Methicillin-resistant Staphylococcus aureus in horses and horse personnel, 2000-2002.

The research article discusses a study of Methicillin-resistant Staphylococcus aureus (MRSA) infections and colonization in horses and personnel at a veterinary hospital and a thoroughbred farm in Ontario from 2000 to 2002, emphasizing the potential for equine MRSA infection as an emerging zoonotic and veterinary disease.

Study Design and Participants

• The study arose from the identification of MRSA infection in two horses treated at a veterinary hospital in 2000.
• Between October 2000 and November 2002, the researchers identified 79 horses and 27 people colonized or infected with MRSA.
• The test subjects involved were largely from the veterinary hospital and one particular thoroughbred farm in Ontario.

Findings and Implications

• A significant proportion of the isolates came from these two locations. 34% of equine isolates were from the veterinary hospital while 51% came from the thoroughbred farm. Among humans, 63% of isolates were recorded at the hospital and 30% at the farm.
• However, most of the isolations occurred in a three-month period in 2002, indicating a sudden flare-up of infections.
• The study found evidence of clinical infection in 16% of the horses and 4% of the humans in the studied pool.
• Almost all isolates in both horses and humans were found to be subtypes of Canadian epidemic MRSA-5, spa type 7 and possessed SCCmecIV. This indicates a common source or carrier of the virus.
• Moreover, none of the tested isolates from clinical infections contained the Panton-Valentine leukocidin genes, which are often associated with virulent strains of MRSA.
• The authors suggest that equine MRSA infection might be an important emerging zoonotic and veterinary disease, signaling the need for improved surveillance and control measures in equine environments.