To stimulate global research on tuberculosis treatments, the UNITE4TB consortium has commenced its work. It is a global network that includes academic institutions and pharmaceutical companies, with the primary aim to identify a new and effective combinational therapy for tuberculosis, based on drugs that are under development. The Scientific Lead of the project, Professor Michael Hoelscher (Director of the Division of Infectious Diseases and Tropical Medicine at the LMU University Hospital Munich ) tells us more.
One third of the world's population is now infected with tuberculosis. Why is the disease so difficult to treat?
Michael Hoelscher: Over 90% of infected individuals have what is called 'latent' tuberculosis. In such cases, any decline in the efficacy of the infected individual's immune response reactivates the dormant bacteria and allows them to propagate. So we not only have to kill the actively dividing bacteria in the lung, but also the dormant bacteria in granulomas. Granulomas can be thought of as capsules of a few centimeters in diameter that are filled with dead phagocytes and dormant mycobacteria - and it is extremely difficult for drugs to penetrate into these capsules.
For decades, patients infected with tuberculosis have been treated with a cocktail of antibiotics. For the past several years, you have been working on new anti-tuberculosis drugs. Why is this necessary?
Michael Hoelscher: A combination of four different antibiotics served as an effective treatment for around 40 years, and in most countries the incidence of tuberculosis has drastically declined. It was a tremendously successful therapy. However, the incidence of infections is rising again, and new strains have developed resistances against one or more drugs. In some parts of the world, 30% of all diagnosed cases are multi-drug-resistant tuberculosis cases. In terms of the incidence of antibiotic resistance, tuberculosis is the biggest problem worldwide, and it causes many deaths.
How high is the risk of contracting the disease in Germany?
Michael Hoelscher: It's very low. We currently have between seven and nine cases per 100,000 inhabitants. From a global point of view, however, tuberculosis is a significant problem. Until the emergence of the COVID-19 pandemic, the bacterium was the biggest threat among all infectious diseases. UNITE4TB is designed to combat this threat.
Romania has the highest incidence of tuberculosis in Europe. Why is that so?
Michael Hoelscher: The simple answer is that tuberculosis is a disease of the poor. The rate at which the infection spreads depends on the overall level of prosperity, on how crowded living conditions are and on the quality of the healthcare system. But other factors are at work as well. For a long time, it was assumed that tuberculosis could be eliminated in Africa. But then the HIV epidemic occurred and because HIV weakens the immune system, the incidence of tuberculosis infections increased.
