Basic Information About Anthrax

All Employee Briefing05 November 2001

Anthrax – The Disease

• An acute, infectious disease

• Can infect animals – herbivores– Cattle– Sheep

• Can infect humans – usually via occupation

• Infects herbivores

• Infect humans

Causative Agent - Anthrax

• B. anthracis (Gk: anthrakis – “coal”)– Large, spore-forming

bacterium• Gram-stain positive• Rod-shaped bacillus• Non-motile

– Two states• Vegetative - causes infection via

toxin production

• Spores – Protective in adverse

environments– May subsist for years

Historical Aspects of Anthrax

• Disease of antiquity– Biblical days

• Fifth Plague – Anthrax in cattle?• Sixth Plague – Anthrax in humans?

– “Black Bane” (Europe – 1600) – Anthrax?

• Important disease in Public Health History– Robert Koch – 1st disease to satisfy postulates– Firmly established microbial etiology (1876)– First immunization for bacterial disease (1881)

Historical Aspects of Anthrax (continued)

• Outbreaks– Zimbabwe Outbreak (October 1979 – March 1980)

• 6,000 cases

– Paraquay – 1987• 25 cases of cutaneous anthrax• Associated with slaughter of a single, infected cow

– Russia (Sverdlovsk)• 77 cases• 66 deaths (primarily inhalational)

Note: few cases have occurred in the US in last century

Forms of Anthrax-Routes of Entry

Inhalational Anthrax - Symptoms

• Initial symptoms– Mild, non-specific (e.g., “flu-like”)– Fever– Malaise– Mild cough, chest pain

• Acute symptoms– Respiratory distress– Shock– Mediastinal widening on chest X-ray

• Fatalities can occur (80-90%)

Cutaneous Anthrax - Symptoms

• Itching of skin• Lesion - progression

– spider bite-like pustule– Vesicle (blisters)– black lesion - eschar

• Lesion – location– Head– Arms– Hands

• Moderate to severe swelling around lesion– Lymph nodes– Secondary infection

• Fatalities can occur

G.I. Anthrax - Symptoms

• May resemble food-borne disease– Abdominal distress– Fever

• Septicemia (toxins in blood)

• Fatalities can occur

Public Health – Geographic Distn

• B. anthracis found globally– Central and South

America– Southern and Eastern

Europe– Asia– Africa– Middle East

• Countries with poor veterinary medicine & public health programs

• Occurs in animals in United States

Public Health – Popn at Risk

• No person-to-person transmission

• Historically associated with occupational exposures– Animal handling– Rendering plants– Preparing animal hides – Woolsorter’s Disease

• Accidental exposures have occurred– Russian experience (Sverdlovsk)– Biological weapons production– Laboratory exposures

• Bioterrorism – recent events

Public Health - General

• Incubation period– 2-60 days– Mean incubation – 7

days

• Susceptibility and Resistance– Uncertain– Some inapparent

infections– Second attacks can

occur (rare)

Factors That Influence Natural History of Disease

• Occupation

• Amount of organisms– Infectious Dose: 8,000-

10,000 spores (est.)

• Spore size – 2-6 um diameter– May bind to larger

particles (static charge?)

• Host Factors– General health– Age– Pre-existing conditions– Immunization status– Hygienic practices

• Treatment– Prompt– Appropriate

Tests For Anthrax

• Nasal swabs – epidemiological tool– Not diagnostic for disease– Determines “Zone(s) of Exposure”

• Cultures– Blood– Exudates

• Antibody tests – antibodies to anthrax

• Polymerase Chain Reaction (PCR)– DNA amplification

• Environmental tests– Swabs– Wipes

Tests for Anthrax

• Antibody tests– Quick antibody test

strips– ELISA test (lab)– Blood test

• Microscopic analysis• Bacterial culture• DNA test – PCR• Environmental

samples– Swabs– Wipes

Medical Prevention and Treatment

• All forms of anthrax– Floroquinolones-oral (Ciprofloxacin)* – Doxycycline-oral**

• 100 mg BID for adults• 1mg/pound BID for children (less than 100 pounds)

– Penicillin– Others available

• Antibiotics effective for exposed persons

• Antibiotics effective early

* Drug of choice

** Approved by FDA for Anthrax on 18 October 2001

Anthrax Vaccine Adsorbed (AVA)

• Licensed by FDA in 1970

• Vaccine consists of:– Noninfectious sterile

filtrate from B. anthracis culture

– Adsorbed to aluminum hydroxide adjuvant

– Formaldehyde stabilizer (<0.02% conc.)

– Benzethonium chloride preservative

– Impossible to contract disease from vaccine

• Dosage schedule:– Six (6) doses

• 0, 2, 4 weeks• 6, 12, 18 months

– Annual booster required

• Administered to:– Healthy people– 18-65 years of age

Who Should Be Vaccinated?

• Work directly with B. anthracis in the laboratory

• Persons who work with imported animal hides or furs in areas where standards are insufficient to prevent exposure to anthrax spores.

• Veterinarians• Handle potentially infected

animal products in high-incidence areas.

• Military personnel

Source: The Advisory Committee on Immunization Practices (ACIP)

Medical Prevention and Treatment

• Vaccine (AVA) information– Produced by Bioport Inc., Lansing, MI– Military/mission-essential civilians vaccinated– Not available to general public– Not used for contacts of index case

• Adverse Events– No unexpected local adverse reactions– No unexpected systemic adverse reactions

Anthrax: Current Issues

Employee Briefing-Part II05 November 2001

Issue of Cross Contamination

• Some letters were intentionally contaminated

• Current evidence points to the likelihood of cross contamination

• What does that mean?

Cross Contamination

• Number of spores should decline farther from the source

• Inhalation vs Cutaneous

• Makes risk low … but not zero

So… What to Do ?

• Don’t panic but take simple steps to protect yourself:

– Watch for suspicious mail– Know the symptoms and act on them if you feel you need to– Wash your hands at appropriate times

We Will Stay Current

As new information is known, we will make every attempt to get

it to you !

* PS: We Will Win !