B18.1

Chronic viral hepatitis B without delta-agent

Chronic viral hepatitis B without delta-agent (B18.1) is a persistent infection with the hepatitis B virus (HBV) that has lasted for six months or longer. It is clinically defined by the continued presence of the hepatitis B surface antigen (HBsAg) in the blood. Chronic HBV infection is a significant global health burden and a leading cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma (HCC). The clinical course of the disease is highly variable, often progressing through several immunopathological phases including the immune-tolerant phase, the immune-active phase (HBeAg-positive or HBeAg-negative), and the inactive carrier state. This specific classification (B18.1) denotes that the patient is not co-infected or super-infected with the hepatitis delta virus (HDV), which typically accelerates liver damage. Long-term management focuses on monitoring viral load (HBV DNA levels), liver enzymes (ALT/AST), and screening for liver fibrosis and malignancy.

Clinical Symptoms

  • Chronic fatigue and malaise
  • Right upper quadrant abdominal discomfort or pain
  • Loss of appetite (anorexia)
  • Nausea and intermittent vomiting
  • Jaundice (yellowing of the skin and eyes)
  • Dark-colored urine
  • Clay-colored or pale stools
  • Pruritus (generalized itching)
  • Joint pain (arthralgia)
  • Spider angiomas (vascular lesions on the skin)
  • Palmar erythema
  • Splenomegaly (enlarged spleen)
  • Ascites (fluid accumulation in the abdomen)
  • Peripheral edema
  • Easy bruising or bleeding
  • Hepatic encephalopathy (confusion or altered sleep patterns in advanced disease)

Common Causes

  • Infection with the Hepatitis B virus (HBV), a partially double-stranded DNA virus
  • Perinatal transmission (vertical transmission from mother to child at birth)
  • Sexual contact with an infected partner
  • Percutaneous exposure to infected blood (sharing needles, syringes, or drug-injection equipment)
  • Exposure to contaminated medical or dental instruments in settings with poor infection control
  • Occupational exposure to blood or body fluids among healthcare workers
  • History of receiving blood transfusions or organ transplants before rigorous screening protocols
  • Household contact with a person chronically infected with HBV

Documentation & Coding Tips

Explicitly state the chronicity of the Hepatitis B infection by documenting its persistence for greater than six months.

Example: Patient is a 45-year-old male with confirmed chronic viral hepatitis B without delta-agent, documented by persistent HBsAg for 12 months. Current management involves Tenofovir Alafenamide 25mg daily. Liver ultrasound shows no evidence of cirrhosis, and the patient remains in a chronic compensated state.

Billing Focus: Chronicity documentation supports the use of B18.1 rather than B16 codes for acute infections.

Always document the presence or absence of the Hepatitis Delta virus co-infection.

Example: The patient has chronic viral hepatitis B without delta-agent as confirmed by negative anti-HDV IgG and IgM testing. No evidence of superinfection or co-infection is present at this time.

Billing Focus: Directly distinguishes B18.1 from B18.0, which requires the presence of the delta-agent.

Link chronic hepatitis B to any associated manifestations such as cirrhosis or hepatocellular carcinoma using causal language.

Example: Chronic viral hepatitis B without delta-agent has progressed to compensated cirrhosis of the liver without ascites. Patient is monitored every 6 months with AFP and RUQ ultrasound for HCC screening.

Billing Focus: Supports the use of multiple codes for manifestation-etiology relationships (e.g., K74.60).

Document the HBeAg status and HBV DNA viral load to indicate the phase of chronic infection.

Example: Patient exhibits chronic viral hepatitis B without delta-agent, HBeAg-positive with a viral load of 2.5 million IU/mL, indicating active viral replication. Liver enzymes are mildly elevated at ALT 68 U/L.

Billing Focus: Supports medical necessity for high-intensity monitoring and specialized antiviral treatment.

Identify the patient as a chronic carrier versus having active chronic hepatitis based on inflammatory activity.

Example: Patient is a chronic carrier of hepatitis B virus without delta-agent, with normal ALT levels and low HBV DNA (under 2000 IU/mL) over the last three visits, indicating an inactive carrier state.

Billing Focus: Differentiates between B18.1 and the carrier state Z22.51, though B18.1 is preferred if chronic infection is clinically managed.

Relevant CPT Codes