Can we eliminate tuberculosis?

By Dr Kerri Viney

Tuberculosis – or TB – is an ancient and well-documented disease.

Termed “the great white plague” and the “captain of these men of death”, TB has plagued mankind for centuries. A cause of untold human suffering, many people think TB has disappeared, but it hasn’t.

Scientists once thought human TB was a mutated form of bovine TB, transmitted from animals to humans and then amplified during the industrial revolution when overcrowding and poverty were rife. However, recent genomic analyses have demonstrated TB has been with humans for thousands of years, ever since modern humans migrated out of Africa.

TB is a bacterial disease that can affect any bodily site. It is transmitted through the air, making everyone vulnerable to infection. It is estimated that about one-third of the world’s population have breathed in the bacteria but only a fraction of these will develop active disease. This risk is heightened by certain other diseases and risk factors such as HIV infection, diabetes and smoking.

The World Health Organization recently released its annual global tuberculosis report. Based on data from 202 countries, the report outlines the magnitude of the problem and steps being taken to address it. The report highlights that the TB epidemic is larger than previously estimated, due to revised estimates from India.

The global TB burden is substantial.

In 2015, there were an estimated 10.4 million cases, of which one million (10 per cent) were children. Men are disproportionately affected by TB, with a male to female ratio of 1.7:1.

Approximately 60 per cent of the world’s TB occurs in six countries: India, Indonesia, China, Nigeria, Pakistan and South Africa.

Globally, TB incidence is declining by about 1.5 per cent per annum. This modest decline is not sufficient to end the global TB epidemic. In 2015 there were 1.4 million TB deaths recorded and an additional 0.4 million deaths among TB patients with HIV infection. Therefore, TB remains one of the top 10 killers worldwide.Ending the global TB epidemic will be a major focus for national governments, international partners, policymakers, researchers and advocates for the next 20 years. One of the key targets of the Sustainable Development Goals (SDGs) is to end the TB epidemic by 2030. Aligned with the SDGs, the End TB Strategy, approved by the World Health Assembly in 2014, calls for dramatic reductions in TB incidence, mortality and patient costs to achieve the target.