BIOTERRORISM AGENTS
Group A agents:
· Can be easily transmitted form person to person
· Can result in high mortality rates
· Can cause panic and social disruption
· They require planning and special action to protect the public
Group B agents:
· They are easily disseminated
· They result in moderate morbidity rates and low mortality rates
· They require special CDC diagnostic capacity and disease surveillance
Group C agents:
· These could be engineered in the future and easily disseminated because they are:
· Readily available
· Easy to produce and disseminate
· Potential of high morbidity and mortality rates thus resulting in a major health impact
The following are some of the agents that are found in Group A
Clostridium botulinum
Clostridium botulinum is the pathogen that causes Botulism a serious muscle paralyzing disease. The toxin that is produce by this C. botulinum is very destructive of nerve cells; the toxin produced inhibits the release of acetylcholine which helps muscles cells move. This is the most potent toxin know 2 to 3 grams can kill the whole world. This is one of the reasons why it falls under category A. The following link shows an excellent video about C. botulinum it talks about the history of its use for warfare.
History of Clostridium botulinum
There are three main categories for botulism:
1. Food borne botulism can be acquired through the ingestion of foods that contain the toxin produced by C. botulinum this has been found in canned foods.
2. Infant botulism also occurs in infants who harbor C. botulinum in their intestinal tracks.
3. Wound botulism occurs when a person has a wound and C. botulinum enters the wound to release its toxin.
In the United States an average of 110 cases of botulism are reported each year. Of these, approximately 25% are foodborne, 72% are infant botulism, and the rest are wound botulism. Botulism is not transmitted form person to person.
Symptom
The symptoms of food borne botulism appear 6hours to 2 weeks after eating the food contaminated with the toxin. The symptoms include: double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth, muscle weakness that always descends through the body: first shoulders are affected, then upper arms, lower arms, thighs, calves, etc. Paralysis of breathing muscles can cause a person to stop breathing and die, unless they are provided with mechanical breathing.
Botulism Diagnosed
The symptoms of botulism can be very similar to other diseases so several tests have to be conducted: a brain scan, spinal fluid examination, nerve conduction test (electromyography, or EMG), and a tension test for myasthenia gravis. One direct method that is used consists of taking the patient's serum or stool by injecting serum or stool into mice to look for botulism.
Treatment
The recovery and treatment of botulism can take several weeks depending on the amount of toxin the person has consumed. If respiratory failure has occurred the patient must be under a breathing machine. However, if the food borne botulism or wound botulism is diagnosed early they can be treated with an antitoxin which blocks the circulation of the toxin in the blood. Another treatment for the wounds is by surgically removing the source of the bacteria.
Prevention
Botulism can be prevented by being careful when eating canned foods that have a low acid content examples of these are green beans, corn, and beats. People should boil canned foods for at least ten minutes because the toxin is destroyed at high temperatures. Proper handling of foods to avoid contamination such as keeping oils infused in herbs or garlic in the refrigerator, and potatoes baked in the oven with aluminum foil. Children who are under the age of 12 months should not be given honey because honey contains spores of C. botulinum. Wound botulism can be prevented by treating wounds medically.
Anthrax
What Is Anthrax?
A category A spore forming bacterium, Bacillus anthracis causes the serious disease Anthrax. This bacterium is a single cell, prokaryote. Spores are cells that are dormant and protected until the right conditions are present to exit from its dormant stage.
There are three types of anthrax:
• skin (cutaneous)
• lungs (inhalation)
• digestive (gastrointestinal)
How Do You Get It?
Anthrax is not known to spread from one person to another.
Anthrax from animals
Humans can become infected with anthrax by using products from infected animals or by breathing in anthrax spores from infected animal products (like wool, for example). Humans can contract gastrointestinal anthrax by consumption of undercooked meat from infected animals.
Anthrax as a weapon
Anthrax also can be used as a weapon by terrorist. This happened in the United States in 2001. Anthrax was deliberately spread through the postal system by sending letters with powder containing anthrax. This caused 22 cases of anthrax infection. Most notable was the case involving Anthrax sent to Senator Tom Daschle. Some of his staff members suffered from inhalation of Anthrax.
What Are the Symptoms?
The symptoms (warning signs) of anthrax are different depending on the type of the disease:
Cutaneous: Blister or ulcer that later forms a black scab; often with extensive surrounding swelling. A few patients may also experience fever, headache, and malaise swollen, painful lymph nodes.
Gastrointestinal: Early symptoms
Nausea
Loss of appetite
Vomiting
Fever
Later symptoms
Abdominal pain
Vomiting of blood
Severe diarrhea
How can Anthrax be treated?
