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#690 - Hidden Costs of Animal Factories, 08-Mar-2000

As the U.S. discards its family farms and in their place erects
factory farms, we might consider the costs. Here we will consider
only one cost: the harm to human health from increased use of
antibiotics in confined livestock operations, sometimes known as
animal factories.

As most people know, modern animal factories in the U.S. now
raise tens of thousands of chickens, cattle and pigs in the
smallest possible space. The animals are physically close to each
other -- jammed together might be a better description -- so an
outbreak of disease can pass readily from animal to animal. To
prevent this from happening -- and to promote rapid growth -- the
animals are regularly treated with antibiotics.

The Institute of Medicine, a division of the National Academy of
Sciences, began to question this practice in 1989.[1] The
Institute identified a hazard to human health: the creation of
antibiotic-resistant bacteria which can cause serious human

Resistance is a well-understood phenomenon. Not all bacteria are
affected equally by antibiotics -- some bacteria are genetically
able to resist the killing effects of an antibiotic. As a result,
when a group of bacteria is dosed with an antibiotic, some hardy
bacteria survive. These resistant bacteria reproduce and the next
time they are dosed with the same antibiotic, a hardy few survive
again. Eventually, the only surviving bacteria are immune to that
particular antibiotic. They have developed "resistance," and that
antibiotic has lost its effectiveness against those bacteria. As
time passes, some bacteria can develop resistance to multiple
antibiotics and these are referred to as "multi-drug-resistant
strains." Such multi-drug-resistant bacteria are a serious
medical concern because they may cause diseases that are
difficult or impossible to cure, the Institute of Medicine said
in 1992.[2,pg.92]

Some of the costs of antibiotic-resistant bacteria were
summarized by the Institute of Medicine:

"An increasingly important contributor to the emergence of
microbial threats to health is drug [antibiotic] resistance.
Microbes that once were easily controlled by antimicrobial drugs
are, more and more often, causing infections that no longer
respond to treatment with these drugs."[2,pg.92]

The Institute went on to outline the human costs of
antibiotic-resistant germs: "Treating resistant infections
requires the use of more expensive or more toxic alternative
drugs and longer hospital stays; in addition, it frequently means
a higher risk of death for the patient harboring a resistant
pathogen. Estimates of the cost of antibiotic resistance in the
United States annually range as high as $30 billion. Even with
the continuing development of new drugs, resistance to
antibiotics is an increasingly important problem with certain
bacterial pathogens."[2,pg.93]

The Institute laid the problem squarely on the doorstep of animal
factories: "New agricultural procedures can also have
unanticipated microbiological effects. For example, the
introduction of feedlots and large-scale poultry rearing and
processing facilities has been implicated in the increasing
incidence of human pathogens, such as SALMONELLA, in domestic
animals over the past 30 years. The use of antibiotics to enhance
the growth of and prevent illness in domestic animals has been
questioned because of its potential role in the development and
dissemination of antibiotic resistance. Approximately half the
tonnage of antibiotics produced in the U.S. is used in the
raising of animals for human consumption. Thus, concerns about
the selection of antibiotic-resistant strains of bacteria and
their passage into the human population as a result of this
excessive use of antibiotics are realistic."[2,pg.64]

Throughout the 1990s, awareness of this problem has been growing.

In May 1998, the federal Centers for Disease Control and
Prevention reported in the NEW ENGLAND JOURNAL OF MEDICINE that a
strain of salmonella bacteria had emerged in the U.S. in the last
5 years which is resistant to 5 different antibiotics.[3] Called
typhimurium DT 104, this rapidly-emerging bacterium is
responsible for an estimated 68,000 to 340,000 illnesses each
year in the U.S. The proportion of salmonella infections caused
by typhimurium DT 104 increased 30-fold in the U.S. between 1980
and 1996.

