Sources of tuberculosis infection

The main source of tuberculosis infection is sick people or domestic animals, mainly cattle.

The causative agent of the disease is Mycobacterium tuberculosis (Koch's bacillus), mainly of the human type. However, bovine Mycobacterium tuberculosis, and even in isolated cases of the avian type, are not excluded. Mycobacterium tuberculosis have high resistance both inside the body and in the environment. At the same time, the viability of Koch's bacillus in the body can last up to 30 years.

Due to poor-quality treatment of pulmonary tuberculosis, mycobacteria can develop a protective reaction to drugs aimed at their destruction and change, up to complete unrecognizability, which in itself is bad enough for further diagnosis of the body and can lead to incorrect diagnosis of the disease and atypical forms of clinical manifestations. If the patient stops taking medications before all pathogenic bacteria die, the surviving microorganisms can mutate and be transmitted to other people in an unrecognizable form.

A tuberculosis infection site poses a danger to others during the period when the patient has an open form of tuberculosis, i.e. he secretes and spreads tuberculosis mycobacteria (MBT). The critical factor in contracting tuberculosis is direct, prolonged and close interaction between a healthy person and a carrier of the infection.

Accordingly, you can most often become infected with tuberculosis from a family member who permanently lives in the same area with healthy people, or in a team from an employee with tuberculosis who secretes mycobacteria. The danger of spreading Koch's bacillus is eliminated when the patient is detected in time and isolated from society.

The following routes of tuberculosis infection are distinguished:

1. airborne (aerogenic);
2. alimentary (through the digestive tract);
3. contact;
4. intrauterine.

Airborne transmission

Tuberculosis mycobacteria enter the air from the respiratory tract with droplets of saliva during coughing, talking or sneezing of a patient with an open form of tuberculosis. When inhaled, these droplets with infection penetrate the lungs of a healthy person. Therefore, this method of infection received a name corresponding to the type of transmission.

Depending on the strength of the cough and the size of the droplets, mycobacteria mix with the air, overcoming various distances: when coughing - about 2 m, when sneezing - about 9 m. Sputum particles are scattered on average directly in front of the patient at a distance of 1 m.

Droplets of infected sputum that settle on the floor and other surfaces of the room dry out and mix with dust. Tuberculosis mycobacteria that were in the sputum retain their viability for some time even in dust.

Researchers have found that by the 18th day, approximately 1% of living pathogenic microorganisms remain in dried sputum. With active air movement, sweeping the floor, and people moving, dust particles containing tuberculosis mycobacteria rise up, enter the lungs with the air and provoke infection of the body.

If you do not know how to behave near a person sick with tuberculosis or suspect that you have the disease, you need to consult a pulmonologist and have your body examined.

Alimentary route of infection through the digestive tract

Medical experiments on animals indicate that the alimentary route of infection requires a significantly larger number of mycobacteria, in contrast to the airborne route of infection. For example, one or two mycobacteria are enough to inhale tuberculosis, while several hundred pathogenic microbes are required to infect through food products.

The methods of spreading tuberculosis mycobacteria in the human body when infected with a tuberculosis culture through the digestive organs are demonstratively covered in the official case materials published in connection with the trial in Lübeck.

By tragic accident, 252 infants were given a tuberculosis culture (Kiel strain) subcutaneously during per os vaccination instead of BCG. Unfortunately, 68 children died from tuberculosis infection, 131 children fell ill, and only 53 of them remained in good health.

During the pathological examination of 20 corpses of deceased children, it was found that in almost all those infected with tuberculosis, the reproduction process was localized in the digestive organs, which became the entry point for the infection.

The peculiarities of this route of infection with tuberculosis in young children include frequent damage to the mesenteric lymph nodes.

It is necessary to take into account that mycobacterium tuberculosis can also enter the intestine when patients with pulmonary tuberculosis swallow their own bacillary sputum, which is noted when using the flotation method of gastric lavage water.

Possibility of infection with tuberculosis by contact

Cases of tuberculosis have been described, mycobacterium of which enters through the conjunctiva of the eye, both adults and small children; in this case, acute conjunctivitis and inflammation of the lacrimal sac can be diagnosed.

It is quite difficult to become infected with tuberculosis through the skin. There are documented cases of tuberculosis of the respiratory organs of milkmaids due to the penetration of MBT through damaged skin of the hands of cows sick with tuberculosis.

Intrauterine infection with tuberculosis

The probability of contracting tuberculosis in the fetus during the period of intrauterine development has been recorded by cases of tuberculosis in newborn children who died in the first days of life. Penetration of the infection into the fetus can occur either through the placenta affected by tuberculosis, or by infecting the damaged placenta of a tuberculous mother during childbirth. This probability of contracting tuberculosis is extremely low.

In conclusion, I would like to note: remember, the sooner you decide to make an appointment with a pulmonologist, having discovered symptoms of the disease, the more chances you will have to easily endure the treatment process and achieve a speedy recovery. It is necessary to always pay attention to deviations in health and undergo timely diagnostics of the body.