Posted on 10/04/2001 12:35:09 PM PDT by NautiNurse
Breaking news on FNC--a 63 year old man from Palm Beach County is in critical condition with anthrax
GandtheD
NEW YORK (Reuters Health) - Using an animal model, scientists have discovered a way to inactivate the lethal toxin produced by the anthrax bacterium, according to a new report.
``The findings provide a potential route to therapy of anthrax that could complement antibiotics,'' principal investigator Dr. R. John Collier of Harvard Medical School (news - web sites) in Boston, Massachusetts, told Reuters Health.
Anthrax infection--lately in the news because of its potential for use as a biological weapon--can be contracted by humans through the skin or by inhalation.
Antibiotics can treat the infection, but they must be given quickly. And while they may kill the anthrax bacterium, they cannot inactivate the lethal toxin it produces.
By the time symptoms of anthrax contracted by inhalation have appeared, Collier explained, it is generally too late to rescue an individual with antibiotics, because he or she will succumb to the toxin the bacteria has already produced.
``This candidate therapeutic offers a way to inactivate the toxin,'' he said.
Anthrax releases three nontoxic proteins that assemble themselves into the toxin. Collier and his colleagues have identified a protein, known as a polyvalent inhibitor, that blocks this assembly. Their findings are published in the October issue of the journal Nature Biotechnology.
``To date, we have tested the polyvalent inhibitor of toxin action by mixing it with a potentially lethal dose of the lethal toxin and injecting the mixture into rats,'' Collier told Reuters Health.
Normally, the lethal dose of toxin will kill the animal within 90 minutes. In the presence of the polyvalent inhibitor, the animals survived and showed no symptoms, he explained.
``This finding supports the notion that this inhibitor could be used to block toxin action in infected humans and rescue them,'' Collier stated.
According to the researcher, inhalation anthrax is the most deadly form of the disease. It is contracted by inhaling anthrax spores--durable, hard-shelled ``seeds'' containing the bacterium.
The spores begin to grow in the lungs and enter the bloodstream, where they produce the anthrax toxin. The toxin acts by killing certain immune system cells that normally guard against bacterial invaders. In so doing it also causes changes in metabolism that lead to death, Collier explained.
SOURCE: Nature Biotechnology 2001;19:958-961.
Anthrax is most common in agricultural regions where it occurs in animals. These include South and Central America, Southern and Eastern Europe, Asia, Africa, the Caribbean, and the Middle East. When anthrax affects humans, it is usually due to an occupational exposure to infected animals or their products. Workers who are exposed to dead animals and animal products from other countries where anthrax is more common may become infected with B. anthracis (industrial anthrax). Anthrax in wild livestock has occurred in the United States.
How is anthrax transmitted?
Anthrax infection can occur in three forms: cutaneous (skin), inhalation, and gastrointestinal. B. anthracis spores can live in the soil for many years, and humans can become infected with anthrax by handling products from infected animals or by inhaling anthrax spores from contaminated animal products. Anthrax can also be spread by eating undercooked meat from infected animals. It is rare to find infected animals in the United States.
What is anthrax?
Anthrax is an acute infectious disease caused by the spore-forming bacterium Bacillus anthracis. Anthrax most commonly occurs in wild and domestic lower vertebrates (cattle, sheep, goats, camels, antelopes, and other herbivores), but it can also occur in humans when they are exposed to infected animals or tissue from infected animals.
Why has anthrax become a current issue?
Because anthrax is considered to be a potential agent for use in biological warfare, the Department of Defense (DoD) has begun mandatory vaccination of all active duty military personnel who might be involved in conflict.
How common is anthrax and who can get it?
Anthrax is most common in agricultural regions where it occurs in animals. These include South and Central America, Southern and Eastern Europe, Asia, Africa, the Caribbean, and the Middle East. When anthrax affects humans, it is usually due to an occupational exposure to infected animals or their products. Workers who are exposed to dead animals and animal products from other countries where anthrax is more common may become infected with B. anthracis (industrial anthrax). Anthrax in wild livestock has occurred in the United States.
How is anthrax transmitted?
