Pathology/Lab Coding Alert

Question: Our lab performed a blood test for Zika virus antigen detection for a patient presenting with fever, joint pain, and headache. How should we code the test and the diagnosis?

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Answer: The most common lab test for Zika virus antigen detection is an amplified nucleic acid probe test. If that’s what your lab performs, you should code the test as 87662 (Infectious agent detection by nucleic acid (DNA or RNA); Zika virus, amplified probe technique).

Don’t confuse this with the code for a Zika virus antibody test, which you would list with code 86794 (Antibody; Zika virus, IgM).

Dx: Labs must use the diagnosis provided by the ordering physician, so in this case, that would mean listing the correct ICD-10-CM codes for the symptoms you mentioned, such as R50.9 (Fever, unspecified), M25.50 (Pain in unspecified joint), and R51 (Headache).

If the physician also lists as a reason for the test that the patient had exposure to Zika virus, you should also report Z20.821 (Contact with and (suspected) exposure to Zika virus).

If the test is positive for Zika virus infection, the ordering physician will select a diagnosis code based on the lab findings and the clinical presentation of the case using A92.5 (Zika virus disease).

Beware: Zika virus may be transmitted from a pregnant mother to the fetus, so you should be aware that the correct ICD-10-CM code for the condition in a newborn is P35.4 (Congenital Zika virus disease). In fact, ICD-10-CM lists an “Excludes1” note under A92.5 directing you to the congenital code.