Anthrax and Anthrax Vaccine

Transcription

1 Anthrax and Anthrax Vaccine Under Supervision of : Prof. Dr\ Ekram M. El-Shabrawy Team Work : Mostafa Emad Ahmed Mohammed Bahaa El-Din Mostafa Abd-Elsamee Ahmed Mohamed Taha

2 Contents Causative Organism. Disease Exit. Pathogenesis. Virulence Factors. Clinical Forms. Clinical Findings. Laboratory Tests Vaccine Treatment Chemoprophylaxis Epidemiology. Prevention & Control

3 Causative Organism Scientific classification:- Kingom Bacteria Phylum Class Family Genus Species Firmicutes Bacilli Bacillacea Bacillus B. anthracis

4 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

5 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.

6 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.

7 Causative Organism Identification On Culture:- Colonies of B anthraces are round and have a "cut glass" appearance. Haemolysis is uncommon with B anthraces.

8 Causative Organism Identification Growth in gelatine stabs resembles an inverted fir tree.

9 Causative Organism Identification Gram-positive, spore-forming, non-motile bacillus

10 Causative Organism Growth 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

11 Type :- Disease Exit Anthrax is primarily a Zoonotic disease ( eg. goats, sheep, cattle, horses, etc;) other animals (eg, rats) are relatively resistant to the infection

12 Disease Exit Infection To Human Humans become infected incidentally by contact with infected animals or their products.

13 Disease Exit Mode 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.

14 From dead body to Env. Pathogenesis growth of the vegetative organisms To Man or Animal via lymphatics to the bloodstream

15 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.

16 Virulence Factors Anthrax Toxin:- Toxin Structure:- Anthrax toxin is made up of three proteins:- protective antigen (PA). edema factor (EF). lethal factor (LF).

17 Virulence Factors Anthrax 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

18 Virulence Factors Anthrax Toxin:- Lethal Factor Protective Antigen Edema Factor Lethal Toxin Edema Toxin Tissue damage, shock Edema

19 Virulence Factors How Toxin Work:-

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21 clinical forms Cutaneous GIT Pulmonary

22 Clinical Findings In humans, approximately 95% of cases are cutaneous anthrax and 5% are inhalation. 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% cutanous Pulmonary GIT Column1 Series 2 Series 1

23 Clinical Findings Gastrointestinal 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.

24 Cutaneous Anthrax Clinical 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.

25 Cutaneous Anthrax Cutaneous Anthrax Vesicle Development Day 2 Day 4 Eschar Formation Day 6 Day 7 Day 10

26 Cutaneous Anthrax Sequelae :- 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.

27 Cutaneous Anthrax Sequelae :- 2) Death In as many as 20% of patients, cutaneous anthrax can lead to sepsis, the consequences of systemic infection (including meningitis ) and death

28 Cutaneous Anthrax

29 Inhalation Anthrax Preview:- 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)

30 Inhalation Anthrax Clinical Picture:- The early clinical manifestations are associated with marked hemorrhagic necrosis and edema of the mediastinum.

31 Inhalation Anthrax Clinical 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.

32 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

33 Inhalation Anthrax Chest X-Ray :- Substernal pain may be prominent, and there is pronounced mediastinal widening visible on x-ray chest films

34 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.

35 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.

36 Laboratory Diagnostic Tests Specimens:- Specimens to be examined are fluid or pus from a local lesion, blood, and sputum. Gram Stain :- Gram stain shows large gram-positive rods.

37 Laboratory Diagnostic Tests Direct 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

38 Laboratory Diagnostic Tests Culture : Nutrient broth motile non on blood agar plates, the organisms produce nonhemolytic gray to white colonies On Mixed Flora a rough texture and a groundglass appearance. Comma-shaped outgrowths (Medusa head) may project from the colony.

39 Laboratory Diagnostic Tests

40 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.

41 1881 Anthrax Vaccines Development By Years 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

42 Anthrax Vaccines Preparation: Immunization to prevent anthrax is based on the classic experiments of Louis Pasteur. In 1881 he proved that cultures grown in broth at 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

43 Anthrax Vaccines Preparation: Four countries produce vaccines for anthrax. Russia and China use attenuated sporebased vaccine administered by scarification. The US and Great Britain use a bacteriafree filtrate of cultures adsorbed to aluminum hydroxide

44 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.

45 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.

46 Anthrax Vaccines Post-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

47 Anthrax Vaccines Precautions 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

48 Treatment Many 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

49 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

50 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.

51 Epidemiology Grazing animals infected through injured mucous membranes serve to perpetuate the chain of infection.

52 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

53 By: El Omda