Anthrax (Bacillus anthracis)

Question 1

Structure

Answer 1

aerobic, gram-positive, endospore-producing rods

Question 2

Reservoir species

Answer 2

None
can infect any mammal
ruminants particularly susceptible (impalas and bison)
carnivores less susceptible and dies less
ostriches, crows, and ducks are susceptible

Question 3

Is it significant issue

Answer 3

yes, in many national parks worldwide

Question 4

Why is it special

Answer 4

spores are highly resistant to destruction in environment

Question 5

History

Answer 5

1st spotted in 700 BC in Egypt and mesopotamia
1877: robert koch used to develop koch postulates
1881: Dr. Louis Pasteur develops 1st vaccine
Used as weapon in WW1

Question 6

Transmission method

Answer 6

through abraded skin, ingestion, inhalation, or direct injection

Question 7

Transmission Cycle

Answer 7

once inside, spore germinate within host-> vegetative cells-> fulminant infection-> death of host -> release of blood and bodily fluids into soil-> form biofilms for protection -> sporulates-> enters new host

Question 8

Rain’s contribution

Answer 8

improving germination and/or bringing spores to surface

Question 9

Pathogenesis

Answer 9

Can survive for decades in soil, animal hair, wool, and hides
Infect macrophages and then germinate and proliferate
lethal toxin and edema toxin- cause necrosis and edema-> can lead to systemic tissue and organ death

Question 10

Cutaneous method

Answer 10

least dangerous, Incubation 1-7 days, proliferates at site of infection and draining lymphnodes

Question 11

Inhalation method

Answer 11

most dangerous (45% mortality), incubation 1-8 weeks

Question 12

Ingestion method

Answer 12

dangerous with 40% mortality with treatment, incubation 1-7 days, proliferates at site of infection and draining lymph nodes

Question 13

Peracute clinical signs

Answer 13

(sheep, cattle, wild ruminants)
staggering, dyspnea, trembling collapse, convulsions

Question 14

Acute clinical signs

Answer 14

sudden onset fever, lethargy, stupor, cardiopulmonary distress, staggering, seizures

Question 15

Clinical signs

Answer 15

can be so quick that death is only sign
edema or head, neck, thorax, and genitalia

Question 16

Pathologic Lesions

Answer 16

-dark blood from mouth, nose, and anus (blood fails to clot)
-rigor mortis lacking or incomplete
-hemorrhages on serosal surfaces or abdomen and thorax, epicardium and endocardium, GI tract mucosa, meninges
-edematous, red-tinged effusions commonly under serosa or organs, between skeletal muscle groups, and in subcutis
-ulcers in GI tract
-enlarged, dark red or black, soft, semifluid spleen is common
-liver, kidneys, and lymph nodes congested and enlarged

Question 17

Diagnostics

Answer 17

PCR, IFA

Question 18

Sample Collection method

Answer 18

cotton swab dipped in blood and allowed to dry, >3 days dead-nasal turbinate swab and removal

Question 19

Treatment

Answer 19

antibiotics, long-acting and followed by vaccination 7-10 days after treatment

Question 20

Management

Answer 20

-preventative vaccination of domestic species
REPORTABLE DISEASE
-move unaffected herds away from contaminated areas
-removal of diseased carcasses
-quarantine of domestic and wild that have movements that can be controlled
-burn affected habitats