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Nurses Continuing Education
Institute Anthrax Bioterrorism
and Health Care
| Course Number |
LWN411 |
| Objectives |
At the end of this course, you will 1)
describe the characteristics of anthrax infections, 2) distinguish
between the three anthrax forms, 3) analyze the effectiveness of anthrax
vaccinations and 4) relate anthrax to bioterrorism .
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| Credit Hours and Fee |
3.0 CE Credit Hours with a fee of $24.00 |
| Instructor |
Rudolf Klimes, PhD (Indiana University), MPH
(Johns Hopkins University) Adjunct Professor, Folsom Lake College,
Folsom, CA. |
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Disclaimer: This course is for general background information
for nurses and other health professionals. It was compiled mainly from existing
CDC and university documents. It is a continuing education course and should not
be used as an authorative document for treatment. Readers are invited to email
updates and possible content additions to
edu@learnwell.org.
Questions
for Self-study
Do the following for self-study. Do not submit the answers.
Anthrax infections can come through the nose, mouth or broken skin.
Anthrax is a bacteria.
Anthrax infection is mainly a human disease.
Anthrax spores are found only in the laboratory or weapons.
1.
Anthrax
Anthrax is an infectious bacterial disease spread by contact with infected
animals, handling infected products, eating infected meat, or breathing
weapon-dispersed anthrax spores.
Bioterrorism is the intentional use of
infectious biological agents, or germs, to cause illness.
Bacillus anthracis, the etiologic agent of anthrax, is a
large, gram-positive, nonmotile, spore-forming bacterial rod. The three
virulence factors of B. anthracis are edema toxin, lethal toxin and a
capsular antigen. B. anthracis is considered to be a likely agent for use
in acts of biological terrorism.
In the United States, incidence is extremely low.
Gastrointestinal anthrax is rare but may occur as explosive outbreaks associated
with ingestion of infected animals. Worldwide, the incidence is unknown, though
B. anthracis is present in most of the world. For
both livestock and humans, anthrax is a notifiable disease in the United States.
Among humans, there has been no increase in naturally acquired infection in the
United States. Recently, considerable attention has been focused on the
potential for B. anthracis to be used in acts of biologic terrorism.
Anthrax is primarily a disease
of domesticated and wild animals, particularly herbivorous animals. Humans
become infected incidentally when brought into contact with diseased animals,
which includes their flesh, bones, hides, hair and excrement, or through
bioterrorism..
If untreated, anthrax in all forms can lead to septicemia and
death. Early treatment of cutaneous anthrax is usually curative. Without
treatment, it has a 20% fatality rate. Early treatment of all forms is important
for recovery. Patients with gastrointestinal anthrax have reported case-
fatality rates ranging from 25% to 75%. Case-fatality rates for inhalational
anthrax are thought to approach 90 to 100%.
Source: CDC,
Dec 2000.
Anthrax is diagnosed by isolating B. anthracis from the blood, skin lesions,
or respiratory secretions or by measuring specific antibodies in the blood of
persons with suspected cases.
Human anthrax has three major clinical forms, namely cutaneous,
inhalation, and gastrointestinal. Cutaneous anthrax is a result of introduction
of the spore through the skin; inhalation anthrax, through the respiratory
tract; and gastrointestinal anthrax, by ingestion.
2.
Cutaneous Anthrax
Cutaneous (skin) anthrax is an infection due to a bacterium (Bacillus
anthracis) that is found in the environment and typically causes illlness in
animals. Cutaneous anthrax is the most common manifestation of infection (about
95% of all cases) with
B. anthracis. It is marked by a boil-like lesion that eventually forms an
ulcer with a black center. The infection occurs when the bacteria enter a cut or
scratch in the skin. Most cutaneous anthrax infections occur when people touch
animal products (like wool, bone, hair, and hide) that come from an animal that
died of anthrax.
If you develop cutaneous anthrax, the drainage from the open sore presents a
low risk of infection to others. The only way cutaneous anthrax can be
transmitted is by direct contact with the drainage from an open sore. It is not
spread from person to person by casual contact, sharing office space, or by
coughing and sneezing. Human-to-human transmission is extremely rare and only
reported with cutaneous anthrax.
The cutaneous form of anthrax responds well to several antibiotics. The
United States has a large supply of these antibiotics and can quickly
manufacture more if needed. With treatment, complete recovery from cutaneous
anthrax is usual.
