Replication of Mycobacterium leprae in hibernating ground squirrels (Citellus tridecemlineatus).

Subcutaneous injections of 10(6) acid-fast bacteria from human lepromatous tissue to hibernating ground squirrels (Citellus tridecemlineatus) is followed by generalized infection of the animals and spontaneous death. The number of mycobacteria is high in the skin of GS during winter and decreases during summer. Animals surviving the first hibernation period invariably die during the second. The number of microorganism in the visceral organs is low at all times. The system of infected hibernating GS is a valuable model for the experimental study of leprosy.