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7/27/2019 Anthrax Smt7

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ANTHRAX

Tropical Infectious Disease Division

Department of Internal Medicine

Faculty of Medicine Brawijaya University / Dr. Saiful Anwar GeneralHoapital

Malang


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Baci l lus anth racis

Gram + rod

Facultative anaerobe

1 - 1.2m in width x 3 - 5m inlength

Belongs to the B. cereusfamily

Thiamin growthrequirement

Glutamyl-polypeptide

capsule Nonmotile

Forms oval, central ly locatedendospores

http://www.bact.wisc.edu/Bact330/l

ectureanthrax


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Endospore Oxygen required for

sporulation

1 spore per cell

dehydrated cells

Highly resistantto h eat,

co ld, chemicaldisin fectants, dry per iod s

Protoplast carries the material

for future vegetative cell

Cortex provides heat and

radiation resistance Spore wall provides protection

from chemicals & enzymes http://www.gsbs.utmb.edu/microbook/ch0


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Where is Anthrax?

http://www.vetmed.lsu.edu/whocc/mp_world.htm


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Anthrax From the Greek word anthrakosfor coal Caused by spores

Primari ly a disease ofdom est icated & wi ld animals

Herbivores such as sheep, cows, horses, goats

Natural reservoir isso i l

Does not depend on an animal reservoir making it hardto eradicate

Cannot be regularly cultivated from soils where there isan absence of endemic anthrax

Anthrax zones Soil rich in organic matter (pH < 6.0)

Dramatic changes in climate


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Anthrax Infection & Spread May be spread by streams, insects, wild animals, birds,

contaminated wastes

Animals infected by soilborne spores in food & water or bitesfrom certain insects

Humans can be infected when in contact wi th f lesh, bones,hides, hair , & excrement

nonindustrial or industrial

cutaneous & inhalational most common

Risk of natural infection 1/100,000

Outbreaks occur in endemic areas after outbreaks inlivestock


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Three forms of Anthrax

Cutaneousanthrax

Skin

Most common

Spores enter to skin through small lesions

Inhalationanthrax

Spores are inhaled

Gastrointest inal(GI)anthrax

Spores are ingested

Oral-pharyngeal and abdominal


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Pathogenesis The infectious dose ofB.

anthracisin humans by anyroute is not precisely known.

Rely on primate data

Minimum infection dose

of ~ 1,000-8,000 spores LD50 of 8,000-10,000

spores for inhalation

Virulence depends on 2factors

Capsule 3 toxins

http://www.kvarkadabra.net/index.html?/biologija/teksti/biolosko_orozje.htm


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Clinical Information

Infection

Symptoms (1st and 2nd phase)

Three forms of Anthrax infection and their

Pathology

Diagnosis


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Infection of Anthrax The estimated number of naturally occurring human cases of

anthrax in the world is 20,000 to 100,000 per year.

Humans are infected through contact with infected animals andtheir products because of human intervention.

Anthrax spores contaminate the ground when an affected animaldies and can live in the soil for many years.

Anthrax can also be spread by eating undercooked meat frominfected animals.

Anthrax is NOT transmitted from person to person.

Humans can be exposed but not be infected


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What are the symptoms for anthrax?

There are two phases of symptom.

1) Early phase - Many symptoms can occur within 7 days of

infection

2) 2nd phase - Will hit hard, and usually occurs within 2 or 3

days after the early phase.


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- Early Phase Symptoms -

Fever (temperature > 100 degrees F)

Chills or night sweats

Headache, cough, chest discomfort, sore throat

Joint stiffness, joint pain, muscle aches

Shortness of breath

Enlarged lymph nodes, nausea, loss of appetite, abdominaldistress, vomiting, diarrhea

Meningitis


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- 2nd Phase Symptoms -

Breathing problems, pneumonia

Shock

Swollen lymph glands

Profuse sweating

Cyanosis (skin turns blue)

Death


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Three clinical forms of Anthrax

3 types of anthrax infection occur in humans:

1) Cutaneous

2) Inhalation

3) GI


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Cutaneous Anthrax 95% of anthrax infections occur

when the bacterium enters a cut or

scratch on the skin due to handling

of contaminated animal products

or infected animals.

May also be spread by biting

insects that have fed on infected

hosts.

After the spore germinates in skin

t issu es, toxin pro duc t ion ini t ial ly

resul ts in i tchy b ump that develops

into a vesicle and then painless

black ulcer.

http://science.howstuffworks.com/anthrax1.htm


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Cutaneous Anthrax (2)

The mo st common natural ly occurr ing form o f anthrax.

Ulcers are usually 1-3 cm in diameter.

Incubation period:

Usually an immediate response up to 1 day

Case fatality after 2 days of infection:

Untreated (20%) With antimicrobial therapy (1%)


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Cutaneous Anthrax (3)

CDC, Cutaneous AnthraxVesicle Development


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Inhalation Anthrax The infection begins with the

inhalation of the anthrax spore.

Spores need to be less than 5microns (millionths of a meter)to reach the alveolus.

Macrophages lyse and destroysome of the spores.

Survived spores aretransported to lymph nodes.

At least 2,500 spores have to beinhaled to cause an infection.

Inhalation Anthrax, Introduction, DRP, Armed Forces Institute of Pathology


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Inhalation Anthrax (2) Disease immediately follows

germination.

Spores replicate in the lymphnodes.

