I am interested in information regarding Pasteurella multocida infection resulting from a dog bite. I would like to know what the symptoms are, how is it treated, if there is a cure and what the prognosis is.

Linda

Pasteurella is a group of bacteria found mostly in animals. Pasteurella multocida is the species most common in cats, but it is also found in dogs and other animals. Humans can be infected with P. multocida after being exposed to these animals, usually through a bite. Occasionally, infection occurs without any known exposure. A recent medical study in The New England Journal of Medicine showed that 75 percent of all cat-bite infections and 50 percent of all dog-bite infections involved Pasteurella species.

Most infections due to P. multocida involve the skin. After a cat or dog bite, the area becomes red and inflamed. This occurs rapidly, sometimes in less than 24 hours. There is usually significant swelling and pain. If the bite is deep, the bone or joint can be involved. This is especially common after a cat bite; because cat teeth are thin and sharp, the wound can be very deep even with minimal surface injury.

There are other syndromes caused by P. multocida. This organism occasionally causes pneumonia and other respiratory infections, usually in people with underlying lung disease. I was involved in a case in which a patient developed an infection of the epiglottis (a flaplike structure in the throat) after a cat licked him on the mouth. Rarely, P. multocida can cause kidney infections and meningitis (infection of the membranes surrounding the brain and spinal cord).

The prognosis of typical skin and soft-tissue infections due to this bacterium is good, assuming the person is promptly treated with antibiotics. Without such treatment, the infection can spread, eventually entering the bloodstream, leading to sepsis and even death. Bone and joint infections, as well as serious skin infections, are treated with intravenous (IV) antibiotics, while more minor infections can be treated with antibiotic pills. Once a patient recovers, he or she should have no further problems with this infection.

For P. multocida infections, as well as most infections with any bacterium, if patients recover, they are usually fully cured. There are occasionally deaths with the serious infections, and bone infections can become chronic. Otherwise, the vast majority of patients have a good outcome.