- by Mike Kroll - November 14,
2001
The term ''anthrax'' conjures up more than a heavy-metal band
these days. Shortly after President Bush declared War on Terrorism
came the first reports of Americans becoming sick and dying with
anthrax. Letters containing it were sent to Congressional offices
and several news organizations. Clearly, terrorists were going
beyond the use of jetliners as missiles and entering the realm
of bioterrorism. Since September 11th, few people in this country
have been unaffected by the fear and uncertainty of what may
happen next.
Trace amounts of anthrax were found in post offices and every
unidentified white powder became ominous to many. A disease few
Americans had even heard of quickly took center stage. Amidst
the growing atmosphere of fear and near hysteria, there has been
little factual information about the true nature of this infection.
According to the Illinois Department of Public Health (IDPH),
''Anthrax is an acute infectious disease caused by the spore-forming
bacterium Bacillus anthracis. Anthrax is most common in agricultural
regions where it occurs in animals. When anthrax affects humans
it is usually due to an occupational or recreational exposure
to infected animals or their products. Anthrax in livestock has
occurred in the United States.''
Douglas Hoefling, Director of the Illinois Department of Agriculture
Animal Disease Laboratory in Galesburg, and a veterinarian by
training, goes a step further. ''Anthrax is naturally present
in soil in parts of the United States with a history of raising
livestock. It's a bacteria most often affecting grazing animals
such as cattle and sheep but very, very rare in dogs or cats.
Most typically it is found in dry and dusty agricultural areas
where anthrax-infected livestock historically had been. When
an animal dies from the effects of anthrax the bacteria can be
maintained in spore form for decades in the soil.''
Hoefling has spent the last 34 years with the Illinois Department
of Agriculture, most of it working specifically with animal diseases,
and has never personally come across a case of anthrax. ''The
last Illinois case of anthrax in animals was in 1978 when an
infected sheep was brought to the Danville area from Texas. It
was discovered after the sheep suddenly died and was brought
to the University of Illinois lab.''
The IDPH claims that the last reported case of humans infected
with anthrax in Illinois was in 1960. Hoefling does say that
naturally occurring anthrax is hardly rare in the U.S. A number
of states -- including Texas, Minnesota, and the Dakotas -- have
historically suffered from repeated outbreaks of anthrax among
livestock and, occasionally, wildlife. Anthrax has been a significant
problem in Texas and, just this year, Minnesota suffered a significant
outbreak.
Anthrax can take any of three forms: cutaneous; respiratory
or intestinal. Cutaneous occurs when anthrax spores are exposed
to cuts or wounds in the skin and seldom results in death. Most
deadly instances of anthrax involve either inhaling spores into
the lungs or eating food contaminated with spores. In either
case, the anthrax spores germinate into bacteria once inside
the body and cause severe flu-like symptoms, fever, abdominal
distress, shock and ultimately, potentially death. The respiratory
and intestinal versions of anthrax ''progress at a rapid rate
with shock developing in 3-5 days, followed shortly by death.''
''Anthrax spores are very hearty and resilient,'' explained
Hoefling. ''They can live for decades or more in the soil until
disturbed and ingested or inhaled by an animal. During the 1993
floods, we were quietly very concerned about the possibility
of anthrax spores being disturbed and carried with the floodwaters
downstream from Minnesota.''
Hoefling and other disease experts agree that anthrax is not
spread via contact either in animals or humans. In the case of
cattle and sheep, the first sign of an anthrax problem usually
is the sudden death or two or three animals and the veterinarian
diagnoses anthrax.
''The generally accepted treatment of livestock presumed to
be infected with anthrax is to inject common antibiotics; typically
penicillin is found to be successful,'' explained Hoefling. ''A
wide variety of commonly available and inexpensive antibiotics
have been shown to be effective in treating anthrax in livestock.
