This test looks for the virus that causes Western equine encephalitis. This is a disease that is spread through bites from infected mosquitoes. Babies and young children who are infected are more likely to get inflammation of the brain (encephalitis). Adults are less likely to have this problem. Horses can also become infected.
This test uses a sample of cerebrospinal fluid (CSF). This fluid is around the brain and spinal cord.
You may need this test to find out if you are infected with the virus that causes Western equine encephalitis. Symptoms can show up quickly. They may include:
Nausea and vomiting
Symptoms of Western equine encephalitis in babies include fussiness, vomiting, fever, failure to eat, and seizures.
You may also have a blood test to check for the virus.
Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you.
This test measures levels of immunoglobulin M (IgM). IgM is a type of antibody that your immune system makes against the virus. If your CSF sample contains IgM antibodies, you may have the disease.
This test is done with a sample of cerebrospinal fluid. The healthcare provider takes the sample during a spinal tap (lumbar puncture) in your lower back. During this test, you either sit up and lean forward or lie down on your side. The provider puts a needle into your lower back. They draw out a sample of fluid through the needle.
Side effects of a lumbar puncture include:
Discomfort while the needle is put in
Brain herniation. This is rare but life-threatening.
Tell your healthcare provider if you're taking medicine or have any other health conditions.
Healthcare providers sometimes use local anesthesia to numb the spot where the needle will be put in. This is especially true for children. Children may get upset about the procedure. So a healthcare provider or child specialist should explain to the child what to expect.
Providers sometimes use a CT scan to make images of the brain before this test. This is to check for high pressure in the skull. High pressure could lead to brain herniation from the procedure.
Be sure your healthcare provider knows about all medicines, herbs, vitamins, and supplements you are taking. This includes medicines that don't need a prescription and any illicit drugs you may use.