Challenges and Controversies

I do not routinely test all people with HBsAg positivity for HDV. If someone is treated with an antiviral, and they do not respond, or liver tests remain elevated on treatment in the setting of low or negative HBV DNA, I will test for HDV, looking for an alternative explanation. I do more often test those at higher risk of HDV infection, in particular if they are pursuing liver transplantation.

In my primary care practice, I follow AASLD recommendations on hepatitis D virus (HDV) screening for patients with chronic hepatitis B and selectively test those with either 1) HDV risk factors (e.g. HIV, injection drug use, MSM, or immigration from a high endemic region including Africa, Middle East, Eastern Europe, Central/Northern Asia and select East Asian countries such as Vietnam, Mongolia, Japan, Taiwan) -OR- 2) low HBV DNA with elevated ALT (since HDV is known to competitively decrease HBV DNA replication).

Since this patient is from China and has normal liver enzymes and high HBV DNA, I would not typically order HDV screening.

HOWEVER, I want to point out that HDV co-infection, being a major risk factor for cirrhosis, is an indication to perform routine liver cancer surveillance with q6mo liver ultrasound +/- AFP in patients with chronic hepatitis B (in addition to a personal history of cirrhosis, a family history of liver cancer in a first-degree relative, and Asian or African/Black M > 40yo and Asian females > 50 yo). Thus, it would be reasonable to screen all patients for chronic hepatitis D.

Further, the recommended ICD-codes for chronic hepatitis B require a delta-agent (HDV) specification, e.g. B18.0 Chronic hepatitis B with delta-agent vs. B18.1 Chronic hepatitis B without delta-agent. Alternative, less specific codes sometimes used for chronic hepatitis B patients such as B19.0 Unspecified viral hepatitis are not encouraged in value-based care systems since they are not associated with an HCC (hierarchical condition category) or RAF (risk adjustment factor) score.

Thus, if cost/coverage is not a consideration, it would be reasonable to screen for HDV in all patients with chronic hepatitis B. If a patient is uninsured, I would lean towards the risk-based approach outlined above.
When I order HDV screening for those in the at-risk groups mentioned previously, I order the HDV Antibody (Total, not IgM) and if positive, I order a follow-up HDV RNA to see if the patient has current HDV infection (vs. prior infection). I have not encountered any insurance coverage issues for HDV Ab and RNA testing of insured patients in the San Francisco Bay Area where I practice.

With the considerations mentioned above, aside from the AASLD recommendations, why do I not universally screen ALL of my chronic hepatitis B patients for HDV co-infection? Because in the 2 community health settings I have worked caring for primarily immigrants from China, for every 300 to 500 patients with chronic hepatitis B screened for HDV, only 1 has tested positive for active HDV Ab (both HDV Ab and HCV RNA positive).