Hepatitis A Overview
Hepatitis is a general term that means inflammation (irritation and swelling) of the liver. Inflammation of the liver can result from infection, exposure to alcohol, certain medications, chemicals, poisons, or from a disorder of the immune system.
Hepatitis A refers to liver inflammation caused by infection with the hepatitis A virus (HAV). HAV is one of several viruses that can cause hepatitis, and is one of the three most common hepatitis viruses in the United States. The other two common types are hepatitis B and hepatitis C; however, there are other named types such as D, E, F, and G, and more types may be discovered in the future. Moreover, these infections are somewhat different from hepatitis A, and from each other.
Unlike hepatitis B and hepatitis C, hepatitis A does not cause chronic (ongoing, long-term) disease. Although the liver becomes inflamed and swollen, it heals completely in most people without any long-term damage. Once a person contracts hepatitis A, they develop lifelong immunity, and rarely contract the disease again.
Because of the way it is spread, the hepatitis A virus tends to occur in epidemics and outbreaks. As many as 1 in 3 adults (>age 19) in the United States have antibody to HAV , meaning they have been exposed to the virus, but most do not become ill. In 2011, researchers report no significant change in seroprevalence (the frequency of people in a population that have particular antibodies, usually reactive against a disease-producing organism in their blood serum) of HAV antibodies in adults before or after the HAV vaccine became available (see reference 3). The number of cases of hepatitis A in the United States varies among different communities, and has been reduced by the introduction of the hepatitis A vaccine. The rate of infection (number of infections per 100,000 people) has declined since 1999 from 6.3 to 0.9 per 100,000 people (2008 CDC statistics). About 2,500 to 3,600 cases of hepatitis A are reported each year in the U. S., but many more people may be exposed to the virus, but have few, if any, report symptoms. Vaccination at age one year may cause the rate and yearly case numbers of HAV to decline.
Signs and symptoms
Acute
Initial features are of nonspecific flu-like symptoms, common to almost all acute viral infections and may include malaise, muscle and joint aches, fever, nausea or vomiting, diarrhea, and headache. More specific symptoms, which can be present in acute hepatitis from any cause, are: profound loss of appetite, aversion to smoking among smokers, dark urine, yellowing of the eyes and skin (i.e., jaundice) and abdominal discomfort. Physical findings are usually minimal, apart from jaundice in a third and tender hepatomegaly (swelling of the liver) in about 10%. Some exhibit lymphadenopathy (enlarged lymph nodes, in 5%) or splenomegaly (enlargement of the spleen, in 5%).
Acute viral hepatitis is more likely to be asymptomatic in younger people. Symptomatic individuals may present after convalescent stage of 7 to 10 days, with the total illness lasting 2 to 6 weeks.[3]
A small proportion of people with acute hepatitis progress to acute liver failure, in which the liver is unable to clear harmful substances from the circulation (leading to confusion and coma due to hepatic encephalopathy) and produce blood proteins (leading to peripheral edema and bleeding). This may become life-threatening and occasionally requires a liver transplant.
Chronic
Chronic hepatitis often leads to nonspecific symptoms such as malaise, tiredness and weakness, and often leads to no symptoms at all. It is commonly identified on blood tests performed either for screening or to evaluate nonspecific symptoms. The occurrence of jaundice indicates advanced liver damage. On physical examination there may be enlargement of the liver.
Extensive damage and scarring of liver (i.e. cirrhosis) leads to weight loss, easy bruising and bleeding tendencies, peripheral edema (swelling of the legs) and accumulation of ascites (fluid in the abdominal cavity). Eventually, cirrhosis may lead to various complications: esophageal varices (enlarged veins in the wall of the esophagus that can cause life-threatening bleeding) hepatic encephalopathy (confusion and coma) and hepatorenal syndrome (kidney dysfunction).
Acne, abnormal menstruation, lung scarring, inflammation of the thyroid gland and kidneys may be present in women with autoimmune hepatitis.
The cause of hepatitis A is hepatitis A virus (HAV) that is transmitted person to person by contaminated foods, water or other drinks (including ice), blood, stool, and direct contact. The virus is a Picornavirus that contains single-stranded RNA as its genome covered by a protein shell. The virus enters through the epithelium in the mouth or gut and migrates to the liver over a period of about two to six weeks. Symptoms (jaundice and other symptoms, see below) then begin to develop as the virus replicates in the liver cells (hepatocytes and Kupffer cells, also termed liver macrophages). HAV reproduces itself by utilizing the liver cell's ribosomes for viral replication; however this interferes with normal liver cell function. If large numbers of liver cells are infected with HAV, the person will develop symptoms. The viruses are secreted into the GI tract by the bile fluid made in the liver. The majority of people infected recover with no lasting damage to the liver.
Hepatitis A Virus (HAV) Courtesy of the CDC
Hepatitis A Self-Care at Home
The following measures can help a patient feel better while they are having symptoms.
- Take it easy; curtail normal activities and spend time resting at home.
- Drink plenty of clear fluids to prevent dehydration.
- Avoid medicines and substances that can cause harm to the liver such as acetaminophen (Tylenol) and preparations that contain acetaminophen.
- Avoid alcoholic beverages, as these can worsen the effects of HAV on the liver.
- Avoid prolonged, vigorous exercise until symptoms start to improve.
Call a health care practitioner if symptoms worsen or new symptoms appear.
Be very careful about personal hygiene to avoid fecal-oral transmission to other members of the household.
Hepatitis A Medical Treatment
- If a person becomes dehydrated, the doctor may prescribe IV fluids.
- If a patient is experiencing significant nausea and vomiting, they will receive medicines to control these symptoms.
- People whose symptoms are well controlled can be cared for at home.
- If dehydration or other symptoms are severe, or if the patient is extremely confused or difficult to arouse, they will most likely be hospitalized.
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