Hepatitis B disease is caused by Hepatitis B virus (HBV). HBV replicates or make its copies in hepatocytes or liver cells of humans and other higher primates. HBV can live outside the human host for at least 7 days and still be infectious. Infection by HBV can be various degrees: asymptomatic (without symptoms), acute or chronic depending on the age of the person. Adults are known to get asymptomatic hepatitis in approximately half of the cases and very rare cases results in acute hepatitis B causing liver failure and death. The main victims of hepatitis B chronic infection are the infants infected at birth from mother (~90%) and children below 6 years(~30%). Healthy adults (<5%) can also get the chronic disease. Persons with chronic HBV infection can die of premature death which occurs due to complications like cirrhosis or hepatocellular carcinoma . The HBV infection takes about 6 weeks to 6 months to show symptoms of the disease.
Vaccination at birth is very essential to protect the newborns from Hepatitis B disease considering the higher percentage of chronic Hep B disease incidence in young ones.
How is Hepatitis B virus spread?
HBV can spread by exposure through needles and cuts from sharp instruments contaminated with HBV infected person’s blood or body fluids. It can also be transmitted by mucosal contact with infected person’s body fluids like semen and saliva.
Certain circumstances and actions responsible for the spread of disease are:
- birth to HBV infected mother
- accidental contact with blood or open wounds of infected person
- cuts through infected needles or sharp instruments contaminated with infected blood or body fluids
- sharing razors and toothbrushes with an HBV infected person
- sharing needles and syringes by drug addicts with infected person
- unprotected sex with an infected person
- HBV is not spread through food, air or water.
Symptoms of HBV infection:
Fever, fatigue, joint pain, gastrointestinal discomforts like loss of appetite, abdominal pain, nausea and vomiting can occur. Dark orangish yellow colored urine, unusually light colored stools, and yellowing of skin or whites of the eyes characteristic of jaundice can also occur. Chronic hepatitis is a long infection which goes on for more than 6 months and can cause hardening and scarring (cirrhosis) of liver tissues leading to cessation of liver functions. Liver cancer can also occur in chronic cases of Hepatitis B.