Human leprosy in normal mice.

It has now been shown that normal mice can be used as models for studying the early stages in the development of leprosy. Inoculation into the foot pads of mice of as few as 10(4) leprosy bacilli leads to infections which spread to distant sites via the blood stream and after two or more years give rise to granulomata and neural damage at the sites of inoculation. Where the tissue response had fully developed it reproduced exactly the histological features of human leprosy in the borderline range.