Pasteurellosis

What is pasteurellosis?

Pasteurellosis in an infection caused by bacteria of the Pasteurella group of micro-organisms. It’s usually contracted from bites or scratches by domestic animals such as cats or dogs. However, it has also been reported following contact with other animals such as rabbits and cows. But often the affected person has had no contact with an animal.

Pasteurella multocida, the commonest of the Pasteurella bacteria to cause problems in humans, is a bacteria found in the mouth and upper respiratory tract of most mammals, including:

• Cats
• Dogs
• Chickens
• Cows
• Pigs
• Rabbits
• Some birds and fish

It's usually carried harmlessly by the animal, but sometimes it can lead to a disease caused pasteurellosis, which is especially prominent in rabbits (where it known as rabbit flu).

Causes and risk factors of pasteurellosis

P. multocida is present in the saliva, respiratory tract and faecal material of animals. The most common form of infection in humans is through a bite or scratch, usually from a cat or dog, from an animal carrying the bacteria.

Once the bacteria have been passed to a person, there is a possibility that they may go on to develop pasteurellosis. However in many cases there is no contact with an animal.

Is pasteurellosis common?

The Health Protection Agency said there are several hundred cases of infection with Pasteurella multocida every year. Deaths are very rare, according to the Office of National Statistics the last recorded death from pasteurellosis was in 2001. In 2009 there were 559 laboratory-confirmed cases. Fortunately deaths are very rare - the last death from pasteurellosis was in 2006.

Symptoms of pasteurellosis

The first signs of pasteurellosis can occur a few hours after infection, and include pain, redness and swelling around the area of the infected wound which results in cellulitis (infection diffusely spread through the tissues), or an abscess (a collection of bacteria and white blood cells) in the soft tissues, bone or joints.

If the infection spreads and gets into the bloodstream (this is called sepsis or septicaemia), it can cause flu-like symptoms such as fever, headaches, chills and swollen glands, and if left untreated can result in abscesses or infection anywhere in the body, particularly pneumonia (especially in those with underlying lung disease), septicaemia or meningitis. On rare occasions it can be fatal.

Treatment and prevention of pasteurellosis

Pasteurellosis is a highly preventable and treatable disease. Standard antibiotics are effective against the bacteria; it causes significant risk only if the infection is untreated. If you have been scratched or bitten by an animal, you are advised to carefully wash the wound, using a disinfectant soap, and to seek medical advice especially if the wound does not quickly settle.

Immuno-suppressed people are at greater risk of serious complications, as with any infection, so should seek medical advice immediately. Vets urge pet owners not to worry – the bacteria is extremely common and usually harmless, but they say bites or scratches should be treated with caution.