Anthrax can be treated with antibiotics. The federal government currently has enough antibiotics stockpiled to treat anthrax in 2 million people exposed to the bacteria. Should exposure to a bioagent occur, information would be provided as to how to obtain appropriate treatment. Early use of antibiotics is essential for survival. In most cases, early treatment with antibiotics can cure cutaneous anthrax. Even if untreated, 80 percent of people who become infected with cutaneous anthrax do not die. Gastrointestinal anthrax is more serious because between one fourth and more than half of cases lead to death. Inhalation anthrax is much more severe. In 2001, about half of the cases of inhalation anthrax ended in death.
Smallpox- Variola
|
|
|
|
Incubation
Period (Duration:
7 to 17 days) Not
contagious |
Exposure
to the virus is
followed by an incubation period during which people do not have any
symptoms and may feel fine. This incubation period averages about 12 to
14 days but can range from 7 to 17 days. During this time, people are
not contagious. |
|
Initial
Symptoms (Prodrome) (Duration:
2 to 4 days) Sometimes
contagious* |
The first
symptoms of smallpox include fever, malaise, head and body aches,
and sometimes vomiting. The fever is usually high, in the range of 101
to 104 degrees Fahrenheit. At this time, people are usually too sick to
carry on their normal activities. This is called the prodrome phase
and may last for 2 to 4 days. |
|
Early
Rash (Duration:
about 4 days) Most
contagious Rash
distribution: |
A rash
emerges first as small red spots on the tongue and in the mouth. These
spots develop into sores that break open and spread large amounts of
the virus into the mouth and throat. At this time, the person becomes most
contagious. Around
the time the sores in the mouth break down, a rash appears on the skin,
starting on the face and spreading to the arms and legs and then to the
hands and feet. Usually the rash spreads to all parts of the body
within 24 hours. As the rash appears, the fever usually falls and the
person may start to feel better. By the
third day of the rash, the rash becomes raised bumps. By the
fourth day, the bumps fill with a thick, opaque fluid and often have a
depression in the center that looks like a bellybutton. (This is a
major distinguishing characteristic of smallpox.) Fever
often will rise again at this time and remain high until scabs form
over the bumps. |
|
Pustular
Rash (Duration:
about 5 days) Contagious
|
The bumps
become pustules—sharply raised, usually round and firm to the
touch as if there’s a small round object under the skin. People often
say the bumps feel like BB pellets embedded in the skin. |
|
Pustules
and Scabs (Duration:
about 5 days) Contagious
|
The
pustules begin to form a crust and then scab. By the
end of the second week after the rash appears, most of the sores have
scabbed over. |
|
Resolving
Scabs (Duration:
about 6 days) Contagious
|
The scabs
begin to fall off, leaving marks on the skin that eventually become
pitted scars. Most scabs will have fallen off three weeks after
the rash appears. The
person is contagious to others until all of the scabs have fallen off. |
|
Scabs
resolved Not
contagious
|
Scabs
have fallen off. Person is no longer contagious. |
The following are some of the agents that are found in Group B:
Coxiella burnetii
What is Coxiella burnetii ?
Coxiella burnetii is a gram negative species of intracellular, pathogenic bacteria, and is the causative agent of Q fever. Q (Query) fever is so-called because for many years its cause was unknown. Cattle and sheep are the most common carriers.
How can you get Coxiella burnetii ?
Humans usually contract Q fever when they breathe in the Q fever microbe. It is very infectious. As few as ten Q fever microbes can start an infection. Coxiella burnetii is found in the afterbirth and birth fluids. Coxiella burnetii is also found in the milk, urine, and feces of infected animals. Human infection usually occurs by inhalation of infected dust or exposure to amniotic fluid or placenta, where the organism can survive for long periods of time.
How do I know if I may be infected with Coxiella burnetii ?
People can have Q fever without knowing it or mistake it for mild flu. Often, it is impossible to tell without laboratory tests. Common signs and symptoms resemble a serious case of the flu such as sudden on set of high fever, chills, sweating, and loss of appetite. Some patients develop a slight, dry cough because of a lung inflammation known as pneumonitis. Most symptoms disappear after 7-10 days. However, afflicted people can feel generally ill with loss of appetite for several weeks. A small percentage of patients develop hepatitis or liver disease and jaundice, a yellowing of the skin and darkening of the urine, caused by a malfunctioning of the liver.
How can Coxiella burnetii be treated?
A vaccine is not commercially available in the United States, but the phase I Henzerling vaccine developed by the US Army may be obtained under an investigational new drug (IND) protocol. Vaccination of humans is apparently effective, but care must be taken not to inoculate people who have had previous exposure. Treatment of acute Q fever depends on the clinical presentation. Pneumonia usually resolves without treatment within 2 weeks. In severely ill patients, treatment must be started within the first 3 days of illness to be effective. Tetracycline compounds and especially doxycycline (200 mg for 15 to 21 days) are still the drugs currently recommended to treat acute Q fever. Chronic Q fever usually requires prolonged chemotherapy with doxycycline and rifampin. More recently, treatment of Q fever with 900 mg of chloroquine and 200 mg of doxycycline/d gave excellent results.
