UConn Professor Calls for Limiting Antibiotic Use in Farm Animals

A UConn professor discusses efforts by a national pharmacists group to curtail the use of antibiotics in healthy farm animals in light of growing antibiotic resistance.

A young pig about to receive an injection. (iStock Photo)

A young pig about to receive an injection. (iStock Photo)

In a major position statement released this month in the journal Pharmacotherapy, the Society of Infectious Disease Pharmacists is calling for significant changes in the way in which antibiotics are given to agricultural animals and how antibiotics and antifungals are used on plants. The panel that crafted the statement was led by Michael Nailor, an associate clinical professor in the UConn School of Pharmacy and at Hartford Hospital Department of Pharmacy. Nailor recently elaborated on this important issue for UConn Today.

Why are antibiotics being given to agricultural animals?

In 1950, a large study found that adding antibiotics to livestock feed accelerated animal growth rates. The practice swept through the industry, and now about 80 percent of all antibiotics consumed in the United States are consumed by agricultural animals. These antibiotics are sold without a prescription, and in almost all cases without the involvement of a veterinarian.

Does this result in increased meat and milk production in the United States?

In the 1950s it did, but there is no compelling data that it still has the same effects, given contemporary agricultural methods for breeding, feeding, and general care. That is something that needs to be further explored so we can determine the benefits versus the known risks of continuing this practice.

A poster from the Centers for Disease Control showing various methods of transfer of resistant organisms from food-producing animals to humans. (Used with permission from www.cdc.gov)
A poster from the Centers for Disease Control showing various methods of transfer of resistant organisms from food-producing animals to humans. (Used with permission from www.cdc.gov)

It sounds like the benefits are uncertain. What are the risks?

The FDA, USDA, and CDC all testified before Congress that the routine use of antibiotics in healthy agricultural animals was a major cause of antibiotic resistance in humans. Approximately 2 million illnesses and 23,000 human deaths annually are directly attributable to antibiotic resistance, and no matter how much effort is spent to decrease antibiotic overuse by primary care physicians and in hospitals, we cannot curtail this rising epidemic without controlling antibiotic use in agricultural animals. Remember that agricultural animals can infect people through bacteria on under-cooked meats and by infecting farm workers, butchers, grocers, or consumers, who then transmit the disease to others. Disease can also be transmitted through insects that act as carriers. It is also a risky proposition for the animals themselves. If antibiotics are being routinely given to animals, their infections are more likely to be lethal because the bacteria are likely resistant to standard treatment.

What does the position statement recommend?

The national panel is made up of pharmacists involved in antimicrobial stewardship programs who help physicians select antibiotic choices that lower the risk of antibiotic resistance. We recommend sensible steps that can bend the curve of antibiotic resistance. First, we would like to see whether the effects seen with antibiotic use and animal growth in 1950 are still occurring today. With changes in breeding, feeding, and other techniques, antibiotics may not be producing any benefits but still causing harm. Second, we would like to limit the use of any antibiotic classes that are currently used in humans to agricultural animals that are actually sick, as verified by a veterinarian. Third, we would support funding of alternative methods to enhance animal growth without the use of antibiotics or other means that are known to risk human health. Finally, we want research to be conducted assessing the use of antibiotics and antifungal drugs on plants. There is increasing use of antifungal drugs that are used in humans to treat grass, bushes, and plants, increasing the risk that resistance will develop. We don’t know about the extent of that problem, but it is better to get out ahead of it than to wait for it to become a crisis, like we have with antibacterial resistance. Ultimately, the panel wants our elected officials to recognize the extent of this problem and help devise prudent solutions that protect human and animal health.

As an associate clinical professor of pharmacy practice, you have a special type of faculty position, tell me more about it.

A majority of the faculty in UConn’s Department of Pharmacy Practice are embedded in hospitals, health systems, and clinics throughout Connecticut. We provide direct patient care, and teach students in a real world, hands-on environment how to provide competent, compassionate care.

I have a co-funded position between the Department of Pharmacy Practice and Hartford Hospital’s Department of Pharmacy, where I have two primary jobs. The first is to direct antimicrobial stewardship practices throughout Hartford Healthcare. This entails devising strategies that are used by our network of providers to use antimicrobials in the most efficient manner. The second major aspect of my position involves performing antimicrobial stewardship at the local level, by helping our providers evaluate patients possibly infected at the hospital and optimizing antibiotics for individual patients. Often these individual patients are infected with the most resistant isolates we encounter at the hospital. That is why this topic is personally very important to me. Seeing patients with no viable antibiotics to treat a serious infection, or someone who has to take an antibiotic with serious adverse effects because it is the only one available, is heart-breaking, and I work every day to ensure that the antibiotics we have today last as long as possible and can benefit those who need it the most.

In this way, I support UConn’s Land Grant charge to give back to the people of Connecticut and our Carnegie Engaged University designation. My scholarship is centered around tracking outcomes (health of patients, costs of care, and development of resistance) of our antimicrobial stewardship efforts within the hospital and health system. These activities support not only UConn’s charge to further scientific inquiry and disseminate it beyond Connecticut, but they also directly facilitate my work at the bedside, informing us of what works and what doesn’t work. In addition, I am a director of a postgraduate training program for pharmacists to develop their antimicrobial stewardship clinical and research skills. All of these programs come together with a terrific group of collaborators both at the hospital and at UConn, including Dr. Jack Ross, chief of infectious diseases at Hartford Hospital; David Nicolau and Joseph Kuti from the Center for Anti-Infective Research and Development at Hartford Hospital, which focuses on optimizing antimicrobial use; and Professors Amy Anderson and Dennis Wright in UConn’s Department of Pharmaceutical Sciences, who are working on developing a new class of antibiotics, so we can try and stay one step ahead of bacteria.

More information about what the federal government and different national agencies are doing to monitor the use of antibiotics in food-producing animals can be found on these sites:

Federation of Animal Science Societies (FASS) Policy Statement on Preserving the Benefits of Antibiotics for People and Animals

FDA Biannual Progress Report on Judicious Use of Antimicrobials in Food-producing Animals

USDA Antimicrobial Resistance Action Plan

White House National Action Plan for Combating Antibiotic-Resistant Bacteria