The exact progression of tuberculosis can vary based on the individual. For individuals that progress to severe disease, which of the following orders the stages of a tuberculosis infection correctly as most commonly experienced?

• A. Active infection → latent infection → dormant infection.
• B. Initial infection → dormant infection → latent infection.
• C. Dormant infection → active infection → latent infection.
• D. Initial infection → latent infection → active infection.

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the terminology related to tuberculosis infection stages. 'Initial infection' refers to the first time Mycobacterium tuberculosis enters the body and begins to multiply, often causing a primary immune response.
2. Step 2: Recognize that after the initial infection, the immune system may contain the bacteria without completely eliminating it, leading to a 'latent infection' stage where the bacteria are present but inactive and the person shows no symptoms.
3. Step 3: Know that 'active infection' occurs when the latent bacteria reactivate, multiply, and cause symptoms of tuberculosis disease, which can be contagious and harmful.
4. Step 4: Analyze the order of progression: the infection starts with the initial infection, then moves to latent infection if the immune system controls it, and finally may progress to active infection if the bacteria reactivate.
5. Step 5: Conclude that the correct sequence of tuberculosis infection stages most commonly experienced is: Initial infection → Latent infection → Active infection.