03
Oct
Children’s Health Threatened by Antimicrobial Use in Agriculture, Pediatric Doctors Say
(Beyond Pesticides, October 3, 2024) The American Academy of Pediatrics published a technical report in September on antimicrobial resistance, which it calls a global public health threat, identifying the health implications of antibiotic use in animal agriculture. The lead authors, both medical doctors from the Department of Pediatrics at Vanderbilt University Medical Center, note the rise in antimicrobial-resistant infections that result in increased morbidity, mortality, and health care costs for not only adults, but infants and children as well. “[A]ll use of antimicrobial agents exerts selective pressure that increases the risk of development of resistance,” the authors state, highlighting the importance of limiting antimicrobial uses.
“Antimicrobial resistance is an organism’s ability to survive exposure to an antimicrobial agent that was previously an effective treatment. Resistance traits can be acquired either through new mutations or through transfer of genetic material between organisms,” the authors report. Antimicrobial-resistant pathogens, such as bacteria and viruses, can be transmitted “through the food supply, direct contact with animals, environmental pathways, and contact with infected or colonized humans,” they continue. Use of antimicrobial agents, especially over extended periods of time or with repeated exposure, can cause resistance to not only that agent, but to multiple agents.
As previously reported by Beyond Pesticides, the increased use of antimicrobial products alarms scientists, public health professionals, farmers, and various other stakeholders concerned with holistic environmental health. Antimicrobial resistance is a global crisis, as recorded in a 2019 study published in Science, where researchers identified hotspots of resistance in northeastern India, northeastern China, northern Pakistan, Iran, eastern Turkey, the south coast of Brazil, Egypt, the Red River Delta in Vietnam, and the areas surrounding Mexico City and Johannesburg. Additional studies have documented that antimicrobial pesticide exposure causes adverse impacts on gut microbiome health and fungal resistance leading to deadly infections, among other health effects. While antimicrobial use and the resulting resistance it causes are a threat all around the world, the authors of this report focus on statistics and implications within the United States (U.S.).
The “One Health” concept that the authors denote is an approach that embraces the interconnectivity between the health of people and the health of animals in a shared environment. Human health is threatened when the health of organisms and the ecosystem are affected. “Antimicrobial-susceptible and -resistant animal pathogens can reach humans through the food supply, by direct contact with animals, or through environmental contamination, including human wastewater treatment runoff, hospital effluent, and birds and other freely moving wildlife,” the authors state. “Children may also be exposed to pathogens through direct interaction with colonized or infected adults or animals, including companion animals (i.e., family pets).”
Of note is that resistant bacteria can be spread through fecal material, such as improperly composted manure that contains resistant organisms being applied to agricultural soils and contaminating food products. Runoff from farms can also impact water bodies as well. Additional contamination can occur in fruits and vegetables when wastewater is used to irrigate crops and when fish are raised in contaminated water, which puts all consumers at risk.
According to the authors, “Active antimicrobial agents have been detected in surface waters and river sediments, and resistance genes identical to those found in swine waste lagoons have been found in groundwater and soil microbes hundreds of meters downstream. These findings raise concerns that environmental contamination with antimicrobial agents from agricultural and human use could present microbial populations with selective pressure, stimulate horizontal gene transfer, and amplify the number and variety of organisms that are resistant to antimicrobial agents.” (See previous coverage from Beyond Pesticides on horizontal gene transfer here.)
Multidrug resistance has been documented in copious studies. The authors highlight a well-known study where chickens, who were given low-dose tetracycline in their food over an extended period of time, developed multidrug resistance that then spread between chickens in the same environment and to people also living on the farm. Beyond Pesticides has also previously reported on this resistance with an important article in The Lancet pointing to a “looming potential pandemic” resulting from a “rise in multidrug-resistant bacterial infections that are undetected, underdiagnosed, and increasingly untreatable, [which] threatens the health of people in the USA and globally.”
The authors reference an abundance of studies that underscore the role of resistance in bacteria with health implications. In 2011, a study showed meat and poultry samples from five U.S. cities had Staphylococcus aureus contamination in 77% of turkey samples, 42% of pork samples, 41% of chicken samples, and 37% of beef samples. From these samples, 96% were resistant to at least one antimicrobial agent while many were resistant to other antimicrobial classes as well. Resistance from Escherichia coli (E. coli) strains, known to cause human urinary tract infections, sepsis, and other infections, are also linked to antibiotic use in food animals.
The majority of foodborne illnesses in children, the authors report, are caused by Salmonella species. A study from 2013 estimated that Salmonella infection results in 123,452 illnesses, 44,369 physician visits, 4,670 hospitalizations, and 38 deaths annually among children younger than five years in the U.S. Additionally, “[t]he CDC [Centers for Disease Control and Prevention] estimated in 2019 that there were 1.35 million nontyphoidal Salmonella infections in the United States per year, of which 20,800 were resistant to 3 or more classes of antibiotics,” the authors state.
