Hepatitis is an inflammation of the liver, most commonly caused by a viral infection. There are five main hepatitis viruses, referred to as types A, B, C, D and E. These five types are of greatest concern because of the burden of illness and death they cause and the potential for outbreaks and epidemic spread. In particular, types B and C lead to chronic disease in hundreds of millions of people and, together, are the most common cause of liver cirrhosis and cancer.
Hepatitis A and E are typically caused by ingestion of contaminated food or water. Hepatitis B, C and D usually occur as a result of parenteral contact with infected body fluids. Common modes of transmission for these viruses include receipt of contaminated blood or blood products, invasive medical procedures using contaminated equipment and for hepatitis B transmission from mother to baby at birth, from family member to child, and also by sexual contact. Acute infection may occur with limited or no symptoms, or may include symptoms such as jaundice (yellowing of the skin and eyes), dark urine, extreme fatigue, nausea, vomiting and abdominal pain.
Hepatitis B is an infectious hepatitis caused by the hepatitis B virus (HBV). This infection has two possible phases; 1) acute and 2) chronic.
1. Acute hepatitis B refers to newly acquired infections. Affected individuals notice symptoms approximately 1 to 4 months after exposure to the virus. In most people with acute hepatitis, symptoms resolve over weeks to months and they are cured of the infection. However, a small number of people develop a very severe, life-threatening form of acute hepatitis called fulminant hepatitis.
2. Chronic hepatitis B is an infection with HBV that lasts longer than 6 months. Once the infection becomes chronic, it may never go away completely.
Most infected adults are able to fight off the virus so their infection is cured. A low percentage of adults infected with HBV go on to develop chronic infection. Children are at much higher risk for chronic infection. A majority of infected young children will fail to clear the virus from their bodies and go on to develop chronic infection.
About two-thirds of people with chronic HBV infection are chronic carriers. These people do not develop symptoms, even though they harbor the virus and can transmit it to other people. The remaining one third develop “active” hepatitis, a disease of the liver that can be very serious.
• The liver is an important organ that filters toxins out of the blood, stores energy for later use, helps with digestion, and makes substances that fight infections and control bleeding.
• The liver has an incredible ability to heal itself, but long-term inflammation caused by HBV can result in permanent damage.
• Scarring of the liver is called cirrhosis, a condition traditionally associated with alcoholism but one that is also caused by chronic active hepatitis B infection. When this occurs, the liver can no longer carry out its normal functions and may fail completely. The only treatment for liver failure is liver transplant.
• Chronic hepatitis B also can lead to a type of liver cancer known as hepatocellular carcinoma.
• Any of these conditions can be fatal. About 15% to 25% percent of people with chronic hepatitis B die of liver disease.
Hepatitis B Transmission and Causes
The hepatitis B virus is known as a blood-borne virus because it is transmitted from one person to another via blood or fluids contaminated with blood. Another important route of transmission is from an infected mother to a newborn child, which occurs during or shortly after birth.
• Direct contract with blood may occur through the use of dirty needles during illicit drug use, inadvertent needle sticks experienced by healthcare workers, or contact with blood through other means. Semen, which contain small amounts of blood, and saliva that is contaminated with blood also carry the virus.
• The virus may be transmitted when these fluids come in contact with broken skin or a mucous membrane (in the mouth, genital organs, or rectum) of an uninfected person.
People who are at an increased risk of being infected with the hepatitis B virus include the following:
• Men or women who have multiple sex partners, especially if they don’t use a condom
• Men who have sex with men
• Men or women who have sex with a person infected with hepatitis B virus
• People with other sexually transmitted diseases
• People who inject drugs with shared needles
• People who receive transfusions of blood or blood products
• People who undergo dialysis for kidney disease
• Institutionalized mentally handicapped people and their attendants, caregivers, and family members
• Health care workers who are stuck with needles or other sharp instruments contaminated with infected blood
• Infants born to infected mothers
What are the symptoms of acute hepatitis B?
Acute hepatitis B is the period of illness that occurs during the first one to four months after acquiring the virus. Only 30% to 50% of adults develop significant symptoms during acute infection. Early symptoms may be non-specific, including fever, a flu-like illness, and joint pains. Symptoms of acute hepatitis may include:
• loss of appetite,
• jaundice (yellowing of the skin and eyes), and
• pain in the upper right abdomen (due to the inflamed liver).
What are the symptoms of chronic hepatitis B?
The liver is a vital organ that has many functions. These include a role in the immune system, production of clotting factors, producing bile for digestion, and breaking down toxic substances, etc. Patients with chronic hepatitis B develop symptoms in proportion to the degree of abnormalities in these functions. The signs and symptoms of chronic hepatitis B vary widely depending on the severity of the liver damage. They range from few and relatively mild signs and symptoms to signs and symptoms of severe liver disease such as cirrhosis or liver failure.
Most individuals with chronic hepatitis B remain symptom free for many years or decades. During this time, the patient’s liver function blood tests usually are normal or only mildly abnormal. Some patients may deteriorate and develop inflammation or symptoms, putting them at risk for developing cirrhosis.
Cirrhosis of the liver due to hepatitis B
Inflammation from chronic hepatitis B can progress to cirrhosis (severe scarring) of the liver. Significant amounts of scarring and cirrhosis lead to liver dysfunction.
Symptoms may include:
• loss of appetite,
• weight loss,
• breast enlargement in men,
• a rash on the palms,
• difficulty with blood clotting, and
• spider-like blood vessels on the skin.