Cutaneous anthrax is diagnosed when the Bacillus anthracis bacterium
is found in the skin lesion by a laboratory culture. It can also be diagnosed by
measuring specific antibodies in the blood of persons who are suspected of
having infection. Cutaneous anthrax is not usually fatal. If treated with
appropriate antibiotics, most individuals make a full recovery.
Source: New York State Dep of Health 10/12/01
3. Inhalation Anthrax
Infection is spread by breathing in anthrax spores that germinate and cause
pneumonia. The anthrax spores settle in the alvioli, the tiny air sacs in
the lungs. The pneumonia develops very rapidly and leads to progressive
respiratory distress. Death can result in less than 48 hours. Meningitis can
also develop.
Inhalation (pulmonary) anthrax occurs in persons working in certain
occupations where spores may be forced into the air from contaminated animal
products, such as animal hair processing. Occupational risk groups include those
coming into contact with livestock or products from livestock, e.g.,
veterinarians, animal handlers, abattoir workers, and laboratorians.
Source: CDC,
Dec 2000.
Inhalation anthrax has an usual incubation period of several days, but the
range is from 1-60 days. Then symptoms appear in two stages
Inhalation anthrax (also known as Woolsorter's disease) is a biphasic
illness. The first phase occurs when the spores are carried to the mediastinal
lymph nodes by pulmonary macrophages and cause a suppurative infection with
edema and hemorrhage. This phase is characterized by nonspecific flu-like
symptoms; fever from 100 to 103 degrees, malaise, fatigue, myalgia, nonproductive cough, and at
times a sensation of chest oppression or pressure. Rhonchi may be heard with a
stethoscope. The presence of such symptoms in a large number of personnel at
once should raise the suspicion of anthrax. This phase can last for several
days (usually 1-3 days), and can be followed by
an asymptomatic period. A helpful radiographic sign is symmetrical enlargement
of the superior mediastinum due to lymph node enlargement. The disease is
treatable in this stage, but blood cultures are probably negative (no data on
this). Sputum cultures might have a higher yield, particularly if anthrax is
specifically looked for. It antibiotic treatment is started early in this phase,
the survival rate is 25 % at best.
The second phase develops suddenly with the development of severe shortness
of breath and cyanosis. Hypotension and shock occur. The temperature may be
elevated or subnormal due to shock, and perspiration is often profuse. Stridor
may be present due to enlargement of the lymph nodes near the trachea. Chest
exam shows moist, crepitant rales and signs of pleural effusion. Blood cultures
are positive, and the bacteremia may be high enough for organisms to be visible
on a Gram stained smear. The second, acute phase typically lasts less than 24
hours and usually ends in death despite therapy, due to the high number of
toxin-producing organisms present by this stage in the illness. Bases mainly on
Author: Sheldon Campbell MD, PhD
12/2/90
Antibiotics should be given to unvaccinated individuals exposed to inhalation
anthrax. Penicillin, tetracyclines and fluoroquinolones (Cipro) are effective if
administered before the onset of lymphatic spread or septicemia, estimated to be
about 24 hours. Antibiotic treatment is also known to lessen the severity of
disease in individuals who acquire anthrax through the skin. Inhaled Anthrax
was formerly thought to be nearly 100% fatal despite antibiotic treatment,
particularly if treatment is started after symptoms appear. A recent Army study
resulted in successful treatment of monkeys with antibiotic therapy after being
exposed to anthrax spores. The antibiotic therapy was begun one day after
exposure.
4. Gastrointestinal Anthrax
Gastrointestinal anthrax is rare but may occur as explosive
outbreaks associated with ingestion of infected animals. Worldwide, the
incidence is unknown, though B. anthracis is present in most of the
world.
Eating anthrax-infected meat can result in gastrointestinal infection
(gastrointestinal anthrax). Gastrointestinal anthrax is generally not considered
a threat to U.S. forces.
Gastrointestinal infection is associated with
ingestion of undercooked contaminated meat, usually that of goats, sheep and
cows(1). There are 2 distinct syndromes of gastrointestinal anthrax:
oral-pharyngeal and abdominal. The oral-pharyngeal form of the disease results
from the deposition and germination of spores in the upper gastrointestinal
tract. Local
lymphadenopathy, edema, and
sepsis develop after an oral or esophageal ulcer.
Dysphagia and respiratory difficulties usually occur as a result. The
abdominal form of the disease develops from the deposition and germination of
spores in the lower gastrointestinal tract, which results in a primary
intestinal lesion
(6). Symptoms appear two to five days after ingestion, and include nausea,
abdominal pain, vomiting, and malaise, eventually progressing to bloody
diarrhea, acute abdomen, or sepsis
(6 and 7). Massive edema and mucosal necrosis occur at the sites of
infection. Due to the ulceration of the gastrointestinal mucosa, blood-tinged
vomiting usually occurs.
