Question

The nurse is interpreting the result of a client's TB skin test. Which one of the following factors is responsible for a false positive TB skin test? A. Vaccination with a live virus B. Weakened immune system C. Inoculation with BCG vaccine D. Poor testing technique

Short answer

Answer: C. Inoculation with BCG vaccine

Step-by-step solution

Analyze the Options

Let us examine each option in detail. A. Vaccination with a live virus - Vaccination with a live virus does not cause a false positive in the TB skin test. B. Weakened Immune System - A weakened immune system doesn't cause a false positive in the TB skin test but may lead to a false-negative result. C. Inoculation with BCG vaccine - BCG (Bacillus Calmette–Guérin) vaccine is used to protect against tuberculosis. It can cause a false-positive TB skin test result, as the test cannot differentiate between a reaction due to the vaccine and a true infection. D. Poor testing technique - Though a poor testing technique may lead to unreliable results, it is not a specific cause of a false positive TB skin test. Based on the analysis, the correct answer is C.

Conclusion

The factor responsible for a false positive TB skin test is: C. Inoculation with BCG vaccine

Key concepts

BCG Vaccine

The BCG vaccine, which stands for Bacillus Calmette–Guérin, is a vaccine primarily used against tuberculosis (TB). It's named after the French scientists who developed it, Albert Calmette and Camille Guérin. This vaccine is not used in every country; it is more common in places with higher rates of TB. In countries where TB is not widespread, the vaccine is usually only given to people at high risk.

In the context of TB skin tests, it's critical to note that one of the known complications of receiving the BCG vaccine is that it can cause a false positive result. This happens because the vaccine contains a small amount of a TB-related bacterium that can elicit an immune response detectable by the skin test. As a result, individuals who have been vaccinated with BCG may test positive even if they are not infected with TB.

False Positive TB Test

A false positive TB test occurs when a person who does not have tuberculosis tests positive on a TB skin test or TB blood test. Various factors can contribute to this, but one of the most common is the prior administration of the BCG vaccine.

Other factors that might cause a false positive TB test include certain infections such as non-TB mycobacteria or a person having had a recent TB infection that the body has cleared without treatment. It's crucial for healthcare providers to consider a patient's history, including vaccination status and risk factors for TB, when interpreting test results. Understanding these nuances is essential for proper diagnosis and to avoid unnecessary treatment for TB.

Nursing Exam Preparation

Preparing for nursing exams requires a comprehensive understanding of medical procedures, patient care, and clinical knowledge. When studying topics like the interpretation of TB skin tests, students should prioritize understanding not only the procedures but also the underlying principles and potential complications such as false positives after BCG vaccination.

To effectively prepare for nursing exams, students should focus on:

• Mastering core concepts through coursework and self-study,
• Practicing with realistic exam questions,
• Developing critical thinking skills to apply knowledge to real-world scenarios,
• Maintaining an up-to-date understanding of healthcare protocols.

Active learning techniques and engagement with study groups can also enhance retention and comprehension. Efficient study habits and seeking clarification on difficult topics, like the BCG vaccine's impact on TB tests, will help ensure success on nursing exams.