Anthrax infection can occur in three forms: cutaneous (skin), inhalation, and gastrointestinal. B. anthracis spores can live in the soil for many years, and humans can become infected with anthrax by handling products from infected animals or by inhaling anthrax spores from contaminated animal products. Anthrax can also be spread by eating undercooked meat from infected animals. It is rare to find infected animals in the United States.
What are the symptoms of anthrax?
Symptoms of disease vary depending on how the disease was contracted, but symptoms usually occur within 7 days.
Cutaneous: Most (about 95%) anthrax infections occur when the bacterium enters a cut or abrasion on the skin, such as when handling contaminated wool, hides, leather or hair products (especially goat hair) of infected animals. Skin infection begins as a raised itchy bump that resembles an insect bite but within 1-2 days develops into a vesicle and then a painless ulcer, usually 1-3 cm in diameter, with a characteristic black necrotic (dying) area in the center. Lymph glands in the adjacent area may swell. About 20% of untreated cases of cutaneous anthrax will result in death. Deaths are rare with appropriate antimicrobial therapy.
Inhalation: Initial symptoms may resemble a common cold. After several days, the symptoms may progress to severe breathing problems and shock. Inhalation anthrax is usually fatal.
Intestinal: The intestinal disease form of anthrax may follow the consumption of contaminated meat and is characterized by an acute inflammation of the intestinal tract. Initial signs of nausea, loss of appetite, vomiting, fever are followed by abdominal pain, vomiting of blood, and severe diarrhea. Intestinal anthrax results in death in 25% to 60% of cases.
Where is anthrax usually found?
Anthrax can be found globally. It is more common in developing countries or countries without veterinary public health programs. Certain regions of the world (South and Central America, Southern and Eastern Europe, Asia, Africa, the Caribbean, and the Middle East) report more anthrax in animals than others.
Can anthrax be spread from person-to-person?
Direct person-to-person spread of anthrax is extremely unlikely to occur. Communicability is not a concern in managing or visiting with patients with inhalational anthrax.
Is there a way to prevent infection?
In countries where anthrax is common and vaccination levels of animal herds are low, humans should avoid contact with livestock and animal products and avoid eating meat that has not been properly slaughtered and cooked. Also, an anthrax vaccine has been licensed for use in humans. The vaccine is reported to be 93% effective in protecting against anthrax.
The anthrax vaccine is manufactured and distributed by BioPort, Corporation, Lansing, Michigan. The vaccine is a cell-free filtrate vaccine, which means it contains no dead or live bacteria in the preparation. The final product contains no more than 2.4 mg of aluminum hydroxide as adjuvant. Anthrax vaccines intended for animals should not be used in humans.
Who should get vaccinated against anthrax?
The Advisory Committee on Immunization Practices has recommend anthrax vaccination for the following groups:
The anthrax Vaccine Immunization Program in the U.S. Army Surgeon General's Office can be reached at 1-877-GETVACC (1-877-438-8222). http://www.anthrax.osd.mil
Pregnant women should be vaccinated only if absolutely necessary.
What is the protocol for anthrax vaccination?
The immunization consists of three subcutaneous injections given 2 weeks apart followed by three additional subcutaneous injections given at 6, 12, and 18 months. Annual booster injections of the vaccine are recommended thereafter.
Are there adverse reactions to the anthrax vaccine?
Mild local reactions occur in 30% of recipients and consist of slight tenderness and redness at the injection site. Severe local reactions are infrequent and consist of extensive swelling of the forearm in addition to the local reaction. Systemic reactions occur in fewer than 0.2% of recipients.
How is anthrax diagnosed?
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.
Is there a treatment for anthrax?
Doctors can prescribe effective antibiotics. To be effective, treatment should be initiated early. If left untreated, the disease can be fatal.
Where can I get more information about the recent Department of Defense decision to require men and women in
the Armed Services to be vaccinated against anthrax?
The Department of Defense recommends that servicemen and women contact their chain of command on questions about the vaccine and its distribution. The anthrax Vaccine Immunization Program in the U.S. Army Surgeon General's Office can be reached at 1-877-GETVACC (1-877-438-8222). http://www.anthrax.osd.mil
|
Accessibility | Privacy Policy Notice | FOIA CDC Home | Search | Health Topics A-Z This page last reviewed October 1, 2001 Centers for Disease Control and Prevention
|
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.