistance, and MDR-TB in stored acid-fast bacilli (AFB)-positive sputum specimens and isolates at a Public TB laboratory in Bangkok, Thailand. 50 stored isolates and 164 stored AFB-positive sputum specimens were tested using both the MGIT AST and the GenoType.sup.R .sup.MTBDRplus assay. The GenoType.sup.R .sup.MTBDRplus assay had a sensitivity of 95.3%, 100%, and 94.4% for INH resistance, RIF resistance, and MDR-TB, respectively. The difference in sensitivity between sputum specimens (93%) and isolates (100%) for INH resistance was not statistically significant (p = 0.08). Specificity was 100% for all resistance patterns and for both specimens and isolates. The laboratory processing time was a median of 25 days for MGIT AST and 5 days for the GenoType.sup.R .sup.MTBDRplus (p less than 0.01). The GenoType.sup.R .sup.MTBDRplus assay has been validated as a rapid and reliable first-line diagnostic test on AFB-positive sputum or MTB isolates for INH resistance, RIF resistance, and MDR-TB in Bangkok, Thailand. Further studies are needed to evaluate its impact on treatment outcome and the feasibility and cost associated with widespread implementation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background: Over the past several years, new diagnostic techniques have been developed to allow for the rapid detection of multidrug resistant tuberculosis. The GenoType super( registered )MTBDRplus ...test is a deoxyribonucleic acid (DNA) strip assay which uses polymerase chain reaction (PCR) and hybridization to detect genetic mutations in the genes that confer isoniazid (INH) and rifampn (RIF) resistance. This assay has demonstrated good performance and a rapid time to results, making this a promising tool to accelerate MDR-TB diagnosis and improve MDR-TB control. Validation of rapid tests for MDR-TB detection in different settings is needed to ensure acceptable performance, particularly in Asia, which has the largest number of MDR-TB cases in the world but only one previous report, in Vietnam, about the performance of the GenoType super( registered )MDRplus assay. Thailand is ranked 18 super(th )of 22 "high-burden" TB countries in the world, and there is evidence to suggest that rates of MDR-TB are increasing in Thailand. We compared the performance of the GenoType super( registered )MTBDRplus assay to Mycobacterial Growth Indicator Tube for Antimycobacterial Susceptibility Testing (MGIT AST) for detection INH resistance, RIF resistance, and MDR-TB in stored acid-fast bacilli (AFB)-positive sputum specimens and isolates at a Public TB laboratory in Bangkok, Thailand. Methods: 50 stored isolates and 164 stored AFB-positive sputum specimens were tested using both the MGIT AST and the GenoType super( registered )MTBDRplus assay. Results: The GenoType super( registered )MTBDRplus assay had a sensitivity of 95.3%, 100%, and 94.4% for INH resistance, RIF resistance, and MDR-TB, respectively. The difference in sensitivity between sputum specimens (93%) and isolates (100%) for INH resistance was not statistically significant (p = 0.08). Specificity was 100% for all resistance patterns and for both specimens and isolates. The laboratory processing time was a median of 25 days for MGIT AST and 5 days for the GenoType super( registered )MTBDRplus (p < 0.01). Conclusion: The GenoType super( registered )MTBDRplus assay has been validated as a rapid and reliable first-line diagnostic test on AFB-positive sputum or MTB isolates for INH resistance, RIF resistance, and MDR-TB in Bangkok, Thailand. Further studies are needed to evaluate its impact on treatment outcome and the feasibility and cost associated with widespread implementation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Antiretroviral therapy is associated with a substantial reduction in deaths during TB treatment for HIV-infected TB patients.
Antiretroviral therapy (ART) is lifesaving in patients with advanced HIV ...infection, but the magnitude of benefit in HIV-infected patients receiving tuberculosis (TB) treatment remains uncertain, and population-based data from developing countries are limited. We prospectively collected data about HIV-infected TB patients from February 2003 through January 2004 in Ubon-ratchathani, Thailand. During 12 months, HIV was diagnosed in 329 (14%) of 2,342 patients registered for TB treatment. Of patients with known outcomes, death during TB treatment occurred in 5 (7%) of 71 who received ART and 94 (43%) of 219 who did not. Using multivariate analysis, we found a large reduction in the odds of death for patients receiving ART before or during TB treatment (odds ratio, 0.2; 95% confidence interval, 0.1–0.5), adjusting for CD4 count, smear status, co-trimoxazole use, and treatment facility. ART is associated with a substantial reduction in deaths during TB treatment for HIV-infected TB patients in Thailand.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Metodos En octubre de 2004 empezamos aponernos en contacto cada mes con servicios de atencion sanitaria publicos y privados a fin de registrar los datos pertinentes sobre las personas con diagnostico ...de tuberculosis, contribuir a la asistencia a los enfermos, ofrecer asesoramiento y pruebas del VIH y obtener muestras de esputo para la realizacion de cultivos y pruebas de sensibilidad. La zona de captacion abarcaba a 3,6 millones de personas en cuatro provincias. Comparamos los resultados de octubre de 2004 a septiembre de 2005 (en adelante 2005) con los datos de partida correspondientes ai periodo de octubre de 2002 a septiembre de 2003 (en adelante 2003).
OBJECTIVE: WHO's new Global Plan to Stop TB 2006-2015 advises countries with a high burden of tuberculosis (TB) to expand case-finding in the private sector as well as services for patients with HIV ...and multidrug-resistant TB (MDR-TB). The objective of this study was to evaluate these strategies in Thailand using data from the Thailand TB Active Surveillance Network, a demonstration project begun in 2004. METHODS: In October 2004, we began contacting public and private health-care facilities monthly to record data about people diagnosed with TB, assist with patient care, provide HIV counselling and testing, and obtain sputum samples for culture and susceptibility testing. The catchment area included 3.6 million people in four provinces. We compared results from October 2004-September 2005 (referred to as 2005) to baseline data from October 2002-September 2003 (referred to as 2003). FINDINGS: In 2005, we ascertained 5841 TB cases (164/100 000), including 2320 new smear-positive cases (65/100 000). Compared with routine passive surveillance in 2003, active surveillance increased reporting of all TB cases by 19% and of new smear-positive cases by 13%. Private facilities diagnosed 634 (11%) of all TB cases. In 2005, 1392 (24%) cases were known to be HIV positive. The proportion of cases with an unknown HIV status decreased from 66% (3226/4904) in 2003 to 23% (1329/5841) in 2005 (P< 0.01). Of 4656 pulmonary cases, mycobacterial culture was performed in 3024 (65%) and MDR-TB diagnosed in 60 (1%). CONCLUSION: In Thailand, piloting the new WHO strategy increased case-finding and collaboration with the private sector, and improved HIV services for TB patients and the diagnosis of MDR-TB. Further analysis of treatment outcomes and costs is needed to assess this programme's impact and cost effectiveness.
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