Hepatitis is the medical term for inflammation of the liver. Hepatitis may be acute (lasting only for the short term, after which a person recovers) or chronic (lasting for the long term, usually more than 6 months).
There are many causes of hepatitis, including viruses, alcoholism, and medications. Viral hepatitis is now a major cause of chronic hepatitis in North America. There are five hepatitis viruses: A, B, C, D, and E. There are also other viruses that can cause liver inflammation, like Epstein-Barr virus and cytomegalovirus, but these viruses are not called hepatitis viruses.
Hepatitis A and B (HAV and HBV) are common causes of liver inflammation in North America. Statistical data from 1999 and 2006 showed that around 600 to 900 new cases per year of HAV and HBV were being diagnosed in Canada. Since many infected people have no symptoms; however, we can assume the true rate of infection is higher than this. Many experts believe that up to one-third of the population has been infected with HAV at some point.
Among people born in North America, hepatitis A is most common in children and young adults, while hepatitis B is most common in adults between the ages of 20 and 40 years.
Hepatitis A is mainly transmitted through the fecal-oral route. That means infected people shed viruses in their feces. If they don't observe proper hygiene, the virus can end up on their hands. It's then spread by food they've handled, or sometimes by touching other people who then bite their nails, handle their food, and so on.
The virus can survive on tabletops, doorknobs, telephones, or other such places for 2 or 3 hours at room temperature. Although less common, you can also get hepatitis A from direct contact such as kissing, through sexual contact, or by sharing needles. Though many people who are infected have no symptoms, they can still pass on the disease.
People at high risk for hepatitis A include:
- anyone who lives with an infected person
- children and workers in daycare centres
- homosexual men
- intravenous drug users
- people with many sexual partners
- people who live in permanent institutions like prisons or homes for the developmentally disabled, or those who are in the armed forces
- those who have recently been in the Middle East, South America, Eastern Europe, Central America, Africa, or Southeast Asia – areas with greater likelihood of exposure to contaminated food or water
Hepatitis B is spread by blood and body fluids. The main routes of transmission are through sexual contact, sharing needles, tattooing and body piercing, and childbirth (when the baby is likely to pick up the virus from the mother through the birth canal). Hepatitis B has an additional complication – some infected people become lifelong carriers, whether they have symptoms or not. Many infected people are asymptomatic (without symptoms) but can pass on the virus.
People at high risk for hepatitis B include:
- intravenous drug users
- people with many sexual partners
- homosexual men
- people who live in prisons
- those who have recently been in the Middle East, South America, Eastern Europe, Central America, Africa, or Southeast Asia
- people who receive hemodialysis
- health care workers
Symptoms and Complications
Hepatitis A has an incubation period (the time between infection and first symptoms) of 2 to 6 weeks. Hepatitis B only shows itself after 2 to 6 months.
Flu-like warning symptoms (called a prodrome) often appear about 3 to 10 days before liver symptoms arrive. Symptoms include low-grade fever, muscle aches, loss of appetite, nausea, vomiting, and fatigue. Smokers may find they suddenly dislike smoking. In hepatitis B, these symptoms may be accompanied by joint pains and skin eruptions resembling urticaria (hives).
After this, the urine may darken and jaundice may appear. In jaundice, the skin and the whites of the eyes take on a yellow tint. The inflamed liver is not able to perform its usual metabolic functions so that a substance called bilirubin (a byproduct from old red blood cells that also causes bile to be yellow) builds up in the body. Bile is a fluid secreted by the liver that contains cholesterol, bile salts, and waste products such as bilirubin.
Usually, you start to feel better when the jaundice arrives, even though you continue to look worse. The jaundice only lasts for about one week in hepatitis A infection. After that you start to recover and will generally feel and look yourself again within a month. Rarely, hepatitis A may come back briefly a month later, but won't last long. After recovering from hepatitis A, you're immune for life.
With hepatitis B, the jaundice lasts for about two weeks. However, the hepatitis B infection doesn't always get cleared out of the system. If this happens, you will probably not have any symptoms, but you'll be a lifelong "carrier" and must take special precautions such as warning sexual partners. You may also suffer from chronic liver inflammation (chronic viral hepatitis) for the rest of your life.
Chronic hepatitis B is most likely to occur in infants (around a 90% chance if infected in the first year of life) and least likely in adults (5% chance overall). It can lead to cirrhosis (scarring) of the liver. It also increases the risk of developing liver cancer.
Making the Diagnosis
Both hepatitis A and B are diagnosed by taking a blood sample, which will be sent to a lab to determine if you have antibodies in your blood specific for those viruses. If you do, then you have been exposed to hepatitis A or B.
In hepatitis B, the lab will also examine whether your blood contains any hepatitis B antigens (proteins on the surface of the virus that help your immune system recognize infections).
Along with blood tests and other tools (e.g., liver enzyme and function tests), your doctor will do a physical examination and ask you questions about your symptoms to make a diagnosis.
Treatment and Prevention
There are vaccines against both hepatitis A and B. They provide about 90% protection that can last from 10 to 20 years. Anyone who is at risk of getting these viruses should be vaccinated. Canadian schools have hepatitis B vaccination programs.
But whether you're immunized or not, the best protection is to be careful when choosing sexual partners. The government estimates that at least 100,000 Canadians are chronic carriers of hepatitis B. You can also reduce the risk of hepatitis B by not sharing personal care items that may be contaminated with blood (e.g., razors, toothbrushes) and by ensuring that tattoos and piercings are performed with cleaned and sterilized equipment. Good personal hygiene can also help prevent the spread of hepatitis A.
If you are exposed to hepatitis A or B (e.g., you have recently had sexual intercourse with a hepatitis A or B carrier), you may also be eligible to receive immune globulin, which contains antibodies that may help prevent and decrease the severity of hepatitis A or B infections. Immune globulin is most effective if given as soon as possible after the exposure.
Pregnant women are routinely screened for hepatitis B. If it's found, they may be treated with oral medications during the pregnancy. The baby is given hepatitis B vaccination and also immune globulin, a preparation made from the immune blood of someone who was previously infected.
Most people with hepatitis A or B will recover without treatment within 4 to 8 weeks after symptoms start.
Antiviral medications such as lamivudine* and peginterferon alfa, along with some others, can be used to treat some people with chronic hepatitis B. These medications do not cure the condition or stop it from being passed on to others, but they may reduce virus levels and activity, which can help reduce the signs of liver damage.
People who have been diagnosed with hepatitis A or B should avoid alcohol for at least 3 months or until their liver tests and liver function are normal.
*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For information on a given medication, check our Drug Information database. For more information on brand names, speak with your doctor or pharmacist.
All material copyright MediResource Inc. 1996 – 2018. Terms and conditions of use. The contents herein are for informational purposes only. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Source: www.medbroadcast.com/condition/getcondition/Hepatitis-A-and-B