Tuberculosis dethrones COVID-19 as world’s top infectious killer again; Half of all new cases from India, Indonesia

After years of intensified focus on COVID-19, tuberculosis (TB) has once again emerged as the leading infectious disease killer worldwide. This resurgence is a sobering reminder that despite our pandemic response, TB has continued to claim lives, especially in low- and middle-income countries (LMICs), where resources are often stretched thin.

According to the latest World Health Organization (WHO) report, approximately 8.2 million people were diagnosed with TB in 2023, marking the highest number of cases recorded since global monitoring began in 1995.

India and Indonesia

The recent spike in TB cases is largely driven by increases in two countries — India and Indonesia. Together, they accounted for 45% of the global rebound in TB diagnoses between 2021 and 2023, underscoring their critical role in the worldwide fight against TB. Three other countries, the Philippines, Nigeria, and Pakistan, also made significant contributions, collectively accounting for another 32% of the increase. This means that more than three-quarters of the global resurgence in TB can be traced to these five countries alone.

One key reason for these increases is the “backlog” effect created by COVID-19 disruptions. During the pandemic, healthcare systems in many countries, including India and Indonesia, had to shift focus to COVID-19, which delayed TB diagnosis and treatment. In 2023, as these countries ramped up recovery efforts, many previously undetected TB cases surfaced, creating an apparent spike in reported numbers. This trend highlights the importance of sustainable healthcare infrastructure capable of handling simultaneous health crises.

Gaps in TB case detection

Despite the daunting increase in TB cases, some countries have made notable progress in treatment coverage. Among the 30 high-burden TB countries, those with the highest levels of treatment coverage in 2023 included Brazil, India, Mozambique, Papua New Guinea, Sierra Leone, Uganda, and Zambia, with coverage rates surpassing 80%. India’s National Tuberculosis Elimination Program (NTEP) has undoubtedly played a pivotal role in this, aiming to eradicate TB by 2025 — five years ahead of the global target. By focusing on expanded testing, improved diagnostic tools, and more accessible treatment options, India has achieved high treatment coverage levels despite the challenges.
However, a significant treatment gap remains. The difference between estimated TB incidence and actual diagnoses still affects millions, especially in countries with large populations like India, Indonesia, Pakistan, China, and Myanmar. These five nations together account for about 50% of the global gap in reported TB cases, with India alone responsible for 16% of the discrepancy.

India’s unique position in the global TB fight

As the nation with the largest share of global TB cases, India has a unique and critical responsibility in addressing the disease. The high TB burden in India is tied to several factors, including undernutrition, poverty, and limited access to healthcare in rural areas. Moreover, with 26% of all TB cases globally, India’s battle against TB will significantly impact the global fight. The government’s financial support for TB-affected households also aims to reduce the economic burden of treatment.

However, challenges remain, especially with multidrug-resistant TB (MDR/RR-TB). While treatment success rates for MDR/RR-TB have reached 68%, diagnosing and treating all drug-resistant cases is an ongoing challenge. In 2023, India’s coverage of preventive treatment for TB among people living with HIV and close contacts of TB patients also saw improvements, but underfunding continues to limit the full scope of TB elimination efforts.

Global funding gaps

Global funding shortages for TB prevention and treatment are a significant hindrance to progress. Only $5.7 billion of the targeted $22 billion in funding was met in 2023, and for LMICs — where nearly all of the TB burden lies — the available funding falls well short of their needs. The United States remains the largest bilateral donor, and contributions from the Global Fund to Fight AIDS, Tuberculosis, and Malaria are crucial. However, these funds are not enough to meet essential TB service requirements, leaving healthcare systems under-resourced.
Even in 2022, only one-fifth of the $5 billion target for research funding was achieved, as per the report. This underfunding hampers the development of improved diagnostics, drugs, and vaccines, which are crucial to TB prevention and treatment.

Moreover, many of the drivers of TB are related to social factors, such as undernutrition, smoking, alcohol use, and diabetes, making it imperative to address these root causes. For instance, almost half of the TB-affected households globally face what the WHO calls "catastrophic costs" in seeking treatment. This burden is particularly severe in India, where low-income families often forgo treatment due to financial constraints.

As WHO’s Director-General Dr Tedros Adhanom Ghebreyesus puts it, "The fact that TB still kills and sickens so many people is an outrage, when we have the tools to prevent it, detect it, and treat it.”

The WHO’s Global tuberculosis report 2024 can be accessed here.