Sheep anthrax

Anthrax, a disease caused by infection by Bacillus anthracis via spores, can be transmitted to humans or animals ruminants such as sheep, goats, cattle, and deer are most susceptible. The handling of infected animals or animal products may also lead to human infection. Recently, anthrax has been considered to be a potential candidate for bioterrorism activity. The spores are extremely hardy and may come into contact with humans through a cut or abrasion, through consumption of infected meat, or by inhalation. The Center for Disease Control (CDC) lists anthrax as a category A disease, and the only vaccine that currently exists has a number of drawbacks and health risks. 

During the course of the next 1,500 years, Europe witnessed sporadic outbreaks of anthrax as they occurred in 14th century Germany and 17th century central Europe and Russia. The disease was classified as anthrax or charbon malin (Morens, 2003) in 1769 by the French physician Nicholas Fournier (Fournier, 1769 Morens, 2003). The name is derived from the black eschar lesions, the hallmark of cutaneous infection. Fournier also noted a link between those who worked with raw animal hair or wool and an increased susceptibility to disease. In the 18th century, an epidemic destroyed half of the sheep in Europe, possible evidence that anthrax was a major problem. Inhalation anthrax became known in the Victorian era as woolsorters disease however, infection was more often the result of contact with goat hair or alpaca than wool. 

In 1850, Pierre-Francoise OHve Rayer (Rayer, 1850) and Casimir-Joseph Davaine (Davaine, 1863) reported the presence of small filiform bodies in the blood of anthrax-infected sheep (Carter, 1988). By 1855, Franz Aloys Antoine PoUender confirmed this discovery and impheated their role in producing anthrax disease (PoUender, 1855). In 1858, Freidrich August Brauell noted the bodies to be absent from healthy animals or animals infected with diseases other than anthrax. Brauell also noted their inability to be transmitted from pregnant sheep to fetus (Brauell, 1857). 

Louis Pasteur demonstrates value of vaccine to protect sheep against anthrax... 

Agent Index A290 Class Index C24 Anthrax Bacillus anthracis Type Bacteria Inhalation Mild and nonspecific (i.e., flu-like) progressing to respiratory distress with fever and shock following in 3 to 5 days. Death occurs shortly thereafter. Routes Inhalation Ingestion Abraded Skin Vector (Biting Flies) Incubation hours to 7 days Mortality Rate Cutaneous < 20% Inhalation < 100% Reservoir Horses, Sheep... 

Let us review. Escape from restriction is the commonest causes of epidemics by really new epidemics encountered so far in prehistorical and historical time. It might typically involve a mutation which, for example, overrides the immune system of a new host or permits entry into the cell of the new host. There are some 60 well-known zoonotic examples, if not exactly running from A to Z, certainly from Acinetobacter pneumonia to Yersiniosis that infect humans. The Z disease if it comes, may be aptly named the analogous Greek letter omega has been used in many science fiction stories for the ultimate bacterial or viral disease The Omega Man was a film in which Charlton Heston played the last uninfected man on Earth. Recent real-life examples include the recent outbreak in Toronto of bird flu (from Asian water birds), SARS (from the civet, etc.), anthrax (sheep), ebola (from rodents), and acquired CJD (sheep, mad cow). 

A. Characteristics. Anthrax is a zoonotic disease caused by Bacillus anthracis. Under natural conditions, humans become infected by contact with infected animals or contaminated animal products. Human anthrax is usually manifested by cutaneous lesions. A biological warfare attack with anthrax spores delivered by aerosol would cause inhalation anthrax, an extraordinarily rare form of the naturally occurring disease. Since Anthrax is a zoonotic disease, deaths in cattle and sheep coincident with human cases may indicate an anthrax attack. 

Whether this epidemic, affecting both man and beast, was anthrax is speculation, but it may well have been. Anthrax is one of the oldest known diseases of animals its manifestations were recorded by Homer, Hippocrates, Galen, and Pliny. The microbe Bacillus anthracis can infect dogs, cats, cattle, sheep, goats, horses, mules, and swine. It is the first infectious disease against which a vaccine was developed, by Louis Pasteur in 1881. 

After the bomb had been filled, it, too, was ferried across to Gruinard. With it went Sutton, Henderson and Younger. Each man was now clad like some science fiction monster, in a rubberized suit, gas mask, high rubber boots and thick gloves. The anthrax weapon was placed on a small mound of earth. Around it, tethered in concentric circles, were the sheep. An explosive charge was carefully attached to the bomb and a fuse laid. While the sheep grazed unconcernedly, the scientists retreated to a safe distance down wind. 

Anthrax is an acutely infectious and deadly disease. In nature it generally occurs in cattle or sheep, but it can be equally deadly to man. If contaminated meat is accidentally handled it can produce coal-black malignant skin ulcers which lead to blood poisoning. Inhaled it is even more deadly. The tiniest of doses can produce, in a matter of hours, a" choking cough, difficulty in breathing, and a high fever in nine cases out of ten, death will follow soon after. It was this latter form of the disease which most interested Porton. 

In the winter of 1943, a year and a half after the first sheep had died on Gruinard, the Allies began to manufacture a biological bomb. It weighed 4 lb and was filled with anthrax spores which were given the code-name N . Its design was largely British, its manufacture exclusively American. 

Outstandingly, protesters claimed to have taken infected soil from the Scottish island of Gruinard and placed it at the Microbiological Defence Establishment at Porton Down, Britain. The island has been closed to the public since germ warfare experiments on sheep were conducted there in 1941. The anthrax spores used in the experiments can remain dangerous for decades. 

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. 

Because of its easy availability and the durability of its spores, B. anthracis has often been mentioned as a tool for bioterrorists. Anthrax has, at times, been an important disease of livestock in many parts of the world. It wasn t until 1876 that the German Robert Koch proved that anthrax was caused by a microbe that can change form into one that is extremely inert and hardy (de Kruif, 1926). That was the reason that sheep could contract anthrax in fields that had not seen sheep in many years. 

In the twentieth century, 18 Americans have fatally inhaled anthrax spores. The victims include a San Francisco woman who played bongo drums made from infected skins. Others included gardeners who handled fertilizer made with ground bone from infected animals (Park, 2001). Goat and sheep skins from the Mideast are a small but persistent source of anthrax in the United States. Five more people died of anthrax in the United States in 2001 as a result of the anthrax-laden letters they handled. 

In 1850, Davaine detected rod-shaped objects in the blood of anthrax-infected sheep and was able to produce the disease in healthy sheep by inoculation of such blood. In the next 25 years, Pasteur of France and John Tyndall of Britain demolished the concept of spontaneous generation and proved that existing microbial life came from preexisting life. In the 1850s, Pasteur detected two... 

Following a lead given a century earlier by the physician Edward Jenner who observed that people who milked cows diseased with cow-pox seldom acquired smallpox and used this information to devise a smallpox vaccine, Pasteur looked for sources of dead bacteria that could be used to trigger immunity and protect against live bacteria. He used such methods successfully to protect sheep from anthrax, then he deliberately injected the 9-year-old Joseph Meister, who had been bitten by a mad dog, with attenuated fluid from rabid dogs and saved his life. 

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