Coal (illness)

(Jrt)

Coal (illness)
Anthrax is an acute infectious disease caused by the bacterium Bacillus anthracis. It is a anthropozoonose, ie a condition that affects both animals than humans.

Bacillus anthracis is a potential biological weapon since the end of World War II and was particularly publicized in the wake of the attacks of September 11, 2001.

Some French journalists have confused anthrax, which refers only to a french staphylococcie skin, and coal, which in English-speaking countries, is called anthrax.

History
The anthrax was identified by the German Aloys Pollender in 1849 (it does published his discovery in 1855) and the french Rayer and Davaine in 1850. In 1863, Davaine fit in a more thorough study, now regarded as the first evidence of the microbial origin of a disease transmissible to humans. In 1876, Robert Koch discovered the ability of the anthrax spores to form, which can make it very strong.

In May 1881, in Pouilly-Le-Fort, near Melun, Pasteur performs extensive experience vaccination of 50 sheep. It prepares two batches of 25. The first lot is at 15-day intervals, two injections of anthrax vaccine prepared by Louis Pasteur and his colleagues. Then both lots receive an injection of living culture of anthrax. All non-vaccinated animals died. All vaccinated survive. Shepherd, who is not a physician but a chemist, is now famous.

It seems well established that, contrary to what Shepherd heard left, the vaccine used in Pouilly-le-Fort had been mitigated by using not oxygen but an antiseptic, potassium dichromate. See this, and in particular on the extent to which one can accuse him of embezzling Pasteur an idea of Henry Toussaint, the article Secret Pouilly-le-Fort.

Description of the germ
Bacillus anthracis is a bacterium to gram positive bacillus is immobile (has no flagellum), which distinguishes it from other Bacilli which are mobile, and the bacterium is sporulante and its type is aerobic respiratory / anaerobic optional. The spores of anthrax are highly resistant. They germinent in a vegetative when they are in environments such as blood or tissues, Men or animals; rich in amino acids, nucleotides and glucose. Despite their high strength, spores do not recur, but they can survive for decades in the soil. There is a problem of destruction by Bacillus anthracis spores resistance to drought, heat, ultraviolet rays, gamma rays and many substances disinfectant. Bacillus anthracis has two virulence factors:

* First capsule enables it to evade phagocytosis.
* Then there are two toxins consisting of three distinct proteins (protective antigen, œdématogène factor and lethal factor). When the first two proteins are involved, they form the toxin œdématogène while when protective antigen is associated with the lethal factor ago formation of the lethal toxin. The latter acts directly on the virulence of the bacteria, if she suffers a disability, virulence will be reduced by a factor of 1000.

Human Pathology
In humans, coal manifests itself most often through its skin: the malignant pustule. It begins with a small red and itchy, and then appears and a blister phlyctène (bulb), which breaks up and forms an ulcer blackish hence the name of the disease.

Inhalation of the infectious agent causing serious pulmonary anthrax, which can be complicated by sepsis anthrax.

The appropriate antibiotics administered early, in sufficient doses and long enough have a certain efficiency.

Routes of contamination, and effects on the body
There are different kinds of contamination of Bacillus anthracis causing various degrees of impact on the body. The infection in humans occurs by spores from ships animals or contaminated animal products, but also at a spread voluntary. There are three forms of contamination from coal:

1. The cutaneous anthrax.
2. Coal gastrointestinal.
3. Anthrax inhalation.

These three forms have different consequences on the body.

The cutaneous form
This contamination is the most common form. The infection resulted from contact between spores and injury. This form of coal accounts for 95% of infections caused by Bacillus anthracis.

The infection causes the formation of a macule on the site of the inoculation and causes itching. One day later, it turns into ulceration surrounded by blisters. The button is pressed and painless, it is dried and then covered with a black crust. In 80% of cases, the wound healed without complications, in spite of everything, in some cases edema intensifies and takes the volume resulting in a distortion of the face. As a first step a high fever appears that without treatment causes severe complications. These complications are moving towards death in 5% to 20% of cases.

