DereKenGavin 2011. Powered by Blogger.
Related Posts Widget for Blogs by LinkWithin

10 January 2009

ANTHRAX as a bioweapon

Two days ago 24 Oras reported anthrax scare shock US Embassy in Manila from a suspicious mail with traces of white powder which immediately stirred the Bureau of Fire Protection (BFP) to start the detection and sanitation while put 13 employees of Philippine Postal Office in quarantine who were eventually pass the “first swabbing” test but will still remain quarantines for further test as per Justice Undersecretary Ricardo Blancaflor, spokesman for the Anti-Terrorism Council (ATC). I believe the sanitation or clean up is time consuming and cost a lot of money. The news enthuse me to search from Google for the meaning of ANTHRAX and refresh us all and here is what I get from Anthrax is an acute disease in humans and animals caused by the bacterium Bacillus anthracis, which is highly lethal in some forms. There are effective vaccines against anthrax, and some forms of the disease respond well to antibiotic treatment. The anthrax bacillus is one of only a few that can form long-lived spores: in a hostile environment, caused perhaps by the death of an infected host or extremes of temperature, the bacteria become inactive dormant spores which can remain viable for many decades and perhaps centuries. Spores are found on all continents except Antarctica. When spores are inhaled, ingested, or come into contact with a skin lesion on a host they reactivate and multiply rapidly. Anthrax most commonly infects wild and domesticated herbivorous mammals which ingest or inhale the spores while eating grass or browsing. Ingestion is assumed to be the most common route by which herbivores contract anthrax, but this is as yet unproven. Carnivores living in the same environment may ingest infected animals and become infected themselves. Anthrax can also infect humans when they are exposed to blood and other tissues from infected animals (via inhalation or direct inoculation through broken skin), eat tissue from infected animals, or are exposed to a high density of anthrax spores from an animal's fur, hide, or wool. Anthrax spores can be grown in vitro and used as a biological weapon. Anthrax does not spread directly from one infected animal or person to another, but spores can be transported by clothing, shoes etc.; and the body of a mammal that died of anthrax can be a very dangerous source of anthrax spores. The name anthrax comes from anthrakitis, the Greek word for anthracite (coal), in reference to the black skin lesions victims develop in a cutaneous skin infection. Mode of infection Anthrax can enter the human body through the intestines (ingestion), lungs (inhalation), or skin (cutaneous) and causes distinct clinical symptoms based on its site of entry. An infected human will generally be quarantined. However, anthrax does not usually spread from an infected human to a noninfected human. But if the disease is fatal the person’s body and its mass of anthrax bacilli becomes a potential source of infection to others and special precautions should be used to prevent further contamination. Inhalational anthrax, if left untreated until obvious symptoms occur, will usually result in death, as treatment will have started too late. Anthrax can be contracted in laboratory accidents or by handling infected animals or their wool or hides. It has also been used in biological warfare agents and by terrorists to intentionally infect humans, as occurred in, for example, the 2001 anthrax attacks. Pulmonary (pneumonic, respiratory, or inhalational) anthrax Respiratory infection in humans initially presents with cold or flu-like symptoms for several days, followed by severe (and often fatal) respiratory collapse. This disease can rarely be treated, even if caught in early stages of infection; mortality is nearly 100%. A lethal infection is reported to result from inhalation of about 10,000–20,000 spores, though this dose varies amongst host species. Like all diseases there is probably a wide variation to susceptibility with evidence that some people may die from much lower exposures; there is little documented evidence to verify the exact or average number of spores needed for infection. Inhalational anthrax is also known as woolsorters' or ragpickers' disease as these professions were more susceptible to the disease due to their exposure to infected animal products. Other practices associated with exposure include the slicing up of animal horns for the manufacture of buttons, the handling of hair bristles used for the manufacturing of brushes, and the handling of animal skins. Whether these animal skins came from animals that died of the disease or from animals that had simply laid on ground that had spores on it is unknown. This mode of infection is used as a bioweapon. Gastrointestinal (gastroenteric) anthrax Gastrointestinal infection in humans is most often caused by eating anthrax-infected meat and is characterized by serious gastrointestinal difficulty, vomiting of blood, severe diarrhea, acute inflammation of the intestinal tract, and loss of appetite. Some lesions have been found in the intestines and in the mouth and throat. After the bacteria invades the bowel system, it spreads through the bloodstream throughout the body, making even more toxins on the way. Gastrointestinal infections can be treated but usually result in fatality rates of 25% to 60%, depending upon how soon treatment commences. Cutaneous (skin) anthrax Cutaneous (on the skin) anthrax infection in humans shows up as a boil-like skin lesion that eventually forms an ulcer with a black centre (eschar). The black eschar often shows up as a large, painless necrotic ulcer (beginning as an irritating and itchy skin lesion or blister that is dark and usually concentrated as a black dot, somewhat resembling bread mold) at the site of infection. Cutaneous infections generally form within the site of