Yersinia spp.

Gram-negative, cold-tolerant, facultative anaerobe, that is rod-shaped.

Incubation Period

May be as short as 24 hours, or as long as 7 days.

Symptoms

Appendicitis-like symptoms, characterized by diarrhea, vomiting, fever, and abdominal pain. Some strains may exhibit a skin rash.

Illness Duration

Usually self-limiting, 1-3 weeks.

Complications

Most are uncomplicated and resolve completely. Occasionally joint pain, most often in the knees, ankles or wrists. Joint pains occur 1 month after initial episode of diarrhea and generally resolve after 1 to 6 months. A skin rash, called "erythema nodosum," may appear on the legs and torso and is more common in women, usualy resolving within a month. Major "complication" is the performance of unnecessary appendectomies. Associated with reactive arthritis, which may occur in the absence of obvious symptoms.

Infective Dose

106 organisms.

Treatments

Supportive care. If septicemia or other invasive disease occurs antibiotics are administered.

Testing

Stool, vomitus, blood culture, requires special media to grow.

Communicability

Can be passed among persons while diarrheal symptoms are present. Untreated persons may excrete organism for 2 to 3 months; a chronic carrier state does exist.

Nationally Notifiable

Is monitored routinely by many states, but is not a nationally notifiable disease.