Ascites eventually develop two to four days after the onset of symptoms
(7).
Mortality rates are high in gastrointestinal anthrax
because of the difficulty of early diagnosis
(6). Intestinal perforation or anthrax toxemia are the usual causes of
death. The morbidity of gastrointestinal anthrax is due to blood loss,
electrolyte imbalance, and subsequent shock
(7).
Gastrointestinal anthrax cases are uncommon, however,
there have been reported outbreaks in Africa and Asia
(6). Abdominal anthrax is more common than the oral-pharyngeal form
(7). The consumption of contaminated buffalo meat resulted in 24 cases of
oral-pharyngeal anthrax in Thailand in 1982. Five years later, 14 cases were
reported in Thailand with both oral-pharyngeal and abdominal disease occurring.
Gastrointestinal anthrax has not been reported in the United States
(6).
Source Brown U
5. Immunization for Anthrax
Currently, the anthrax vaccine is produced under contract
to the Department of Defense, and only small quantities are made available as
needed to civilians who are exposed to anthrax hazards in their work
environment, such as veterinarians, lab workers and others. An attempt to
immunize 2.5 million members of the military ended three years ago, but that
policy is being reevaluated. If the manufacturer receives approval from the
FDA, vaccine production will resume.
The anthrax vaccine is a preparation of the protective
antigen (a fraction of the toxin) recovered from the culture filtrate of an
avirulent, nonencapsulated strain of Bacillus anthracis. Anthrax
immunization consists of three subcutaneous injections given two weeks apart
followed by three additional subcutaneous injections given at 6, 12, and 18
months. Annual booster injections of the vaccine are required to maintain a
protective level of immunity.
A segment of the U.S. military population has been
vaccinated against anthrax. The first vaccine of the series must be given at least
four weeks before exposure to the disease. This vaccine protects against anthrax
that is acquired through the skin and it is believed that it would also be
effective against inhaled spores in a biowarfare situation.
Source: UW
The CDC course of action for preventing anthrax after
exposure in the civilian population would be with antibiotics. Vaccination is
not recommended, and the vaccine is not available to health care providers or
the general public. We do not recommend that physicians prescribe antibiotics
for anthrax at this time. We currently have enough antibiotics to prevent the
disease in 2 million persons exposed to anthrax, therefore we could rapidly get
preventive medicine to those who may be affected by this disease, which cannot
be transmitted between people. Source www.cdc.gov
6.
Anthrax Bioterrorism
The possibility of creating aerosols containing anthrax
spores has made B. anthracis a chosen weapon of bioterrorism. Iraq,
Russia and as many as ten nations have the capability to load spores of B.
anthracis into weapons. Domestic terrorists may develop means to distribute
spores via mass attacks or small-scale attacks at a local level.
As an agent of biological warfare it is expected that a
cloud of anthrax spores would be released at a
strategic location to be inhaled by the individuals under attack. Spores of
B. anthracis can be produced and stored in a dry form and remain
viable for decades in storage or after release.
There is no evidence of person-to person transmission of
anthrax. Quarantine of affected individuals is not recommended. Anthrax spores
may survive in the soil, water and on surfaces for many years. Spores can only
be destroyed by steam sterilization or burning. Disinfection of contaminated
articles may be accomplished using a 0.05% hypochlorite solution (1 tbsp. bleach
per gallon of water). It has also been reported that boiling (100 degrees C) for
two minutes kills endospores of B. anthracis.
As far as getting dangerous mail with anthrax, there is
first the logistics of sending out a large number of envelopes containing
spores. Anthrax spores need to be dispersed in the air with very advanced
equipment to become the dangerous form, pulmonary anthrax, that is lethal.
But. (1) Check the address, is it someone you know? If it is someone you know,
no problem (2) Check the post mark, where is it mailed from? (3) Is it a
catalog? It is not likely that any retailer is going to send you something
dangerous. (Note, glossy magazines will often put baby powder in between the
pages to prevent them from sticking together. Keep that in mind.) If you are
still worried and receive a suspicious package that does have a powder in it,
report it to your local authorities and consult your physician.
