The causative agent of anthrax. Diagnosis of anthrax, symptoms, treatment

Anthrax is an infectious disease. It has a high probability of death. The causative agent of anthrax - Bacillus anthracis. In the risk zone are people working on farms, since infection occurs when contacting animals. The disease of anthrax, the photo of the results of which can frighten anyone, is dangerous for several reasons: it is quite common in the animal world, the spores of the causative agent are stored for a long time in the soil of the cattle graveyard, the disease is leaking and gives complications.

Description

The causative agent of anthrax is immobile large bacterium. Being in the body of man or animal, it forms a capsule, in an external environment - a spore.

Disputes of the causative agent of the disease may persist for about 10 years in the soil, and in the cattle grains - five times longer. They are not afraid of frost and heat, they are able to survive in solutions of bleach and chloramine, and boil they stand for 7 minutes.

Everyone knows cases when an agent of anthrax was used by terrorists and distributed in envelopes.

The vegetative form of a bacterium quickly perishes after disinfection and boiling. The bacterium of anthrax is able to go into a sleeping form and activate under favorable environmental conditions.

History

Since ancient times anthrax has struck mankind. Homer and Hippocrates also referred to it as "sacred coal". In the Middle Ages, this disease took the lives of many people and animals in different countries. For the first time the disease was described in the XVII century. Russian scientist S.S. Andreevsky proved that anthrax in animals and humans is one and the same disease that occurs through self-infection. He also appropriated this infirmity of the modern name.

At the end of the XIX century, Louis Pasteur was able to create the first vaccine. He injected the animals with a weakened strain of the bacterium of anthrax, which led to the development of immunity. Pasteur was able to prove the need for vaccination for the prevention of the disease.

WHO reports 20 thousand cases of anthrax every year. Now studies are under way to improve the vaccine and extend its duration. In 2010, US scientists were able to introduce the anthrax gene into the tobacco genome. As a result of these actions, an antigen was developed in plants, which was used to create a new vaccine, which practically does not cause side effects.

Epidemiological process

Anthrax is transmitted to humans through livestock. Immune to this disease of the bird, but they can tolerate spores on feathers, claws and beaks.

A Siberian bacillus in a sick animal is found in feces, blood, liquid secreted from the nose and mouth. The causative agent enters the soil and water with urine and feces.

The soil in place of the case of sick cattle becomes infected, and wild animals, by taking away the corpse, are able to spread the disease for many kilometers.

Infection from one person to another does not occur, so the level of disease in people directly depends on the epidemic in animals.

Infection can occur through soil, in contact with infected livestock products, in caring for sick animals, in opening their corpses, through trauma to the skin, food and inhaled air.

In African countries, where anthrax is particularly common in animals, its transmission to humans can occur through the bite of a blood-sucking insect.

Who is at risk?

There are several groups of people who are especially at risk of infection:

• Veterinary workers in contact with animals;
• Manufacturers, sellers, as well as buyers of products made from natural fur and wool, brought from regions where the disease is common;
• Hunters;
• Military personnel and other categories of citizens in the epidemic areas;
• People working in laboratories, directly in contact with the causative agent of anthrax.

Prevalence

An anthrax has not been completely destroyed in any country. Most often it occurs in Africa and South America, as well as in the countries of the Asian region. In Europe, the epidemic periodically occurs in its southern part, on the Black Sea and Mediterranean coasts. Leaders in the number of patients with anthrax are Turkey, Iran and Iraq.

In Russia, most often this disease occurs in the North Caucasus region. The main reason for its occurrence in our country is the slaughter of an infected animal without notification of this to the veterinary service and without taking the necessary decontamination measures.

Features of the spread of the disease:

• In developing countries, infection occurs after contact with the animal, care for it, slaughter;
• In developed countries, the infection is transmitted mainly through production raw materials of animal origin.

Classification of the disease

The following forms of anthrax are distinguished:

• Cutaneous;
• Intestinal;
• Pulmonary.

The cutaneous form is most common (approximately 95% of the total number of cases). It can be carbuncular (the most common), bullous, endematous and erysipeloid.

Pulmonary and intestinal forms are often united under one name - generalized, or septic ulcer. The least common is the intestinal form of the disease (less than 1% of cases).

Symptoms and course of the disease

The latent period of the disease can last from a few hours to a week. From the moment the pathogen enters the person before the appearance of the first symptoms, it may take a different amount of time (depending on the route of infection). With the air and food way of infection, the development of the disease occurs lightning-fast, and death may occur in a few days.

Regardless of the form of the anthrax, the mechanism of its development is the same: the toxin damages the vessels, breaks their permeability, resulting in edema, inflammation and loss of sensitivity.

The most common carbuncular anthrax (photo of the pathogen of the disease is presented below).

