The incalculable costs of tuberculosis

“Zimkitha was the world to us”, her mother says. “When she died, we lost everything: our hopes, our future, and our faith. She was more precious than any gem, and we will never recover from the fact that she is gone.”

The pain felt by the relatives of Zimkitha (name changed to protect privacy) after the 32-year-old woman died from tuberculosis is evident in these words. In addition to their sorrow, however, her family, struggling to maintain a living in southern Africa, have also lost the only income source for their household of seven, since Zimkitha was the only working member of the family.

What is the value of a human life? Although this question might best be answered by philosophers or religious scholars, it also confronts public health experts, especially when deciding whether a clinical intervention is worthy of investment.¹ Indeed, it is the language of economics (instead of medicine) that often dominates discourse around health and illness, particularly in so-called resource-poor settings.² In such parlance, human beings are reduced to disability-adjusted life-years and suffering is only worth addressing if doing so is deemed to be sustainable or cost-effective.³

Accepting that such valuations may be morally distasteful, making them is often considered a necessary part of public health advocacy. This is certainly the case for tuberculosis, which, until 2020, was the leading infectious killer of adults worldwide. With an estimated 1·4 million people dying annually from the treatable infectious disease, funding efforts to tackle tuberculosis would seem to be a winning investment.⁴ Data on tuberculosis financing, however, tell another story. In 2017, an estimated US$10·9 billion was spent on tuberculosis compared with $20·2 billion spent on HIV.⁵ The Stop TB Partnership has estimated a $7 billion shortfall in tuberculosis funding per year.⁶ In contrast with the estimated $291·1 billion for COVID-19 health spending up to June, 2021, a stark, disease-based inequality emerges.⁷

The study by Sachin Silva and colleagues⁸ in The Lancet Global Health stands as a dire warning of the heavy financial perils of continuing to neglect tuberculosis. Using an analysis focused on annual mortality risk changes for 120 countries, the authors estimate a business-as-usual scenario of 31·8 million tuberculosis-related deaths between 2020 and 2050, resulting in economic losses of $17·5 trillion. If a 90% reduction in tuberculosis mortality were to be reached by 2030 (as specified in the Sustainable Development Goals⁴), 23·8 million deaths would be averted, with costs reduced by $13·1 trillion. However, if the 90% target is, more realistically, reached by 2045, only 18·1 million deaths would be averted and costs would be reduced by $10·2 trillion relative to this business-as-usual scenario.

These economic losses are staggering, and probably only represent the tip of the iceberg when it comes to failing to reach global tuberculosis targets. The analysis focused on mortality only, excluding costs associated with disability resulting from tuberculosis disease.⁹ In addition, the WHO End TB strategy aims to eliminate catastrophic costs for people living with tuberculosis and their families by 2020. Data suggest that a majority of households incur costs equating to more than half their annual income over the course of tuberculosis illness.¹⁰ However, to date, little has been done to reduce patient-level costs and the 2020 target has not been reached, with an estimated 49% of people living with tuberculosis still facing catastrophic costs. Even this high figure is likely to be an underestimate because methods to monitor progress towards this target are not yet in place in most countries. Also absent from the analysis by Silva and colleagues are considerations of the collateral damages incurred by families and communities, as illustrated in the above scenario.

Importantly, Silva and colleagues also estimate economic losses due to COVID-19-related disruptions to tuberculosis services to be an additional $290 billion in the scenario in which the 90% target is reached by 2045. In contrast to tuberculosis, the economic impacts of the COVID-19 pandemic have been immediately apparent globally and have resulted in economic support packages in the trillions. As the analysis by Silva and colleagues suggests, tuberculosis exacts an enormous toll, but the economic impact is not immediately apparent nor, importantly, felt across all countries. Although the COVID-19 pandemic has been devastating, it has highlighted both the human and economic impacts wrought by infectious disease and demonstrated the neocolonial nature of health spending. We hope that the clear inequalities in funding and access to innovations shown by COVID-19 will ultimately serve to improve commitments to tackle tuberculosis at a global level in the long term.