What
is anthrax?Anthrax is a bacterial infection caused by the spore-forming
bacterium Bacillus anthracis. Where is anthrax
usually found?Anthrax exists naturally in wild and domestic animals, such
as cattle, sheep, goats, and other herbivores, it can also occur in humans who
are exposed to infected animals or tissue from infected animals. Anthrax
can be found globally, but it is more common in developing countries or countries
without veterinary public health programs. Antrax is found parts of South and
Central America, Southern and Eastern Europe, Asia, Africa, the Caribbean, and
the Middle East. How common is anthrax?Worldwide
incidence is unknown, but outside of 'at risk' areas, anthrax is extremely rare.
In the United States, only 236 anthrax cases were reported between 1955 and 1999,
an average of about five per year. Most of those were in people who work with
animal products. Anthrax has, however been seen as a convenient and inexpensive
biological weapon, and this unquantifiable risk should be taken seriously. How
is anthrax transmitted?Anthrax affects humans via occupational exposure
to infected animals or their products. Workers in other counties, who are exposed
to imported dead animals and animal products, may become infected with B. anthracis
(industrial anthrax). Anthrax can be transmitted in three different ways:
- Cutaneous (skin), B. anthracis spores can live in the soil for many
years, and humans can become infected by contact with the soil, or handling products
from infected animals
- Inhalationor of anthrax spores from contaminated
animal products. i, and .
- Gastrointestinal: Anthrax can be spread by eating
undercooked meat from infected animals.
Can
anthrax be spread from person-to-person?There is no evidence of unintended
infection, even from people with inhalation anthrax; ther is a risk of infection
from spores released into the atmosphere or air supply accidentally (eg from a
laboratory) or intentionally (eg terrorism) Who is most
at risk? - People working with imported meat or hides from
endemic areas
- People travelling 'rough' in endemic areas
- Military
personnel
What are the symptoms of anthrax?Cutaneous:
Infection usually occurs when spores enter via a cut or abrasion on the skin,
such as when handling wool, hides, leather or hair from infected animals. Skin
infection begins as a raised itchy bump that may be mistaken for an insect bite;
within 48 hours, it develops into a vesicle and then a painless ulcer, usually
1-3 cm in diameter, with a characteristic black necrotic (dead) area in the center.
Lymph glands in the adjacent area may swell. About one in five untreated cases
of cutaneous anthrax will result in death. Inhalation: Flu-like
symptoms will progress over several days to severe breathing problems; inhalation
anthrax is usually fatal. Gastrointestinal: Acute inflammation of
the gut shows as nausea, loss of appetite, vomiting, and fever. These usually
lead to abdominal pain, severe diarrhea, and vomiting of blood. Intestinal anthrax
has a death rate approaching 50%. How is anthrax
diagnosed?Diagnosis is confirmed by isolating B. anthracis from
the blood, skin lesions, or respiratory secretions or by measuring specific antibodies
in the blood. Tests are available to confirm the diagnosis within an hour;
testing is taking place in Switzerland for a test that will confirm the presence
of anthrax in a few minutes. Is there a treatment
for anthrax?Antimicrobial treatment is usually effective if commenced
in good time. If left untreated, the disease can be fatal. Treatment success (and
the time available) depends on the form of the disease (cutaneous, inhalation
or intestinal). Ciprofloxacin is still the antibiotic of choice ('first line therapy')
- but antimicrobial therapies are subject to culture and sensitivity results from
the laboratory; doxycycline and procaine penicillin may be used. Is
there a way to prevent infection?There is an animal vaccine, which is
not unioversally used; there is also an anthrax vaccine for use in humans, which
offers over 90% protection against anthrax. In areas where anthrax is common
and animal vaccination levels are low, contact with livestock and animal products
must be avoided, meat that has not been properly slaughtered and thoroughly cooked
should also be avoided. What is the mortality rate
for anthrax?Untreated cutaneous anthrax has a mortality rate which varies
from five to twenty per cent. Deaths are rare with early diagnosis and appropriate
antibiotic therapy. What is the anthrax vaccine?The
vaccine is a cell-free filtrate vaccine, which means it contains no dead or live
bacteria in the preparation. Mild local reactions, such as tenderness and redness
at the injection site, occur in almost a third of recipients. Severe local reactions,
involving extensive swelling of the forearm as well as the local reaction, are
infrequent. Systemic reactions are rare. What is
the protocol for anthrax vaccination?The immunization consists of three
subcutaneous injections given two weeks apart followed by three additional subcutaneous
injections given at 6, 12, and 18 months. Annual booster injections of the vaccine
are recommended thereafter. Pregnant women are only vaccinated if absolutely necessary. Who
should get vaccinated against anthrax? - People who work with the organism
in laboratories
- People who work with imported animal hides or furs where
there is a risk of exposure to anthrax spores.
- People who handle potentially
infected animal products in high-incidence areas.
- Military personnel posted
in high risk locations.
Are there adverse reactions
to the anthrax vaccine?The most common reactions are temporary redness,
swelling or a small lump at the injection site; even these occurrancies have been
uncoomon, with about 100 reports after some 400,000 people had received the vaccine.
Can anthrax be controlled environmentally?Antrax
can survive in the ground as a spore for many years before being activated and
infecting animals or people; in its natural cylcle, the death of the infected
creature then allows reinfection of the ground. Until the next time. Is
there legal protection for workers and others? Workers are entitled to
appropriate training and protective equipment Where
can I get more information about anthrax? I regret I cannot assist with individual cases or essays and school projects,
but if it's something I've missed, I'll be happy to try and help. © Andrew Heenan January 2006 | 
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