Hepatitis inflammation of the liver is nearly always caused by a viral infection. (Inflammation of the liver caused by drugs or toxic substances may also be called hepatitis, but most commonly the term indicates an infectious origin.) Depending upon the type of virus involved and the individual’s response to it, the inflammation may go undetected or at the other extreme produce profound illness. A child or adolescent with clinically significant hepatitis will typically experience fever, flulike symptoms, fatigue, jaundice (yellow orange skin and yellow color in the white area of the eyes), light or gray stools, and dark urine.
Many forms of viral hepatitis have been identified, and undoubtedly more will be discovered in the future. Of these, A and B are by far the most common.
Hepatitis A (previously called infectious hepatitis) is transmitted through contaminated food or water and is often acquired during foreign travel. The time from exposure to onset of symptoms is usually 15 to 40 days. The illness usually begins with five to ten days of nonspecific flulike symptoms, which may be followed by jaundice. (Fewer than 10 percent of children under age six who have hepatitis A develop jaundice. Among older children with hepatitis A infection, about half become jaundiced.) In the vast majority of cases, this infection resolves without complications in about a month, with rest as the primary treatment. Severe illness (or death) resulting from hepatitis A is extremely uncommon.
People who have ongoing close contact with the infected person may benefit from an injection of immune (gamma) globulin given within one or two weeks after exposure. This provides temporary protection that may prevent or minimize the impact of infection. Equally if not more important is good hygiene, including frequent hand washing, especially after any contact with stool from the infected individual. Children and infants may shed the virus in stool for several weeks after the illness has begun.
People who are planning to travel to high-risk areas (especially in developing countries) should consider obtaining specific hepatitis A vaccine, which is safe and nearly always effective, prior to departure.
Hepatitis B (formerly called serum hepatitis transmitted in ways similar to those that HIV/AIDS:
- From an infected mother to her baby before or x the time of birth.
- Through shared needles during intravenous drug use or through improperly cleaned tattoo needles that have been in contact with an infected person.
- Through contaminated blood products during transfusion. (Careful screening of donors and blood products has virtually eliminated this type of transmission.)
- Through an accidental needle stick of a healthcare worker who is drawing or processing blood from an infected person.
- Through sexual contact with an infected individual.
- In as many as one in three cases, the source of infection is unknown.
The incubation period for hepatitis B is longer—to 150 days—than for hepatitis A. The initial signs may be minimal or nonspecific, such as fever, vomiting, and fatigue. In some cases, jaundice is the first sign that the infection is present. Rarely do life-threatening illnesses occur. At the outset of about 90 percent of cases, the infection resolves in about two weeks without any specific treatment or long-term problems. However, one in ten individuals develop a chronic form of the infection, which after a number of years poses a risk for cancer or scarring (cirrhosis 3 the liver). In addition, those with chronic hepatitis B transmit the virus through sexual contact. They should never donate blood because even a tiny amount of it will infect another person.
Infants who acquire hepatitis B from an infected mother before birth are at higher risk for complication in the future. However, newborn hepatitis B infections can be prevented if an injection of hepatitis B immune globulin (or HBIG) is given within twelve hours of birth. To anticipate births at which this treatment will be necessary, pregnant women are now screened hepatitis B virus as part of routine prenatal care.
Specific treatment for chronic hepatitis B is expensive and unpredictable in its effectiveness. However, a vaccine that is both safe and highly effective in preventing this infection has been available for the past few years. Because of the significant number of new cases of hepatitis B that continue to occur each year and its potency for causing serious long-term consequences, immunization of all children against this virus is now widely recommended and in many states required for school entry. The vaccine may be given at any age, starting at birth, and involves three injections – the second given one month after the first, and the third injection at least four months after the second.
In the past Hepatitis C was usually acquired from infusions, but now sexual contact and the use of illegal intravenous drugs are the typical modes of transmission. Since blood products are now routinely screenedtin evidence of hepatitis C infection, the risk for acquiring the virus from a transfusion is now extremely low. Hepatitis C causes acute symptoms such as fever, fatigue, and jaundice in fewer than 25 percent of cases. It’s more likely to cause no immediate illness but smolder for years as a chronic infection. Fifty percent of infected adults develop chronic infection, and of these, 20 percent cirrhosis of the liver. Less is known about medical long-term outcome in children.
Very often the first indication of a prior hepatitis C infection is an abnormal blood test found during a physical routine later in life or more often noted among the screening tests done when an adolescent or young adult donates blood. Whenever such abnormalities are found, the donated blood is never given to a patient, and the potential donors notified of his or her results so that further evaluation can be carried out.