The main source of infection is a person who has tuberculosis.
Transmission occurs through the small droplets which are produced when we speak and, especially, when we sneeze or cough. The microbes are present in these small droplets when expelled by a person with tuberculosis, and they act as sources of infection.

Those who are  most likely to suffer the illness are those who have been in contact with a person who has the disease.
The microbe may remain dormant within a body, but could become active at any moment and produce the illness. There are, therefore, people who are infected without being ill. To identify an infected person, a tuberculin test must be carried out.

The tuberculin test is the only test able to diagnose a tuberculosis infection.
The test consists of injecting a substance between skin layers on the inside of the forearm.
A result is considered positive if a reaction of certain dimensions is produced between 48 and 72 hours around the point of the injection. This reaction consists of a small reddish hardening, which disappears after some days and does not represent any danger to health.

A positive reaction only indicates previous contact with the microbe and does not necessarily mean that the person is ill.
The test can be carried out on anybody, including pregnant women, children and those who suffer allergies. It is essential for all those who live with a person who has been diagnosed tuberculosis to take the test.

If the result is positive,  an X-ray must be taken of the thorax, in order to know whether the person is ill or is only infected, and to specify the cure or preventative treatment, respectively.

• If ill:

Tuberculosis can be cured once discovered, if the ill person collaborates. The treatment takes a long time and the patient must be consistent and take the necessary doses of all the mendicines, every day.

Even if they feel well, it must be remembered that if the treatment is interrupted or not applied properly, a relapse very easily occurs and, as the microbe tends to become resistant to the medicines that are used, ways of curing the illness are made more difficult.

After two or three weeks of regularly taking the recommended doses of medication, the sick person stops being contagious. Furniture, clothes and personal objects do not represent a danger or favor the transmission of the tuberculosis bacteria, which dies after a few hours in contact with air and sunlight. Disinfection with chemical products is not necessary. Airing the room is enough.

• If infected:

• There is a cure for  tuberculosis. This is achieved by following the prescribed treatment correctly.
  
• A person with tuberculosis stops being contagious after 2 or 3 weeks of following the treatment.
  
• A person can be infected by the tuberculosis microbe (and give a positive tuberculin test result) but may not be ill.
  
• A person with a positive tuberculin test result and a normal thorax X-ray is not infectious.
  
• The youngest amonst those who have been infected must follow a harmless treatment.