Under Supervision of :Prof. Dr\ Ekram M. El-Shabrawy

Team Work : Mostafa Emad Ahmed Mohammed Bahaa El-Din Mostafa Abd-Elsamee Ahmed Mohamed Taha

Anthrax and Anthrax Vaccine

ContentsCausative

Organism.Disease Exit.Pathogenesis.Virulence Factors.Clinical Forms.Clinical Findings.

Laboratory TestsVaccineTreatmentChemoprophylaxisEpidemiology.Prevention &

Control

Causative OrganismScientific classification:-

Kingom

• Bacilli

Phylum

• Bacteria

Class

• Firmicutes

Family

• Bacillacea

Genus

• Bacillus

Species

• B. anthracis

Causative Organism

* Bacillus Species

The genus bacillus includes large aerobic.

Gram-positive rods occurring in chains.

Most members of this genus are saprophytic organisms prevalent in soil, water, and air and on vegetation.

Spores may remain viable in soil for years

Causative Organism

B cereus can grow in foods and produce an enterotoxin or an emetic toxin and cause food poisoning.

may occasionally produce disease in immunocompromised humans .

B anthracis, which causes anthrax, is the principal pathogen of the genus.

Causative Organism* Morphology

The typical cells, measuring 1 x 3 - 4 micron.

have square ends and are arranged in long chains.

spores are located in the center of the nonmotile bacilli.

Causative OrganismIdentification

On Culture:-Colonies of B anthraces are

round and have a "cut glass" appearance.

Haemolysis is uncommon with B anthraces.

Causative Organism

Identification

Growth in gelatine stabs resembles an inverted fir tree.

Causative OrganismIdentification

Gram-positive, spore-forming, non-motile bacillus

Causative OrganismGrowth Characteristics:-The saprophytic bacilli utilize simple

sources of nitrogen and carbon for energy and growth.

The spores are resistant to environmental changes, withstand dry heat and certain chemical disinfectants for moderate periods, and persist for years in dry earth

Disease ExitType :-

Anthrax is primarily a Zoonotic disease ( eg. goats, sheep, cattle, horses, etc;)

other animals (eg, rats) are relatively resistant to the infection

Disease ExitInfection To Human

Humans become infected incidentally by contact with infected animals or their products.

Disease ExitMode Of Transmision cutaneous anthrax

by the entry of spores through injured skin.

gastrointestinal anthrax (rarely) by the mucous membranes.

inhalation anthrax :- by inhalation of spores into the lung .

Pathogenesis

via lymphatics to the bloodstream

growth of the

vegetative

organisms

From dead

body to Env.

To Man or Animal

Pathogenesis

B anthracis that does not produce a capsule is not virulent and does not induce anthrax in test animals.

The poly-D-glutamic acid capsule is antiphagocytic. The capsule gene is on a plasmid.

Virulence FactorsAnthrax Toxin:-

Toxin Structure:-

Anthrax toxin is made up of three proteins:-

protective antigen (PA).

edema factor (EF).

lethal factor (LF).

Virulence FactorsAnthrax Toxin:-

EF is an adenylyl cyclase; with PA it forms a toxin known as edema toxin.

LF plus PA form lethal toxin, which is a major virulence factor and cause of death in infected animals.

Toxins responsible for tissue damage and edema

Virulence Factors

Anthrax Toxin:-

Protective AntigenLethal Factor Edema Factor

Edema ToxinLethal Toxin

Tissue damage, shock Edema

Virulence Factors How Toxin Work:-

clinical forms

Cutaneous

GIT Pulmonary

Clinical Findings In humans, approximately 95% of cases are

cutaneous anthrax and 5% are inhalation.

0%10%20%30%40%50%60%70%80%90%

100%

cutanous Pulmonary GIT

Column1

Series 2

Series 1

Clinical FindingsGastrointestinal anthrax is very rare; it

has been reported from Africa, Asia, and the United States following occasions where people have eaten meat from infected animals.

The bioterrorism events in the fall of 2001 resulted in 22 cases of anthrax: 11 inhalation and 11 cutaneous. Five of the patients with inhalation anthrax died. All the other patients survived.

Cutaneous AnthraxClinical Picture :-

The lesions typically are 1–3 cm in diameter and have a characteristic central black eschar. Marked edema occurs.

Lymphangitis and lymphadenopathy and systemic signs and symptoms of fever, malaise, and headache may occur.

Cutaneous Anthrax

Eschar Formation

Day 6

Day 4

Cutaneous Anthrax Vesicle Development

Day 2

Day 7Day 10

Cutaneous AnthraxSequelae :-

1) Healing After 7–10 days the eschar is fully developed.

Eventually it dries, loosens, and separates.

healing is by granulation and leaves a scar.

It may take many weeks for the lesion to heal and the edema to subside.

Cutaneous AnthraxSequelae :-

2) Death In as many as 20% of

patients, cutaneous anthrax can lead to sepsis, the consequences of systemic infection (including meningitis ) and death

Cutaneous Anthrax

Inhalation AnthraxPreview:-

Incubation period: 1-7 days (range up to 43 days).

Infection occure by inhalation of B.Anthrasis spores.

