There are three stages of tuberculosis (TB): exposure, latent TB infection, and active TB disease.
Here's a breakdown of each stage:
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Exposure: This stage occurs when a person comes into contact with someone who has active TB. The person is exposed to Mycobacterium tuberculosis, the bacteria that causes TB, but they are not yet infected. A TB skin test or blood test will be negative during this stage.
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Latent TB Infection (LTBI): In this stage, the person has been infected with Mycobacterium tuberculosis, but the bacteria are inactive. They have no symptoms, cannot spread TB to others, and usually feel well. A TB skin test or blood test will be positive, indicating infection. People with LTBI can develop active TB disease later in life, especially if their immune system weakens. Treatment is available for LTBI to prevent the development of active TB disease.
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Active TB Disease: This stage occurs when the Mycobacterium tuberculosis bacteria become active and multiply. The person has symptoms such as cough, fever, weight loss, and night sweats. Active TB can affect the lungs (pulmonary TB) or other parts of the body (extrapulmonary TB). People with active TB disease are infectious and can spread the disease to others. Treatment is necessary to cure the disease and prevent its spread.
Here's a table summarizing the three stages:
| Stage | Infection Status | Symptoms | Infectious | Test Results |
|---|---|---|---|---|
| Exposure | Not infected | None | No | Negative |
| Latent TB Infection | Infected | None | No | Positive |
| Active TB Disease | Infected | Present | Yes | Positive |
It is important to get tested for TB if you have been exposed to someone with active TB or if you have symptoms of TB. Early diagnosis and treatment are essential to prevent the spread of the disease and ensure a full recovery. You can learn more about Tuberculosis from resources like Johns Hopkins Medicine.