spore penetration between 2 and 5 days after exposure. Unlike bruises or most other lesions, cutaneous anthrax infections normally do not cause pain. Cutaneous anthrax is rarely fatal if treated], but without treatment about 20% of cutaneous skin infection cases progress to toxemia and death. Treatment and prevention Anthrax cannot be spread directly from person to person, but a patient’s clothing and body may be contaminated with anthrax spores. Effective decontamination of people can be accomplished by a thorough wash down with anti-microbe effective soap and water. Waste water should be treated with bleach or other anti-microbial agent. Effective decontamination of articles can be accomplished by boiling contaminated articles in water for 30 minutes or longer. Chlorine bleach is ineffective in destroying spores and vegetative cells on surfaces, though formaldehyde is effective. Burning clothing is very effective in destroying spores. After decontamination, there is no need to immunize, treat or isolate contacts of persons ill with anthrax unless they were also exposed to the same source of infection. Early antibiotic treatment of anthrax is essential—delay seriously lessens chances for survival. Treatment for anthrax infection and other bacterial infections includes large doses of intravenous and oral antibiotics, such as fluoroquinolones, like ciprofloxacin (cipro), doxycycline, erythromycin, vancomycin or penicillin. In possible cases of inhalation anthrax, early antibiotic prophylaxis treatment is crucial to prevent possible death. If death occurs from anthrax the body should be isolated to prevent possible spread of anthrax germs. Burial does not kill anthrax spores. If a person is suspected as having died from anthrax, every precaution should be taken to avoid skin contact with the potentially contaminated body and fluids exuded through natural body openings. The body should be put in strict quarantine. A blood sample taken in a sealed container and analyzed in an approved lab should be used to ascertain if anthrax is the cause of death. Microscopic visualization of the encapsulated bacilli, usually in very large numbers, in a blood smear stained with polychrome methylene blue (McFadyean stain) is fully diagnostic, though culture of the organism is still the gold standard for diagnosis. Full isolation of the body is important to prevent possible contamination of others. Protective, impermeable clothing and equipment such as rubber gloves, rubber apron, and rubber boots with no perforations should be used when handling the body. No skin, especially if it has any wounds or scratches, should be exposed. Disposable personal protective equipment is preferable, but if not available, decontamination can be achieved by autoclaving. Disposable personal protective equipment and filters should be autoclaved, and/or burned and buried. Bacillus anthracis bacillii range from 0.5-5.0 μm in size. Anyone working with anthrax in a suspected or confirmed victim should wear respiratory equipment capable of filtering this size of particle or smaller. The US National Institute for Occupational Safety and Health (NIOSH) and Mine Safety and Health Administration (MSHA) approved high efficiency-respirator, such as a half-face disposable respirator with a high-efficiency particulate air (HEPA) filter, is recommended. All possibly contaminated bedding or clothing should be isolated in double plastic bags and treated as possible bio-hazard waste. The victim should be sealed in an airtight body bag. Dead victims that are opened and not burned provide an ideal source of anthrax spores. Cremating victims is the preferred way of handling body disposal. No embalming or autopsy should be attempted without a fully equipped biohazard lab and trained and knowledgeable personnel. Delays of only a few days may make the disease untreatable and treatment should be started even without symptoms if possible contamination or exposure is suspected. Animals with anthrax often just die without any apparent symptoms. Initial symptoms may resemble a common cold – sore throat, mild fever, muscle aches and malaise. After a few days, the symptoms may progress to severe breathing problems and shock and ultimately death. Death can occur from about two days to a month after exposure with deaths apparently peaking at about 8 days after exposure. Antibiotic-resistant strains of anthrax are known. In recent years there have been many attempts to develop new drugs against anthrax, but existing drugs are effective if treatment is started soon enough. Early detection of sources of anthrax infection can allow preventative measures to be taken. In response to the anthrax attacks of October, 2001 the United States Postal Service (USPS) installed BioDetection Systems (BDS) in their large scale mail cancellation facilities. BDS response plans were formulated by the USPS in conjunction with local responders including fire, police, hospitals and public health. Employees of these facilities have been educated about anthrax, response actions and prophylactic medication. Because of the time delay inherent in getting final verification that anthrax has been used, prophylactic antibiotic treatment of possibly exposed personnel must be started as soon as possible. The most effective form of prevention is vaccination against infection but this must be done well in advance of exposure to the bacillus, and does not protect indefinitely. Components of tea, such as polyphenols, have the ability to inhibit the activity both of bacillus anthracis and its toxin considerably; spores, however, are not affected. The addition of milk to the tea completely inhibits its antibacterial activity against anthrax. Activity against the anthrax bacillum in the laboratory does not prove that drinking tea affects the course of an infection. Anthrax vaccines An FDA-licensed vaccine, produced from one non-virulent strain of the anthrax bacterium, is