MRSA infections that are transmitted between dogs/cats and their human handlers, and vice-versa, are increasing—with infections of the skin, soft-tissue, and surgical infections the most common. This and other bite-related and septic syndromes caused by cats and dogs are discussed in a Review in the July edition of The Lancet Infectious Diseases, written by Dr Richard Oehler, University of South Florida College of Medicine, Tampa, FL, USA, and colleagues.
In the USA, dog and cat bites comprise roughly 1% of emergency room visits annually, with similar numbers reported in Europe. Women and the elderly are most at risk of being bitten by a cat. Men in general and those aged under 20 of both sexes are most likely to be injured. Most bite exposures occur in young children, involve unrestrained dogs on the owner's property, and about 20% involve a non-neutered dog. Risk is highest in young boys aged 5—9 years, due to their small size and lack of understanding of provocative behaviour. Children, due to their small height, often receive bites to the face, neck, or head. Adults are most frequently bitten on the hand, followed by face, scalp, neck, thigh or leg.
Proper treatment of dog and cat bites should involve treatment of the immediate injury (whether superficial or deep) and then management of the risk of acute infection, including washing with high pressure saline if possible, and antibiotics in selected cases. Severe infections can occure in about 20% of all cases, and are caused by Pasteurella, Streptococcus, Fusobacterium, and Capnocytophaga bacteria from the animal's mouth, plus possibly other pathogens from the human's skin. In countries with endemic rabies, rabies prophylaxis should be considered.
Sepsis can be a severe complication of bite wounds, particularly those infected with C. canimorsus, P. multocida, Staphylococcus spp (including MRSA), and Streptococcus spp. Meningitis, endocarditis, and peritonitis can also complicate bite-wound infections. Several other species, including Bacteroides, Fusobacterium, Neisseria, and Prevotella, might also produce bite-wound sepsis in individuals with leukaemia and lupus, and in those receiving chronic steroids.
As community-acquired strains of MRSA increase in prevalence, a growing body of clinical evidence has documented MRSA colonisation in domestic animals, often implying direct acquisition of S aureus infection from their human owners. MRSA colonisation has been documented in companion animals such as horses, dogs, and cats, and these animals have been viewed as potential reservoirs of infection. MRSA-related skin infections of pets seem to occur in various manifestations, including simple dermatitis, and even perineal cellulitis, and can be easily spread to owners (see photos supplied with this release). Specific therapy for pet-associated MRSA infections is similar to regimens used in most community-acquired MRSA syndromes. The authors say: "Much more remains to be learned about MRSA and pet-associated human infections."
They conclude: "Pet owners are often unaware of the potential for transmission of life-threatening pathogens from their canine and feline companions. Bite injuries are a major cause of injury in the USA and Europe each year, particularly in children. Bites to the hands, forearms, neck, and head have the potential for the highest morbidity... Health-care providers are at the forefront of protecting the vital relationships between people and their pets. Clinicians must continue to promote loving pet ownership, take an adequate pet history, and be aware that associated diseases are preventable via recognition, education, and simple precautions."
Dr Richard Oehler, University of South Florida College of Medicine, Tampa, FL, USA T) 813-972-2000 extension 6184 E) richard.oehler@va.gov
For full Review, see: http://press.thelancet.com/tlidcatsdogs.pdf
You may also use the pictures supplied in the links below in your publications, please credit The Lancet Infectious Diseases:
Man with face injury: http://press.thelancet.com/manfacebit.JPG
MRSA cat—girl transmission: http://press.thelancet.com/mrsacatgirl.JPG
Journal
The Lancet Infectious Diseases