SETTING: The microscopic observation drug susceptibility (MODS) assay is a rapid, sensitive, low-cost liquid culture technique. OBJECTIVE: To establish the accuracy of MODS for the detection of active pulmonary tuberculosis (TB), and to document the costs and challenges of setting up this assay in a low-income setting. DESIGN: Prospective blinded pilot study of 200 adult TB suspects at a tertiary referral hospital in India. Reference standard included culture (Löwenstein-Jensen and automated liquid culture) and clinical diagnosis. RESULTS: Patients were mostly male (n = 122, 61.1%) and out-patients (n = 184, 92.0%), with a mean age of 40.4 years (standard deviation 16.2). Seventeen (8.5%) were human immunodeficiency virus infected and 47 (23.5%) were reference culture-positive. Compared to reference culture, MODS was 78.9% sensitive (95%CI 62.2-90.0) and 96.7% specific (95%CI 92.0-98.8). Clinical assessment suggested that MODS was false-negative in 3/8 reference culture-positive MODS-negatives and true-positive in 4/6 reference culture-negative MODS-positives. MODS was faster than solid (P < 0.001) and liquid culture (P = 0.088), and cheaper than both. CONCLUSION: MODS may be a good alternative to automated liquid culture, but there were several challenges in setting up the assay. Prior training and validation, setup costs and inability to rule out cross-contamination need to be taken into account before the test can be established.
SETTING: The microscopic observation drug susceptibility (MODS) assay is a rapid, sensitive, low-cost liquid culture technique. OBJECTIVE: To establish the accuracy of MODS for the detection of active pulmonary tuberculosis (TB), and to document the costs and challenges of setting up this assay in a low-income setting. DESIGN: Prospective blinded pilot study of 200 adult TB suspects at a tertiary referral hospital in India. Reference standard included culture (Löwenstein-Jensen and automated liquid culture) and clinical diagnosis. RESULTS:Patients were mostly male (n = 122, 61.1%) and out-patients (n = 184, 92.0%), with a mean age of 40.4 years (standard deviation 16.2). Seventeen (8.5%) were human immunodeficiency virus infected and 47 (23.5%) were reference culture-positive. Compared to reference culture, MODS was 78.9% sensitive (95%CI 62.2-90.0) and 96.7% specific (95%CI 92.0-98.8). Clinical assessment suggested that MODS was false-negative in 3/8 reference culture-positive MODS-negatives and true-positive in 4/6 reference culture-negative MODS-positives. MODS was faster than solid (P < 0.001) and liquid culture (P = 0.088), and cheaper than both. CONCLUSION: MODS may be a good alternative to automated liquid culture, but there were several challenges in setting up the assay. Prior training and validation, setup costs and inability to rule out cross-contamination need to be taken into account before the test can be established.
Authors: David A J Moore; Daniel Mendoza; Robert H Gilman; Carlton A W Evans; María-Graciela Hollm Delgado; Jose Guerra; Luz Caviedes; Daniel Vargas; Eduardo Ticona; Jaime Ortiz; Giselle Soto; Jose Serpa Journal: J Clin Microbiol Date: 2004-10 Impact factor: 5.948
Authors: Richard A Oberhelman; Giselle Soto-Castellares; Luz Caviedes; Maria E Castillo; Patricia Kissinger; David A J Moore; Carlton Evans; Robert H Gilman Journal: Pediatrics Date: 2006-06-02 Impact factor: 7.124
Authors: L Caviedes; T S Lee; R H Gilman; P Sheen; E Spellman; E H Lee; D E Berg; S Montenegro-James Journal: J Clin Microbiol Date: 2000-03 Impact factor: 5.948
Authors: A Mendoza; E Castillo; N Gamarra; T Huamán; M Perea; Y Monroi; R Salazar; J Coronel; M Acurio; G Obregón; M Roper; C Bonilla; L Asencios; D A J Moore Journal: Int J Tuberc Lung Dis Date: 2011-02 Impact factor: 2.373
Authors: Benson R Kidenya; Rodrick Kabangila; Robert N Peck; Stephen E Mshana; Lauren E Webster; Serena P Koenig; Warren D Johnson; Daniel W Fitzgerald Journal: PLoS One Date: 2013-02-28 Impact factor: 3.240