Although there are very few cases of tuberculosis in Belgium, this disease continues to be a significant public health problem that requires continual vigilance.

Not all people infected with Koch’s bacillus necessarily develop tuberculosis. Overall, 10% of infected people are at risk of developing the disease. 
However, risk factors increase the likelihood that latent tuberculosis will become active. Indeed, the development of active tuberculosis depends on the status of the infected person’s immune system, in other words, on the body’s ability to fight infection.

The people most at risk of developing tuberculosis are therefore those with weakened immune systems:

• people living with HIV 
• children under five years of age
• the elderly 
• people suffering from chronic diseases (diabetes, cancer, kidney disease, etc.) ;
• people undergoing burdensome medical treatment (chemotherapy etc.)
• people suffering from malnutrition 
• people with heavy alcohol, drug or tobacco use.