Today, 24 March, is World TB Day. This milestone in the calendar is a reminder, not a celebration. It can in no way be a celebration while tuberculosis remains a major global health issue. In 2023, an estimated 10.8 million people fell ill with TB worldwide, including 6.0 million men, 3.6 million women, and 1.3 million children. TB is present in all countries and age groups, and, despite our failure to do so, it is curable and preventable [1].
Global efforts to combat TB have saved an estimated 79 million lives since the year 2000. However, $22 billion is needed annually for TB prevention, diagnosis, treatment, and care to achieve the global target by 2027 agreed at the 2023 UN high-level meeting on TB. Ending the TB epidemic by 2030 is among the health targets of the United Nations Sustainable Development Goals (SDGs).
Recent funding cuts to the U.S. Agency for International Development (USAID) have raised concerns about a potential surge in TB cases and deaths. The World Health Organization (WHO) has warned that these cuts could endanger millions of lives, as many countries rely on foreign aid for TB prevention, testing, and treatment. The discontinuation of USAID funding may have led to an estimated 3,600 additional TB deaths and 6,400 additional infections since January 2025 [2].
Multidrug-resistant TB (MDR-TB) remains a public health crisis and a health security threat. Only about 2 in 5 people with drug-resistant TB accessed treatment in 2023. The rollback of USAID funding has disrupted drug supply chains, laboratory services, and surveillance systems in many countries, making it difficult to identify, monitor, and treat TB cases.
Ensuring that all TB patients worldwide have access to the drugs needed to treat the disease, as well as extending prevention measures and current diagnostic tests to all people at risk of infection, is essential to reduce TB-related morbidity or mortality. But it is also imperative to continue to invest in innovative technologies to combat two crucial TB problems, latent infection (LTBI) and multidrug-resistant manifestations of TB.
The airborne route is by far the most important route of disease transmission. Although TB can affect any organ, the lung is the route of entry in virtually all cases. Infection is caused by small particles of respiratory secretions containing bacilli that a sick person expels into the air when talking, laughing, singing, coughing or sneezing. But, after entering the body, the infection can remain latent without symptoms for months or even years and reactivate due to a weakened immune system.
People with LTBI may unconsciously spread the disease. This is why it is so important to develop new forms of diagnosis, which can go beyond the limitations of the current ones. Traditional diagnosis techniques —such as sputum smear microscopy and culture for Mycobacterium tuberculosis— are blind spots in sensitivity terms —especially where extrapulmonary infection or co-infection with HIV is concerned. This has led to ongoing development and use of ever more sensitive, specific, rapid and easy-to-use diagnostic technologies. Among these new diagnosis techniques there are nucleic acid amplification tests (NAATs), line probe assays (LPAs), imaging techniques like digital chest radiography, whole genome sequencing (WGS), and interferon-gamma release assays (IGRAs), which in a recent Health Technology Assessment conducted in Ontario [3] has been shown to offer higher diagnostic accuracy than the standard tuberculin skin test (TST), to be cost-effective and to have a positive impact on the public budget to serve the target population.
There have also been numerous advances and innovations in TB treatment. Among them, it is worth mentioning the approval and implementation of novel drugs such as bedaquiline and delamanid for the treatment of multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB), as well as the ongoing research and clinical trials to evaluate shorter, effective treatment regimens for drug-susceptible and drug-resistant forms of TB.
Digital technologies have also come to change how we deal with TB. More and more, telemedicine and digital health platforms are used to support remote monitoring of medication adherence, treatment response, and side effects in TB patients. We have also seen a progress in the development and deployment of rapid point-of-care tests for drug susceptibility testing, contributing to personalised treatment approaches, and enhanced efforts to integrate TB and HIV care services, addressing the unique treatment challenges faced by individuals co-infected with TB and HIV.
Nor should we forget that there are a dozen new vaccines in various stages of clinical development which, if they achieve the expected effectiveness, could represent a giant step forward in the prevention and a drastic reduction in the incidence of TB.
4,000 years after the first recorded cases of tuberculosis, this resilient and complex disease remains a major global health challenge. That is why we must continue investing in research, strengthening healthcare systems and ensuring that everyone at risk of TB has equitable access to quality diagnostics.
References:
[1] https://www.who.int/news-room/fact-sheets/detail/tuberculosis