July 02, 2007

hepatitis D and E


Five viruses cause infection of the liver as their main effect (many other viruses cause hepatitis as part of a range of other problems, eg glandular fever). The five are Hepatitis A,B,C,D, and E. This topic looks at hepatitis D.

What is hepatitis D?
Hepatitis D is caused by a very small virus. (It has the smallest amount of genetic material of all of the known human viruses).

Hepatitis D cannot cause an infection unless it is caught at either the same time as hepatitis B, or after the person has already caught hepatitis B.
This is because it needs some of the genetic material of the hepatitis B virus to be able to multiply.

Effects of infection with hepatitis D
If a person gets hepatitis D viruses at the same time as getting hepatitis B, the person will usually become ill with hepatitis (see the topic 'Hepatitis B' for signs and symptoms). Although the person may become seriously ill, usually he or she will recover. This is called a 'co-infection'.

Sometimes a person gets hepatitis D when that person is already a carrier of hepatitis B (the person has been infected, but the immune system has not destroyed all of the hepatitis B virus). This can cause a very severe hepatitis illness, with ongoing liver damage which can lead to an early death. This is called a 'super-infection'.

How hepatitis D is spread
Hepatitis D is spread in very similar ways to hepatitis B.
The blood of a person who is ill with hepatitis D is infectious (it will have the virus particles in it), and blood to blood contact can spread the infection in the same ways that hepatitis B is spread. Other body fluids can also carry the virus, and it can be spread by unprotected sexual intercourse.

In some parts of the world, hepatitis D infection rates are low (such as in Australia, North America and Western Europe). Most hepatitis D in these areas occurs in people who are injecting drug users and it is spread the same way as hepatitis B.
In other parts of the world, such as parts of Italy, the Middle East and South Africa, infection is much more common and can be spread within household settings to other members of a family.
Health care workers can also be at risk.

How long it takes to develop ?
This is not known.

Treatment of hepatitis D
Treatment of a person who gets hepatitis D at the same time as hepatitis B is the same as for hepatitis B (see the topic 'Hepatitis B' ).
If a person who is a hepatitis B carrier gets a hepatitis D infection, treatment of the hepatitis D infection with Interferon may help, but the illness appears to return when treatment stops, and the person may have severe ongoing problems such as liver failure.
No other medication has been found to be of use.

Preventing the spread of hepatitis D
Immunisation against hepatitis B will also protect against hepatitis D, since hepatitis D cannot cause infection or illness unless hepatitis B viruses are in the body at the same time.

If a person has already had hepatitis B, and is a carrier of the virus, the only way to protect against hepatitis D is to follow all of the recommendations for preventing spread of hepatitis B so that the person does not get exposed to the hepatitis D virus (see 'Hepatitis B').

A person who has had hepatitis B but is not a carrier is not at risk of getting a hepatitis D infection, because that person does not have hepatitis B viruses in his body any longer.

Catching hepatitis E late in pregnancy is likely to be very serious, and often fatal. Pregnant women from countries where there is little hepatitis E are strongly advised not to travel to areas where there is a lot of hepatitis E, especially during the last 3 months of pregnancy.

What is hepatitis E?
Hepatitis E is an infection of the liver, which is common in many developing countries where there is not a safe water supply, especially South Asian countries and North and East African countries. Currently there is an outbreak in refugee camps in Darfur, Sudan.

Although the virus has only been found recently, it is likely that the virus has been causing illness for a very long time.

The country with the highest risk seems to be Nepal, where outbreaks generally occur each wet season in the Kathmandu Valley (May to September) with larger epidemics every few years.

The hepatitis E virus causes an infection of the liver that is similar to Hepatitis A.

How hepatitis is E spread
It is usually spread by contaminated drinking water, but it might also be spread by food which has the virus in it.

Person to person spread is possible, when hands that have touched faeces transfer the virus to the mouth but it is not the usual way it is spread.

Although at least one case of hepatitis E has been caught in the Northern Territory of Australia, most cases of hepatitis E in Australia occur in people who have caught it overseas, for example people who have recently returned from travel in high risk areas, migrants and refugees.

Who is at risk?
Illness from hepatitis E is usually seen in young adults. It may be that, like hepatitis A, many children who are infected do not become ill (this is called 'subclinical' infection).

Most people recover fully.
Pregnant women seem to be more likely to get a severe hepatitis E infection, and up to 30% of those who get it in the last three months of pregnancy die from the infection. In countries where hepatitis E is common, it is likely that most young women will have had the infection before becoming pregnant, but in countries where there is little hepatitis E, very few women will have had it before they become pregnant.
Travellers Medical Centres usually recommend that pregnant women from developed countries do not travel to areas where there is a high risk for getting hepatitis E.

How long it takes to develop
It takes from 2 weeks to two months for hepatitis E to develop after being in contact with it. The average has varied from 26 to 42 days in different epidemics.

Signs and symptoms
Most people who get hepatitis E have a mild illness which usually lasts about 2 weeks, sometimes longer (up to a few months).
Common symptoms include loss of appetite, feeling sick, vomiting, abdominal (tummy) pains, sore joints and mild fever.
Other common signs include jaundice (yellowing of the skin and eyes), swelling of the liver, dark wee (urine) and pale coloured poo.
People who have hepatitis E (who are not pregnant) recover fully, and do not go on to 'carry' the virus (as those with hepatitis B and C do).
Hepatitis E does not cause lasting liver disease.

What you can do
There is no specific treatment needed for most people with hepatitis E, which is usually a mild illness.
Pregnant women who become ill and who might have hepatitis E need to see their doctor as soon as possible. They may need specialised hospital care.
Rest and extra drinks are important.
The person who is ill should not prepare food for others for at least one week after jaundice appears.

Protecting your family from hepatitis E
No vaccine is available to protect people from hepatitis E, although research is being done.
Personal hygiene is important, including hand washing before food preparation and eating.

Travellers from areas where there is little hepatitis E to areas where hepatitis E is common should only drink water that is known to be safe. Bottled or canned drinks, and drinks made with boiled water should be safe. Raw fruit and vegetables should be avoided unless they can be peeled (by the person eating them) or washed with safe water before they are eaten, and uncooked shellfish should not be eaten.
A safe water supply and sewerage system are the best ways to control spread of hepatitis E.

Centers for Disease Control and Prevention (USA) 'Viral Hepatitis D: Fact sheet' http://www.cdc.gov/ncidod/diseases/hepatitis/d/fact.htm

Department of Human Services, Victoria, Australia 'Infectious diseases: the Blue Book: Hepatitis D' http://www.health.vic.gov.au/ideas/bluebook/hepatitis_d.htm
Centers for Disease Control and Prevention (USA): Viral Hepatitis E Fact Sheet

US Food and Drug Administration, Center for Food Safety and Applied Nutrition. 'Foodborne Pathogenic Micro-organisms and Natural Toxins Handbook' (The "Bad Bug Book"):

Adapted from: Child and Youth Health - CYH (South Australia)