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The Impacts of Antibiotic Use
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The
most obvious consequence of antibiotic use has been the increased
rates of mortality caused by the inability to treat patients effectively
and in a timely manor. Fatal
cases are also common when the only drug available to treat a particular
infection is ineffective, rendering the patient and physician without
a cure. A recent study
in the U.S. suggests the scope of antibiotic resistant is larger
than expected, with the highest rate of cases in hospitals.
The researchers estimate that over 2 million patients will
become infected with an antibiotic resistant microbe while visiting
the hospital; 90 thousand of those will die.
The frequency of fatality, directly attributable to antibiotic
resistance, appears to be increasing as the array of antibiotics
increases. This impact
is not surprising, however, what was not expected were the numerous
other consequences of antibiotic resistance.
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Probably
the most unwanted consequence, for the individual taking an antibiotic,
is the side effects that are inherent in all drugs.
Side effects, ranging from drowsiness to nausea and cramps,
are often mild and accepted in return for the benefits.
However, in some cases the side effects can be fatal.
Individuals allergic to penicillin have a 30% death rate
if penicillin is consumed.
Other times prolonged use of antibiotics may lead to toxicity
of internal organs. Gentomycin,
an antibiotic used for a broad range of infections, causes extensive
damage to the kidneys after prolonged use.
In China, streptomycin is commonly used to treat tuberculosis
and is now attributed to causing hearing defects in a large population
of children.
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| An image of Staphylococcus
aureus as seen through a microscope. Almost all S. aureus
are resistant to penicillin, however, most are still susceptible to
Vancomycin. Image from University
of Texas Medical School. |
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Another
side effect of antibiotic usage is the overgrowth of natural bacteria
in the body with other bacteria.
Treatment with antibiotics, especially broad-spectrum antimicrobials,
destroys benign indigenous bacteria as well as unwanted bacteria.
Not only do the benign bacteria provide important functions
within the body, like the digestion of certain foods, they inherently
inhibit unwanted bacteria by preventing them from colonizing in
the body. In the case
of diarrhea, treatment is usually with broad-spectrum antibiotics,
leading to resistance by the Clostridium difficile bacteria
and death of benign bacteria.
Consequently, the patient may suffer from an enhanced case
of diarrhea that in some cases causes death.
Thus, the unintentional impact of antibiotic usage results
in unwanted side effects and increased susceptibility to harmful
microbes, both of which can be fatal in extreme cases.
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The
largest area of antibiotic misuse is from the prophylactic treatment
within the agricultural industry.
Antibiotics are used frequently in the cattle, salmon, and
catfish industries, not to mention the numerous uses for plants
and vegetables. The
concern from treating these organisms with antibiotics resides in
the fact that resistance can easily accumulate within a species
and then be transferred to humans through food consumption.
In the last decade, the infectious microorganism, Salmonella,
has caused sickness, hospitalizations, and even deaths.
The Center for Disease Control reports that the number of
Salmonella infections, multiply-resistant to antibiotics, is on
the rise. In 1970 there
were virtually no reported cases of Salmonella outbreaks resistant
to antibiotics. However,
by 1995 outbreaks were occurring frequently via meat and milk from
cattle. A 1983 outbreak
of multiple-drug resistant bacteria Salmonella was observed in Minnesota
where 40,000 pounds of beef were shipped to several states, resulting
in numerous deaths. Again, in 1987, an outbreak of Salmonella infected
over 200,000 people via packaged milk.
Ultimately, the low levels of antibiotics used in the agricultural
industry have recently developed a new source for bacteria to develop
antibiotic resistance and ultimately infect humans.
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| An
image of Streptococcus pneumoniae, the common cause of pneumonae
and meningitis. Image from The
University of Texas Medical School. |
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A subtler outcome of antibiotic use has been increased costs for
patients, hospitals, and drug companies.
A recent Office of Technology Assessment report estimated
that six common antibiotic resistant bacterial strains cost an additional
$661 million per year in hospital charges.
Other studies using mathematical models estimate that antibiotic
resistance costs the U.S. $5 billion annually after considering
treatment for the resistant microbes.
Analysis of tuberculosis treatment shows that total cost
of treating one patient with the infection is $12,000, yet the cost
of treating a resistant strain of tuberculosis is over $180,000.
The cost of antibiotic resistance, however, has had an even
larger impact on the pharmaceutical industry.
The
continuous evolution of antibiotic resistant microbes has led to
dramatically escalating research expenses to develop new and more
effective drugs. The
US Food and Drug Administration has also imposed more stringent
guidelines in order to minimize the number of resistant cases.
The combined effect of these forces has created a stagnant
pharmaceutical industry. In
a 1991 survey of pharmaceutical companies in the US and Japan, more
than 50% had ceased or significantly diminished the research into
new antibiotics. The
lack of research and development by pharmaceutical companies comes
at the precise time when new and more effective treatment is needed. Consequently, unique alternative methods must be employed to
combat the resistant microbes.
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