Disease tuberculosis of the lungs open form is transmitted?
Pulmonary tuberculosis in the open form as it is transmitted, what are its causes? This should be known to every adult, as timely treatment can save lives.
Tuberculosis is a serious infectious disease, which is the causative agent, the tubercle Bacillus (the tubercle Bacillus). Mycobacterium tuberculosis resistant to both chemical and physical effects. She is not afraid of the dryness, cold, can survive in dust for up to 14 days, on items – up to 3 months. Dies just exposed to direct sunlight and high temperatures. The most frequent source of infection is the person is suffering from open tuberculosis of the lungs. The tubercle Bacillus have such a patient is in the saliva and sputum.
As already mentioned, the main source of the disease (90% of all cases) is a person with open tuberculosis. During coughing, sneezing or talking can release tiny droplets of sputum containing the pathogen. Their contact with the mucosa of the nose or mouth in danger of infection of healthy people.
But not everyone with TB is infectious. When a latent form of the disease in the sputum mycobacteria not, therefore, to others and family a man is not a threat. The patient closed pulmonary tuberculosis is a carrier, but not a vector of infection. Contact with such a person poses no risk of infection.
Along with the human type of Bacillus tuberculosis, bovine allocate its shape. In this case the source of infection may be a sick animal, or rather its meat or milk. Consumption of unboiled milk of a sick cow or her nedovrsenoj meat with a high probability can lead to the development of disease in humans.
Route of infection
The causative agent of tuberculosis is transmitted from an infected person or animal, emitting into the environment of mycobacteria. There are the following ways of infection:
- food (nutritional);
- in utero.
The main mode of transmission of tuberculosis according to the statistics is airborne.
Contact and food ways of infection are less common. Are considered to be minimal chance of fetal infection from a patient with tuberculosis of the mother during intrauterine development.
The release of Mycobacterium tuberculosis into the environment occurs together with saliva when coughing, sneezing or eventhe conversation of the patient with an open form of tuberculosis. The radius of the spread of the bacteria can reach several meters, but high risk only those in the immediate vicinity of an infected person (up to 1 meter).
Another form of air-droplet way of transmission – airborne dust pathway. In this case, the infection also occurs through the air, but not Mycobacterium tuberculosis contains in the saliva or sputum, and is posted in the form of dust. It occurs in contact with secretions from the oral cavity ill person to objects or the ground. Later they dry and turn to dust. Due to the high viability of the virus, in this state, it can stay in the air for several weeks.
But not always after inhalation of the microbe is an infection of the body. If a person's immune system is fully functional, that got inside the infection does not cause illness. It is blocked by protective mechanisms of the body and can in this state be in the body for several years (latent TB). Distribution of Bacillus in the human body occurs when a weakened immunity due to malnutrition, exposure to cold, other illness, etc.
Contact a way of Contracting TB is quite rare. This is due to the high resistance of the skin of a healthy person to infection. The risk increases in case of violation of the integrity of the skin. Mycobacterium is much easier to enter the body through wounds on the body.
The contact route of infection often has professional. It may be the milker while milking a sick cow, the doctors on examination, the patient with tuberculosis with no means of protection. The probability of infection increases with the decrease in immunity. Particularly at risk are children.
Alimentary the spread of the disease probably by eating products, which hit the bacteria of tuberculosis, or when intake of milk (and derived products from it food) sick cow. Transmitted infection can and when eating nedovrsenoj meat of the animal.
The dose penetration of mycobacteria in the organism should be much higher than when airborne route of infection. Due to the bactericidal capacity of gastric juice, the virus in the minimum amounts might not survive in the stomach. Especially insignificant risks of tuberculosis through the food the way people with high acidity.
Infection from mother to child occurs more frequently in a very advanced stage of tuberculosis and social problems.Lose of the fetus with Mycobacterium leprae possible:
- during childbirth when the baby will pass through the birth canal;
- when TB infection of the placenta;
- in the first days after birth.
It should be noted that such cases are extremely rare. In the womb, the baby is not infected due to the high protective ability of the placenta, and postpartum infection does not occur due to isolation from mother to child and his or her vaccinations.
Risk of infection
Of course, the highest risk of getting sick prone family members of a person suffering from an open form of pulmonary tuberculosis, as well as people whose profession involves constant interaction with infected people or animals.
Medical factors are the following groups of people that have a high chance of getting sick:
- not having vaccination against tuberculosis;
- patients with diabetes or peptic ulcer disease;
- with chronic diseases of the respiratory system.
The assignment of the risk group is primarily due to the body's inability to fully resist the tubercle Bacillus, due to reduced immune system due to another illness.
Social risk groups:
- people living in closed institutions (prisons, boarding schools);
- persons with deviant behavior, (homeless, homeless).
Prevention of tuberculosis infection
As you know, any better to prevent disease than to treat it. Therefore, knowing the main ways of infection with tuberculosis, it will be important to identify some preventive measures. All the methods of prevention of pulmonary tuberculosis can be grouped into two large groups:
- specific prevention;
- nonspecific prophylaxis.
Specific prophylaxis of tuberculosis aimed at preventing human infection, which are more than others susceptible to infection. It represents the immunization in the form of the introduction of the vaccine containing attenuated Mycobacterium tuberculosis. Bacteria are not active enough for human infection, but their activity is enough for the development of human immunity to tuberculosis.
Vaccination does not guarantee complete protection from infection but reduces the risk of Contracting 65-75%. More efficient vaccine to children up to 16 years. After 35 years, it is not introduced, since the use of it practically are not present. However, in the interval from 16 to 35 years of vaccination exposed persons whose profession is associated with a high risk of infectionTB.
Nonspecific methods of prophylaxis aims to prevent infection of people who have regular contact with people suffering from open form of tuberculosis, the disinfection of surfaces he'd touched, his bedding, etc.
Nonspecific prevention includes daily ventilation of the room. It also includes measures to prevent the infection of others by the patient to cover mouth with hand or tissue when coughing or sneezing, to give some distance when dealing with healthy people, do not spit not cough phlegm everywhere.
Thus, we can conclude that, despite the prevalence and danger of open forms of pulmonary tuberculosis, with the knowledge of major sources and compliance with prevention measures, the risk of Contracting this infectious disease can be minimized.