**7. Challenges in diagnosis of tuberculosis**

In the diagnosis of tuberculosis in both humans and animals, the challenges have always been the availability of better and affordable diagnostic methods. While conventional tests such as ZN test for sputum has been in place and are the gold standard, it can miss some cases due to low-sensitivity. Mycobacterial cultures can improve detection but takes longer to get results. Molecular characterization to nucleotide level that is, through sequencing is perfect but usually unaffordable in low-income countries diagnostic settings. In addition, DNA isolation, species identification, and obtaining cultures from a sophisticated system may face limitations as well. All these challenges necessitate for advocacy focusing on innovations that deliver better tools to confidently diagnose TB and at affordable costs [71]. Although, international and national laboratory partnerships are encouraged particularly to boost diagnostic services in resource-poor countries, the need for diagnostic tests that allow rapid testing at point-of-care is necessary [72]. However, all these need acceptance by health authorities in respective countries for incorporation into countries diagnostic algorithms while ensuring inherent and adequate quality assurance programs in dedicated laboratories. In marginalized communities, refusal of diagnosis, high indirect costs, and anticipated treatment side-effects have posed barriers to TB diagnosis [73]. All these need to be considered if we want to perform right diagnosis and management of tuberculosis across endemic regions. Screening programs for both human and animal tuberculosis could cut the costs of modern molecular diagnostics and characterization but these programs are costly and might currently not be of primary priority by responsible authorities. Otherwise, screening programs despite potentially expected high initial capital investment, their value on cutting down diagnostic costs for TB cannot be overemphasized.
