Isolation of Mycobacterium tuberculosis from inner cheek and tongue of children with presumptive tuberculosis in a community, southwestern Nigeria

Background: Burden of tuberculosis (TB) is widespread worldwide with children accounting for a major proportion of the disease, especially in endemic areas of the world. Accurate diagnosis of childhood TB remains a major challenge, particularly in developing countries where active case finding programmes and sensitive diagnostic tools are lacking or inadequate. This is exacerbated by inherent inadequacies associated with difficulties related to sputum collection in children.This study aimed at exploring a less invasive, novel diagnostic matrix of inner cheek and tongue swab samples for diagnosing childhood tuberculosis. Methods and materials: Children of less than 15 y who are presumptive TB cases were screened during an active case finding project in a rural pastoralist community in Ibarapa Area, Oyo State, Nigeria. Inner cheek and tongue swab samples were collected from each child and subjected to bacteriological processing and culture. Molecular analyses (genus and deletion typing techniques) were used for confirmation and identification of the isolates. Results: Overall, a total of 176 children were sampled with almost same number of males and females. Up to 39.8% (70/176) were within 5–9 y age range. A culture positivity of 5.1% (9/176) and 6.8% (12/176) were recorded for cheek and tongue swabs, respectively. Using molecular techniques, six and four Mycobacterium tuberculosis isolates from inner cheek and tongue swab samples were identified, respectively. Conclusion: Detection of mycobacteria specie from inner cheek and tongue swab from children with presumptive TB is a positive step towards improving TB diagnosis through non-invasive, non-viscous and easy to assess means of diagnosing childhood TB. This becomes very important considering the challenges associated with diagnosis of childhood TB and the endemicity of the disease in Nigeria. Finally, we propose further investigations to explore the full spectrum of diagnostic utility of this non-invasive method as an add-on for childhood tuberculosis.