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).
What is hepatitis B? Hepatitis B is a virus that infects the liver. Most adults who get it have it for a short time and then get better. This is called acute hepatitis B. Sometimes the virus causes a long-term infection, called chronic hepatitis B. Over time, it can damage your liver. Babies and young children infected with the virus are more likely to get chronic hepatitis B. You can have hepatitis B and not know it.