An infection of local animal populations such as sheep and
cattle could follow a biological attack with spores. Infected animals could then
transmit the disease to humans through the human's skin, mouth or nose. Source:
UW
Dealing with Anthrax, a Summary:
1. If you think you have been exposed to anthrax,
contact your doctor or health officials. If you need more information, search
the links on this page or contact CDC at 888-246-2675 or 770-488-7100.
2. Anthrax spores can be washed off with soup and water or regular laundering.
3. Hard surfaces that may have been exposed to anthrax should be wiped down with
a solution of one quart of water and 3 ounces of bleach.
4. If you think you may get exposed to anthrax, use disposable light-weight
surgical gloves and N95 half-masks.
5. To guard against anthrax, open you mail carefully and wash your hands after
opening the mail.
6. Never self-treat yourself for anthrax, seek professional help.
CDC Health Advisory on Anthrax
Ciprofloxacin is a broad-spectrum antibiotic
agent active against several bacteria including anthrax. The use of ciprofloxacin is warranted
only under the supervision of a physician. Ciprofloxacin is one antibiotic often
recommended to prevent anthrax after a person has been exposed to B. anthracis.
Supplementary information for general information only
and not as a guide for treatment (The standard therapy for inhalation
anthrax is intravenous penicillin G by continuous infusion, 50 mg/kg or 80,000
U/kg in the first hour, followed by 200 mg/kg or 320,000 U/kg over the following
24h. No data are available on the value on penicillin IM, but it would likely be
less effective and larger doses might be required. Streptomycin, 1-2 g/24h IM
has been described to be synergistic in combination with penicillin. An
alternative regimen is erythromycin, 4g/24h by continuous infusion. In a
biological warfare situation, however, it is recommend that vancomycin be a part
of any regimen, in a dose of 500 mg every 6 hours. Intramuscular injection of
vancomycin is painful. An inferior but possibly useful substitute for vancomycin
would be oxacillin, methicillin, or nafcillin in appropriate dosages (use the
PDR). Other drugs to which B. anthracis is generally considered susceptible
include the first-generation cephalosporins, tetracycline, and chloramphenicol.
Adjuvant therapy with hydrocortisone, 100-200 mg/day may be helpful in the case
of malignant chest-wall and neck edema. As soon as in vitro susceptibility data
are available, therapy should be adjusted to include effective drugs, and drugs
to which the isolate is resistant should be eliminated.}
Source: Sheldon Campbell
7.
Anthrax Library
Study
the Case Rounds
Explore recent updates via
More
Deadly
www.bt.cdc.gov
- The most complete site for information on biological terrorism.
http://www.dhs.ca.gov/Bioterrorism%20Headline/Revised%20BT%20Response%20master%20document.pdf
-California Hospital Bioterrrorism Response
Planning Guide DRAFT
Turnbull PCB, Bohm R et al., 1993, Guidelines for the Surveillance and
Control of Anthrax in Humans and Animals, Geneva. WHO/Zoon/93.170.
Smego R., Gebrian B., Desmangels G. Cutaneous Manifestations of Anthrax in Rural
Haiti. Clinical Infectious Diseases, 1998; 26:97-102.
Harrison L., Ezzell J., Veterinary Laboratory Investigation Center; Abshire T.,
Kidd S., Kaufmann A. Evaluation of Serologic Tests for Diagnosis of Anthrax
after an Outbreak of Cutaneous Anthrax in Paraguay. J Infect Dis 1989;160:4.
Suffin S., Carnes W., Kaufmann A. Inhalation Anthrax in a Home Craftsman.
Clinical Infectious Diseases, 1998;26:97-102.
CDC. Bioterrorism Alleging Use of Anthrax and Interim Guidelines for Management
- United States, 1998. MMWR Morb Mortal Wkly Rep 1999;48:4.
Manchee RJ et al (1981), Bacillus Anthracis on Gruinard Island, Nature 294,
254-255.
Manchee RJ et al (1983), Decontamination of Bacillus Anthracis on Gruinard
Island?, Nature 303, 239-240.
Wiener SL (1987), Strategies of Biowarfare Defense, Military Medicine 152,
25-28.
Brachman PS (1980), Inhalation Anthrax, Proc. NY. Acad. Sci., 83-93.
Knudson GB (1986), Treatment of Anthrax in Man: History and Current Concepts,
Military Medicine 151, 71-77.
Multiple Authors (1963), Defense Against Biological Warfare -- A Symposium,
Military Medicine 128, 81-146.
Health Aspects of Chemical and Biological Weapons, Report of a WHO Group of
Consultants, World Health Organization, Geneva, Switzerland, 1970.
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