[ed. note: We feature the writings of Doc Gumshoe, our favorite medical scribe, every few weeks here at Stock Gumshoe. He is not a doctor, but we value his insight, research, contrariness and skepticism … and, most importantly, his ability to explain complex health issues for our readers. He generates a lot of discussion with his pieces, so today he decided to share some longer responses to a few of the questions and comments that have come up in recent pieces. As always, his words and opinions are his own and we continue to welcome feedback on Doc Gumshoe’s commentaries or on any of our other work. You can see all of Michael’s previous commentaries here.]
Antibiotics in animal feed
Several readers responded sharply to my brief mention of the use of antibiotics in animal feed, noting that I gave the topic short shrift and didn’t condemn it, beyond saying that it shouldn’t be used to promote faster growth so that these creatures could get to market sooner and make more profits for the agribusiness concerns.
This is an exceedingly complicated topic, and the best I can do is offer some observations.
I entirely agree that the best way of raising animals for food, whether chickens, cows, sheep, pigs, or any other, is to give them as much space as possible and permit them to roam as they feed. Keeping them penned in cramped spaces (besides being inhumane) maximizes the potential for disease and increases the proportion of fat to lean meat – i.e., not good for the animals, and not good for the human consumers of the animal meat.
Using antibiotics to control outbreaks of disease seems to me rational, with the emphasis on controlling outbreaks. Routine use of antibiotics to prevent outbreaks is another matter.
It is certainly the case that restricting the use of antibiotics in animal feed would raise the price of meat, since the animals would grow more slowly and take longer to get to market. And raising the price of meat might also have some beneficial consequences – some people might eat less meat and more fruits and vegetables. The emphasis in that sentence is on “some people.” Unfortunately, this is unlikely to be the response of many Americans to higher meat prices – especially poorer people, who would be most affected by higher prices and who are already consuming a diet that is low in fruits and vegetables and high is sugar, salt, and fats. So restricting the use of antibiotics in animal feed might have the unintended consequence of pushing the poorest onto an even unhealthier diet.
It was pointed out that antibiotics fed to animals wind up in manure, in the soil, and in the water supply, and there have been instances where these have been implicated in creating antibiotic-resistant pathogens. Putting small quantities of antibiotics containing tetracycline and ampicillin in cattle feed has resulted in levels of the pathogen Escherichia coli that are resistant to both drugs approaching 40% in the feces. Resistant E. coli, in turn, have been found in vegetables raised for human consumption on farms that are close to cattle feedlots, and there have been outbreaks of resistant E. coli in humans traced to salad greens from those farms. This is not a good thing!
There has been some confusion in the press and media regarding the so-called “flesh-eating” bacteria cases. These are not caused by resistant E. coli, but usually by a variant of Group A Streptococcus pneumoniae, and don’t seem to have any connection with resistance due to antimicrobials in animal feed.
So, the bottom line appears to be that routine use of antibiotics in animal feed can lead to resistant pathogens that can cause disease in humans. A question that has not been answered is, are there adverse consequences in using antibiotics to control the spread of disease in animals. There has never been an easy fix for this. And preventing the transmission of diseases from animals to humans has presented many major problems over the years. We recall the killing of hundreds of thousands of chickens in Chinese cities to try to prevent the spread of avian flu, and also the killing and burning of millions of cattle in the U. K. to prevent the transmission of mad cow disease, not to mention the extermination of entire herds of cattle potentially infected with anthrax. This is not to say that those particular diseases could have been controlled by putting antibiotics in the animal feed.
On balance, it doesn’t look to me as though totally banning the use of antibiotics in animal feed is feasible, as long as a big proportion of the human race gets a lot of its protein from meat. But it certainly could be limited and controlled.
More on Lyme disease
Several readers suggested that doctors are reluctant to diagnose Lyme disease even when the symptoms point to it, because they are afraid of being in some way discredited in the eyes of the established medical community. Some even suggested that doctors might opt for a diagnosis of a disease other than Lyme, for which the treatment was straightforward, out of self-interest, including, possibly, a profit motive.
I acknowledge that the diagnosis and treatment of Lyme is something of a puzzle. However, some things are clear:
In parts of the country where Lyme is prevalent, a patient who presents with typical Lyme symptoms, especially the bulls-eye rashes, will likely be treated for Lyme without waiting for positive blood test