TB Regains Title Of World's Deadliest Infectious Disease, WHO Calls It 'An Outrage'

The scourge of tuberculosis, an infection that has tormented humankind for centuries, has resurfaced as the deadliest infectious disease on the planet. According to the World Health Organization's (WHO) 2024 Global Tuberculosis Report, 1.25 million lost their lives to TB in 2023, which far surpassed COVID-19 as it claimed 320,000 lives in the same year. The startling statistics further emphasize the ever-present and challenging nature of TB while underlining a much-required global fight against its emergence.

The WHO report points out that the number of cases for TB has grown by disturbing proportions, with 8.2 million new cases diagnosed in 2023-the most since the agency started documenting the disease back in 1995. The cases recorded this year stood at a high of 7.5 million in 2022. Though the deaths due to TB decreased from 1.32 million in 2022, the figures are still "unacceptably high," the WHO members said.

TB disproportionately affects the most vulnerable populations, including impoverished communities, migrants, and people with weak health. The disease thrives in conditions where malnutrition, poor living conditions, and limited access to healthcare prevail.

Despite the existence of effective tools to prevent, detect, and treat TB, the global response remains inadequate. WHO has identified significant funding gaps as a primary obstacle. Global funding for TB prevention and care fell from $6 billion annually in recent years to $5.7 billion in 2023, far below the annual target of $22 billion set at the 2023 UN High-Level Meeting on TB.

This funding gap limits the scaling up of rapid diagnostic tests, timely treatment, and reduction in cost to patients and their households. For most, traveling costs, loss of earnings, and treatment costs serve as a barrier to accessing healthcare services, and this worsens the vicious cycle of ill health and poverty.

One of the most important advances in the fight against TB is the progress made in vaccine research. M72/AS01E is the candidate vaccine in late-stage clinical trials, and it is expected to be the first new TB vaccine in over a century. The existing vaccine, Bacillus Calmette-Guérin (BCG), is only effective in children and has shown inconsistent protection for adults.

Still, no matter the success of a good vaccine, without proper financing, there is nothing that can be done. TB burden mostly lies on the shoulders of middle-income countries which do not receive sufficient international financing for vaccinations. The organization calls for a positive policy action along with proper financing to allow vaccine distribution.

The COVID-19 pandemic has worsened the TB crisis. The pandemic has disrupted TB programs and caused delays in diagnosis and treatment, adding to the number of cases. Ironically, lockdown measures reduced the rate of TB transmission but also restricted access to health care. Post-pandemic, there is an urgent need to rebuild TB programs and clear up the backlog of undiagnosed and untreated cases.

A less-discussed factor in TB's resurgence is its possible association with climate change. Climatic factors such as temperature increases, overcrowding of urban areas, and climatic disasters leading to more people migrating can create favorable conditions for the spread of TB. For example, chronic exposure to poor air quality in crowded areas compromises the strength of the respiratory system, increasing vulnerability to infections such as TB.

Climate-induced displacement also throws millions into overcrowded and unsanitary living conditions, which increases the risk of disease spread. To control TB in a warming world, climate resilience must be integrated into public health strategies, such as ensuring access to healthcare in disaster-prone regions and improving air quality in urban centers.

The resurgence of TB as the world's deadliest infectious disease is a timely reminder of the need for continuing global efforts to combat this disease. WHO calls on increased investment in TB research, prevention, and care to bridge funding gaps and accelerate progress. Key priorities include scaling up rapid diagnostic testing: Early detection can be a great reduction in transmissibility rates and improved results in treatment:

- Increasing access to treatment: Subsidies on treatment costs, along with compensation for lost wages and travel, could persuade more patients to seek treatment.

- Investing in infrastructure for vaccine distribution: Equal access to new vaccines when they are developed will be an essential part of the approach.

- Integrate climate resilience: Awareness of environmental causes for the spread of TB will enhance long-term prevention strategies.