Malaria: How data drives our decision making
Go behind the scenes to understand how and why we reviewed donation eligibility criteria related to malaria.
Every change to blood donation rules starts with the same question: can we improve donors’ experience, while keeping the blood supply safe?
When it comes to malaria, years of research and data analysis have helped us answer that question with increasing confidence. The result is a change approved by the TGA and state, territory and federal governments that simplifies the donor journey while maintaining Australia's exceptionally high safety standards.
To learn more about the disease malaria, visit our companion article, Malaria: The story of a tiny parasite with a big impact.
The hidden challenge
One of the great challenges for maintaining a malaria-free blood supply is that some people can carry malaria parasites without knowing it. This is called ‘asymptomatic malaria’ and usually occurs when the infected person’s immune system has learnt how to keep the parasite under control, but not fully eliminated it from the body. They show no symptoms of malaria, but still pose a risk of transmitting malaria via a blood donation.
Following the evidence
Our researchers delved through years of malaria testing datasets to determine how malaria poses a risk to Australia’s blood supply. The data shows that the risk of transfusion-transmission of malaria was already low in our existing system, but there’s room to improve how we screen and test for malaria.
Through mathematical modelling, our researchers found that new donors, or donors who haven’t donated within the last 2 years, who have lived continuously in high malaria risk areas for prolonged periods are the most likely to carry asymptomatic malaria (we modelled prolonged periods as 6 months or more, but note those at risk typically spend several years in a malaria area). People who travel temporarily to a high-risk area are much less likely to develop asymptomatic malaria, because it occurs typically with multiple exposures and/or infections over time. That means regular donors who visit overseas for up to 6 months are at low risk of carrying malaria.
Importantly, our modelling showed that changes to how we manage malaria will maintain Australia’s extremely low risk of transfusion-transmitted malaria.
Good news for travellers
The changes mean that new donors won’t be asked to remember every holiday they’ve ever been on in the last 3 years. Instead, we’ll focus on travel within the last four months, which is the most relevant period for assessing acute malaria risk.
Why four months? Because malaria infections can take time to develop, and four months provides an important safety buffer.
If a donor has travelled to a malaria risk area, we’ll ask them to only donate plasma for the next 120 days. That’s because their plasma can be processed into 18 different life-saving treatments, and the processing eliminates any risk of malaria transmission. After 120 days, it’s your call – blood or plasma are both available.
What’s not changing
Meanwhile, things won’t change for new or returned donors who’ve lived continuously in malaria risk areas for 6 months or more. Just like travellers, we’ll first ask this group of donors to only donate plasma for the next 120 days. At the end of that period, we’ll test their blood to see if it contains malaria antibodies. Carrying malaria antibodies indicates past exposure to malaria. This doesn’t mean they’re currently infected, but it does mean they’re more likely to carry the hidden challenge, asymptomatic malaria. If that’s the case, we’ll continue to ask these donors to donate plasma only. But if the test is negative, it’s their call again – donating blood or plasma is possible.
A more efficient approach
These changes make life a lot simpler for our teams. We’re expecting to reduce malaria risk assessments and malaria testing by about two-thirds as we won’t need to check for malaria antibodies in regular donors who’ve travelled overseas temporarily. This will be a significant time and cost saving, which means we can focus on other areas of our role in keeping Australia’s blood supply safe and sufficient.
Good news for everyone
The safety of Australia’s blood supply is unchanged. Our risk assessments show that adjusting our approach to malaria testing is the best option to protect the blood supply, balancing operational ease and risk. And in even better news, our estimates show these changes will unlock approximately 300 more donations every year without compromising on safety.
So no matter where you’ve travelled to, or from, we can’t wait to welcome you at a donor centre soon.
Doctor Patrick Capon
Scientific Communications Specialist
Patrick is a science communications specialist who's passionate about the role of science communication in increasing research impact. He works closely with all Lifeblood researchers to translate their research into meaningful content and enable anyone to connect with our outcomes - whether that's scientists, journalists, donors, or the wider community.Patrick holds a PhD in Chemistry, is an award-winning presenter, and has experience in medical writing and science communication for audiences ranging from school students to medical professionals.
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