Background: Diagnosis of pediatric pulmonary tuberculosis (PTB) is a challenge. Symptoms are
nonspecific. Young children are unable to expectorate sputum samples; the procedures for obtaining
respiratory samples are invasive. Thus Mycobacterium tuberculosis cultures and smears
often are not performed. Stool samples were used as an alternative to respiratory samples for the
diagnosis of pediatric PTB using stool Xpert MTB/RIF and its sensitivity for detecting the DNA of
MTB in stool was determined. Methods: The study was a laboratory-based cross-sectional prospective
design. Stool specimen was collected from PTB suspected children (<15 years) attended in
Gertrude’s Children’s Hospital Nairobi and Kiambu District Hospital from September 2013 to
March 2014. Stool for Xpert was processed in two ways, direct and prior extraction of DNA using
QIAGEN stool DNA extraction kit. Result: A total sample of 91 stool specimen was collected from
patients. Of these 53 (58.2%) had sputum ZN smear microscopy. Six (11.3%) of them were confirmed
smear positive for PTB. Stool Gene Xpert was positive in all the six smear positive children.
Four (7.5%) smear negative patients tested positive by stool Gene Xpert test. This association is
significant (P = 0.000). Conclusion: This study reports that Mycobacterium tuberculosis DNA can be
detected in stool using Xpert testing with a higher sensitivity. Therefore stool which can easily be
obtained is an appropriate alternative sample for the diagnosis of PTB using Xpert assay for children
unable to give respiratory samples. Furthermore Xpert turn round time is less than 2 hours.
Cite this paper
Welday, S. , Kimang’a, A. , Kabera, B. , Mburu, J. , Mwachari, C. , Mungai, E. , Ndwiga, S. , Mbuthia, J. and Revathi, G. (2014) Stool as Appropriate Sample for the Diagnosis of Mycobacterium tuberculosis
by Gene Xpert Test. Open Journal of Respiratory Diseases
, 83-89. doi: 10.4236/ojrd.2014.43012
 World Health Organization (2012) Global Tuberculosis Control. World Health Organization, Geneva.
 Grange, J.M. and Zumela, A. (2002) The Global Emergency of Tuberclosis: What Is the Cause? Journal of Royal Society for the Promotion of Health, 122, 78-81. http://dx.doi.org/10.1177/146642400212200206
 GOK, Ministry of Public Health and Sanitation (2009) DLTLD Guidelines on Management of Leprosy and Tuberculosis. Government Printer, Nairobi.
 World Health Organization (2003) Treatment of Tuberculosis Guideline for National Programs. World Health Organization, Geneva.
 Khan, E.A. and Starke, J.R. (2006) Diagnosis of Tuberculosis in Children: Increased Need for Better Methods. International Journal of Tuberculosis and Lung Disease, 10, 1091-1097.
 Mukherjee, A., Lodha, R. and Kabara, S.K. (2012) Recent Advances in Diagnosis of Tuberculosis. Journal of Pediatric Infectious Diseases, 4, 45-50.
 Medicines Sans Frontieres for HIV and Tuberculosis (TB) (2010) Diagnosing Children, a Terrible Neglect. WHO, Geneva.
 Cordova, J., Shilho, R., Gilman, R.H., et al. (2010) Evaluation of Molecular Tools for Detection and Drug Susceptibility Testing of Mycobacterium Tuberculosis in Stool Specimens from Patients with Pulmonary Tuberculosis. Journal of Clinical Microbiology, 48, 1820-1826. http://dx.doi.org/10.1128/JCM.01161-09
 Nicol, M.P., Spiers, K., Workman, L., Isaacs, W., Munro, J., Black, F., Zemanay, W. and Zar, H.J. (2013) Xpert MTB/RIF Testing of Stool Samples for the Diagnosis of Pulmonary Tuberculosis in Children. Clinical Infectious Disease Oxford Journals, 57, 2-12.
 QIAamp (2012) QIAamp DNA Stool Handbook for DNA Purification from Stool Samples. 2nd Edition, New England Biolabs, Ipswich. www.qiagen.com
 GOK, Ministry of Public Health and Sanitation (2013) National Guidelines on Management of Tuberculosis in Children. 2nd Edition, Government Printer, Nairobi.
 Wolf, H., Mendez, M., Gilman, R.H., Sheen, P., Soto, G., Velarde, A.K., Zimic, M. and Escombe, A.R. (2008) Diagnosis of Pediatric Pulmonary Tuberculosis by Stool PCR. America Journal of Tropical Medicine Hygiene, 79, 893-898.
 Triasih, R. and Graham, S.M. (2011) Limitations of the Indonesian Pediatric Tuberculosis Scoring System in the Context of Child Contact Investigation. Paediatrica Indonesiana, 51, 332-337.
 Fjallbrant, H. (2008) BCG Vaccination and the Tuberculin Skin Test in a Country with Low Prevalence of Tuberculosis. Geson Hylte Tryck, Sweden.