Based on photomicrographic data, this illustration depicts the ultrastructural morphology exhibited by a single Gram-positive Clostridium difficile bacillus. (Centers for Disease Ccontrol and Prevention)

Jordan Cooper is a health-care policy expert. Ellen Silbergeld, a MacArthur Foundation fellow, is the author of “Chickenizing Farms and Food” and a special consultant to the World Health Organization Food Safety Program.

Maryland's Keep Antibiotics Effective Act of 2017 is one step in the right direction — but only one step, thanks to a loophole in the legislation large enough for a battleship to pass through.

The bill, which went into effect last month, attempts to limit the prophylactic use of antibiotics in livestock and poultry to arrest the spread of antibiotic-resistant strains of bacteria so as to prolong the efficacy of our antibiotic drugs. The legislation is to be commended for prohibiting the use of antibiotics in livestock and poultry to promote weight gain or to improve feed efficiency. Unfortunately, the bill does not require confirmation of disease in a herd or flock before animals can be treated with antibiotics.

The World Health Organization opposes this sort of loophole because, given the crowded conditions characteristic of factory farms, it would not be difficult for a veterinarian to conclude that every animal stands a reasonable risk of contracting a disease. This situation is analogous to how a pediatrician might conclude that every child who attends day care should take antibiotics on a daily basis throughout childhood simply because they have an increased risk of contracting strep throat.

The most compelling argument for closing this legislative loophole is that without these changes we will continue to erode the efficacy of our limited armory of antibiotics for use in medicine. It is important to administer the proper class and dose of antibiotics to animals, limiting their use to appropriate situations to prolong the effectiveness of antibiotics for use by humans and animals. While all uses of antibiotics contribute to the diminishment of their effectiveness, the volume of antibiotic use in food-animal production is greatly accelerating, increasing antibiotic resistance in bacteria that cause human disease.

Humans who consume meat from animals that received prophylactic antibiotics are exposed to strains of bacteria that have evolved to survive the effects of the antibiotics. In effect, our demand for cheap and abundant meat has led to our careless use of prophylactic antibiotics in animals. That has reduced the efficacy of antibiotics for human use. The results are shocking.

Widespread antibiotic resistance has become a crisis on a global scale in urgent need of redress. The Centers for Disease Control and Prevention indicates that Marylanders endure a rate of health-care-associated infections that is higher than the national baseline. We incur large costs associated with antibiotic-resistant strains of bacteria that infect hospitalized patients. This results in extended hospital stays, increased medical complications, increased costs and increased loss of life. Some of the most well-known culprits, sometimes referred to as "super bugs," are methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile (C. diff). These bacteria have developed resistance to many different antibiotics.

This crisis is exacerbated by the lack of new antibiotic molecules. Developing and testing new antibiotics is a time-consuming process. While we wait for these new discoveries, we must protect the antibiotics that we have by prohibiting the administration of sub-effective and inappropriate prophylactic doses of antibiotics in industrial food-animal production.

We support the actions of the Maryland legislature in developing the Keep Antibiotics Effective Act of 2017. There is much that is good in this legislation but, in failing to prevent the abuse of prophylactic antibiotic uses in livestock, fish and poultry, we will fall short of accomplishing its intent of protecting the health of Marylanders.