What are the similarities and differences between the various forms of hepatitis?
Hepatitis means inflammation of the liver, and all forms of the hepatitis virus attack this organ. But the features of the three main types of hepatitis virus and their specific effects on the body vary considerably.
Of the main types of hepatitis (A, B and C), hepatitis A is usually the least harmful. After around a four-week incubation period, the virus typically manifests in ways similar to influenza, causing a mild fever, muscle and joint pain, sore throat, nausea and diarrhoea. This is known as the prodromal stage.
Next, the icteric stage occurs. This can include jaundice, where the eyes and skin turn yellow, itchy skin, and pain and swelling in the liver. It is common for people to recover completely within a couple of months. In some cases, however, the symptoms can last for up to six months. Once your body has rid itself of the virus, you are immune to it.
The virus is transmitted by ingesting faecal material – for example, in contaminated food or water. So hepatitis A is more prevalent in areas with poor sanitation. Eating shellfish that has fed in sewage-infected water can lead to infection, and it’s not clear if certain food-processing methods currently in use are sufficient to kill the virus. Anilingus (where the anus is licked during sex) can pose a risk, as can sharing needles when injecting drugs.
While there is no specific cure or treatment, painkillers, rest and avoiding alcohol can help ease the symptoms and assist recovery. There is also a vaccine, which, while not given to the general population in the UK, can be obtained if you’re at risk of infection. For example, in the UK, it is offered at most sexual health clinics to men who have sex with men.
Each year there are around 1.4 million new cases of hepatitis A in the world. It is relatively rare in the UK (there were 284 cases in England and Wales in 2013). By contrast, in some low-income countries, 90 per cent of children contract the virus before the age of ten.
The initial symptoms of hepatitis B are very similar to those of hepatitis A: tiredness, achy limbs, vomiting, weight loss and jaundice. However, many people experience no symptoms at all, and it can take between 30 and 180 days for symptoms to appear.
Six months after infection, hepatitis B reaches the chronic stage, at which point the symptoms tend to lessen or go away completely. But over time the virus can damage the liver, causing liver disease or, for 20 per cent of people, cirrhosis. Of people with cirrhosis from hepatitis B, 10 per cent will develop liver cancer. Each year approximately 780,000 people die from complications of hepatitis B around the world.
The vast majority of healthy adults who get hepatitis B will recover from the virus before it reaches the chronic stage. The real danger comes when children or babies are infected: 80–90 per cent of babies infected before the age of one, and 30–50 per cent of children infected before the age of six, will develop chronic hepatitis B.
Hepatitis B is not transmitted through faeces or contaminated food or water, like hepatitis A, but it can exist outside the body for up to a week. Most commonly, it is transmitted from mother to baby at birth (‘vertical transmission’) or between sexual partners or injecting drug users. However, the use of unsterilised medical equipment or the re-use of razors by barbers can also spread the virus, as can the use of unsterilised equipment for tattooing or piercing.
In the UK, this type of hepatitis is found mostly in certain ethnic groups, drug users and men who have sex with men. There were over 5,700 new cases reported in England in 2013.
The hepatitis B vaccine is extremely effective and recommended at birth by the World Health Organization. However, most people have not been vaccinated. In the UK, the vaccine is available from genito-urinary medicine clinics and GPs for people in high-risk groups. While there is no cure, treatment in the chronic stage includes the use of antiviral drugs such as tenofovir and interferon.
During the initial six-month acute stage, 75 per cent of people infected with hepatitis C virus (HCV) won’t suffer any symptoms, but those who do can experience exhaustion, nausea and flu-like symptoms. About 20 per cent of those with symptoms will also get jaundice.
Around 10–30 per cent of those infected will clear the virus within the acute phase. Other people develop chronic infection. While there may be no symptoms for many years, when symptoms begin they include lethargy, depression, problems with concentration and memory, digestive problems, mood swings, itchy skin, and pain in the abdominal and liver area. Chronic infection can lead to cirrhosis and liver cancer.
HCV is blood-borne, so it can be transmitted at birth, through sharing needles, through certain sexual practices where blood–blood contact can occur (such as anal sex or fisting), through unsafe blood transfusions (although all blood used in the UK has been screened since 1991), and – typically outside the West – in unsterilised settings such as hospitals, barbers’ and tattoo parlours where instruments are shared. It is not routinely screened for antenatally in the UK. There is currently no vaccine, although vaccines are in development.
HCV was traditionally treated with interferon and ribavirin, drugs that need 6–12 months to work. There are now some highly effective drugs emerging that work within three months and have fewer side-effects than standard treatment.
It is estimated that around 200,000 people in the UK have chronic hepatitis C, and there are over 10,000 new infections each year in England alone. Worldwide there are thought to be 130 to 150m people with chronic infection. Up to 500,000 people die every year from the consequences of the virus.
Hepatitis D is a rarer form of infection than hepatitis A, B and C. It occurs only in people who already have hepatitis B.
Hepatitis E is very rare in the UK. The infection is usually mild and does not last long.