Accidental laboratory infection with Treponema pallidum, Nichols strain.

This case report describes a laboratory-acquired infection with Treponema pallidum, Nichols strain. The specific details of the accidental exposure are presented, along with a description of the clinical observations. This infection indicates that the rabbit adapted Nichols strain of T pallidum retains its capability to infect humans. In addition, aerosols of concentrated preparations of these organisms, generated within the laboratory, represent a definite biohazard.