The Centers for Disease Control blamed the rapid emergence of
this infectious agent on the use of antibiotics in livestock,
summarizing its recommendations this way: "More prudent use of
antimicrobial agents [antibiotics] in farm animals and more
effective disease prevention on farms are necessary to reduce the
dissemination of multi-drug-resistant typhimurium DT 104 and to
slow the emergence of resistance to additional agents in this and
other strains of salmonella."[3]

In March of 1999 the FDA began a multi-year process to regulate
the use of antibiotics in farm animals. Here is how the NEW YORK
TIMES reported the FDA's action in a front-page story March 8:

"Faced with mounting evidence that the routine use of antibiotics
in livestock may diminish the drugs' power to cure infections in
people, the Food and Drug Administra- tion has begun a major
revision of its guidelines for approving new antibiotics for
animals and for monitoring the effects of old ones.

"The goal of the revision is to minimize the emergence of
bacterial strains that are resistant to antibiotics, which makes
them difficult or even impossible to kill. Drug-resis- tant
infections, some fatal, have been increasing in people in the
United States, and many scientists attribute the prob- lem to the
misuse of antibiotics in both humans and ani- mals.

"Of particular concern to scientists are recent studies showing
bacteria in chickens that are resistant to fluoroqui- nolones,
the most recently approved class of antibiotics and one that
scientists had been hoping would remain effective for a long

The NEW YORK TIMES then described[4] the May, 1998, study by the
federal Centers for Disease Control,[3] adding new information
from an interview with Dr. Fred Angulo, one of the authors of the

"Last May, a team from the centers reported in the New England
Journal of Medicine that the prevalence of a salmonella strain
resistant to five different antibiotics increased from 0.6
percent of all specimens from around the country tested by the
centers in 1980 to 34 percent in 1996.

"Similarly, drug resistance in campylobacter bacteria rose from
zero in 1991 to 13 percent in 1997 and 14 percent in 1998, said
Dr. Fred Angulo, an epidemiologist in the food- borne and
diarrheal disease branch at the centers. He said epidemiologists
had been alarmed by the campylobacter figures, because the
resistance was to fluoroquinolones, the very drugs the F.D.A. was
trying hardest to preserve.

"Dr. Angulo said that he and his colleagues had attribut- ed much
of the increase in fluoroquinolone resistance to the drug
agency's approval of the drugs to treat a respiratory infection
in chickens in 1995. It was an approval that the disease control
centers opposed, because it would lead to tens of thousands of
the birds being treated at one time.

"Dr. Angulo said he thought the rising levels of resis- tance in
bacteria taken from sick people had been caused by the heavy use
of antibiotics in livestock. 'Public health is united in the
conclusion,' he said. 'There is no controversy about where
antibiotic resis- tance in food-borne pathogens comes from.'"[4]

Two months later, in May, 1999, a report by the Minnesota Health
Department, published in the NEW ENGLAND JOURNAL OF MEDICINE,
found that infections by antibiotic-resistant bacteria increased
nearly 8-fold between 1992 and 1997. Part of the increase was
linked to foreign travel, and part of the increase was linked to
the use of antibiotics in chickens. Even the increase due to
foreign travel may have been caused by the use of antibiotics in
chickens in countries such as Mexico where the use of antibiotics
in poultry has quadrupled in recent years, the report said.[5]
The study's lead author, Dr. Kirk E. Smith, told the Associated
Press, "There is definitely a public health problem with using
quinolone [antibiotic] in poultry, and we need to take a hard
look at that."[6]

In November 1999 a new report appeared in the NEW ENGLAND JOURNAL
OF MEDICINE linking an outbreak of fatal salmonella in Denmark to
the use of antibiotics in pigs.[7] Here is how the NEW YORK TIMES
reported the story:

"An outbreak of severe, drug-resistant salmonella infections in
27 people in Denmark, traced to meat from infected pigs, is being
described by American scientists as a warning on what can happen
in the United States unless steps are taken to limit the use of
antibiotics in farm animals.

