An assessment of nucleic acid amplification testing for active mycobacterial infection

Linked evidence of diagnostic effectiveness of NAAT in the diagnosis of NTM

Literature on NTM generally falls into four categories: MAC, which is associated with lung disease in immunocompromised patients; M ulcerans, which is associated with Buruli ulcer disease, a skin disorder endemic to certain regions of Africa but also identified in Australia (sometimes known as ‘Daintree ulcer’); M avium spp. paratuberculosis, a strain found predominately in animals, causing Johne’s disease, which is implicated in Crohn’s disease in humans; and the other less common mycobacteria, which form the fourth category.

Although there was a considerable body of literature about NTM, very little of it was relevant to the review. Many of the studies were case reports or outbreak investigations; most of the literature on Crohn’s disease compared the presence of mycobacteria in people with and without Crohn’s disease, rather than how it is diagnosed. Indeed, none of the literature on M. avium in Crohn’s disease was eligible for inclusion in the review. No direct evidence was found comparing NAAT with culture. Thus, a linked evidence approach was used. However, the studies that met the inclusion criteria only reported on diagnostic accuracy. No studies reporting on the effect of a change in management resulting from the use of NAAT were identified.