How a new blood test detects active, infectious Tuberculosis: Here’s everything to know

A surprising breakthrough has been achieved by the UC Davis Department of Pathology and Laboratory Development in developing a new tuberculosis (TB) blood test designed to identify the active and infectious form of the disease. The prime motive behind this discovery is to enable faster diagnosis and treatment while helping prevent the spread of TB by contagious individuals. Current TB screening tests do not differentiate between active TB disease, a latent, or inactive, infection.

While TB is caused by the bacterium Mycobacterium tuberculosis, only those with active infections can spread the disease through coughing, sneezing or speaking. The new blood tests measure the immune system’s response to TB proteins, similar to the interferon-gamma release assay (IGRA). It has been observed that unlike the IGRA, this test specifically identifies antibodies linked with active tuberculosis.

This allows clinicians to identify patients who are currently sick and contagious rather than those who have simply been exposed to the bacteria in the past. The test’s credibility was analysed in a clinical trial in India from 2029 to 2023, involving more than 600 participants. Results demonstrated that the test performed very well in identifying adult pulmonary TB, which accounts for approximately 60% to 70% of infections.

The data analysis and clinical trial report have been successfully submitted to the Council of Medical Research. Upon approval, the test could be expanded to neighboring countries. It is estimated that India, Pakistan, and Bangladesh account for approximately 30% to 40% for the global TB population. This new technology could mark a significant milestone in the global fight against tuberculosis, improving disease control and mitigating transmission worldwide.