How does Tuberculosis spread?
The TB germ is carried on droplets in the air, and can enter the body through the airway. A person with active pulmonary tuberculosis can spread the disease by coughing or sneezing. The process of catching tuberculosis involves two stages: first, a person has to become infected; second, the infection has to progress to disease. To become infected, a person has to come in close contact with another person having active tuberculosis. In other words, the person has to breathe the same air in which the person with active disease coughs or sneezes.
TB is not spread by:
- Shaking someone's hand.
- Sharing food or drink.
- Touching bed linens or toilet seats.
- Sharing toothbrush.
- Kissing.
Symptoms
The primary stage of the disease may be symptom-free, or the individual may experience a flu-like illness. In the secondary stage, called active disease, there might be a slight fever, night sweats, weight loss, fatigue and various other symptoms, depending on the part of the body affected. Tuberculosis of the lung is usually associated with a dry cough that eventually leads to a productive cough with blood-stained sputum. There might also be chest pain and shortness of breath. This secondary stage, if affecting the lungs, is the contagious stage - when the bacteria can be spread to others.
TB risk factors
Once a person is infected with TB bacteria, the chance of developing TB disease is higher if the person:
- Has HIV infection.
- Has been recently infected with TB bacteria ( in the last 2 years)
- Has other health problems, like diabetes, that make it hard for the body to fight the bacteria.
- Abuses alcohol or uses ilegal drugs,
- Was not treated correctly for TB in the past.
Latent TB infection and TB disease
Not everyone infected with TB bacteria becomes sick. As a result, two TB-related conditions exist: latent TB infection and TB disease.
Latent TB Infection
TB bacteria can live in the body without making you sick. This is called latent TB infection. In most people who breathe in TB bacteria and become infected, the body is able to fight the bacteria to stop them from growing. People with latent TB infection do not feel sick and do not have any symptoms. People with latent TB infection are not infectious and cannot spread TB bacteria to others. However, if TB bacteria become active in the body and multiply, the person will go from having latent TB infection to being sick with TB disease.
TB Disease
TB bacteria become active if the immune system can't stop them from growing. When TB bacteria are active (multiplying in your body), this is called TB disease. People with TB disease are sick. They may also be able to spread the bacteria to people they spend time with every day.
Many people who have latent TB infection never develop TB disease. Some people develop TB disease soon after becoming infected (within weeks) before their immune system can fight the TB bacteria. Other people may get sick years later when their immune system becomes weak for another reason.
For people whose immune systems are weak, especially those with HIV infection, the risk of developing TB disease is much higher than for people with normal immune systems.
Latent TB Infection
TB bacteria can live in the body without making you sick. This is called latent TB infection. In most people who breathe in TB bacteria and become infected, the body is able to fight the bacteria to stop them from growing. People with latent TB infection do not feel sick and do not have any symptoms. People with latent TB infection are not infectious and cannot spread TB bacteria to others. However, if TB bacteria become active in the body and multiply, the person will go from having latent TB infection to being sick with TB disease.
TB Disease
TB bacteria become active if the immune system can't stop them from growing. When TB bacteria are active (multiplying in your body), this is called TB disease. People with TB disease are sick. They may also be able to spread the bacteria to people they spend time with every day.
Many people who have latent TB infection never develop TB disease. Some people develop TB disease soon after becoming infected (within weeks) before their immune system can fight the TB bacteria. Other people may get sick years later when their immune system becomes weak for another reason.
For people whose immune systems are weak, especially those with HIV infection, the risk of developing TB disease is much higher than for people with normal immune systems.