Where is the TB intradermal skin test performed in apes?

The tuberculin (TB) intradermal skin test is performed in apes at the eyelid area. This site is preferred due to several reasons related to the anatomy and physiology of the animal. The eyelid offers a relatively accessible location for testing, allowing for proper observation of any reactivity or swelling that may indicate a positive reaction to the test. Additionally, the eyelid has a thinner layer of skin and fewer layers of subcutaneous tissue, which can enhance the accuracy of the test by allowing for better absorption of the tuberculin antigen. Monitoring reactions at this site is also easier, as the eyelid can be readily visualized and assessed for any changes post-injection.

The other locations, while they might seem plausible, do not present the same advantages for tuberculin testing in apes. The forelimb, neck, and ear would not provide the same level of ease for observation and may have more surrounding tissue that could complicate the assessment of a reaction. Thus, the eyelid is the optimal choice for performing the TB intradermal skin test in this species.