Case-fatality:

1) without antibiotic treatment – 85%- 97%

2) with antibiotic treatment – 75% (45% in 2001)

Inhalation AnthraxClinical Picture:-The early clinical manifestations are associated

with marked hemorrhagic necrosis and edema of the mediastinum.

Inhalation AnthraxClinical Picture:-

Rapid deterioration with fever, dyspnea, cyanosis and shock.

Hemorrhagic pleural effusions follow involvement of the pleura; cough is secondary to the effects on the trachea.

Inhalation Anthrax

Chest X-Ray :-Chest X-rays is advised as an initial method of inhalation anthrax detection, but it is sometimes not useful for patients without symptoms.

Find a widened mediastinum and pleural effusion

Inhalation AnthraxChest X-Ray :-

Substernal pain may be prominent, and there is pronounced mediastinal widening visible on x-ray chest films

Gastrointestinal anthrax

Preview:-Animals acquire anthrax through

ingestion of spores and spread of the organisms from the intestinal tract

This is Rare in Humans, Gastrointestinal anthrax is Extremely Uncommon.

Gastrointestinal anthrax

Clinical Picture :-

Abdominal pain, vomiting, and bloody diarrhea are clinical signs.

Sepsis occurs, and there may be hematogenous spread to the gastrointestinal tract, causing bowel ulceration, or to the meninges, causing hemorrhagic meningitis.

Laboratory Diagnostic TestsSpecimens:-

Specimens to be examined are fluid or pus from a local lesion, blood, and sputum.

Gram Stain :- Gram stain shows

large gram-positive rods.

Laboratory Diagnostic TestsDirect Examination :Stained smears from the local lesion or of

blood from dead animals often show chains of large gram-positive rods.

Carbohydrate fermentation is not useful. . Anthrax can be identified in dried smears by

immunofluorescence staining techniques.

immunofluorescence staining of sporation

Laboratory Diagnostic Tests

Culture : Nutrient broth non

motile

on blood agar plates, the organisms produce nonhemolytic gray to white colonies

On Mixed Flora a rough texture and a ground-glass appearance.

Comma-shaped outgrowths (Medusa head) may project from the colony.

Laboratory Diagnostic Tests

Laboratory Diagnostic Tests

Lab Characters

Virulent anthrax cultures kill mice upon intraperitoneal injection.

Demonstration of capsule requires growth on bicarbonate-containing medium in 5–7% CO2.

Lysis by a specific anthrax -bacteriophage may be helpful in identifying the organism.

Anthrax VaccinesDevelopment By Years

1881 Pasteur develops first live attenuated veterinary vaccine for livestock

1939 Improved live veterinary vaccine

1954 First cell-free human vaccine

1970 Improved cell-free vaccine licensed

Anthrax VaccinesPreparation:Immunization to prevent

anthrax is based on the classic experiments of Louis Pasteur.

In 1881 he proved that cultures grown in broth at 42–52 °C for several months lost much of their virulence

be injected live into sheep and cattle without causing disease; subsequently, such animals proved to be immune.

Louis Pasteur

Anthrax VaccinesPreparation: Four countries produce

vaccines for anthrax. Russia and China use

attenuated spore-based vaccine administered by scarification.

The US and Great Britain use a bacteria-free filtrate of cultures adsorbed to aluminum hydroxide

Anthrax Vaccines

Pre-exposure Vaccination

The current US FDA approved vaccine contains cell-free filtrates of a toxigenic nonencapsulated nonvirulent strain of B anthracis.

The vaccine is available only to the US Department of Defense and to persons at risk for repeated exposure to B anthracis.

Anthrax Vaccines

Vaccination Schedule

Initial doses at 0, 2, and 4 weeks.

Additional doses at 6, 12, and 18 months.

Annual booster doses thereafter.

Alternative schedules being investigated.

Anthrax VaccinesPost-exposure Vaccination

No efficacy data for postexposure vaccination of humans.

Postexposure vaccination alone not effective in animals

Combination of vaccine and antibiotics appears effective in animal model

Anthrax VaccinesPrecautions and Contraindications

Severe allergic reaction to a vaccine component or following a prior dose.

Previous anthrax disease.

Moderate or severe acute illness.

• By: El Omda

TreatmentMany antibiotics are

effective against anthrax in humans, but treatment must be started early.

Ciprofloxacin is recommended for treatment; penicillin G, along with gentamicin or streptomycin, has previously been used to treat anthrax. • By: El Omda

Chemoprophylaxis

prophylaxis with ciprofloxacin or doxycycline should be continued for 4 weeks while three doses of vaccine are being given, or for 8 weeks if no vaccine is administered.

In the setting of potential exposure to B anthracis as an agent of biologic warfare. • By: El Omda

Epidemiology

Soil is contaminated with anthrax spores from the carcasses of dead animals.

These spores remain viable for decades. Perhaps spores can germinate in soil at pH 6.5 at proper temperature.

EpidemiologyGrazing animals infected through

injured mucous membranes serve to perpetuate the chain of infection.

Prevention & Control Control measures include :-(1) disposal of animal carcasses by

burning or by deep burial in lime pits, (2) decontamination of animal products.(3) protective clothing and gloves for

handling potentially infected materials.(4) active immunization of domestic

animals with live attenuated vaccines. Persons with high occupational risk should be immunized.

• By: El Omda

THANK YOU

• By: El Omda