When you get really sick, you want your medicine to work.

That is why, beginning in 2000, Health Canada made major efforts to educate people on the use of antibiotics. If antibiotics are used too often, bacteria living in the body can begin to build up resistance, making it more difficult to treat serious bacterial infections such as tuberculosis.

But other animals besides humans are given antibiotics too. For example, chickens are given antibiotics if they come down with bronchitis or other respiratory diseases. And Health Canada has expressed concerns that if antibiotics are given too freely to animals, it raises the risk of antibiotic-resistant diseases developing in people.

David Patrick is director of epidemiology at the B.C. Centre for Disease Control and an associate professor at UBC. As part of his duties, he investigates the misuse of antibiotics in B.C.

Patrick told the Georgia Straight that there are increased risks to human health associated with the administration of antibiotics to animals. Just like humans, animals can develop resistance to antibiotics, which can then be passed on to bacteria.

Anyone can get infected with salmonella if they consume a chicken that was improperly prepared, Patrick said. If antibiotics were given to that chicken, there will be an increased risk of that salmonella causing an infection that will not respond to certain antibiotics.

“It’s possible that some of that [resistance] is caused by human consumption of the drugs,” Patrick said. “But you can’t ignore the fact that these [resistant] bugs can come across from chickens.”

Another concern that Patrick highlighted is the possibility of harmless bacteria with antibiotic resistance passing their genes on to more harmful bacteria already present in a human consumer. The development of multiple-antibiotic resistance would be the result.

Patrick’s concerns are supported by an October 2007 report in the journal Applied and Environmental Microbiology, which was explained to the Straight by one of its authors, Moussa Diarra, who works for Agriculture and Agri-Food Canada at the Pacific Agri-Food Research Centre in Agassiz.

His report found that multi-antibiotic-resistant Escherichia coli was present in chickens regardless of the antibiotic used with a flock but that the resistance could be modified by what antibiotics were given to chickens through their feed.

Echoing Patrick, Diarra said that for humans, this meant that if a person was infected by E. coli, for example, from a chicken with resistance to several antibiotics, those antibiotics could not be used to treat the disease.

Diarra cautioned against jumping to conclusions based on his report. “Even though we found antibiotic resistance in chickens, we don’t know where they came from,” he said. What must now be investigated further is what circumstances can affect antibiotic resistance levels.

The administration of antibiotics to animals in Canada is monitored by the Canadian Integrated Program for Antimicrobial Resistance Surveillance, a division of the Public Health Agency of Canada.

CIPARS publishes annual reports on trends in antimicrobial use and resistance levels in humans and in species at different points along the food chain.

According to CIPARS’s 2005 report (the most recent completed report available), 77 percent of chickens tested in Canada showed signs of E. coli resistance to one or more antibiotic and 40 percent showed signs of resistant salmonella.

“In the last few years, E. coli from human urinary tract infections”¦has become increasingly resistant to drugs like ciprofloxacin,” Patrick said. He noted that Cipro is a drug that is routinely used to treat infections in humans. But it is also related to drugs that are commonly used in the raising of poultry. That increases the risk of the development of multidrug resistance, Patrick said.

Lateef Adewoye, a leader for the policy and programs team of Health Canada’s Veterinary Drugs Directorate, told the Straight that antimicrobial resistance has been a “major public health issue” for a long time.

But he stressed that causal relationships between an antibiotic’s use in animals and increased resistance levels in humans are difficult to prove.

The B.C. Chicken Marketing Board’s general manager, Bill Vanderspek, explained how and when antibiotics are administered to poultry in the province. When a chicken is found to have a disease, a veterinarian must write a prescription for the bird’s flock, he said. The medicine is then administered through the animals’ feed or water system.

Under the Canadian On-Farm Food Safety Program, a medication’s use is recorded on a flock information reporting form, Vanderspek continued, which is then forwarded to the diseased flock’s scheduled processing plant.

When the Straight called Vanderspek, he had Steve Leech, national program director for Chicken Farmers Canada, in his office. Leech is also the administrator for the on-farm program. He told the Straight that each antibiotic has a specific “withdrawal time” that must run its course before a flock arrives at its processing plant. The idea is to ensure that an antibiotic has cleared a chicken’s system before it is consumed by humans, Leech said.

Speaking from UBC, Patrick said that in addressing concerns about antibiotic resistance, the European Union, certain states in the U.S., and provinces in Canada such as Quebec and Ontario have ceased to use certain antibiotics in agriculture.

“The point is that we are seeing resistance to humans in some of these drugs,” Patrick said. He argued that although the matter is being addressed in humans, the time has come for the focus to shift to agriculture.

“What I would like to see is a North American–based consensus on the relatively rapid removal of most antibiotics from animal husbandry and poultry rearing,” he said.