CPT® Code 86794

The CPT® Code 86794 refers to the serologic testing for Zika virus-specific IgM antibodies. This testing is crucial for diagnosing Zika virus infections, particularly in individuals who exhibit symptoms. The serologic test is typically performed starting at the end of the first week of illness, as this is when the body usually begins to produce detectable levels of IgM antibodies against the Zika virus. The specific test utilized for this purpose is the Zika IgM Antibody Capture Enzyme-Linked Immunosorbent Assay (Zika MAC-ELISA). This assay involves a series of steps where the patient's serum is mixed with a known, noninfectious viral antigen, and the presence of antibodies is detected through a colorimetric reaction facilitated by an enzyme-conjugated anti-viral antibody. The results are quantified using a spectrophotometer, which measures the intensity of the color change. However, interpreting the results can be challenging due to the potential for cross-reactivity with antibodies from other viruses and the occurrence of nonspecific reactions. To enhance diagnostic accuracy, IgM serology testing is often conducted alongside DNA or RNA testing, especially in symptomatic pregnant women. In cases where results are equivocal, presumed, or inconclusive, it is essential to forward these to designated CDC laboratories that specialize in plaque-reduction neutralization testing (PRNT) for further confirmation.