Anthrax
Anthrax
Anthrax
What is anthrax?
Anthrax infection can occur in three forms: cutaneous (skin), inhalation, and
gastrointestinal. B. anthracis spores can live in the soil for many years, and humans
can become infected with anthrax by handling products from infected animals or by
inhaling anthrax spores from contaminated animal products. Anthrax can also be
spread by eating undercooked meat from infected animals. It is rare to find infected
animals in the United States.
Symptoms of disease vary depending on how the disease was contracted, but
symptoms usually occur within 7 days. Although incubation periods up to 60 days are
possible .
Cutaneous: Most (about 95%) anthrax infections occur when the bacterial spore
enters a cut or abrasion on the skin, such as when handling contaminated wool,
hides, leather or hair products (especially goat hair) of infected animals. Skin infection
begins as a raised itchy bump that resembles an insect bite but within 1-2 days
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develops into a vesicle and then a painless ulcer, usually 1-3 cm in diameter, with a
characteristic black necrotic (dying) area in the center. Edema or swelling of the
surrounding tissues may develop and lymph glands in the adjacent area may swell.
About 20% of untreated cases of cutaneous anthrax will result in death. Deaths are
rare with appropriate antimicrobial therapy.
Inhalation: Initial symptoms may resemble a common cold. After several days, the
symptoms may progress to severe breathing problems and shock. Inhalation anthrax
is usually fatal, and even with aggressive antibiotic and supportive therapy 45% of
inhalation anthrax cases were fatal.
Intestinal: The intestinal disease form of anthrax may follow the consumption of
contaminated meat and is characterized by an acute inflammation of the intestinal
tract. Initial signs include nausea, loss of appetite, vomiting, fever are followed by
abdominal pain, vomiting of blood, and severe diarrhea. Symptoms may also include
lesions and soreness in the throat, difficulty swallowing, marked swelling of the neck
and regional lymph glands. Intestinal anthrax results in death in 25% to 60% of cases.
Susceptability:
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Can anthrax be spread from person-to-person?
Methods of Control:
A- Preventive measures :
1) Immunization :
In countries where anthrax is common and vaccination levels of animal herds are low,
humans should avoid contact with livestock and animal products and avoid eating
meat that has not been properly slaughtered and cooked. Also, an anthrax vaccine
has been licensed for use in humans. The vaccine is reported to be 93% effective in
protecting against anthrax.
The vaccine is a cell-free filtrate vaccine, which means it contains no dead or live
bacteria in the preparation. The final product contains no more than 2.4 mg of
aluminum hydroxide as adjuvant. Anthrax vaccines intended for animals should not
be used in humans.
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What is the protocol for anthrax vaccination?
Mild local reactions occur in 30% of recipients and consist of slight tenderness and
redness at the injection site. Severe local reactions are infrequent and consist of
extensive swelling of the forearm in addition to the local reaction. Systemic reactions
occur in fewer than 0.2% of recipients.
3) Control dust and properly ventilatework area. Vaporized formaldehyde has been
used for disinfection of work places contaminated with B. Anthracis .
4) Wash, disinfect or sterilise hair,wool, and bone meal or other feed of animal origin
prior to processing .
1) report to local health authority , also report to agriculture authority . Even a single
case of human anthrax especially of the inhalation type.
2) Isolation :standerd precaution for the duration of illness for cutaneous and
inhalation anthrax . Antibiotherapy sterilizes skin lesion withen 24 hours, but the
lesion progress to ulceration, sloughing , and resolution .
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212oF) for 30 minutes (the actual reported time is considerably less) . Spores require
steam.
To be effective, treatment should be initiated early. If left untreated, the disease can
be fatal. Antibiotics should be given to unvaccinated individuals exposed to inhalation
anthrax. Penicillin, tetracyclines and fluoroquinolones are effective if administered
before the onset of lymphatic spread or septicemia, estimated to be about 24 hours.
Antibiotic treatment is also known to lessen the severity of disease in individuals who
acquire anthrax through the skin. Inhalation anthrax was formerly thought to be
nearly 100% fatal despite antibiotic treatment, particularly if treatment is started
after symptoms appear. A recent Army study resulted in successful treatment of
monkeys with antibiotic therapy after being exposed to anthrax spores. The antibiotic
therapy was begun one day after exposure.