During the ninetheenth century most people in Belgium died from infectious disearses, such as tuberculosis and cholera. 

Between 1870 and 1930,  there was a rapid decline in deaths due to infectious diseases and a rise in deaths due to cancer and cardiovascular disease. This shift in the cause of death pattern is called the epidemiological transition.

Scientists know that this shift happens, but they still don’t fully understand how or why it happens. Studying how specific diseases evolve and spread over time can help researchers learn more about the patterns behind the epidemiological transition.