1. anthrax
Definition: is An acute bacterial disease usually
affecting the skin, but which may very rarely
involve the oropharynx, lower respiratory tract,
mediastinum or intestinal tract. Infectious agent
Bacillus anthracis, spore forming bacteria .
2. Epidimology
• Occurrence- Worldwide. Primarily a disease of herbivores.
Humans and carnivores are incidental hosts. Primarily an
occupational hazard of workers who process hides, hair
(especially from goats), bone and bone products and wool:
and of veterinarians and agriculture and wildlife workers
who handle infected animals. Human anthrax is common
(endemic) in those agricultural regions of the world where
anthrax in animals is common, including countries in South
and Central America, southern and eastern Europe, Asia
and Africa.
• Reservoir- Animals, normally herbivores, both livestock and
wildlife, shed the bacilli in terminal hemorrhages or spilt
blood
3. Mode of transmission
• ƒCutaneous anthrax: Contact with tissues of
animals (Cattle, sheep, goats, horses, pigs and
others) dying of the disease. Bite of flies that
had partially fed on such animals,
contaminated hair, wool, hides, or products
made from them such as drums or brushes or
contact with soil associated with infected
animals.
4. Cont…
• Inhalation anthrax: inhalation of spores in
risky industrial processes such as tanning of
hides, or wool or bone processing, where
aerosols of B. antracis spores may be
produced.
• Intestinal and oropharyngeal anthrax:
ingestion of contaminated meat; but there is
no evidence that milk from infected animals
transmits anthrax.
5. • N:B. The disease is transmitted among grazing
animals through:
• contaminated soil and feed, and among
omnivorous bone meal or other feeds and
among wildlife from feeding on anthrax
carcasses.
• Vultures have been reported to spread the
organism from one area to another.
6. Incubation period
• - A few hours to seven days; most cases occur
within 48 hours of exposure.
• Period of communicability- transmission from
person to person is very rare. Articles and soil
contaminated with spores may remain
infective for decades.
• Susceptibility and resistance- uncertain
7. Clinical manifestation
• Cutaneous Anthrax :ƒApproximately 95% of
human cases of anthrax are cutaneous form and
about 5% are the inhalation form.
• ƒFound on exposed areas of skin (head, neck, face
and hands). ƒSmall red macules appear.
• ƒLesion- progress to papule, vesicle or pustule
during the next week and formation of an ulcer
with blackened necrotic eschar surrounded by a
highly characteristic, expanding zone of brawny
edema.