Campylobacter infections are also prevalent. They have been estimated as the cause of 81,796 illnesses, 28,040 physician visits, 1,042 hospitalizations, and six deaths annually in U.S. children younger than five years old. “One outbreak of extremely drug-resistant Campylobacter,” the authors share, “included 168 patients with 117 (70%) reporting contact with a dog before symptoms and 69 (41%) reporting contact with a pet store puppy,” which brings a spotlight on the transmission potential between animals and humans. CDC estimated that in 2019 there were 1.5 million infections involving species of Campylobacter, 448,400 of which had reduced susceptibility to antibiotics in the classes of fluoroquinolones and macrolides that are commonly prescribed.
Pesticides, such as the weed killer glyphosate, can also induce antibiotic resistance. In a previous article, Beyond Pesticides highlights resistance in deadly hospital-acquired bacteria as detailed in a 2022 study in Scientific Reports. This finding is one of many connecting commonly used herbicides to the rise of antibiotic-resistant bacteria, with prior research showing glyphosate, 2,4-D, and dicamba able to create resistance in Salmonella and E. coli.
In additional coverage, Beyond Pesticides reports that antibiotic-resistant genes, considered a class of pollutants, are found in certain types of bacteria and can spread through the environment and subsequently to humans and animals, with an increase in specific bacterial families that host these genes linked to pesticide exposure. (See additional study on E. coli resistance when exposed to pesticides.) These studies add to the history of pesticide usage that correlates with higher antibiotic resistance.
The authors of the technical report also call attention to the statistics from 2020 in which 18,462 infections, 4,788 hospitalizations, and 118 deaths of both children and adults were reported to the Foodborne Diseases Active Surveillance Network, a surveillance system of CDC that covers only 15% of the U.S. population. Among the infections, the number of cases was highest among individuals younger than five years of age, which shows disproportionate risk for very young children.
According to the U.S. Food and Drug Administration (FDA), antimicrobial sales for food animals (defined as animals that are raised and used for food production or consumption by humans), in the U.S. in 2020 accounted for more than 23 million pounds of antimicrobial drug active ingredients. In the same year, FDA implemented a guidance under the Veterinary Feed Directive to control the use of antibiotics. For 2020, only “4% of antibiotics used in agriculture were dispensed over-the-counter without a prescription, and the remainder were dispensed under the direction of a licensed veterinarian or with a prescription,” the authors say. “Additionally, in 2021, the FDA issued GFI #263, and as of June 11, 2023, all sales of antimicrobial agents are now under veterinary oversight, eliminating over-the-counter sales of medically important antimicrobial agents for animal production in the United States.”
The 2023 guidance, requiring a veterinary prescription for all medically important animal antimicrobial agents, states that antimicrobial use in food animals can only include treatment, prevention, and control of infectious diseases. Use of antibiotics, however, is prohibited in all certified organic food production. While the standards of the National Organic Program require that sick animals be treated, any meat and other products from such animals cannot be sold with the Certified Organic designation. While guidance improvements from FDA help to curb over-the-counter use of antibiotics, antimicrobial resistance is still rampant. Adopting organic methods, especially in food production, mitigates high resistance rates from contaminated food and environmental exposure.
Apart from the human health risks, antimicrobial-resistant infections are “often costly to treat, increase health care utilization, and increase morbidity and mortality,” the authors say. CDC findings “report that more than 2.8 million Americans become ill with antimicrobial-resistant infections each year, with more than 35,000 resulting deaths. Antimicrobial-resistant infections are estimated to cost between $21 billion and $34 billion annually, resulting in 8 million additional hospital days.”
Even with these estimations, the true impact of antimicrobial use in animal agriculture in the U.S. is unknown, as are the subsequent health effects that occur as a result of resistance. In contrast to the limited data in the U.S., “the European Union has implemented legislation to increase transparency, such as mandatory monitoring of antimicrobial use on farms,” the authors share. They also note, “Because of legislation in the European Union, antimicrobial sales for food animal production dropped by 43.2% on a biomass-adjusted (mg per population correction unit) basis from 2011 to 2020.”
While the increase in antimicrobial resistance in the U.S. necessitates a need for similar increased transparency, a switch to a system, such as organic, that eliminates antimicrobial uses in food products provides a more holistic alternative with many additional benefits. As the authors conclude, “The majority of antibiotic sales in the United States occurs for use in farm animals, potentially selecting for emergence and spread of drug-resistant pathogens than can harm the health of all individuals, including children.” The solution that protects human health, as well as the health of all organisms and the environment, is organic.
As noted in past coverage, prior research on resistance in agriculture has shown that the only true way to eliminate resistance is to stop using the material that was causing resistance to occur in the first place. Organic agriculture, with its strong restrictions on allowed synthetic materials, provides a path out of the industrialized chemical farming system that overtook agricultural production over the last century. Rising resistance, and the need to retain life-saving medication for protecting people’s health, not growing crops, is another reason why investing in organic is the right choice for the future.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source:
Katz, S.E. and Banerjee, R. (2024) Use of Antibiotics in Animal Agriculture: Implications for Pediatrics: Technical Report, Pediatrics. Available at: https://publications.aap.org/pediatrics/article/doi/10.1542/peds.2024-068467/199441/Use-of-Antibiotics-in-Animal-Agriculture.
