Ventricular Septal Defect Causes No one knows what causes ventricular septal defects, but they probably come from a malformation of the heart that occurs while the infant is developing in the womb. There may be just one hole or several holes in the septum.
Definition. Hepatitis B is a potentially serious form of liver inflammation due to infection by the hepatitis B virus (HBV). It occurs in both rapidly developing (acute) and long-lasting (chronic) forms, and is one of the most common chronic infectious diseases worldwide. Contact with infected blood is a common means of transmitting hepatitis B. 2  One way this may happen is by being stuck with a needle. 3  Both health care workers and those who inject drugs into their veins are at risk in this way. 4  Having sex with a person infected by HBV is an important risk factor (especially anal sex).
Hepatitis B is an infectious liver disease. It is caused by the hepatitis B virus (HBV). Infections of hepatitis B occur only if the virus is able to enter the blood stream and reach the liver. Once in the liver, the virus reproduces and releases large numbers of new viruses into the bloodstream. To combat the disease, the body has several defenses.