manufactured by BioPort Corporation, subsidiary of Emergent BioSolutions. The trade name is BioThrax, although it is commonly called Anthrax Vaccine Adsorbed (AVA). It is administered in a six-dose primary series at 0,2,4 weeks and 6,12,18 months; annual booster injections are required thereafter to maintain immunity. The injections are typically very painful, and may leave the area of injection with swelling; this area may be painful for several days. Unlike the West, the Soviets developed and used a live spore anthrax vaccine, known as the STI vaccine, produced in Tbilisi, Georgia. Its serious side effects restrict use to healthy adults. Site cleanup Anthrax spores can survive for long periods of time in the environment after release. Methods for cleaning anthrax-contaminated sites commonly use oxidizing agents such as peroxides, ethylene oxide, Sandia Foam, chlorine dioxide (used in Hart Senate office building), and liquid bleach products containing sodium hypochlorite. These agents slowly destroy bacterial spores. A bleach solution for treating hard surfaces has been approved by the EPA. It can be prepared by mixing one part bleach (5.25%-6.00%) to one part white vinegar to eight parts water. Bleach and vinegar must not be combined together directly, as doing so could produce chlorine gas. Rather some water must first be added to the bleach (e.g., two cups water to one cup of bleach), then vinegar (e.g., one cup), and then the rest of the water (e.g., six cups). The pH of the solution should be tested with a paper test strip; and treated surfaces must remain in contact with the bleach solution for 60 minutes (repeated applications will be necessary to keep the surfaces wet). Chlorine dioxide has emerged as the preferred biocide against anthrax-contaminated sites, having been employed in the treatment of numerous government buildings over the past decade. Its chief drawback is the need for in situ processes to have the reactant on demand. To speed the process, trace amounts of a non-toxic catalyst composed of iron and tetro-amido macrocyclic ligands are combined with sodium carbonate and bicarbonate and converted into a spray. The spray formula is applied to an infested area and is followed by another spray containing tertiary-butyl hydroperoxide.[citation needed] Using the catalyst method, a complete destruction of all anthrax spores takes 30 minutes.[citation needed] A standard catalyst-free spray destroys fewer than half the spores in the same amount of time. They can be heated, exposed to the harshest chemicals, and they do not easily die. Cleanups at a postal facilities and other government and private office buildings showed that decontamination is possible, but it is time-consuming and costly. Clean up of anthrax-contaminated areas on ranches and in the wild is much more problematic. Carcasses may be burned, though it often takes up to three days to burn a large carcass and this is not feasible in areas with little wood. Carcasses may be buried, though the burying of large animals deeply enough to prevent resurfacing of spores requires much manpower and expensive tools. Carcasses have been soaked in formaldehyde to kill spores, though this has obvious environmental contamination issues. Block burning of vegetation in large areas enclosing an anthrax outbreak has been tried; this, while environmentally destructive, causes healthy animals to move away from an area with carcasses in search of fresh graze and browse. Some wildlife workers have experimented with covering fresh anthrax carcasses with shadecloth and heavy objects. This prevents some scavengers from opening the carcasses, thus allowing the putrefactive bacteria within the carcass to kill the vegetative B. anthracis cells and preventing sporulation. Biological warfare Anthrax spores can and have been used as a biological warfare weapon. Its first modern incidence occurred when Scandinavian "freedom fighters"(the rebel groups) supplied by the German General Staff used anthrax with unknown results against the Imperial Russian Army in Finland in 1916. There is a long history of practical bioweapons research in this area. For example, in 1942 British bioweapons trials severely contaminated Gruinard Island in Scotland with anthrax spores of the Vollum-14578 strain, making it a no-go area until it was decontaminated in 1990. The Gruinard trials involved testing the effectiveness of a submunition of an "N-bomb"—a biological weapon. Additionally, five million "cattle cakes" impregnated with anthrax were prepared and stored at Porton Down in 'Operation Vegetarian'—an anti-livestock weapon intended for attacks on Germany by the Royal Air Force The infected cattle cakes were to be dropped on Germany in 1944. However neither the cakes nor the bomb were used; the cattle cakes were incinerated in late 1945. More recently the Rhodesian government used anthrax against cattle and humans in the period 1978–1979 during its war with black nationalists. American military and British Army personnel are routinely vaccinated against anthrax prior to active service in places where biological attacks are considered a threat. The anthrax vaccine, produced by BioPort Corporation, contains non-living bacteria, and is approximately 93% effective in preventing infection.[citation needed] Weaponized stocks of anthrax in the US were destroyed in 1971–72 after President Nixon ordered the dismantling of US biowarfare programs in 1969 and the destruction of all existing stockpiles of bioweapons. Research is known to continue in the United States on ways to counteract bioweapons attacks. The Soviet Union created and stored 100 to 200 tons of anthrax spores on Vozrozhdeniya Island. They were abandoned in 1992 and destroyed in 2002.

Related Posts by Categories

Widget by Simran

0 comments on "ANTHRAX as a bioweapon"

Add your comment. Please don't spam!
Subscribe in a Reader

DereKenGavin | Copyright © 2011 | Jesse's Blog | Twitter