The form gastrointestinal
The infection resulted from the consumption of meat containing endospores, an infection caused by Bacillus anthracis gastrointestinal however, is not widespread.

Coal gastrointestinal appears in the case where spores are found in the gastrointestinal tract higher or lower. In the first case, the form oropharyngienne is characterized by the occurrence of an esophageal or oral ulcer with a regional lymph adenopathy and sepsis. In cases where the spores are present in the gastrointestinal tract lower, nausea and vomiting were quickly followed by bloody diarrhea, perforation of the intestines and sepsis, a massive ascites can occur. The mortality rate from this form is variable, but high and can reach 100%.

The respiratory form
This form of coal comes from the inhalation of spores via an aerosol particles or contaminated. The inhalation of spores is followed by a few specific influenza-like illness with fever, muscle aches, headaches and dry cough.

The spores are deposited in the pulmonary alveoli. Macrophages phagocytose who burst and released spores are carried by the lymphatic system to the lymph nodes trachéobronchiques. Spores give birth to vegetative forms that multiply and produce toxins that up to sixty days later.

Two to four days after the onset of symptoms, there is a sudden worsening of the overall situation. There is a severe respiratory insufficiency, rétrosternales acute pain and hypotension. Meningitis bleeding can be an additional complication in addition to syndromes.

Sometimes the patient died a few hours after the beginning of this second phase. At this time, a chest X-ray image shows a typical expansion characteristic of the mediastinal lymphodénopathie hemorrhagic mediastinal and médiastinite. This certainly represents only 5% of all cases of coal, but its mortality rate is estimated at between 90 and 100%.

Propagation Coal
The form of inhaled coal being the most deadly, spreading malicious Bacillus anthracis can be dangerous when large amounts of spores are dispersed in an aerosol. This threat must be taken seriously because the body can be relatively easily manufactured from natural sources.

It is not clear to produce an aerosol infectious coal. Indeed, the need to be dispersed particles with a size between 1 and 5 microns and should be enough to enable an energy dispersion in the air.

And the infectious dose 50 for the inhalation of coal is estimated at 10000 spores. This is a dose of spores necessary to ensure that 50% of those exposed develop the disease.

The greatest risk to humans is when the anthrax was released into the air and as long as they remain in the air. Once spores on the ground, the risk of contamination is much diminished. The dispersal of spores must therefore take into account the weather factors and characteristics of the aerosol.

Transmission of Bacillus anthracis
The transmission can be done only when contact with the remains of infected animals or animals themselves. Indeed transmission between humans has not been proven. Patients do not constitute any danger, so there is no need to isolate them.

Salaries
The infection with Bacillus anthracis can be destroyed by treatment. It must be precise and started after symptom onset. There is a vaccine, which is recommended for laboratory personnel frequently exposed to clinical specimens and cultures.

There are different drugs for use during an infection Bacillus anthracis. These will vary depending on age and the degree of the disease. The main drugs are:

* Ciprofloxacin
* Ofloxacin
* Vafloxacine
* Doxycycline
* Amoxicillin
* Péfloxacine.

The risk of terrorism
The events in the United States in late 2001 showed that Bacillus anthracis was one of the germs that could be a major biological terrorist threat.

Some strains (several virulences) are held in collections official such as the Institut Pasteur in Paris. Some strains "savages" from contaminated cattle are more rare than in France. The last two episodes on french herds date from 1990 (in Haute-Savoie and in the Pyrenees-Atlantiques). The culture requires bacteriological culture media classics but great caution regarding the risk of contamination of the operator and is available only in specialized laboratories type P3. All strains of Bacillus anthracis have different pathogenicity and often lose in many passages. The spread of the spores is variable, low in general, and military strains are specially treated surface to increase the power of dissemination. The threat is real, but it may not be as timely, designed to frighten people and / or kill a small number of people after an incubation period which makes it very difficult location of the place of release and counting.

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