Ricinus communis
What is Ricin?
Seeds from the castor bean plant, Ricinus communis, are poisonous to humans, animals and insects. The main toxic protein is ricin. Herman Stillmark found in 1888 performed test on the bean’s extract on red blood cells and saw them agglutinate. The agglutination was due to another toxin present, called RCA (Ricinus communis agglutinin). Poisoning by ingestion of the castor bean is due to ricin, not RCA, because RCA does not penetrate the intestinal wall, and does not affect red blood cells unless given intravenously. If RCA is injected into the blood, it will cause the red blood cells to agglutinate and burst by hemolysis. One milligram of ricin can kill an adult.
How can you get Ricin?
It would take a deliberate act to make ricin and use it to poison people. Accidental exposure to ricin is highly unlikely. People can breathe in ricin mist or powder and be poison. Ricin can also get into water or food and then be swallowed. Pellets of ricin, or ricin dissolved in a liquid, can be injected into people’s bodies. Depending on the route of exposure (such as injection or inhalation), as little as 500 micrograms of ricin can be enough to kill an adult. A 500microgram dose of ricin would be about the size of the head of a pin. Some reports have indicated that ricin may have been used in the Iran-Iraq war during the 1980s and that quantities of ricin were found in Al Qaeda caves in Afghanistan. Ricin poisoning is not contagious and contact be spread from person to person contact.
How do I know if I may be infected with Ricin?
Ricin-contaminated material causes diarrhea, nausea, vomiting, abdominal cramps, internal bleeding, liver and kidney failure, and circulatory failure. Rapid heartbeat can also occur. Breathing of aerosol mist that contains ricin causes cough, weakness, fever, nausea, muscle aches, difficult breathing, chest pain, and cyanosis (blue skin). Breathing the mist can result in respiratory and circulatory failure. Exposure to concentrated ricin particles in the air is only likely during an act of bioterrorism where large numbers of people would likely experience the signs and symptoms in one place and time. Injection of ricin toxin would likely result in tissue (muscle) necrosis near the injection site, probable multiple organ failure, and death. A chest x-ray may reveal excess fluid in the lungs. All routes of exposure are very dangerous and can result in death.
How can Ricin be treated?
There is no known treatment or vaccine available for ricin poisoning. Ricin poisoning is treated by supportive care to minimize the effects of the poisoning. The types of supportive medical care would depend if the victim was poisoned by inhalation, ingestion, or injection. Helping the victim breathe and giving them intravenous fluids and medications to treat swelling.
The following is an agent that is found in Group C
Hantavirus
What is the Hantavirus pulmonary syndrome?
Hantavirus pulmonary syndrome (HPS) is a deadly disease
transmitted by infected rodents through urine, droppings, or saliva.
Humans can
contract the disease when they breathe in aerosolized virus. HPS was
first recognized
in 1993 and has since been identified throughout the United States.
Although
rare, HPS is potentially deadly. Rodent control in and around the home
remains
the primary strategy for preventing hantavirus infection.
How can you get Hantavirus
pulmonary syndrome?
Four hantaviruses (Sin Nombre,
Black Creek Canal, New York and Bayou) cause the hantavirus pulmonary
syndrome
in the United States. Humans contract the infection by inhaling
airborne mice
excreta, by contact with rodent saliva during a bite, by direct contact
of
rodent excreta with broken skin, and possibly through contaminated food
or
water. The infected animals do not themselves become ill. The
infection
is not thought to be transmissible from one person to another.
How to know if you may have been infected
with
Hantavirus pulmonary syndrome?
The first symptoms are general and flu-like: fever (101oF-104oF),
headache, stomach pain, pain in the joints and lower back, coughing,
and
sometimes nausea and vomiting. The main symptom is difficulty breathing
as the
lungs fill with fluid. This can quickly lead to an inability to breathe
and, in
severe cases, death from suffocation.
How can
Hantavirus pulmonary syndrome be treated?
Supplemental oxygen, mechanical
ventilation when
indicated, fluid management, and the appropriate use of pressors are
crucial to
patient care. Hemodynamic monitoring with a pulmonary artery catheter
will
facilitate fluid and pressor management and can aid in establishing a
preliminary diagnosis by documenting the characteristic HPS hemodynamic
profile. While awaiting serologic confirmation, broad-spectrum
antibiotics
should be initiated.
Bioterrorism Homepage
Introduction
to Bioterrorism
History of
Bioterrorism
How
Bioterrorism Works
What to do
about Bioterrorism
References