Australia has one of the safest blood supplies in the world – but this could easily be compromised without active research to identify emerging risks and develop procedures to control them.
To keep track of emerging risks, Dr Helen Faddy and her team in Brisbane use a combination of blood tests (measuring antibodies nucleic acids in blood), demographic data and computer modelling to estimate the risk posed by emerging diseases. The Blood Service uses these risk estimates to set policy on donor selection and routine testing.
Recently, the team examined how the distribution of dengue fever varied geographically and seasonally to develop a predictive model which estimates how climate change may change the incidence of dengue and affect the donor blood supply.
The hepatitis E virus poses a growing concern to blood services around the world. While there have been no known cases of transfusion-transmitted HEV in Australia to date, cases have been reported in the United Kingdom, Germany, France and Japan. In Australia, the virus is relatively uncommon, with approximately 25 new cases reported each year. A recent study by the Blood Service looked for antibodies (HEV IgG and HEV IgM) to the virus in over 3000 donor plasma samples.
Dr Faddy explains: “We found the HEV IgG antibody (a marker of prior infection with the virus) in 194 samples, which demonstrates previous exposure to the virus in these individuals. None of these samples contained the infectious virus (HEV RNA).
“We also found HEV IgG sero-prevalence was higher (7.73 per cent) in donors who had travelled to a malaria endemic country, many of which are also endemic for HEV,” said Dr Faddy.
“A small proportion of donors (3.37 per cent), who had not reported travel outside Australia, also had the antibodies. We’re now planning a larger study to measure the rate of HEV viraemia (the presence of virus in the blood stream) in blood donations in order to allow us to estimate the risk this virus poses to the Australian blood supply.”
In addition to the work on hepatitis E, research is now underway to track the incidence of Ross River Virus, Babesia and Q fever in donor samples throughout Australia to ensure the ongoing safety of the blood supply.