Assessment of the Xpert MTB/RIF assay for diagnosis of tuberculosis with gastric lavage aspirates in children in sub-Saharan Africa: a prospective descriptive study

• Published in: The Lancet infectious diseases 2013, Vol.13 (1), p.36-42
• Main Authors: Bates, Matthew, PhD, O'Grady, Justin, PhD, Maeurer, Markus, Prof, Tembo, John, MSc, Chilukutu, Lophina, BSc, Chabala, Chishala, MMed, Kasonde, Richard, BSc, Mulota, Peter, BSc, Mzyece, Judith, BSc, Chomba, Mumba, BSc, Mukonda, Lukundo, BSc, Mumba, Maxwell, BSc, Kapata, Nathan, MBChB, Rachow, Andrea, MD, Clowes, Petra, MD, Hoelscher, Michael, Prof, Mwaba, Peter, FRCP, Zumla, Alimuddin, Prof
• Format: Article
• Language: English
• Subjects: Adolescent; Africa South of the Sahara; Bacterial diseases; Biological and medical sciences; Child; Child, Preschool; Children; Clinical Laboratory Techniques - methods; Clinical trials; Developing countries; Gastric Lavage - methods; Hospitals; Human bacterial diseases; Human immunodeficiency virus; Humans; Infectious Disease; Infectious diseases; LDCs; Lung; Medical sciences; Medicin och hälsovetenskap; Microscopy; Multidrug resistance; Mycobacterium; Mycobacterium tuberculosis; Nasopharynx - microbiology; Pediatrics; Prospective Studies; Rifampin; Sensitivity and Specificity; Sputum; Sputum - microbiology; Tuberculosis; Tuberculosis and atypical mycobacterial infections; Tuberculosis, Multidrug-Resistant - diagnosis; Tuberculosis, Multidrug-Resistant - microbiology; Tuberculosis, Pulmonary - diagnosis; Tuberculosis, Pulmonary - microbiology
• ISSN: 1473-3099; 1474-4457; 1474-4457
• DOI: 10.1016/S1473-3099(12)70245-1

Summary Background Rapid and accurate diagnosis of pulmonary tuberculosis in children remains challenging because of difficulties in obtaining sputum samples and the paucibacillary nature of the disease. The Xpert MTB/RIF assay is useful for rapid diagnosis of childhood tuberculosis with sputum and nasopharyngeal samples. We assessed this assay for the detection of tuberculosis and multidrug resistant (MDR) tuberculosis with gastric lavage aspirate (GLA) samples in children admitted to hospital. Methods We did a prospective study to assess the sensitivity and specificity of the Xpert MTB/RIF assay with GLA samples for the detection of pulmonary tuberculosis and MDR tuberculosis in new paediatric inpatient admissions at the University Teaching Hospital, Lusaka, Zambia. Children aged 15 years or younger were recruited between June, 2011, and May, 2012. GLA and sputum were analysed by standard smear-microscopy, mycobacterial growth indicator tube (MGIT) culture, MGIT drug-susceptibility testing, and the Xpert MTB/RIF assay. Sensitivity of the Xpert MTB/RIF assay was assessed with the Pearson χ2 or Fishers exact test. Findings Of 930 children, 142 produced sputum and GLA was obtained from 788 non-sputum producers. Culture-positive tuberculosis was identified in 58 (6·2%) of 930 children: ten from sputum producers and 48 from GLA of non-sputum producers. The sensitivity and specificity of the Xpert MTB/RIF assay were similar: sensitivity was 68·8% (95% CI 53·6–80·9) for GLA versus 90·0% (54·1–99·5; p=0·1649) for sputum samples; specificity was 99·3% (98·3–99·8) for GLA and 98·5% (94·1–99·7; p=0·2871) for sputum samples. The Xpert MTB/RIF assay detected an extra 28 tuberculosis cases compared with smear microscopy and was significantly more sensitive than smear microscopy for both sputum (90·0% [54·1–99·5] vs 30·0% [8·1–64·6], p=0·01) and GLA (68·8% [53·6–80·9] vs 25·0% [14·1–40·0], p