Evaluation of Xpert MTB/RIF and MODS assay for the diagnosis of pediatric tuberculosis

BMC Infectious Diseases

Research Article

Nguyen Thi Quynh Nhu¹  Nguyen Duc Anh¹  Do Dang Anh Thu¹  Maxine Caws²  Jeremy Farrar²  Marcel Wolbers²  Do Chau Giang³  Dang Thi Minh Ha³  Vo Thi Ha⁴  Nguyen Dang Quang⁴  Nguyen Thi Ngoc Lan⁴  Tran Ngoc Duong⁴  Nguyen Thi Bich Tuyen⁴  Tran Van Quyet⁴  Nguyen Huy Dung⁴ 

[1] Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Vietnam;Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Vietnam;Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, Old Road, HeadingtonOxford, UK;Oxford University Clinical Research Unit, Hospital for Tropical Diseases, 764 Vo Van Kiet, District 5, Ho Chi Minh City, Vietnam;Pham Ngoc Thach Hospital for Tuberculosis and Lung Diseases, 120 Hung Vuong, District 5, Ho Chi Minh City, Vietnam;Pham Ngoc Thach Hospital for Tuberculosis and Lung Diseases, 120 Hung Vuong, District 5, Ho Chi Minh City, Vietnam;

关键词: Tuberculosis;    GeneXpert MTB/RIF;    MODS;    Pediatric;    Childhood;   

DOI  :  10.1186/1471-2334-13-31

 received in 2012-08-02, accepted in 2013-01-21,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundTuberculosis (TB) in children is rarely confirmed due to the lack of effective diagnostic tools; only 10 to 15% of pediatric TB is smear positive due to paucibacillary samples and the difficulty of obtaining high-quality specimens from children. We evaluate here the accuracy of Xpert MTB/RIF in comparison with the Micoroscopic observation drug susceptibility (MODS) assay for diagnosis of TB in children using samples stored during a previously reported evaluation of the MODS assay.MethodsNinety-six eligible children presenting with suspected TB were recruited consecutively at Pham Ngoc Thach Hospital in Ho Chi Minh City Viet Nam between May to December 2008 and tested by Ziehl-Neelsen smear, MODS and Mycobacterial growth Indicator (MGIT, Becton Dickinson) culture. All samples sent by the treating clinician for testing were included in the analysis. An aliquot of processed sample deposit was stored at −20°C and tested in the present study by Xpert MTB/RIF test. 183 samples from 73 children were available for analysis by Xpert. Accuracy measures of MODS and Xpert were summarized.ResultsThe sensitivity (%) in detecting children with a clinical diagnosis of TB for smear, MODS and Xpert were 37.9 [95% CI 25.5; 51.6], 51.7 [38.2; 65.0] and 50.0 [36.6; 63.4], respectively (per patient analysis). Xpert was significantly more sensitive than smear (P=0.046). Testing of additional samples did not increase case detection for MODS while testing of a second sputum sample by Xpert detected only two additional cases. The positive and negative predictive values (%) of Xpert were 100.0 [88.0; 100.0] and 34.1 [20.5; 49.9], respectively, while those of MODS were 96.8 [83.3; 99.9] and 33.3 [19.6; 49.5].ConclusionMODS culture and Xpert MTB/RIF test have similar sensitivities for the detection of pediatric TB. Xpert MTB RIF is able to detect tuberculosis and rifampicin resistance within two hours. MODS allows isolation of cultures for further drug susceptibility testing but requires approximately one week to become positive. Testing of multiple samples by xpert detected only two additional cases and the benefits must be considered against costs in each setting. Further research is required to evaluate the optimal integration of Xpert into pediatric testing algorithms.

【 授权许可】

Unknown   
© Nhu et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.