Australia is faced with the challenge of rising demand for universal RBC units from group O RhD-negative donors at a time when donations from this group are in decline.

The first national data update on ABO RhD blood groups since the mid-90s has revealed that Australia’s RhD negative blood in first time blood donations have declined to just 16.2% in 2019.

A study on this data has been published in the Medical Journal of Australia. The blood group results were provided by 28 pathology agencies, and included over 1.3 million patients, and almost 500,000 blood donors.

“In our study we report that the proportion of Australians with O negative blood group has decreased from a prevalence of about 9% in 1993/94 to 7% in 2019.  In fact, what we saw was that the overall proportion of RhD negative individuals has decreased from 19% in 1993/94 to 14% in 2019,” senior research fellow at Australian Red Cross Lifeblood and first author of the study Dr Rena Hirani told the limbic.

“This finding is most likely linked to that fact that immigration into Australia from countries such as China, India and South East Asia has increased in the last 10 years and that RhD positive blood groups are more prevalent in these countries.”

The team also showed that the percentage of Australians with blood group B had increased from 8% in the 90s to 12% in 2019 and blood group AB had increased from 2% to 4% in the same timeframe.

This provided important information about what types of blood will be required in hospitals in the upcoming years, as well as what can realistically be collected as blood donations, the authors said.

“The current demand of O negative is 15% of hospital orders but only 7% of the population has this type.  It will become increasingly challenging to collect O negative blood into the future,” explained Dr Hirani.

If the trend continued continues, it’s possible in the future that we may see O positive more widely used in emergencies, as our O negative population continues to decline, Dr Hirani said.

“Providing evidence to show that nearly 86% of the population is RhD positive could encourage discussion around whether O positive can be used more frequently during emergencies situations, particularly as some states and territories of Australia have more RhD positive individuals than others,” she said.

“O negative can be given in emergency situations where a patient’s blood group is unknown and is often stocked in ambulances and rescue helicopters. Just one trauma patient can need huge quantities of blood in a short amount of time, which is why it’s so important for us to have this on hand.”

Lifeblood says it needs 12,000 new donors of all blood types every month to continue meeting the need for blood.