Sunday, September 2, 2012

The Antibiotic Paradox

Antibiotics are a family of drugs used to treat bacterial infections, including diseases like the bubonic plague, pneumonia, typhus, cholera, and tuberculosis.  The first antibiotic to hit the market was penicillin, in 1941.  It was soon seen to be a wonder drug, because it saved so many lives.  Prior to antibiotics, there were no effective treatments for many life-threatening diseases — they were incurable.  The new drugs revolutionized the practice of medicine, giving doctors power that had previously been unimaginable.
Of course, every technological miracle has a dark shadow of harmful side effects, unintended consequences, and fatal flaws.  Dr. Stuart Levy described this ominous shadow in his book, The Antibiotic Paradox.  He did an excellent job of explaining a very complicated subject in a manner that ordinary folks could readily comprehend.
Our skin and digestive system are home to far more bacteria than the number of cells in our body.  Sometimes bacteria get under our skin, and reproduce faster than our immune system can kill them.  This is an infection, and infections can sometimes be fatal.
“An antibiotic is a natural substance made by one microorganism that inhibits growth of another microorganism.”  Most antibiotics originated as molds or soil bacteria.  Both friendly and unfriendly microorganisms enjoy reproducing at a phenomenal rate, and they often mutate genetically.  Some of these mutants are drug-resistant, because they can survive contact with one or more antibiotics.  These resistant survivors then proceed to produce large numbers of bulletproof offspring. 
Science has attempted to eliminate resistant strains by developing new forms of antibiotics.  Naturally, the bacteria continued reproducing and mutating until they became resistant to the new super drug in town, sometimes as soon as two years after its introduction.
As fast as science created new antibiotics, infectious bacteria developed resistance to them.  It’s the same story with herbicide-resistant weeds, fungicide-resistant plant diseases, and insecticide-resistant crop pests.  No matter how hard they try, or how much money they spend, scientists will never put Mother Nature in a cage.
There are a finite number of substances suitable for use as antibiotics.  They must be effective, free of serious side effects, and capable of being mass produced.  The low-hanging fruit has already been picked, and inventing new antibiotics is becoming more and more challenging and expensive.
Drug companies are losing interest in creating new antibiotics, because they are not highly profitable.  This is because they usually work very well, curing the patient in a matter of days, ending the need for further treatment.  Drug makers are far more interested in creating medicines that patients have to take for the rest of their lives, because they are goldmines.
Everyone agrees that the problem of antibiotic-resistant disease pathogens will never be solved.  The microbes will inevitably develop resistance to any new pharmaceutical weapon.  It’s only a matter of time.  No amount of money or magic can fix this.  Most antibiotic-resistant pathogens are resistant to more than one antibiotic, or MDR (multiple drug resistant).  Some MDR pathogens are resistant to all drugs, and are uncontrollable.  The magic bullets are losing their spunk. 
We are moving inevitably toward the post-antibiotic world, and we are doing little to delay this.  Indeed, the way we are using these drugs is speeding us toward the end of their usefulness.  Many forms of antibiotic use result in increased profits, and we are far more interested in profits than in the future.
The more we use antibiotics, the faster resistance develops.  If our main objectives were to protect human lives, and to delay the arrival of the post-antibiotic era, we would limit their use to treating sick humans.  Doctors would quit giving antibiotics to patients suffering from colds or flu, no matter how loud they whine, because these drugs are useless against viral diseases.  The misuse of antibiotics by doctors is widespread.
The US produces 50 million pounds of antibiotics annually, and about 70 percent of them are given to livestock and poultry.  Most of the drugs given to animals are not to treat disease, but to prevent disease, and to make them grow bigger and faster.  Typically, the drugs pass through the animals in active form, in their manure, and persist in the environment.  The manure is often spread on fields where food crops are grown.  Some of the drugs run off the farm and into drinking water and fish. 
Antibiotics are also used on dogs, cats, fur-bearing animals, shellfish, aquarium fish, fish farms, horses, fruit trees, palm trees, ornamental plants, honey bees, potatoes, tobacco, peppers, tomatoes, and celery.  The drugs are everywhere, and wherever they are, they promote drug resistance.  MDR pathogens are also literally everywhere.
The world of microorganisms is a spooky place.  There are harmless bacteria that are MDR, and they can transfer their drug-resistant characteristics to disease-causing bacteria.  Genetic material is readily exchanged between different types of microbes.
In one experiment, a calf was given a marked variety of E. coli bacteria.  Before long, the bacteria were found in nearby mice and flies.  It spread to pigs, chickens, and turkeys living at a significant distance from the calf.  Humans on the farm began excreting the E. coli. 
Antimicrobial hand soaps provide no real protection, and may actually be harmful.  After the collapse of the Soviet Union, we discovered that rates of allergies and asthma were far lower in Eastern Europe, an environmental disaster area.  Some theorize that reduced hygiene inspires healthier immune systems, because they get regular “exercise.”  Being too tidy may be unhealthy.
Levy’s objective was to publicize the problem of antibiotic misuse.  If we used them with great care, then we could extend their usefulness in treating human diseases.  The future of antibiotics is highly uncertain, but Levy is not out to scare us.  He suspects that we might not experience a complete antibiotic wipeout in the “foreseeable future” (a fuzzy timeframe). 
But the danger is real and substantial.  MDR pathogens are now very common.  “This situation raises the staggering possibility that a time will come when antibiotics as a mode of therapy will be only a fact of historic interest.”  Optimists can celebrate the notion that when antibiotics become useless, far fewer people will die from cancer and heart disease.
Our wild ancestors experienced far less infectious disease because they lived in small, isolated groups.  They didn’t live in close contact with other species, nor did they congregate in filthy cities.  By living in their traditional, time-proven manner, they remained healthy, and had no need for wonder drugs.
Levy, Stuart B., M.D., The Antibiotic Paradox, Second Edition, Perseus Publishing, Cambridge, Massachusetts, 2002.


Gary Gripp said...

Some twenty years ago I read a book titled The Coming Plague, by Laurie Garrett, which made the same points. It's interesting the way our econimic system manages to override not only common sense but even the instinct for self-preservation. All the actions we're taking to avert climate change illustrate the same principle at work. Their epitath read: Short term profit trumped long-term survival. And they showed such promise, too.

What Is Sustainable said...

Gary, yes there seems to be a pattern of this business. Hopefully our big brains will kick in and start learning from our mistakes.