There is almost zero risk of Ross River virus transmission via blood transfusion in Australia however donors should be encouraged to report any illness shortly after donation as an added precaution.

A study of Ross River virus prevalence in 7,500 blood donors from 10 fixed donor centres across the country found no virus RNA in any samples despite collection during peak season for transmission and in a major outbreak year.

The research included donor centres in Bunbury, Rockingham and Albany in WA, Darwin (NT), Mildura (NSW) and Townsville, Rockhampton, Gladstone, Nambour and Strathpine in Queensland – areas which typically have more than 60 Ross River virus notifications per 100,000 residents each year.

Spatial mapping revealed that areas that have an even higher risk of transmission, such as western Queensland or the north of WA, do not have donor centres.

“This was encouraging for the management of RRV transfusion-transmission risk in Australia, because the risk does not depend on prevalence in Australia but on the prevalence in donation blood donors,” the study said.

Australia has had only one known probable case of Ross River virus transmission via transfusion.

The researchers said in addition to the low prevalence of detectable virus RNA, stringent donation restrictions in Australia and the donation recall system for post-donation illness provide additional protection to the system.

“Thus, it is imperative that staff in collection centres located in areas with significant RRV transmission, and indeed nationwide, remain vigilant in their communication with donors in relation to education and post-donation illness reporting, as we have previously recommended.”

The authors added that other arboviruses including Zika, West Nile and dengue virus are also potential threats to the global blood supply.

Treating clinicians are notified if their patients have been recipients of transfused components later recalled due to a RRV risk, the study said.