The 3 Varieties of Hepatitis Infection
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.
Hepatitis B can cause the same symptoms as hepatitis A. However, a large number of people never develop overt signs of infection and may not even know that they are infected. Although most people are able to fight the virus and eliminate hepatitis B infection from their body, 5% to 10% of infected individuals develop a lifelong infection that can cause extensive scarring of the liver and liver failure as well as liver cancer.
Hepatitis B vaccination is recommended for all young adults who were not immunized during childhood, and for the following groups of high-risk adults: men who have sex with men; people who use intravenous drugs; men and women who have multiple sex partners; household members of individuals infected with hepatitis B; sexual partners of individuals infected with hepatitis B; international travelers to countries where hepatitis B is common; residents and staff of institutions for the developmentally disabled; individuals receiving kidney dialysis; prisoners; and people frequently exposed to blood or blood-contaminated body fluids (such as laboratory workers and doctors).
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Hepatitis C (formerly known as “non-A non-B hepatitis”) resembles hepatitis B in several ways. To contract hepatitis C, you must come into contact with the blood of an infected individual. Transfusions with infected blood were once the most common cause of hepatitis C. The development of an accurate screening test for blood donors has nearly eliminated the risk of infection from a transfusion, and the sharing of needles during drug use is currently the most common cause. Hepatitis C can also be spread through sex with an infected person, and pregnant women can pass the virus to their infants at the time of delivery (however, such cases are much less common than with hepatitis B). Hepatitis C is not spread through casual contact, such as touching, hugging, or sharing eating utensils and drinking glasses.
The hepatitis C virus can cause symptoms within several weeks of infection, but about two-thirds of those infected never experience symptoms. Hepatitis C infection is particularly difficult for the immune system to overcome. For that reason, more than 80% of people infected with this virus develop lifelong infection. Only a small proportion of these people suffer hepatitis C symptoms. Among those who do, fatigue is the most common problem; other symptoms include nausea, poor appetite, muscle aches, weakness and weight loss. Whether symptomatic or not, lifelong hepatitis C infection can lead to liver failure and can cause cancer of the liver.
The CDC recommends that the following groups of individuals be tested for hepatitis C infection: men and women who ever injected illegal drugs (including individuals who only injected a few times and do not consider themselves drug users); individuals who were ever on long-term hemodialysis; people who received clotting-factor concentrates produced before 1987; men, women and children who received a transfusion of blood or blood components before July 1992; people who received blood or blood components from donors who subsequently tested positive for hepatitis C; individuals who received an organ transplant before July 1992; children born to mothers infected with hepatitis C. Testing is not currently recommended for household contacts of people with hepatitis C.
It is important to identify people infected with hepatitis C because medications are available that can slow liver damage (not everyone, however, responds to these medications). Once diagnosed, infected individuals can reduce their risk of further liver damage by avoiding alcohol and medications that are toxic to the liver. Immunization against hepatitis A and B may be indicated in some cases. The risk of spreading the disease to others can also be lowered through the use of safe sexual practices and latex condoms, and the avoidance of blood or organ donation.
Dr. Jonathan Fielding is the director of public health and health officer for the L.A. County Department of Health Services. Dr. Valerie Ulene is a board-certified specialist in preventive medicine practicing in Los Angeles. They can be reached at ourhealth@dhs.co.la.ca.us. Our Health runs the second and fourth Mondays of the month.