"The episode in Denmark, in which 11 people were hospitalized and
2 of them died, is especially worrisome because the bacteria had
made them partly resistant to a class of antibiotics called
fluoroquinolones that doctors had considered one of their most
powerful weapons against severe cases of salmonella and other
bacteria that infect the intestinal tract. If those bacteria
invade the bloodstream, which occurs in 3 percent to 10 percent
of salmonella cases, the illness can be fatal.

"'Fluoroquinolones become a drug of last resort for some of these
infections,' said Dr. Stuart Levy, director of the Center for
Adaptation Genetics and Drug Resistance at Tufts University. 'If
we're beginning to lose these drugs, where do we go from here?'

"Fluoroquinolones are the most recently approved class of
antibiotics; nothing comparable is expected to become available
for several years," the Times said.[8]

Deaths due to infectious diseases have been increasing in the
U.S. in recent years. In the '50s and '60s, public health
specialists were predicting that infectious diseases would
disappear as a problem. However, this prediction was entirely
wrong. According to a 1996 report in the JOURNAL OF THE AMERICAN
MEDICAL ASSOCIATION, between 1980 and 1992, the death rate due to
infectious diseases as the underlying cause of death increased
58%, from 41 to 65 per 100,000 population in the U.S. (See REHW
528.) Some of this was due to an increase in AIDS during the
period. However, AIDS is typically a disease of young people.
Among those aged 65 and over, deaths due to infectious diseases
increased 25% during the period 1980-1992 (from 271 deaths per
100,000 to 338 deaths per 100,000). Thus there seems to have been
a real and substantial increase in deaths due to infectious
diseases in the U.S. during the past 20 years.[9]

In sum, serious infectious diseases are enjoying a resurgence in
the U.S. Our national policy of replacing family farms with
animal factories in the name of "economic efficiency" is one of
the key reasons.

--Peter Montague (National Writers Union, UAW Local 1981/AFL-CIO)


[1] Institute of Medicine, HUMAN HEALTH RISKS FROM THE
(Washington, D.C.: National Academy Press, 1989).

National Academy Press, 1992). ISBN 0-309-04741-2.

[3] M. Kathleen Glynn and others, "Emergence of
Multidrug-resistant SALMONELLA ENTERICA Serotype Typhimurium
DT104 Infections in the United States," NEW ENGLAND JOURNAL OF
MEDICINE Vol. 338, No. 19 (May 7, 1998), pgs. 1333-1338.

[4] Denise Grady, "A Move to Limit Antibiotic Use in Animal
Feed," NEW YORK TIMES March 8, 1999, pg. A1.

[5] Kirk E. Smith and others, "Quinolone-Resistant CAMPYLOBACTER
JEJUNI Infections in Minnesota, 1992-1998," NEW ENGLAND JOURNAL
OF MEDICINE Vol. 340, No. 20 (May 20, 1999), pgs. 1525-1532.

[6] Associated Press, "U.S. Antibiotics Countered by Foreign
Meat, Study Says," NEW YORK TIMES May 20, 1999, pg. A20.

[7] Kare Molbak and others, "An Outbreak of Multidrug-Resistant,
Quinolone-Resistant SALMONELLA ENTERICA Serotype Typhimurium
(November 4, 1999), pgs. 1420-1425.

[8] Denise Grady, "Bacteria Cases in Denmark Cause Antibiotic
Concerns in U.S.," NEW YORK TIMES November 4, 1999, pg. A15.

[9] Robert W. Pinner and others, "Trends in Infectious Diseases
Mortality in the United States," JOURNAL OF THE AMERICAN MEDICAL
ASSOCIATION Vol. 275, No. 3 (January 17, 1996), pgs. 189-193.

Descriptor terms: farming; animal welfare; animal health;
poultry; swine; antibiotics; infectious diseases; resistance;
morbidity statistics; mortality statistics; confined
livestock operations; animal factories;

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