The cause of the disease is a trypanosome, brother of the trypanosome which causes human sleeping sickness and distant relative of Treponema pallidum which causes syphilis.
Man is the only natural host of the microbes, called Treponema pallidum, but some animals, notably rabbits and monkeys, can be infected with them.
In the blood of syphilitics, they found specific antibodies (counter-substances) against Treponema pallidum, the spirochete that causes syphilis.
Valley Views: Major initiative needed to fight tick-borne infections It took medical science some 500 years to gain a good understanding of syphilis. We are but 40 years into Lyme disease, a complex infection by another spirochetal organism, B. burgdorferi, more genetically complex than even the wily Treponema pallidum.
Oct. 27, 2013 - The Journal News