General Information

General Information
Members of the Hepadnaviridae Family | Clinical Manifestations | Epidemiology | High Risk Populations | Transmission | Tropism | Cancer

Members of the Hepadnaviridae Family:

HEPADNAVIRIDAE family lineage

Orthohepadnavirus (mammals) genus

DHBV - Duck Hepatitis Virus (Ducks and Geese)

HHBV - Heron Hepatitis B virus

Others: Ross' Goose Hepatitis B virus, snow goose hepatitis B virus, and stork hepatitis B virus

Avihepadnavirus (avian) genus

HBV - Hepatitis B Virus (Humans and Chimps)

WHV - Woodchuck Hepatitis Virus (Woodchucks)

GSHV - Ground Squirrel Hepatitis Virus (Squirrels, woodchucks, chipmunks)

WMHV - Wooly Monkey Virus (Wooly Monkey)

Others: Old World and New World primate viruses

WHV and GSHV both are morphologically the same as HBV and have about 60% of the same sequence as HBV. HBV only grows in humans and chimps, but not baboons or lower animal species.

Clinical Manifestations: How do you know you have Hepatitis B?

30% of infected individuals do NOT have symptoms. Those who do present with jaundice, fatigue, abdominal pain, loss of appetite, nausea, vomitting, and joint pain. Fever can be absent or mild. After infection, the incubation period between exposure and first symptoms is 45-120 days, averaging around 60-90 days. This period is affected by the amount of virus in the inoculum, mode of transmission, and factors relating to the host. Primary infection is usually associated with little or no liver disease and mild to fulminant hepatitis.

The next phase of disease, icteric phase, usually occurs 10 days after symptoms begin. Dark urine followed by pale stools, yellowish coloring in the mucous membranes, conjunctivae, sclerae (whites of eyes), and skin then appear. Clinically, Jaundice is indicated by bilirubin levels of 20-40mg/L. It is accompanied by hepatomegaly and splenomegaly.

The infection usually resolves after 4-8 weeks. Most patients recover with few consequences and without recurrence in the future. Young children rarely are affected and develop disease; however those that are are at a high risk of becoming chronic carriers, especially if they are under the age of 7.

The hallmark of acute Hep B infection is a large increase in serum transaminase (aminotransferase) activity.
Epidemiology: Where is Hepatitis B found?

There are 350 million carriers of Hepatitis B worldwide and most of them are concentrated in developing countries. Hepatitis B is a disease of the poor. Sub-Saharan Africa, most of Asia, and the Pacific are hit hardest. The Amazon, southern parts of Eastern Europe, and Central Europe are also affected. In Western Europe and the United States, the prevalence is only 1%. It is estimated that there are 1.2 million carriers in the United States. Most of these individuals are infected during childhood and up to 10% of them become chronically infected. In these regions, liver cancer is one of the top 3 killers of adult males.