FOODBORNE ILLESSES . . .
by PCRM
Foodborne diseases are a serious and
growing problem. Literature reports of the yearly incidence
of foodborne illness range from 6.5 to 81 million people
affected. The costs to patients, food producers, and
the national economy is estimated to be $7.7 to $8.4
billion per year.1 The vast majority of cases, however,
go unreported. From 1973 to 1987, 7,458 outbreaks, involving
237,545 cases of food poisoning, were reported to the
Centers for Disease Control and Prevention (CDC). Bacterial
pathogens caused 66 percent of the outbreaks, 87 percent
of the cases, and 90 percent of the fatalities. Approximately
50 percent of the outbreaks were caused by salmonella,
mostly from beef
and turkey. During this time period, three previously
unrecognized foodborne pathogens emerged, including Campylobacter
jejuni (associated with poultry products), Escherichia
coli 0157:H7 (ground beef), and Listeria monocytogenes
(dairy products). Other less common pathogens included
Bacillus cereus, Clostridium botulinum, Clostridium perfringens
(found in beef),Shigella, and Staphylococcus aureus (found
in pork). In 1998, an estimated 8 million cases of foodborne
illness occurred according
to the CDC. Escherichia coli 0157:H7 Outbreaks In the
early 1980s, Escherichia coli 0157:H7 began causing severe
foodborne disease outbreaks. Before then, E. coli was
considered a harmless inhabitant of the digestive tract
of humans and animals.
Today, the CDC estimates that
there are 20,000 cases of E. coli 0157:H7 infection
in the U.S. each year, associated with the consumption
of contaminated
beef, raw milk, and water. Infections are characterized
by abdominal cramping and bloody diarrhea, and can
progress to the hemolytic uremic syndrome (HUS), leading
to kidney
failure and sometimes blindness. Death rates from HUS
range from 5 to 10 percent, but can be much higher in
elderly
people and children. The infection can also lead to
neurological disease causing seizures, comas, and cerebral
blood clots,
and can so severely damage the lining of the large
intestine that it may have to be removed to save the
patient. E.
coli 0157:H7 is a major cause of HUS in the U.S., and
HUS is most common cause of acute renal failure in
children.
The overall trend of E. coli infections
is difficult
to determine due to under-reporting by physicians,
but it is estimated to be increasing. The incidence
of HUS,
which can be used as a marker for E. coli infections,
is definitely increasing in the U.S. During January
1993, there were more than 230 cases of culture-confirmed
E. coli infection in Washington
state residents, causing four deaths. The infections
were traced to undercooked hamburger. A 1987 study
tested
for the presence of E. coli 0157:H7 in supermarket
meats. The bacteria was found in 3.7 percent of beef,
1.5 percent
of pork, 1.5 percent of chicken and turkey, and 2.0
percent of lamb samples tested. These researchers suggested
that “the organism is not a rare contaminant
of freshmeats and poultry.” From 1987 to 1990, the
Food Safety and Inspection Service (FSIS) found E.
coli 0157:H7 in 2 out of 1,668 brisket and ground beef
samples, and 8 out of 6,950 veal
kidneys. These products were sold to consumers. E.
coli appears
to be a common inhabitant of the bovine digestive
tract. Studies from 1993 found the organism in 12
out of 50
dairy herds tested. Yet traceback systems to determine
the source of infected meat are not in place, and
routine tests for the presence of bacteria are not
done in slaughterhouses or meat processing plants.
Salmonella Outbreaks
The proportion of
bacterial outbreaks due to salmonella increased 130 percent
between the two-year study periods of 1973 to 1975 and
1985 to 1987. Currently, about 45,000 salmonella isolates
(cultures taken from sick patients) are reported to the
CDC annually. These are associated with about
20,000 hospitalizations, 500 deaths, and medical
expenses of at least $50 million. But the CDC estimates
that only 1 to 5 percent of an actual 1 to 5 million salmonella
infections are reported.
Slaughter operations
can spread contamination from one carcass to another.
After defeathering, chicken
carcasses are plunged into chill tanks, which can
become quite dirty by the end of the day. A 1990 article
in The Atlantic Monthly notes that the debris at the
bottom of the tank may be one foot
deep, and quotes an inspector who complained, “At
the beginning of the day the chill-tank water is
clear and clean, but as the day goes on, it becomes murky,
dirty-brownish, and bloody.”studied by FSIS were 25-gram
uncooked samples of beef (1.4 percent positive for salmonella),
pork (4.8 percent), chicken (15.7 percent), and turkey
(8.5 percent). These bacteria-infected samples were taken
from products sold to consumers.
Other Foodborne
Pathogen
During 1992, an
FSIS survey was taken of cooked, ready-to-eat products
for salmonella and Listeria
monocytogenes. Products from 75 establishments were
found to contain either salmonella or L. monocytogenes.
Most of the infected products had been held, and
the rest was recalled.
Campylobacter was the leading cause of foodborne
illness in 1998, according to the CDC. These organisms
readily colonize the avian intestinal tract but
generally cause no illness in the bird. This means that
infected birds are unlikely to be detected using the
current methods of inspection in the slaughterhouse.
