An outbreak of Hepatitis A in Australia in recent weeks has been linked to frozen berries imported from China. The most recent figures show that 20 people have been infected, and up to 450,000 exposed. But what is Hepatitis A, and what can be done about it?

Hepatitis means inflammation of the liver. Hepatitis can be caused by a number of different (unrelated, yet imaginatively named) viruses, by substance abuse or by some autoimmune diseases. Hepatitis A is caused by the Hepatitis A virus, which enters the body through the mouth and digestive tract and from there gets into the blood where it’s carried to the liver. The virus infects and replicates in liver cells (hepatocytes) and specialised immune cells that reside in the liver called Kupffer cells. The liver inflammation that ensues from Hepatitis A infection is caused by the immune reaction against the virus. Virus is shed from the liver into the bile fluid and then released from the body in the faeces (or poo, if you wish!).

Hepatitis A is usually transmitted via food or water contaminated with faeces from an infected person. It is quite a hardy virus and can survive at ambient temperatures for up to a month. In the case of the berries, the virus has obviously survived the freeze/thaw process too. Symptoms of disease usually emerge 2-6 weeks after infection, and an infected person will be infectious sometimes for up to two weeks before they show any symptoms, providing a handy window for the virus to be passed on before anyone realises. The usual precautions against Hepatitis A include avoiding dirty water and washing your hands well, especially before eating and after going to the toilet or changing nappies.

If you’re unlucky enough to contract Hepatitis A, you’re probably in for a few weeks to months of illness. The symptoms of infection can vary from none through to fever, stomach upsets, tiredness and jaundice (yellowing of the skin and eyes). Generally, the symptoms are worse the older you are – children typically don’t show any signs of infection, and adults can sometimes end up in hospital. Fortunately, unlike other forms of infectious hepatitis, Hepatitis A usually resolves itself on its own and doesn’t go on to cause chronic liver disease.

There is a pretty good vaccine available against Hepatitis A. Unlike influenza which has a lot of strain variability, there is only one serotype of Hepatitis A. That means that the parts of the virus that our bodies recognise as characteristic of Hepatitis A are the same, regardless of where the virus originated, so the vaccine is about 95% effective at preventing Hepatitis A infection if you’ve had it at least 4 weeks before exposure to the virus. Usually, two doses of the vaccine are needed to make sure that the protection lasts for life. If you’ve already had Hepatitis A, you’re protected for life too. The vaccine is made from inactivated virus, so generally the side effects (if there are any) are mild and gone within 1-2 days of vaccination.

In Australia, Hepatitis A is not part of the standard childhood vaccination schedule. It is recommended for Aboriginal and Torres Strait Islander children living in designated ‘high risk’ areas, presumably those where the water sources are not reliably hygienic (the outrageous fact that this can occur in a country like Australia is an issue beyond the scope of this blog). If you’re planning to travel to countries where Hepatitis A is endemic, then the vaccine is recommended.

So, what can we conclude from all of this? If you haven’t been buying Nanna’s frozen berries and aren’t planning overseas travel, then there’s little need to worry. If you have had Nanna’s berries in the last couple of months, then be on the lookout for the symptoms of Hepatitis A. The vaccine can be of some use if you’ve been exposed to Hepatitis but haven’t yet developed symptoms, but it’s best to speak to your doctor if you’re worried. Anyone over the age of 1 should consider the vaccine if travelling somewhere where Hepatitis A is endemic, and washing your hands properly is always a good idea!