Antimicrobial Stewardship
Among the numerous concerns regularly addressed by Cummings School of Veterinary Medicine at Tufts University, antimicrobial stewardship has become a significant topic of interest.
Clinical Assistant Professor Ian DeStefano and Assistant Professor Claire Fellman of the Department of Clinical Sciences lead the Henry and Lois Foster Hospital for Small Animals’ Infection Control and Antimicrobial Stewardship Team (ICAST).
The mission of the Infection Control and Antimicrobial Stewardship Team
“ICAST’s mission is to critically review our infection control efforts at the hospital and to provide a sounding board for antimicrobial stewardship efforts and how that affects clinical practice and patient outcomes,” DeStefano shares.
As active stakeholders, the group aims to reduce antimicrobial resistance and develop strategies to counteract the emergence of bacteria that are resistant to commonly used antibiotic drugs. According to DeStefano, antimicrobial resistance has increased in human medicine over several decades and has become more prevalent in veterinary medicine as well.
“So, how do we preserve the effectiveness of the drugs that we use to treat common infections?” DeStefano asks. “And is there a way to mitigate the drug-resistant bacteria through the prescriptions that are regularly provided?”
Overzealous prescribing can lead to higher rates of antimicrobial resistance, so, to counteract that the monitoring of drug prescriptions for drug-resistant infections has led to a link between focusing stewardship efforts on prescribing antibiotic drugs when they are appropriate and choosing the right drug for the right indication.
“We now know there is a risk of the emergence of resistant bacterial infections, depending on how long people or animals are treated with antimicrobials,” DeStefano explains. “And the use of antimicrobials should be appropriately stopped when they’re either not indicated or not needed anymore.”
How Stewardship Started
Antimicrobial stewardship in veterinary medicine initially focused on the use of antibiotics in food animal species, according to DeStefano. “On a widespread scale, antibiotics were given to beef cattle, for example, without any obvious signs of infection because they could enhance calf growth,” he explains.
“But we know exposing those animals to antibiotics affects the bacteria in their bodies and on their skin, and also affects the food supply and the emergence of resistant bacteria there. This sort of use is no longer allowed. That’s where stewardship in veterinary medicine began, but we know that resistant bacteria also affect species like cats and dogs.”
Much of Fellman’s research involves the effect of antimicrobial use in cats and dogs and how that might affect the emergence of drug-resistant bacteria and the possible transfer of those microbes between humans and their pets.
Fellman explains, “There are a lot of studies about the potential for shared bacteria within households. For example, dogs can be a reservoir for resistant E. coli from which owners can get a urinary tract infection (UTI). Ultimately, when an antibiotic is used, we need to be more mindful to preserve them for future generations.”
Analyzing infections
Much of ICAST’s recent work focuses on analyzing the types of infections seen in patients. Testing for infection is performed by taking a sample for a culture—often blood, urine, or fluid from a body cavity—and submitting it to a lab where they try to grow bacteria. “They identify the type of bacteria and test their susceptibility to a host of different drugs for us to use clinically. We submit at least 100 cultures per month in Foster Hospital, then use that data to see what types of bacteria they are growing in patients who, for instance, might have pneumonia, and then identify the drugs to which they are susceptible.”
The way that an animal responds to medicine can change over time. “There’s evidence in some cats and dogs that after a certain course of antimicrobials they can host specific bacteria that are drug-resistant,” DeStefano explains. “Later in life, they might develop a new infection and that might be harder to treat if it happens to be caused by one of those bugs.”
DeStefano added that the small animal veterinary field often focuses on making an individual pet better, so it is a paradigm shift to remember to be mindful about prudent antibiotic use and thinking about the whole population.
Administer medications as directed
Pet owners are warned to not take matters into their own hands. Fellman cautions that medications should be administered as directed by your veterinarian. “There’s always been a recommendation to complete a full course of antibiotics, but now we’re starting to learn that for people maybe you should stop taking antibiotics when your sinus infection symptoms are better. In dogs there is a study testing the administration of antibiotics one day past resolution of clinical signs for a UTI,” she says.
“Shorter courses of antibiotics are increasingly recognized to be as effective as longer courses. This has been well-documented in humans, and there are increasing numbers of studies for veterinary species as well,” Fellman added.
While admitting that some infections are probably overtreated, Fellman reiterated that the best advice is to follow the direction of your veterinarian.
With the maintenance and continuous monitoring of the culture data, as well as ongoing research at Cummings School and beyond, the information of best practices and recommendations for doctors, technicians, pet owners, and students are updated regularly.
“There is an evolving landscape in terms of prescribing,” DeStefano insists. “The way I learned about treating infections and prescribing antibiotics a decade ago is very different than now.” We’re gaining more evidence that some traditional practices should be questioned about whether they still represent best medicine.
Through ICAST, research projects are developed on-site or in partnership with other hospitals, and infection control policies are consistently monitored and adjusted as needed to reflect the latest information.
“We have a guideline for antibiotic prescribing in the hospital that’s one of our education tools,” Fellman explains. “The information is available digitally or in print so if, for example, a dog has a UTI or pneumonia, this is our hospital’s recommendation for therapy.”
As another example, the hospital recently launched a remedy to provide to owners whose dog is experiencing acute diarrhea. “We used to give an antibiotic, but we realized it didn’t consistently decrease the length of diarrhea, so we’re giving these kits prepared with food and a probiotic, which are effective without the use of an antibiotic,” says Fellman.
According to Fellman, ICAST is also working to define what constitutes a hospital-associated infection to increase recognition within the hospital, as well as standardizing when gloves are required for hospitalized cases, and improving the infection control practices.
“There are many things we’d like to do, but we stay focused on our mission and target our efforts to the most critical interventions to reduce resistant infections in our patients,” Fellman concludes.