FSIS recently performed surprise inspections which serve
to demonstrate how serious inspection problems are today.
In May 1993, 90 beef slaughterhouses across the country
were
inspected without warning, and of those plants,
30 were temporarily closed due to noncompliance
with federal inspection regulations, suggesting that
new procedures will do no goodif enforcement is not improved.
Slaughterhouse Inspection
Since 1906, meat
inspection has been limited to organoleptic methods,
which rely on detecting changes in
the sight, smell, or feel of the tissues. But
this does not detect foodborne microorganisms. For the
past several years, the National Academy of Sciences
has recommended that a more complete inspection be instituted,
which would include microbiological monitoring, since
many contaminants could be present in numbers high enough
to cause disease without altering the sight, smell, or
feel of the carcass, or even without causing visible
disease in living cows, pigs, or chickens. FSIS reacted
to foodborne outbreaks by instituting the Hazard Analysis
and Critical Control Point program (HACCP) and began
a microbiological baseline study of meat products called
the Microbiological Baseline Data Collection Program.
HACCP is a method of analysis designed to identify areas
within the food processing chain where chemical or microbial
contamination is likely to occur. Steps are then taken
to alter the processing procedures at key steps,
called critical control points, so as to reduce
the possibility of foodborne disease or spoilage. Monitoring
of the control points is performed by physical, chemical,
or microbiological tests. However, the program is useless
if the government is unwilling to
mandate changes in plant operations. Slaughter
line speeds, for example, contribute to contamination
and make inspection more difficult. Yet producers and government
regulations continue to sidestep this problem
because slowing the slaughter line reduces profits.
In summary, microbial
contamination of meat and poultry is a big problem, and
it’s getter bigger.
And with contaminated products in our kitchens
and restaurants, cross-contamination and contagion will
be increasing problems.
Cross-Contamination
And Contagion: Persistent
Dangers
Cross-contamination
is a serious concern for the consumer, and its evaluation
is critical in any
discussion of meat safety. There are
three ways people are exposed to pathogenic (disease-causing)
bacteria. The first is through ingestion of contaminated
products; the second through contact with persons already
infected with the bacteria, which can be a particular
problem in group settings such as nursing homes or day-care
centers; and lastly, through ingestion of foods contaminated
by contact with infected meat or contaminated utensils
or kitchen surfaces. Findings published in the February
1993 issue of the Journal of the American
Medical Association described evidence of transmission
of E. coli 0157:H7 from child to child in daycare centers,
and suggested that household transmission may
also occur.
Since both E. coli and Shigella require
only a small number of organisms to
cause disease, and the infectious dose of salmonella
is often low, cross-contamination becomes a major threat,
and one that widens the scope of susceptible persons
beyond those who eat undercooked ground beef and
unpasteurized milk.
Even if bacterial
contamination could be eliminated, meat should still
not be considered a
safe food, due to the longterm risks
posed by its cholesterol and fat content, and its lack
of fiber and complex carbohydrates. This combination
is
implicated in heart disease, various cancers,
obesity, kidney disease, diabetes,
hypertension, and other serious illnesses. Nonetheless,
the acute risks of bacterial contamination are serious
and often life-threatening, and have not been adequately
addressed by the U.S. Department of Agriculture.
PCRM Recommendations
- 1. Federal authorities must set specific
timetables and goals
for dealing with food contaminants.
To date, government
efforts are inadequate.
- 2. The USDA seal of approval,
which reads, “Inspected for
wholesomeness, USDA,” should be
dropped until federal
food inspection authorities
have developed and implemented
a workable detection method
for microbial contaminants.
- 3.
Slaughter operations must have more inspectors, reduced
line speeds, and comprehensive
traceback systems that
identify
the sources of tainted
meat. Federal authorities
should
begin the implementation
of other recommendations
already
made by consumer groups
to improve inspection
procedures.
- 4. The federal government
must require meat producers
to
withdraw pathogen-tainted
meat from routine consumer
use. Otherwise, detection
is useless to the consumer.
- 5. Public education
efforts must
be stepped up to
alert consumers
to the risks from undercooked
meat, cross-contamination,
and contagion. Other
consumer measures,
such as simple cooking
gauges on retail meat
and poultry
packages, should be
considered.
- 6. Information
on plant contamination levels,
compliance,
violations, and recalls
should be released
to the public.
- 7.
Because the USDA has demonstrated
that it
is unable and
unwilling to address
food contamination
issues, responsibility
for food safety
should be removed
from them.
- 8. Health
professionals should become familiar
with E. coli
0157:H7 and the
illnesses it
can cause, and
should test for
the organism
in all persons
with
acute
bloody diarrhea.
- 9.
State and federal regulations
should
require that
E. coli
0157:H7 infection
and hemolytic
uremic syndrome
(HUS)
be reported
to public health
officials.
- 10.
Imported meat should
be subject
to the same
level of
inspection
as domestically
produced
meat.