Illustration of the kidneys (top right and top left) and bladder (bottom) from a case of tuberculosis of the urinary tract. Tuberculosis (TB) is a bacterial infection that usually affects the lungs but can affect other body tissues. Here, the kidneys are engorged and the cortex (outer potion) contains many abscesses filled with yellow-brown pus. The bladder is small, thick and the mucous membrane (inner lining) is covered with small nodules, called tubercles. Commonly called consumption in the 1800s, TB was a widespread cause of death during this period before the invention of vaccines (1921) and antibiotics (1943). Artwork by Leonard Portal Mark in 1889.