Treponema pallidum is an organism that causes syphilis. Syphilis is a contagious disease spread through sexual activity. It results in the formation of sores. In pregnant women, the disease may even spread to the fetus. The disease has three stages, primary, secondary and tertiary syphilis. The Treponema-Pallidum-Heamagglutinition test is used to find out the presence of antibodies to Treponema pallidum in the blood.