The transmission of MRSA is not just a concern for humans

Hand hygiene products and personal protective equipment, longtime hospital staples, are playing a greater role in production-animal veterinary practices. Given the growing awareness of zoonotic transmission of methicillin-resistant Staphylococcus aureus (MRSA), that is the transmission of MRSA from animals to humans or from humans to animals, more large-animal practitioners are taking steps to protect themselves.
At one time, MRSA was considered a human disease only. But, for the last 35+ years, infection has been reported in cows, horses, cattle and pigs, as well as dogs, cats and pet birds. Although the prevalence of MRSA in animals is not currently known, the Schaumburg, Ill.-based American Veterinary Medical Association (AVMA) acknowledges that, as with people, animals with weakened immune systems are at greater risk for infection. As such, veterinarians are encouraged to take precautions.

What’s the risk?
Animals carry MRSA similarly to humans, on the skin or in nasal passages, according to AVMA. If an infection is present, it can be anywhere on the animal or human, particularly in skin wounds or sores. Animals and humans who carry the bacteria on their body but do not exhibit symptoms of the disease are said to be colonized, while those who exhibit symptoms are said to be infected. Those with weakened immune systems are at greater risk for colonization and infection.

MRSA is spread through direct physical contact between animals and animals, animals and humans, or humans and humans. The bacteria can also be spread when the animal or human comes into contact with infected materials, such as bandages, clothing, towels and bedding, or medical or sports equipment. At one time, it was believed that MRSA could only spread from humans to animals (reverse zoonotic) via contact between the human’s hands and the animal’s nostrils, notes AVMA. Today, experts understand MRSA can be spread from animals to humans (zoonotic transmission) as well, however there is no evidence that people who work with large animals are at higher risk than those who work with companion animals. “While it has been shown that large-animal practitioners are at a higher risk of being colonized by MRSA, there is no indication [that they face] a higher risk of MRSA infection,” says Christine Hoang, DVM, MPH, CPH, assistant director, Scientific Activities Division, American Veterinary Medical Association. “In terms of transmission, there is no system for monitoring how often transmission of MRSA occurs in the human population or how often zoonotic transmission occurs in large or small animal practices.”

The risk of acquiring MRSA varies from companion animals to large animals, according to AVMA. For large animals, the risk factors include:

• Nasal or facial contact with human handlers.
• Transportation of animals. The more the animals are in contact with other animals, the greater the risk of transmission.

Although there is no proven method for decolonizing animals that are colonized with MRSA, experts at AVMA stress the importance of isolating colonized animals from humans to help prevent reinfection of the human. Animals with skin infections may benefit from treatment with antibiotics, antibiotic cream or both.

Safe practices
As awareness of animal-related transmission of MRSA has grown, so too has veterinarian interest in practicing safe hygiene and other precautionary steps. “Veterinarians should be aware of concerns regarding MRSA and should develop an understanding of appropriate disease surveillance, diagnostic testing and infection control in order to lessen the impact of MRSA on both animals and their caretakers,” according to the Methicillin-resistant Staphylococcus aureus Backgrounder (June 2009), published by AVMA with the cooperation of the American College of Veterinary Internal Medicine (ACVIM).
“Veterinarians not only need to practice proper hygiene and prevention of transmission of zoonotic disease in their work environments, they also have a duty to educate the owners/handlers of MRSA-colonized or infected animals on the risks and proper hygiene prevention when dealing with these animals,” the Backgrounder continues. This includes attention to proper hand hygiene and use of hand sanitizers; eye protection in the presence of aerosols or splashing; the use of gloves, disposable aprons and masks when changing dressings on infected wounds; and maintaining a “high standard of cleanliness” throughout the clinic or work environment.
As consultants, distributor reps can help their veterinarian customers in the following ways:

• Communicate the importance of adhering to safe practices, such as those mentioned above.
• Encourage veterinarians to inform their clients about the roles of both animals and humans in MRSA transmission.
• Provide literature and direct veterinarians to helpful sources to facilitate continued awareness of MRSA and zoonotic transmission of infection.

Groups such as AVMA “work diligently to educate our member veterinarians, as well as the public, on zoonotic diseases, including MRSA, through our many communication channels,” says Hoang. These include the association’s online backgrounders and FAQs, blogs and podcasts, and JAVMA (the Journal of AVMA). “We would hope that our diligence has helped veterinarians take the necessary precautions to protect themselves and their patients against any infectious disease,” she adds.

Sidebar:
The role reps play

Proper hand hygiene, protective equipment and standard precautions
help reduce the risk of zoonotic transmission of MRSA.
It’s the responsibility of every veterinarian to take steps to protect himself or herself and his/her staff and patients from the spread of infectious disease, such as methicillin-resistant Staphylococcus aureus (MRSA). For distributor reps, it’s an opportunity to help them do so.

In 2008, the National Association of State Public Health Veterinarians (NASPHV) and the Veterinary Infection Control Committee (VICC) collaborated on the Model Infection Control Plan for Veterinary Practices (http://www.nasphv.org/documentsCompendia.html). The plan recommends the following protective actions and equipment, which veterinarians should comply with to reduce zoonotic transmission of MRSA:

• Hand hygiene. Keep handwashing supplies well-stocked. Veterinarians should wash hands before and after each patient encounter and following contact with blood, body fluids, secretions, excretions, exudates or articles contaminated by these substances. Hands should also be washed after cleaning animal-care areas or cages and prior to eating or drinking. Alcohol-based rubs may be used when hands are not visibly soiled, but soap (antimicrobial) and water is preferred.
• Use of gloves and sleeves. Gloves and sleeves should be worn when touching feces, blood, body fluids, secretions, excretions, exudates and non-intact skin, as well as for dentistry, resuscitations, necropsies and obstetrical procedures. Gloves should also be worn for cleaning animal-care areas/cages, handling diagnostic specimens and when handling an animal with a suspected infectious disease. Gloves should be changed between examination of animals and between dirty and clean procedures performed on the same patient. Hands should be washed immediately following removal of gloves.
• Use of facial protection. Surgical masks with goggles or a face shield should be worn when exposure to splashes or sprays is likely to occur (e.g., when lancing abscesses, flushing wounds, during dentistry, suctioning, obstetrical procedures, necropsies, etc.).
• Use of protective outerwear. Lab coats, non-sterile gowns or coveralls should be worn when attending animals and conducting cleaning chores. Outerwear should be changed whenever soiled. Disposable shoe covers should be worn in the presence of heavy amounts of infectious materials.
• Bite prevention. When working with aggressive animals, veterinarians should use physical restraints, muzzles, bite-resistant gloves and sedation or anesthesia, depending on practice policies.
• Needlestick prevention. Veterinarians should not recap needles unless required as part of a medical procedure or protocol. All sharps should be disposed of in sharps containers.
• Surface and instrument disinfection. Veterinarians should follow manufacturer directions for disinfection of equipment. Surfaces should be cleaned using a disinfectant, according to manufacturer directions.

Pregnant and immuno-compromised veterinarians and staff are at increased risk from zoonotic diseases, and all veterinarians/staff are encouraged to receive an influenza vaccine, according to NASPHV. By ensuring their staff is educated and trained in safe practices to avoid zoonotic transmission of MRSA, veterinarians can do their part to reduce the spread of disease.