Pneumonia Q 38

---

A client has a positive reaction to the PPD test. The nurse correctly interprets this reaction to mean that the client has:

  

     A. Active TB

     B. Had contact with Mycobacterium tuberculosis.

     C. Developed a resistance to tubercle bacilli.

     D. Developed passive immunity to TB.

    

    

Correct Answer: B. Had contact with Mycobacterium tuberculosis.

---

A positive PPD test indicates that the client has been exposed to tubercle bacilli. Exposure does not necessarily mean that active disease exists. If the infection risk is very high, the PPD test need not be repeated. The positive PPD test is usually followed by TB symptom assessment, physical exam, and chest radiograph. If there are no TB symptoms and no evidence of active tuberculosis infection on physical exam and chest radiograph, the patient most likely has latent TB. The treatment of latent TB should be encouraged once detected.

---

Option A: A person with active infection usually presents with symptoms of the part affected and constitutional symptoms such as unexplained weight loss, fever, fatigue, loss of appetite, and night sweats. The latent TB, however, is asymptomatic and non-infectious. Early diagnosis of active TB is crucial to managing the disease in time and preventing its spread. The latent TB infection is non-infectious and asymptomatic, with a significant worldwide prevalence (33%).

Option C: The benefit to the PPD test is the rapid identification of the presence of TB infection and, thus, the rapid diagnosis of TB. Although sometimes the infection may not be active, the detection of latent TB allows for treatment and decreases the risk of progression to active TB. It is a very simple and inexpensive skin test (not routinely recommended).

Option D: Some individual’s ability to react to tuberculin antigen wanes over time, which results in a false-negative reaction. In individuals with very old tuberculosis infection (many years), sensitization to tuberculin is weak, and the PPD test may be a false negative. However, if a subsequent test is administered, the tuberculin PPD may stimulate the immune system.

---