The onset of the disease is characterized by the appearance of a red stain on the skin at the entry site, which later turns into a papule, and then into a dark vesicle. Having burst, the vesicle transforms into an ulcer with raised edges, around which new vesicles can appear. After a while in the ulcer a black scab, similar to the scorched skin, is formed. The sensitivity of the cover around the scab disappears. Its external similarity with coal led to the emergence of the old Russian name for anthrax - a carbon.

A swelling appears around the affected skin. It is dangerous when a carbuncle occurs on the face and can lead to swelling of the airways and death.

The course of the disease is accompanied by high fever, lability, headache. A few weeks later, the ulcer heals and a scar appears.

Endematous anthrax is edematous, the carbuncle appears at a later stage of the disease and is large in size.

With a bullous version of the disease at the entrance of the infection appear bubbles, which after dissection turns into ulcers.

The pulmonary form of the disease is often called the disease of the wool sorter. Anthrax bacterium with air gets into the lungs, and from there - to the lymph nodes that become inflamed. Initially, the patient has a high fever, chest pain and weakness. After a few days there is shortness of breath and a decrease in the level of oxygen in the blood. Once in the lungs, the causative agent of anthrax quickly spreads throughout the human body. Often there is a cough with blood, an X-ray can show the presence of pneumonia, the temperature of the patient's body often rises to 41 degrees. There is edema of the lungs and cardiovascular insufficiency, as a consequence, cerebral hemorrhage is possible.

After the causative agent enters the human body with food and drink, the intestinal form of anthrax develops. The first phase of the disease lasts about 2 days and is accompanied by sore throat, fever, fever. Subsequently, these symptoms are accompanied by vomiting with blood, severe abdominal pain, diarrhea. There is cardiovascular failure, the face becomes crimson or cyanotic in color, papules are formed on the skin. At an intestinal anthrax the probability of death of the patient is great.

When the septic form of the disease occurs rapidly, there is intoxication, internal hemorrhage. The consequence of such an ailment can be an infectious-toxic shock.

Diagnostics

Laboratory diagnosis of anthrax includes the following:

• Serological studies ;
• Bacteriological studies;
• Skin and allergic tests.

With a cutaneous form of the disease, the doctor will diagnose, based on changes in the skin of the patient. If there are suspicions of a pulmonary form, do a fluorography and a tomography, take smears from the nose and samples of sputum.

Infectious agents can also be determined by taking blood for bacterial cultures, examining abdominal fluid samples, lumbar puncture, and analyzing skin scrapes.

Possible complications

Anthrax can lead to cerebral edema, lungs, gastrointestinal bleeding, and meningitis. In generalized forms of the disease, infectious-toxic shock often develops.

Treatment

Patients should be in the infectious department, with a severe course of the disease - in the intensive care ward. In no case can not open the carbuncle, so the dressings should be carried out with extreme caution. In the generalized form of the disease, the patient must be under constant monitoring to prevent toxic shock in time.

The causative agent of anthrax is destroyed by antibiotics. Apply them for 7-14 days, depending on the severity of the disease. Simultaneously with antibiotic therapy, the patient is administered antisybirolacyl immunoglobulin. Affected skin areas are treated with antiseptics. At home, anthrax can not be treated.

Forecast

The discharge of patients with a cutaneous form of the disease occurs after scarring of the affected skin, with a generalized form, full recovery and a double negative result of bacteriological studies is necessary .

Most often, death is caused by pulmonary and intestinal forms of the disease. When the skin anthrax is fully recovered in the event that timely medical assistance is provided.

People who have been in contact with an anthrax pathogen take antibiotics for 60 days.

Prevention: general information

Veterinary and medical-sanitary prophylaxis of anthrax is carried out.

Veterinary services are obliged to identify sick animals with subsequent treatment or slaughter. The fallen cattle are disinfected and destroyed, and disinfection is carried out in the hearth of the disease.

Health services should:

• To monitor compliance with public health standards;
• Time to diagnose and treat the disease;
• To examine and disinfect the focus of the disease;
• To carry out vaccination.

There is a silybrox vaccine, which reliably protects animals from this disease. In farms, vaccination is carried out entirely, but not all people with livestock own the facility, understand the need for this procedure.

The main measures for the prevention of anthrax

• Annual grafting of cattle against anthrax;
• An explanation by the veterinary services of slaughter rules for animals that died from anthrax;
• Reliable protection of cattle cemeteries and epidemic sites;
• Refusal to purchase meat that does not have the stigma of the veterinary service, as well as leather and fur from the hands;
• Burning of a dead animal infected with anthrax, burning the ground where the sick cattle lay, disinfection of premises with bleach;
• The imposition of quarantine on the place where the disease of cattle is diagnosed with anthrax;
• Grafting people whose professional activities are associated with the risk of contracting such an ailment as anthrax (the vaccine is valid for a year);
• The conduct of sanitary supervision at the enterprises processing raw material;
• The causative agents of infectious diseases can be found in food, so the rules of processing and preparation of meat and dairy products should be observed.