This week, we will talk about six liver diseases. These diseases are caused by six different viruses. Doctors have one name for all of them: hepatitis.
The liver is located in the upper right part of the abdomen. This dark red organ is large. It weighs more than one kilogramme. It has an important job, too. The liver helps to clean the blood and fight infection. It also breaks down food and stores energy until the body needs it.
However, hepatitis destroys liver cells. Some types of hepatitis are much more serious than others. The type a person has can only be determined through blood tests for antibodies.
These antibodies are special proteins produced by the body’s natural defences in response to a threat. Identify the antibody and you identify the threat.
Hepatitis A is usually spread through human waste in water or food. It belongs to the same group of viruses as those that cause polio.
The hepatitis A virus causes a high temperature, pain and weakness. It can also cause stomach and intestinal problems, making it difficult to digest food. Also, a person with hepatitis may develop jaundice. This is a sign that the liver is not functioning properly.
To help prevent the spread of hepatitis A, people should wash their hands after using the toilet or changing a baby’s nappy. They should also wash their hands before eating or preparing food.
Hepatitis A can spread quickly to hundreds or even thousands of people. However, the virus is fatal in fewer than one percent of cases. Many people infected with the virus never get sick. Those who do usually recover within two months.
According to the World Health Organization, hepatitis A is prevalent in Africa, Asia, and Central and South America. Once a person has had hepatitis A, they cannot get it again. A vaccine is available to prevent hepatitis A, and the US Centers for Disease Control and Prevention says it is the best way to protect against the disease.
According to the World Health Organization, as many as two billion people are infected with the hepatitis B virus. Of those infected, more than 350 million have a lifelong infection. According to WHO officials, an estimated 600,000 people die each year as a result of hepatitis B.
The virus belongs to the same group as the herpes and smallpox viruses. Hepatitis B vaccines have been available since the 1980s. The WHO says the vaccine is 95% effective in preventing infection.
Hepatitis B is spread when blood from an infected person enters another person’s body. An infected mother can pass the virus to her baby during birth. The virus can also be transmitted through sexual activity and by sharing injection devices.
Blood products from an infected person can also spread hepatitis B, as can personal care products that might have blood on them if they are shared. Examples include toothbrushes and sharp hair-cutting instruments.
Worldwide, most hepatitis B infections are found in children. Young children are most likely to develop a chronic, lifelong infection. The risk of such an infection is low for children over four years old.
Around 90% of babies infected with hepatitis B in the first year of life develop chronic infections. These individuals are at high risk of dying from liver disease or liver cancer. The hepatitis B vaccine is considered to be the first medicine that can protect against liver cancer.
Hepatitis C is even more dangerous. Like hepatitis B, it is spread when blood from an infected person enters someone who is not infected.
The hepatitis C virus belongs to the same group as the viruses that cause yellow fever and West Nile disease. Most people living with hepatitis C develop chronic infections, often without showing any signs. They are at high risk of developing liver disease and liver cancer.
The World Health Organization (WHO) says that approximately 170 million people are infected with hepatitis C, which equates to around 3% of the global population. The WHO also says that as many as four million more people become infected each year. It warns that those infected may develop liver diseases, including cancer. The organisation states that the highest rates of infection are found in Africa, Asia and Central and South America.
The hepatitis C virus was first observed in 1974. However, it was not officially recognised as a new type of hepatitis until 1989. Scientists have been working to develop a vaccine and other treatments.
Last month, the Lancet reported that a combination of two experimental drugs could clear the infection within eight to twelve weeks. However, the effects of the treatment are still being studied.
According to the Centers for Disease Control and Prevention, approximately three million Americans are infected with hepatitis C, with the highest rates observed among individuals born between 1945 and 1965. Those especially at risk include people who inject drugs and those who received blood or blood products before 1992.
Hepatitis D is also spread through blood, but it only infects people who already have hepatitis B, and it greatly increases the risk of severe liver damage. Experts estimate that the virus infects around fifteen million people worldwide. It also appears in five percent of people infected with hepatitis B.
Doctors say the best way to prevent hepatitis D is to get a vaccine that protects against hepatitis B, and they can treat some cases of hepatitis B, C and D, although the drugs used are costly. However, they are less costly than a liver transplant.
The fifth virus is hepatitis E, which experts say spreads in the same way as hepatitis A — through infectious waste. Cases often result from polluted drinking water. Medical science recognised hepatitis E as a separate disease in 1980.
It is also found in animal waste. Studies have shown that the virus can infect many different species of animal.
According to the WHO, many hepatitis E cases have been reported in Central and Southeast Asia, North and West Africa, and Mexico. There are currently no effective vaccines or medicines against hepatitis E, but most people recover within several weeks or months. However, the disease can cause liver damage. In some cases, hepatitis E can be fatal.
The virus is particularly dangerous for pregnant women. Twenty percent of women living with hepatitis E die in the last three months of pregnancy.
In the 1990s, scientists discovered yet another kind of hepatitis. This has been named hepatitis G and is completely different from any of the other hepatitis viruses.
Donald Poretz is an infectious disease specialist based in Washington, DC. He says that hepatitis G is spread through blood and blood products. However, he adds that the virus has not yet been found to cause any significant disease.
The World Hepatitis Alliance works to raise awareness of the dangers of hepatitis. The group says people should be aware that hepatitis kills around 1.5 million people each year. It also states that one in twelve people worldwide is living with hepatitis B or C, and most of those infected are unaware of it.
There is no cure for hepatitis. The only ways to protect against infection are to be vaccinated against hepatitis A and B and to avoid contact with the other viruses. This may be difficult.
Remember that certain types of hepatitis are transmitted through sexual contact or sharing needles. Blood products must be carefully tested for hepatitis. People in high-risk groups and those who have had hepatitis should not donate blood. They should also not agree to donate their organs to others after they die. Donated organs can also spread hepatitis.
Experts say there are other steps people can take to protect themselves. These include always washing your hands with soap and water after using the toilet and before preparing or eating food.
When visiting foreign or unfamiliar areas, experts say travellers should not drink water of unknown quality. They should also avoid eating uncooked fruit and vegetables.