Some members of Yersinia are pathogenic in humans. One in particular, Y. pestis, is the causative agent of the plague called Yersiniosis. Rodents are the natural reservoirs of Yersinia; less frequently other mammals serve as the host. Infection may occur through blood (in the case of Y. pestis it is spread by flea bites). The symptoms of plague depend on the concentrated areas of infection in each person. Examples are: bubonic plague in lymph nodes, septicemic plague in blood vessels, pneumonic plague in lungs, and so on.

Yersinia may also be spread via consumption of food products (especially vegetables, milk-derived products and meat) contaminated with infected urine or feces. Because Yersinia are known to be intracellular parasites, it is also believed that they can be acquired if a person is contaminated with certain kinds of parasites -the bacteria live within the parasite.

Yersinia is implicated as one of the causes of reactive arthritis worldwide, and suspected to be the cause of some Crohn's disease and pseudoappendicitis, which are symptoms of appendicitis but not actually an apendix condition.

While Yersinia bacteria can survive extreme cold and may not be affected by freezing, they are inactivated by oxidizing agents such as exposure to hydrogen peroxide.

This Quantum Formula antidotes the various species in the Yersinia genus and its subspecies.