Complete Blood Count (CBC) Test: What It Is, How It Is Done, and What Your Results Mean

What is this test? A complete blood count, or CBC, is a common blood test that measures the different cells in your blood, including red blood cells, white blood cells, and platelets, to help evaluate your overall health.

The Baylisascaris IgG antibody test is a specialized immunoassay that detects immunoglobulin G (IgG) antibodies against Baylisascaris species parasites in cerebrospinal fluid (CSF). Baylisascaris procyonis, also known as the raccoon roundworm, is the most common species known to infect humans. When larvae migrate through the central nervous system, they cause a condition called neural larva migrans (NLM), which can lead to severe neurological damage.

How is the sample collected? A healthcare professional will draw a small amount of blood, usually from a vein in your arm, using a thin needle. The procedure takes only a few minutes, and the sample is then sent to a laboratory for analysis.

This test requires a lumbar puncture (spinal tap) to collect cerebrospinal fluid. During this procedure, a healthcare provider inserts a thin needle between vertebrae in the lower back to withdraw CSF from the spinal canal. The sample is then sent to a laboratory for analysis. While the procedure may cause some discomfort, it is generally safe and takes only a few minutes.

Why is this test performed? Doctors order a CBC as part of a routine checkup or to help diagnose conditions such as anemia, infection, and certain blood disorders. It is also used to monitor an existing condition or to track how well a treatment is working.

This test is ordered when a patient shows symptoms of potential neural larva migrans, especially after known or suspected exposure to areas contaminated by raccoon feces. Symptoms may include severe headaches, seizures, nausea, vomiting, loss of coordination, visual problems, or altered mental status. Early diagnosis is critical because the condition can progress rapidly and cause permanent neurological damage.

What do the results mean? Your results show whether the levels of your blood cells fall within the normal range. Values that are too high or too low may point to conditions such as anemia, infection, inflammation, or a clotting problem, and your doctor will interpret them together with your symptoms and medical history.

A positive result indicates the presence of IgG antibodies against Baylisascaris in the cerebrospinal fluid, suggesting an infection of the central nervous system. A negative result does not completely rule out infection, as antibodies may not be detectable in early stages. Your healthcare provider will interpret these results along with your clinical symptoms, exposure history, and other diagnostic findings.