Point-of-care test for tuberculosis - a boon in diagnosis.

Rapid diagnosis of tuberculosis (TB) is an effective measure to eradicate this infectious disease worldwide. Traditional methods for screening TB patients do not provide immediate diagnosis and thus delay treatment. There is an urgent need for early detection of TB through point-of-care test (POCT). Several POCTs are widely available at primary health care facilities which assist in TB screening. In addition to currently used POCT, advancement in technology has led to the discovery of newer methods that provide accurate and fast information independent of access to laboratory facilities. In the present article, the authors tried to include and describe the potential point of care test for screening TB in patients. Several molecular diagnostic tests such as NAATs including GeneXpert and TB-LAMP are being currently used as point-of-care tests. Besides these methods, the pathogenic component of Mycobacterium tuberculosis can also be utilized as a biomarker for screening purposes through immunological assays. Similarly, the host immune response to infection has also been utilized as a marker for the diagnosis of TB.  These novel biomarkers might include Mtb85, IP-10, VOCs, Acute phase proteins, etc. Radiological tests have also been observed as point-of-care test in the TB screening POCT panel. Various POCTs are performed in samples other than sputum which further eases the process of screening. These POCTs should not require large-scale manpower and infrastructure. Hence, POCT should be able to identify patients with Mtb infection at the primary health care level only. There are several other advanced techniques that have been proposed as future point-of-care test and have been discussed in the present article.