Hepatitis A, B and C are three viruses known to cause inflammation of the liver. Although their names are similar, these viruses are very different structurally, are spread from one person to another in different ways, and require different strategies for prevention.
In the United States, hepatitis A causes almost half of all cases of hepatitis. Hepatitis A is spread when traces of fecal material from an infected individual are ingested by an uninfected person (this can happen, for example, when infected food handlers fail to wash their hands thoroughly after using the bathroom). Sexual contact with an infected person can also result in transfer of the hepatitis A virus. Although it occurs much less often, this virus can be transferred from person to person through routine household contact.
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Typically, infection with hepatitis A causes fatigue, nausea and vomiting, yellowing of the skin and dark urine. Left untreated, these problems usually are resolved in four to eight weeks, although they can persist for up to six months.
Although serious consequences are uncommon, hepatitis A can cause severe, even life-threatening, disease in a small percentage of cases.
A safe and effective vaccine is available to prevent hepatitis A. The federal Centers for Disease Control and Prevention recommends it for the following adults, who have a higher-than-average risk of infection: people traveling to or working in countries with high or intermediate rates of hepatitis A (even if they stay in clean hotels and are careful about what they eat and drink); homosexual and bisexual men; men and women who use illegal drugs; people with certain blood-clotting disorders (e.g. hemophiliacs); and men and women who work with monkeys and other primates infected with hepatitis A, or who work with hepatitis A in a research laboratory. Individuals with liver disease should also be immunized to prevent additional damage from hepatitis.
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Unlike hepatitis A, infection with hepatitis B requires contact with blood or infected body fluids of an infected individual. Intravenous drug use and sexual contact are two of the most common ways that the virus is spread. The virus can also be transmitted from infected mothers to newborns at birth.
