The World Health Organisation (WHO) and other international organisations (including the World Organisation for Animal Health (OIE) and the International Union Against Tuberculosis and Lung Disease), have recently called for action to accurately diagnose and treat zoonotic1 tuberculosis in people, caused by Mycobacterium bovis2. Its contribution to human tuberculosis, otherwise primarily caused by Mycobacterium tuberculosis, may be globally underestimated. Nationally representative data on this zoonosis are especially lacking in the world regions (Asia, Africa) where the burden is presumably the highest.
M. bovis is a bacterium responsible for bovine tuberculosis, which is also capable of infecting humans. This bacterium frequently causes extrapulmonary tuberculosis in people, which is difficult to diagnose. Also, in contrast to M. tuberculosis, M. bovis is naturally resistant to pyrazinamide, an important antibiotic in the standard short course tuberculosis treatment.
Accurate diagnosis of M. bovis is therefore important to define appropriate patient treatment. This diagnosis can also guide the detection of infected animals and contaminated food sources (meat, dairy products, etc.), representing zoonotic risks that can escape TB control measures. However, the most commonly used phenotypic and molecular diagnostic tests do not differentiate M. bovis from M. tuberculosis.
To address these problems, Al Ashkar and colleagues used the new Deeplex® Myc-TB test to reveal for the first time the national prevalence of zoonotic tuberculosis in a lower-middle-income country, namely Lebanon. Unlike the other tests, this comprehensive assay developed by GenoScreen enables the users to distinguish M. bovis from M. tuberculosis, identify more than 100 other mycobacterial species, and to simultaneously detect resistance to pyrazinamide, as well as to 14 other anti-tuberculosis drugs. The test can be applied directly on clinical samples, with a turnaround time of one to two days, instead of weeks when using culture-based tests.
The use of the Deeplex® Myc-TB test, which specifically identifies M. bovis, will thus help better detect zoonotic infections, allowing definition of more appropriate treatment of patients and providing guidance to uncover zoonotic sources.
- Discover the study: El Achkar S, Demanche C, Osman M, Rafei R, Ismail MB, Gaudin C, Duthoy S, De Matos F, Yaacoub H, Pinçon C, Hamze M, Supply P. Zoonotic tuberculosis in humans assessed by next-generation sequencing: an 18-month nationwide study in Lebanon. Eur Respir J. 2020 Jan 2;55(1)
- Discover Deeplex® Myc-TB
1. Zoonosis: human disease contracted from an animal or animal product source (for instance: cattle, dairy products, meat…)
2. Olea-Popelka F, Muwonge A, Perera A, Dean AS, Mumford E, Erlacher-Vindel E, Forcella S, Silk BJ, Ditiu L, El Idrissi A, Raviglione M, Cosivi O, LoBue P, Fujiwara PI. Zoonotic tuberculosis in human beings caused by Mycobacterium bovis-a call for action. Lancet Infect Dis. 2017 Jan;17(1):e21-e25. doi:10.1016/S1473-3099(16)30139-6. Epub 2016 Sep 30. Review. PubMed PMID: 27697390