Vibrio cholerae eltor has been shown to exist in two variants: epidemic (V. cholerae eltor Hly-, tox+) and nonepidemic, or endemic (V. cholerae eltor Hly+, tox-); each of these variants determines the corresponding form of manifestation of the infection among the population and requires a differentiated complex of antiepidemic measures, as well as different tactics for the treatment of patients.