Hepatitis A and hepatitis B are two members of a family of closely related diseases -- the others being hepatitis C, D, and E -- that are caused by a viral infection. Although the virus that causes each is different - along with their modes of transmission -- the diseases are similar. Hepatitis is marked by liver inflammation, and the consequences of getting the disease are potentially serious and, in some cases, fatal.
Although there are no vaccines for hepatitis C, D, or E, there are safe and effective vaccines that can prevent hepatitis A and hepatitis B. There is even a combination vaccine that can protect against both diseases.
Did You Know?
Under the Affordable Care Act, many health insurance plans will provide free children’s preventive care services, including checkups, vaccinations and screening tests. Learn more.
Hepatitis A is an acute liver disease that's caused by the hepatitis A virus or HAV. To say it's acute means it comes on suddenly and usually has a sharp rise and short course -- and so doesn't linger.
The virus is present in the stool of someone who has the disease and is commonly spread by close personal contact. If one member of a family has hepatitis A, he or she can easily pass the disease to others living in the same household. Commonly associated with unsanitary conditions, the virus can also be spread through ingesting food or water that's been contaminated with HAV. Although it's less common, it's also possible for the virus to be passed on in blood from an infected person.
Symptoms of HAV infection include a mild flu-like illness, jaundice, and severe stomach pains and diarrhea. Approximately 20% of people with symptoms need to be hospitalized, and three to five people out of every 1,000 cases die from the disease. Most children -- about 90% -- under the age of 6 who develop hepatitis A are symptom-free. But even though they don't appear to be ill, the virus is still present in their stool, and they can pass the disease on to others.
Once a person has had hepatitis A, he or she develops a natural lifelong immunity. However, if you've had hepatitis A, it's still possible for you to get other types of hepatitis, such as B or C.
What Is Hepatitis B and How Does It Differ From Hepatitis A?
Hepatitis B is caused by the hepatitis B virus or HBV. Like hepatitis A, it may start as an acute disease, causing a mild illness that lasts for a few weeks. But in some people, especially infants, the hepatitis B virus lingers, causing a lifelong chronic illness that causes long-term liver problems. Even people who have had the disease for 20 or 30 years without symptoms are at risk for serious liver problems, such as cirrhosis or liver cancer.
Hepatitis B is spread when blood, semen, or other bodily fluid of someone who has it enters the body of someone who doesn't. An infected mother can pass the disease on to her child at birth. You can also get the disease by:
Having unprotected sex with an infected partner
Sharing needles, syringes, or other drug paraphernalia
Using something that may contain an infected person's blood, such as a razor or toothbrush
Coming in direct contact with the blood of someone who has the disease
Being exposed to blood from needle sticks or other sharp instruments