Rapid Antigen Test for meningitis organisms in a child can be done on the following specimens except
**Core Concept**
Rapid antigen tests are used for the detection of bacterial meningitis-causing organisms such as Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis in cerebrospinal fluid (CSF) specimens. These tests are based on the principle of detecting specific antigens present in the CSF.
**Why the Correct Answer is Right**
The correct answer is based on the principle that rapid antigen tests are not suitable for all types of specimens due to the complexity of the test and the availability of the target antigens. The test is usually performed on CSF specimens, which are obtained through lumbar puncture. The test is not recommended for blood specimens as the sensitivity and specificity of the test may be affected by the presence of antibodies and other substances in the blood.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as rapid antigen tests can be performed on CSF specimens, which are obtained through lumbar puncture.
**Option B:** This option is incorrect as rapid antigen tests are not recommended for blood specimens due to the complexity of the test and the availability of the target antigens.
**Option C:** This option is incorrect as rapid antigen tests can be performed on CSF specimens, which are obtained through lumbar puncture.
**Option D:** This option is incorrect as rapid antigen tests can be performed on CSF specimens, which are obtained through lumbar puncture.
**Clinical Pearl / High-Yield Fact**
Rapid antigen tests for meningitis organisms are not recommended for blood specimens as the sensitivity and specificity of the test may be affected by the presence of antibodies and other substances in the blood.
**Correct Answer:** B. Blood