Animal bites and pasteurella infections information for healthcare staff.
Pasteurellosis is a zoonotic disease. It is caused by infection with bacteria of the Pasteurella genus. Pasteurella multocida is the most commonly reported organism in this group, and is well known as both a common commensal (part of the normal bacterial flora) and pathogen in a variety of animal species. P. multocida is found worldwide. Soft tissue infection following dog or cat bites or scratches is the most common form of pasteurellosis in humans.
Disease in animals
Pasteurella multocida is normally found in the upper respiratory tract of healthy livestock and domestic animal species, including chickens, turkeys, cattle, swine, cats, dogs and rodents. P. multocida can also cause disease in wild and domesticated animals, including ‘avian cholera’ in birds and poultry, respiratory disease and septicaemia in cattle, mice and rabbits, and atrophic rhinitis in pigs.
Disease in humans
Human infections are usually contracted following exposure to domestic pets such as cats and dogs. The most common manifestation of pasteurellosis in humans is a local wound infection, usually following an animal bite or scratch. This can develop into a serious soft tissue infection, and can also be complicated by abscesses, septic arthritis and osteomyelitis. Pasteurella spp can also cause meningitis, ocular infections, and respiratory infections, usually in patients with underlying pulmonary disease.
Pasteurella spp. are transmitted by animal bites, scratches or licks. Animals do not have to be ill to pass the bacterium to humans, as they can carry the organism without showing symptoms.
Diagnosis and management
All bites should be thoroughly cleaned and debrided as required. Broad spectrum antimicrobials usually chosen empirically for bite wounds, such as co-amoxiclav, are likely to be effective against Pasteurella in the setting of simple wound infections. Treatment of confirmed Pasteurella spp infections can be guided by local susceptibility testing of the isolate.
Pasteurellosis is relatively uncommon. There are around 600 laboratory confirmed cases reported in humans each year in England and Wales, of which about 70% are due to P. multocida. Most of these cases occur in people over 50 years of age. In 2013 there were 714 laboratory confirmed cases reported in the UK.