CPT® Code 86653

The CPT® Code 86653 refers to a laboratory test specifically designed to measure antibodies associated with St. Louis encephalitis in serum and/or cerebrospinal fluid (CSF). St. Louis encephalitis is a viral infection transmitted by mosquitoes, predominantly found in regions such as the Western United States, Texas, the Ohio-Mississippi Valley, and Florida. This disease tends to have peak outbreak periods during the summer and autumn months. Initial symptoms of St. Louis encephalitis can include fever, chills, headache, and malaise, with additional symptoms such as sleepiness, nausea, sore throat, and cough potentially manifesting. Following the onset of these early symptoms, central nervous system (CNS) symptoms may develop within 1 to 4 days, which can persist for months or even years. The risk of experiencing CNS symptoms is notably higher in elderly patients, who may exhibit signs such as irritability, sleepiness, depression, and memory loss. The laboratory test measures IgG antibody titers, which can indicate either current or past infections, while IgM antibodies are indicative of current or recent infections. It is essential to consider the patient's travel history, along with relevant medical and epidemiological data, particularly in cases where the virus has not been isolated. The test requires a blood sample, which is obtained through a separately reportable venipuncture, and CSF, which is collected via a separately reportable lumbar puncture. The analysis of serum and CSF is conducted using semi-quantitative indirect fluorescent antibody or immunofluorescent assay techniques.