Ten millions. This is the estimate of the number of people suffering from tuberculosis each year in the world. With 1.5 million deaths per year, it is the deadliest infectious disease, ahead of HIV (AIDS) and malaria. It affects the lungs and is transmitted mainly by coughing. These 2019 figures are a reminder that infectious diseases existed before Covid-19 and that they are still there.

“TB is a global public health emergency. We have to find new treatments and new vaccines”, summarizes Dr Olivier Neyrolles, CNRS researcher, director of the Institute of Pharmacology and Structural Biology in Toulouse (1), laboratory which co-organized this 6^and World Forum placed under the high patronage of the President of the French Republic. From February 22 to 25, nearly 300 experts, biologists, clinicians from 40 countries will take stock.
In Toulouse, five teams worked on tuberculosis (screening, treatments and vaccines), which makes the IPBS one of the most important French centers with the Institut Pasteur in Paris and that of Lille.

BCG not effective enough in adults

“100 years old, the BCG vaccine protects well against infantile tuberculosis but it is not sufficiently effective in adults and therefore on the transmissible and contagious forms. Global research programs are working on two axes: boosting the BCG vaccine with a booster; replace it with another vaccine”, specifies Olivier Neyrolles. “Tuberculosis involves a complex cellular immunity that is still poorly understood. One can thus spend 20 years with the tubercle bacillus (Bacillus of Koch) in the body without knowing it, until the activation of the disease. According to the WHO (World Health Organization), a quarter of the world’s population has been in contact with the bacteria. The challenge is also to identify them,” adds the researcher.

A disease that affects the most vulnerable

Contrary to popular belief, tuberculosis has not disappeared. It is found in particular in India, Indonesia, China, the Philippines, as well as in sub-Saharan Africa. It still circulates in Europe, among homeless people and migrants. Seine-Saint-Denis is the most affected French department (23.8 cases per 100,000 inhabitants in 2020). “In France, the average incidence does not exceed 7 cases per 100,000 inhabitants, it is not a public health problem here, moreover BCG no longer appears in the vaccination schedule. But tuberculosis hides important manifestations, it affects precarious, fragile populations. It remains a marker of poverty,” emphasizes Isabelle Saves, CNRS research engineer and head of international cooperation at IPBS. Malnutrition and HIV are aggravating factors of the disease. “With climate change, the waves of migration will increase further, so this is a subject that concerns us all. And all the more so as we are seeing the emergence of tuberculosis that is multi-resistant to treatment,” adds Olivier Neyrolles.

The Covid has scrambled the cards

In the best case, tuberculosis is treated in six months by speculation. “But the treatment is cumbersome, expensive and not accessible to all populations. For resistant tuberculosis, the treatment can last up to 24 months with perhaps poorly tolerated drugs that must be administered intravenously”, continued the researchers whose teams also worked on screening, especially after two years of Covid-19 which have confused the cards. The WHO estimates that 4.1 million people were not obtained in 2020, 1.2 million more than in 2019.