Introduction
HBV (hepatitis B virus) is estimated to infect over 40,000 people each year. According to the Centers for Disease Control and Prevention, the total number of people living with the virus in the U.S. is over 1 million, with about 4,000 deaths annually from chronic liver disease. HBV is also strongly implicated in the development of liver cancer.
Life Cycle of HBV
Hepatitis B virus is a relatively stable virus that's heat resistant and resistant to acids and alkali. It's also stable in most organic solvents.
The virus gains access to the bloodstream and heads for the liver cells, where it makes its home. In the liver cells, the virus replicates by hijacking the host cellular mechanisms to produce infective units. The hepatitis virus is able to produce huge numbers of infective units even before any signs of infection. The infection is classified as acute or chronic, based on the symptoms. Those with stronger immune responses usually have significant acute illness; among the immunosuppressed, there is more likelihood of chronic infections with possible development of liver cancer or cirrhosis.
How HBV is Transmitted
The hepatitis virus is available in body fluids in high amounts. Its stability in almost every standard environment in the body increases its availability in all body fluids including semen, saliva and serum, and body secretions such as cervical and vaginal secretions.
Contact with body fluids from an infected person increases the likelihood of an infection. Unprotected sexual intercourse is a common mode of transmission. Sharing a toothbrush or shaving razors can also serve as a medium of transmission. Another significant mode of transmission is sharing of needles among intravenous drug users. Needle stick injuries constitute a significant threat of infection among medical personnel and workers in medical waste disposal. Unprotected handling of materials soiled by blood or other body fluids of an infected individual by caregivers also exposes such caregivers to serious risks of infection. Unsterilized cosmetic tools such as those used for tattoos, pedicures, manicures, circumcision and barbing can also be avenues of infection, although these are more significant in developing countries.
Another significant mode of transmission is mother-to-child transmission. The virus is able to cross the placental barrier and infect the unborn child in the womb.
Prevention
There is a very effective HBV vaccine available. It's given in three doses and confers strong immunity against the disease. The National institutes of Health recommends that those inadvertently exposed to the virus should get an injection of hepatitis immunoglobulins with the vaccines for better protection from the illness.
Other prevention modalities are to avoid the means of transmission mentioned here if possible. For health workers, sticking to Occupational Safety and Health Administration guidelines for handling potentially infective materials minimizes the risks of getting the infection. Those caring for loved ones with the illness should use gloves while handling soiled clothing.
