What are the main types and causes of hepatitis?

There are a variety of hepatitis types which directly relate to an underlying cause. Hepatitis types can be classified as viral and non-viral.

The main types of hepatitis are:

• Hepatitis A (HAV): A viral type of the condition due to an infection with the hepatitis A virus (HAV). Highly contagious, hepatitis A infections are typically acute (short-term) but capable of being transmitted through contaminated food or water (water may be contaminated with faeces). HAV can also be contracted via direct contact with faeces. Hepatitis A  can resolve (clear up) on its own.
• Hepatitis B (HBV): This viral form of the condition occurs as a result of an infection with the hepatitis B virus (HBV). The condition is also contagious and easily spread through direct contact with the bodily fluids of an infected person (saliva, urine, blood or semen). Those at an increased risk of an HBV infection typically share needles (usually when engaging in illicit drug use), have unprotected sex or even share razors. HBV can also happen during childbirth, being passed on from mother to new-born baby. HBV can become a chronic infection (the infection develops gradually) with symptoms only showing when complications develop. In acute instances, symptoms develop quickly. A person infected with HBV can still be contagious even without the presence of symptoms. The virus can also live outside the body, sometimes for up to 7 days.
• Hepatitis C (HCV): This refers to an infection with the hepatitis C virus (HCV), this type is also highly contagious, and easily transmitted through direct contact with the bodily fluids of an infected individual (i.e. it is often sexually transmitted). HCV can also be classified as either acute (symptoms develop quickly and last for several weeks) or chronic (symptoms develop gradually within several months).
• Hepatitis D (HDV): An infection with the hepatitis D virus (HDV) is a rare form of the condition that often occurs in conjunction with a HBV infection. Hepatitis D is not typically contracted on its own and commonly develops in a person already infected with hepatitis B. HDV is typically contracted through exposure to infected blood. The virus is prevalent in Central Asia, West Africa, South America, the Pacific islands, the Mediterranean and Russia. An infection that develops slowly and lasts more than 6 months is classified as chronic, and typically increases a person’s risk for further complications such as cirrhosis of the liver. Acute infections develop symptoms quickly which tend to be more severe.
• Hepatitis E (HEV): Infection with the hepatitis E virus (HEV) typically occurs in areas with poor sanitation (common in developing countries) and where exposure to contaminated water is high. Faecal matter is commonly ingested causing a serious acute infection. An infection can clear up on its own, but it can also worsen and cause complications such as acute liver failure.

Hepatitis can also have a non-viral cause. This includes:

• Autoimmune diseases: The liver may come under attack from the body, particularly the immune system. Normally, the body’s immune system operates as a protective means against illness and infection (viruses, bacteria and pathogens). When there is an impairment in this function, the immune system works against the natural flow of protection and instead attacks its own tissues and cells. A complication of this is when the immune system ‘regards’ the liver as a ‘harmful object’ in the body and works against it, hindering its normal function. This can result in inflammation and damage, causing non-contagious hepatitis. There are three classifications of autoimmune hepatitis – Type 1 autoimmune hepatitis (which affects people of all ages and gender), Type 2 autoimmune hepatitis (which is less common and usually affects girls and young women) and Type 3 autoimmune hepatitis  (which affects adults aged 30-50 years).
• Alcohol-related: Excessive alcohol consumption over prolonged periods can result in damage to the liver. The knock-on effect of this can result in hepatitis, often referred to as ‘alcoholic hepatitis’. Alcohol aggravates the liver and causes swelling. In the process of breaking down alcohol in the system, the body retains toxic chemicals which trigger inflammation. This leads to scarring, which compromises the normal healthy function of the liver, leading to hepatitis symptoms. Medication overuse and exposure to poisonous chemicals can have a similar effect on the liver, causing toxic hepatitis. Heavy drinkers are also often malnourished. A lack of nutrients in the body combined with alcohol by-products which aren’t properly absorbed ultimately result in liver cell damage. In this instance, hepatitis is not caused by a virus and is thus not contagious.