1. Reason for surveillance
2. Case definition
3. Notification criteria and procedure
4. The disease
5. Managing single notifications

1. Reason for surveillance

To monitor the epidemiology and so inform the development of better prevention strategies.

2. Case definition

A confirmed case requires laboratory definitive evidence only, in a person known to be hepatitis B surface antigen (HbsAG) positive.

Laboratory definitive evidence

• Detection of IgM or IgG to hepatitis D virus, or
• Detection of hepatitis D virus on liver biopsy.

Clinical evidence

Not applicable.

Epidemiological evidence

Not applicable.

Factors to be considered in case identification

Hepatitis D is always associated with a coexistent hepatitis B infection. Hepatitis D can occur simultaneously with an acute infection of HBV. Coinfection usually results in a self-limiting hepatitis. Hepatitis D can also occur in an HBV carrier. Superinfection often causes a fulminant acute hepatitis which progresses to chronic active hepatitis.

3. Notification criteria and procedure

Hepatitis D is to be notified by laboratories on serological confirmation (ideal reporting by routine mail). Only confirmed cases should be entered onto NCIMS.

4. The disease

Infectious agent

The hepatitis D virus (HDV), a virus-like particle.

Mode of transmission

The mode of transmission for hepatitis D is similar to that for Hepatitis B.

Timeline

The typical incubation period is 14 to 60 days. Peak infectivity probably occurs just prior to onset of acute illness, when particles containing delta antigen are readily detected in the blood. Following onset, viraemia probably falls rapidly to low or undetectable levels.

Clinical presentation

The usual clinical presentation resembles Hepatitis B.

5. Managing single notifications

No specific public health follow up is required apart from the routine follow up for Hepatitis B notification.