Decreased absorption of vitamins A and D can cause impaired vision at night and thinning of bones (osteoporosis). Patients with liver cirrhosis also are at risk of infections because the liver plays an important role in the immune system.
Advanced cirrhosis of the liver due to hepatitis B
In patients with advanced cirrhosis, the liver begins to fail. This is life-threatening condition.
Several complications occur in advanced cirrhosis:
• Confusion and even coma (encephalopathy) results from the inability of the liver to detoxify certain toxic substances.
• Increased pressure in the blood vessels of the liver (portal hypertension) causes fluid to build up in the abdominal cavity (ascites) and may result in engorged veins in the swallowing tube (esophageal varices) that tear easily and may cause massive bleeding.
• Portal hypertension can also cause kidney failure or an enlarged spleen resulting in a decrease of blood cells and the development of anemia, increased risk of infection and bleeding.
• In advanced cirrhosis, liver failure also results in decreased production of clotting factors. This causes abnormalities in blood clotting and sometimes spontaneous bleeding.
• Patients with advanced cirrhosis often develop jaundice because the damaged liver is unable to eliminate a yellow compound, called bilirubin
Tests and diagnosis
If your doctor suspects you have hepatitis B, he or she will examine you and likely order blood tests. Blood tests can determine if you have the virus in your system and whether it’s acute or chronic. Your doctor might also want to remove a small sample of your liver for testing (liver biopsy) to determine whether you have liver damage. During this test, your doctor inserts a thin needle through your skin and into your liver and removes a tissue sample for laboratory analysis.
Screening healthy people for hepatitis B
Doctors sometimes test certain healthy people for hepatitis B infection because the virus can damage the liver before causing signs and symptoms. Talk to your doctor about screening for hepatitis B infection if you:
• Live with someone who has hepatitis B
• Have had sex with someone who has hepatitis B
• Have a liver enzyme test with unexplained abnormal results
• Have HIV or hepatitis C
• Are an immigrant from, have parents from or have adopted children from places where hepatitis B is common, including Asia, the Pacific Islands, Africa and Eastern Europe
• Inject illegal drugs
• Are an inmate
• Are a man who has sex with men
• Receive kidney dialysis
• Take medications that suppress the immune system, such as anti-rejection medications used after an organ transplant
• Are pregnant
Treatments and drugs
Treatment to prevent hepatitis B infection after exposure
If you know you’ve been exposed to the hepatitis B virus, call your doctor immediately. If you haven’t been vaccinated or aren’t sure whether you’ve been vaccinated or whether you responded to the vaccination, receiving an injection of hepatitis B immune globulin within 12 hours of coming in contact with the virus may help protect you from developing hepatitis B. You should be vaccinated at the same time.
Treatment for acute hepatitis B infection
If your doctor determines your hepatitis B infection is acute — meaning it is short-lived and will go away on its own — you may not need treatment. Instead, your doctor might recommend rest and adequate nutrition and fluids while your body fights the infection.
Treatment for chronic hepatitis B infection
If you’ve been diagnosed with chronic hepatitis B infection, you may have treatment to reduce the risk of liver disease and prevent you from passing the infection to others. Treatments include:
• Antiviral medications. Several antiviral medications — including lamivudine (Epivir), adefovir (Hepsera), telbivudine (Tyzeka) and entecavir (Baraclude) — can help fight the virus and slow its ability to damage your liver. Talk to your doctor about which medication might be right for you.
• Interferon alfa-2b (Intron A). This synthetic version of a substance produced by the body to fight infection is used mainly for young people with hepatitis B who don’t want to undergo long-term treatment or who might want to get pregnant within a few years. It’s given by injection. Side effects may include depression, difficulty breathing and chest tightness.
• Liver transplant. If your liver has been severely damaged, a liver transplant may be an option. During a liver transplant, the surgeon removes your damaged liver and replaces it with a healthy liver. Most transplanted livers come from deceased donors, though a small number come from living donors who donate a portion of their livers.
The hepatitis B vaccine is typically given as three or four injections over six months. You can’t get hepatitis B from the vaccine.
The hepatitis B vaccine is recommended for:
• Children and adolescents not vaccinated at birth
• Anyone who has a sexually transmitted infection, including HIV
• Developmentally disabled people who live in an institutional setting and staff
• Health care workers, emergency workers and other people who come into contact with blood
• Men who have sex with men
• People who have multiple sexual partners
• People with chronic liver disease
• People who inject illicit drugs
• People who live with someone who has hepatitis B
• People with end-stage kidney disease
• Sexual partners of someone who has hepatitis B
• Travelers planning to go to an area of the world with a high hepatitis B infection rate
Take precautions to avoid HBV
Other ways to reduce your risk of HBV include:
• Know the HBV status of any sexual partner. Don’t engage in unprotected sex unless you’re absolutely certain your partner isn’t infected with HBV or any other sexually transmitted infection.
• Use a new latex or polyurethane condom every time you have sex if you don’t know the health status of your partner. Remember that although condoms can reduce your risk of contracting HBV, they don’t eliminate the risk.
• Stop using illicit drugs. If you use illicit drugs, get help to stop. If you can’t stop, use a sterile needle each time you inject illicit drugs. Never share needles.
• Be cautious about body piercing and tattooing. If you get a piercing or tattoo, look for a reputable shop. Ask about how the equipment is cleaned. Make sure the employees use sterile needles. If you can’t get answers, look for another shop.
• Ask about the hepatitis B vaccine before you travel. If you’re traveling to a region where hepatitis B is common, ask your doctor about the hepatitis B vaccine in advance. It’s usually given in a series of three injections over a six-month period.