The two lungs are separated by astructure called the mediastinum,which contains the heart, trachea,esophagus, and blood vessels.

Bacter ial toxin s released dur in grepl icat ion result in mediast inalwidening and pleural ef fus ions(accumulat ion of f lu id in thepleu ral space).

Inhalation Anthrax, Introduction, DRP, Armed Forces Institute of Pathology


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Inhalation Anthrax (3) Death usually results 2-3 days after the onset of symptoms.

Natural infection is extremely rare (in the US, 20 cases werereported in last century).

Inhalat ion Anth rax is themo st lethal typeof Anthrax.

Incubation period:

17 days

Possibly ranging up to 42 days (depending on how manyspores were inhaled).

Case fatality after 2 days of infection:

Untreated (97%)

With antimicrobial therapy (75%)


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Gastrointestinal Anthrax

GI anthrax may follow afterthe consumption ofcontaminated, poorlycooked meat.

There are 2 different formsof GI anthrax:

1) Oral-pharyngeal

2) Abdominal

Abdominal anthrax is morecommon than the oral-pharyngeal form.

http://science.howstuffworks.com/anthrax1.htm


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GI Anthrax (2)

Oral-pharyngeal form - results from the deposition and

germination of spores in the upper gastrointestinal tract.

Local lumphadenopathy (an infection of the lymph glands

and lymph channels), edema, sepsis develop after an oralor esophageal ulcer.

Abdominal form - develops from the deposition and

germination of spores in the lower gastrointestinal tract,

which results in a primary intestinal lesion.

Symptoms such as abdominal pain and vomiting appear

within a few days after ingestion.


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GI Infection (3)

GI anthrax cases are uncommon.

There have been reported outbreaks in Zimbabwe, Africaand northern Thailand in the world.

GI anthrax has not been reported in the US.

Incubation period:

1-7 days

Case fatality at 2 days of infection: Untreated (25-60%)

With antimicrobial therapy (undefined) due to the rarity


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How is anthrax diagnosed?

Gram stain

Culture ofB. anthracisfrom the blood, skin lesions, vesicularfluid, or respiratory secretions

X-ray and Computed Tomography (CT) scan

Rapid detection methods

- PCR for detection of nucleic acid

- ELISA assay for antigen detection- Other immunohistochemical and immunoflourescence

examinations

- These are available only at certain labs


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Distinguishing inhalation Anthrax from

cold or influenza

Anthrax, cold, and influenza patients have similar symptoms at earlyphase such as flu-like symptoms (fever, chills, cough, and muscleaches etc.)

Symptoms o f Anthrax do not inc lude arunny nose, which is commonin cold and inf luenza .

Anthrax involves severe breath ing problems and more vomit ing.These symptom s are not very common in cold or inf luenza.

Anthrax have high white blood cell counts and no increase in thenumber of lymphocytes.

Flu usual ly have low wh i te blood cell cou nts and an inc rease in thenumber of lymphocy tes.

Inhalation anthrax has abnormality in X-ray or CT scan


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Treatment Before 2001, 1st line of

treatment was penicillin G Stopped for fear of

genetically engineeredresistant strains

60 day course of antibiotics

Ciprofloxacin

fluoroquinolone

500 mg tablet every 12h or400 mg IV every 12h

Inhibits DNA synthesis

Doxycycline

6-deoxy-tetracycline

100 mg tablet every 12h or100 mg IV every 12h

Inhibits protein synthesis

For inhalational, need anotherantimicrobial agent

clindamycin

rifampin

chloramphenico

http://nmhm.washingtondc.museum/new


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Treatment Penic i l lin and doxy cyc l ine

Intravenous administration

inhalational, gastrointestinal, and

meningeal anthrax

Cutaneous anthrax with signs of systemicinvolvement

Cutaneous anthrax:oral penicillin

Chloramphenicol, erythromycin, tetracycline,or ciprofloxacin (allergic to penicillin)

Doxycycline and tetracycline :not for pregnant

women or children


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Treatment

IV penicillin G :4 million units every 4 to 6 hrs

continued for 7 to 10 ds

Streptomycin had a synergistic effect with penicillin in

experiments

Ciprofloxacin :400 mg iv every 8 to 12 hrs

Doxycycline :200 mg iv then 100 mg iv every 8 ~12 hrs

Prophylaxis:Ciprofloxacin 500 mg or Doxycycline 100

mg by mouth twice a dayfor at least 6 wks Systemic corticosteroids for cervical edema and

meningitis


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"anthrax vaccine adsorbed" (AVA)

aluminum hydroxide-precipitated preparation of

protective antigen from attenuated, nonencapsulated

B. anthracis cultures of the Sterne strain

AVA :subcutaneously 0.5-ml dose ,repeated at 2

and 4 wks and at 6, 12, and 18 months

Boosters are then given annually

Decontamination :

vaporized formaldehyde

formaldehyde in seawater

Autoclaving and incineration

From N Engl J Med . 341(11):815-26, 1999 Sep 9


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Potential Biological Warfare Agent

US military's current M17 and M40 gas masks

provide excellent protection against the 1- to 5-

micrometers particulates needed for a successful

aerosol attack

preexposure useof the current AVA anthrax vaccine postexposure antibiotic prophylaxis

doxycycline plus postexposure vaccination survived a

lethal aerosol challenge

From Archives of Internal Medicine 158(5):429-34 1998 Mar 9

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