Yersinia pestis [Alexandre E.J. Yersin; L, pestis, plague] , a species of small gram-negative bacteria that causes plague. The primary host is the rat, but other small rodents also harbor the organism. A person without symptoms may be a carrier, but this happens rarely. Yersinia pestis is hardy, living for long periods in infected carcasses, the soil of the host’s habitat, or sputum. Also called Pasteurella pestis. See also plague, bubonic plague, pneumonic plague, septicemic plague. ▪ OBSERVATIONS: Symptoms of infection are dependent on the method of exposure; however, fever and weakness are common. ▪ INTERVENTIONS: Antibiotics should be administered as soon as the infection is recognized. Circulatory and other supportive care based on symptoms is necessary. ▪ PATIENT CARE CONSIDERATIONS: When treatment is not provided, serious illness and death can occur. Infection can occur anywhere, but is more common in Africa and Asia.