There also exist vaccines for animals that have been demonstrated
to be effective. Here in Illinois use of such a vaccine requires
a Department of Agriculture permit and both the animals receiving
the immunization and the farm involved will be placed under quarantine.''
Veterinary pathologist Neil Dyer is Director of the Diagnostic
Laboratory at North Dakota State University in Fargo. That state
has been unfortunate enough to suffer endemically from outbreaks
of anthrax among livestock. He says: ''Most of our experiences
are cases where a rancher sees the sudden unexpected death of
cattle or horses. While there have been instances of anthrax
in North Dakota wildlife, it is rare and we don't have many sheep
ranches here. Anthrax in North Dakota is essentially a problem
for cattle; we see some 50 infected cattle for every infected
horse.''
''The most common means of infection seems to be alimentary
or ingested. Infected animals and even humans are not contagious.
It takes the ingestion of thousands of spores to become infected
and we seldom see more that two or three animals die at a time
from anthrax. Penicillin is the antibiotic of choice in treating
anthrax in cattle but tetracycline has also proven effective.
It is not uncommon for those of us in regular contact with infected
livestock to be exposed to anthrax spores, usually cutaneous
or respiratory, but I know of no human that has died from such
anthrax exposure.''
Knox County Health Department Director Greg Chance shares
the feelings of both Hoefling and Dyer that undue concern by
the general public over the potential exposure to anthrax is
unfortunate. Dyer and Chance noted that trace evidence of anthrax
is not unusual in rural livestock-producing areas and not cause
for alarm.
''The consensus among Illinois public health authorities is
that we would not be a likely target of bioterrorism,'' stated
Chance. ''The current evidence suggests that the anthrax spores
involved in the Washington and New York incidents specially produced
as a biological weapon to be very fine and almost aerosol in
nature. Anthrax spores offer the advantage of persistence as
a weapon but they are also a very difficult biological agent
to use if one intends to inflict widespread casualties.''
Hoefling seconded Chance's point: ''There are very few researchers
doing legitimate work with anthrax and it would require significant
training in microbiology and bacteriology to work in this area
safely. There are many technical challenges involved in using
anthrax as an effective weapon and very few people are properly
trained or equipped to produce effective aerosol agents like
those discovered in Washington. Many of us in the field of disease
prevention are more concerned over the potential of a number
of other biological agents that could be employed much more easily
than anthrax.''
The Illinois Department of Agriculture has warned the state's
veterinarians of the '''dirty dozen' diseases believed most likely
to be spread by biological warfare. As we have seen earlier this
year, diseases like foot and mouth that are not a threat to humans,
can still significantly alter the economy if it strikes a particular
nation.''
The consensus of these experts is that the fear of anthrax
is probably overblown. Humans are not easily infected with the
disease and both treatments and vaccines already exist. The recent
news accounts have focused on the drug Cipro®, manufactured
and sold by Bayer, as treatment for anthrax. This is a costly
antibiotic that also has a short shelf life and a bevy of side
effects. As in animals, penicillin, tetracycline and other common,
comparatively inexpensive antibiotics have also proven effective
in the treatment of anthrax.
The IDPH reports that the anthrax vaccine ''is 93 percent
effective but seldom used in this country because of the low
risk of exposure.'' Manufactured by a Michigan company, this
vaccine ''is a cell-free filtrate vaccine, which means it contains
no dead or live bacteria in the preparation. Currently, anthrax
vaccine is not recommended for the general public and is not
available commercially.'' It has been mandated for all military
personnel and is recommended for civilians who are at high risk
of exposure to anthrax.
While the bioterrorism threat of anthrax is real, the probability
of being exposed to a health-threatening amount of the spores
is remote. The available evidence suggests that there have been
a very few carefully targeted terrorist attacks using anthrax
resulting in the death of only four persons.
Chance probably summed it up best: ''It is always wise to
be vigilant and informed but the available evidence hardly merits
either hysteria or a total overhaul of our mail system.'' [ TheZephyr.com
] |