The Blood Service has just started a study to understand how common the Hepatitis E virus (HEV) is in Australia to help ensure we’re doing everything we can to keep Australia’s blood supply safe.
Currently, we don’t routinely test for HEV because, although observed worldwide, it’s not thought to be commonly acquired in Australia, with only around 25 reported cases per year. But, as it’s an emerging issue, we’ve decided to investigate how prevalent HEV is in the Australian blood donor population.
HEV poses a growing concern to blood services around the world and has recently become the subject of debate in transfusion medicine as HEV is a known transfusion-transmissible agent. In addition, in developed countries, studies of blood donors have demonstrated the majority of individuals demonstrate HEV seroconversion with no known history of HEV infection. The UK and Ireland have recently implemented HEV donation screening for high-risk recipients and other countries are considering risk management options for managing HEV transfusion transmission.
In Australia, HEV is a nationally notifiable disease. The majority of cases are due to travellers returning from disease endemic countries, with few reported cases of locally acquired HEV. It is mainly transmitted by either the faecal-oral route, where faeces contaminates water or food, or from consuming undercooked contaminated pork products.
For most patients with HEV if symptoms occur, they are generally mild and self-limiting. However, HEV can be dangerous for those who are immunosuppressed, such as transplant recipients. Not everyone who is infected develops clinical symptoms, but symptoms can include upper abdominal pain, diarrhoea, jaundice, and an enlarged liver (hepatomegaly). In developed countries, most people who test positive for HEV antibodies have no known history of HEV infection. HEV has a varied incubation period ranging from two weeks to two months, with the clinical presentation of the disease often being indistinguishable from other acute hepatitis infections. The virus can stay in the blood for at least two weeks and up to 42 days after the onset of symptoms.
Helen Faddy, Senior Research Fellow and Veronica Hoad, Public Health Physician, from the Blood Service’s Clinical Services and Research division are coordinating the study. The team expect to have findings in around six months’ time, and will use those results to help shape Blood Service policy around HEV testing of blood donations in Australia.
Emerg Infect Dis. 2014 Nov;20(11):1940-2. doi: 10.3201/eid2011.140412. Hepatitis E virus and implications for blood supply safety, Australia. Shrestha AC, Seed CR, Flower RL, Rooks KM, Keller AJ, Harley RJ, Chan HT, Holmberg JA, Faddy HM. (available from: http://wwwnc.cdc.gov/eid/article/20/11/14-0412_article)
Pathology. 2015 Feb;47(2):97-100. doi: 10.1097/PAT.0000000000000229. Hepatitis E virus: do locally acquired infections in Australia necessitate laboratory testing in acute hepatitis patients with no overseas travel history? Shrestha AC, Faddy HM, Flower RL, Seed CR, Keller AJ. (available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4341517/)