AN OVERVIEW OF ANTHRAX
Introduction:
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Commonly known as called Malignant pustule, Malignant edema Charbon, Wool sorters’
disease, Ragpickers’ disease, and Siberian ulcer.
•
Zoonotic and an Occupational Disease .Majorly, disease of ruminant animals.
•
Human Beings are incidentally infected, from handling infected animals, carcasses, meat,
hides, or wool, products derived from infected animals, such as drumheads and wool clothing,
are also documented sources of human infection.
•
Potentially fatal, which can be obviated through prompt diagnosis and treatment.
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The most commonly reported form of anthrax in humans is cutaneous anthrax (95%–99%)
•
BioThrax® vaccine is available and is recommended more for those having been suspected of
having an exposure. May also be recommended for those who could have an occupational
exposure.
•
Anthrax can be either natural disease or due to Deliberate release (spores).
•
Potential weapon for bio-terrorism as Anthrax spores can remain viable for decades.It can
enter the body through skin abrasions, inhalation or ingestion and multiply to produce
exotoxins.
•
It is the first disease for which the causative agent was demonstrated by the German
bacteriologist Robert Koch in 1876 who isolated the organism in pure culture.
Disease Distribution:
Global scenario:

Anthrax is most common in agricultural regions in Central and South America, subSaharan Africa, central and south-western Asia, and southern and eastern Europe.

Although outbreaks still occur in livestock and wild herbivores in the United States, Canada,
and Western Europe, human anthrax in these areas is now rare.

In South Asia, anthrax is highly endemic particularly in India and Bangladesh.
Indian Scenario:
•
Anthrax is enzootic (normally present in an area in animals) in southern India but is less
frequent to absent in the northern Indian States.
•
In the past years the anthrax cases have been reported from Andhra Pradesh, Jammu and
Kashmir, Tamil Nadu, Orissa and Karnataka.
•
Integrated Disease Surveillance Programme (IDSP), National Centre for disease control
(NCDC), Delhi, India reported outbreaks of anthrax from sixty one districts during the year
2022.
Transmission:
•
Can be transmitted from animals to humans but not from human-human or between animals
•
Spores are extremely resistant and survive for years in soil, or on wool or hair of infected
animals.
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If ingested or inhaled by an animal, or after entering through cuts in the skin, they can
germinate and cause disease.
•
Insects can spread the bacteria to other animals by feeding on the unclotted leaking blood
from animal bodies.
•
Carnivores and humans can become infected by eating meat from an infected animal.
Reservoir:
•
The important reservoir of infection are Soil and domestic and wild animals
(primarily herbivores, including goats, sheep, cattle, horses, and swine)
Agent:
•
Gram+ve, Rod shaped spore forming Bacteria – Bacillus anthracis
Diseases Progression:
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Cutaneous Anthrax: usually develops 1–7 days after exposure, but incubation periods as
long as 17 days have been reported.
•
Ingestion or Gastrointestinal anthrax: usually develops 1–7 days after eating contaminated
meat; however, incubations as long as 16 days have been reported.
•
Injection anthrax: usually develops within 1–4 days of exposure;
•
Inhalation anthrax: usually develops within a week after exposure, but the incubation period
may be prolonged (up to 2 months)
Symptoms:
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A group of small blisters or bumps that may itch
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A painless skin sore (ulcer) with a black center small blisters or bumps(usually on face, neck,
arms, or hand)
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Fever and chills
•
Chest Discomfort
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Shortness of breath, cough
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Confusion or dizziness
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Swelling of neck or neck glands
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Sore throat, Painful swallowing
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Nausea and vomiting
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Diarrhea or bloody diarrhea
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Headache, Flushing (red face) and red eyes
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Stomach pain, Swelling of abdomen (stomach)
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Fainting
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A painless skin sore with a black center.
Laboratory Diagnostics:
Diagnostic Techniques
Presumptive diagnostic tests
Confirmatory Diagnostic Tests
Microscopic test Biochemical tests Serology
Culture method Susceptibility
to penicillin G
Blood agar
Gram staining
Nitrate reduction
test(Annexure-IV)
Methylene Blue
Staining
Catalase
(Mcfaydean
reduction test
reaction)
Motility test
Malachite green
Sugar fermentation test
stain for spores
Real TimePolymerase
Chain Reaction
(RT-PCR)
Nutrient agar
Nutrient agar
plates containing
0.7% sodium
bicarbonate
Note: Culturing B. anthracis from clinical specimens is the gold standard for diagnosing anthrax.
Disinfection:
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Anthrax spores are resistant to heat, sunlight, drying and many disinfectants.
•
They can be killed with formaldehyde or glutaraldehyde; overnight soaking is recommended.
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A 10% NaOH or 5% formaldehyde solution can be used for stockyards, pens and equipment.
•
To become an effective sporicidal agent, household bleach must be diluted with water and
adjusted to pH 7. Prolonged contact is recommended.
•
Gaseous sterilization can be accomplished with agents such as chlorine dioxide, vapor-phase
hydrogen peroxide and formaldehyde gas, under specific conditions of humidity and
temperature.
•
Anthrax spores can also be eliminated by autoclaving at 121°C (250°F) for at least 30
minutes. Gamma radiation has been used to decontaminate animal products, as well as mail
from contaminated postal facilities.
•
Exposed arms and hands can be washed with soap and hot water, then immersed for one
minute in a disinfectant such as an organic iodine solution or a 1 ppm solution of mercuric
perchloride.
•
Alcohol-based disinfectants commonly used for hand cleaning are not effective against
spores.
Treatment:
•
Prompt recognition and institution of therapy is the key to saving the patient.
•
Treatment should ideally be done based on drug sensitivity testing results. A combination of
broadly active agents should be used for treatment.
Antibiotics - Penicillin, ciprofloxacin, levofloxacin, doxycycline regimens.
Antitoxins- Intravenous anthrax immune globulin (human): Raxibacumab, and Obiltoxaximab
monoclonal antibodies
Prevention:

BioThrax® is the vaccine against Anthrax, but it is not approved for widespread use.

The vaccine is sometimes given to people who are likely to be exposed to anthrax through
their occupation, for example, tannery workers, military personnel, laboratory workers who
work with anthrax, people who handle animals or animal products.

Recommended for people 18 to 65 years of age.

Should get 5 doses of vaccine (in the muscle): the first dose when risk of a potential exposure
is identified, and the remaining doses at 4 weeks and 6, 12, and 18 months after the first dose.

Annual booster doses are recommended for ongoing protection.

Recommended for unvaccinated people who have been exposed to anthrax in certain
situations. These people should get 3 doses of vaccine (under the skin), with the first dose as
soon after exposure as possible, and the 2nd and 3rd doses given 2 and 4 weeks after the first.