How we manage known, unknown and emerging disease risks
Blood is essential to the delivery of nutrients and oxygen to the body but it can also harbour infectious disease – sometimes days or even weeks before the person shows symptoms.
Known risks are managed by screening donors, however many diseases avoid detection in testing during the early stages of infection. That’s why we screen all donors with both a Donor Health Questionnaire and a pre-donation interview before they give blood.
The Donor Health Questionnaire
Donor screening ensures that someone who appears to be healthy does not make a blood donation that could put a seriously-ill patient at risk. Donors are required to complete a Donor Health Questionnaire in centre prior to each donation. This questionnaire contains a number of personal questions about the donor's health, including medical condition(s), travel history and personal activities. It’s completely confidential and designed to protect both the donor and the person who receives blood.
For anyone who answers ‘yes’ to the screening questions then the Blood Service has a comprehensive eligibility framework which guides its staff on the best course of action. For example, a person could be indefinitely deferred from donating blood while we investigate or if there is insufficient information relating to their personal circumstances.
For health conditions unrelated to infectious disease, such as having suffered a heart attack, the person may be deferred to protect them from any potential negative health effects experienced when giving blood.
What if a person is unwell after donating blood?
If at any time after giving blood a donor feels unwell they should contact the Blood Service immediately on 13 14 95. This ensures the safety of the donor and allows us to assess any potential risks to patients receiving their blood donation that may have been made during the incubation period of an illness.
The Blood Service has a dedicated recall office that works closely with our medical team to assess post-donation events.
Any post-donation illness identified is assessed for risk of infectivity and if a risk is identified, the blood donation and associated blood components are recalled and destroyed.
Why screen when you could just test?
Unfortunately it is not possible to test for every infectious disease across the 1.3 million blood donations we need to collect each year - this is due largely to the time, cost and availability of accredited testing for blood donation. Although we use the very best testing available, even the most sophisticated of tests cannot reliably detect the early signs of an infection
This is why we screen all donors for all relevant risks before collecting their blood. This process helps us identify a potential infectious disease including: HIV, hepatitis B, hepatitis C, syphilis, and human t-cell lymphotropic virus which may not be picked up by our testing in its early stages and protects the patient from being passed a serious infection through the blood they receive.
How do you determine which infectious diseases to screen for, and which to screen and test for?
There are three criteria that the Blood Service uses to determine the risk an infectious disease poses to blood and patient safety and guide our risk management processes.
- Whether the infectious disease is known to be, or could potentially be, transfusion-transmissible;
- How common the disease is in the population; and
- The severity of infection to recipients of blood.
We look at all available evidence and consider all research in determining the risk and our management approach. From time to time, our rules for donor selection and our testing practices will be updated to reflect changes to risk factors.
Can screening help prevent unknown or emerging risks?
The Blood Service has a surveillance framework managed by a dedicated team that closely monitors emerging, re-emerging or emerged infectious diseases.
Existing screening practices can protect the blood supply from new and emerging threats because the process ensures that we do not collect blood from people carrying an infection disease.
An example of this is the Zika Virus. Zika is prevalent in places with existing mosquito-borne infectious diseases such as malaria, dengue or chikungunya. Because its incubation period is shorter than, or similar to, these infections, our existing deferrals for mosquito-borne disease are applied and therefore able to protect the Australian blood supply.
Unknown or emerging risks are managed by ongoing surveillance
Over time, infectious diseases come, go, and sometimes return in a different state that resists previous medical controls.
The emergence or re-emergence of new diseases which cannot be reliably detected in tests, have no effective vaccines, or affect a large number of potential donors and could pose a threat to blood donations.
Fortunately, the Blood Service has in place a thorough surveillance framework that keeps a watching brief on more than 70 emerging, re-emerging and emerged infectious diseases which is referred to internally at the Blood Services as EREEIDs.
Under the EREEID framework, a dedicated team actively monitors and engages with national and international stakeholders and researchers regarding infectious disease developments, taking into account the Australian context, to ensure we maintain one of the safest blood supplies in the world.
They also liaise closely with government departments with communicable disease expertise, and with various international groups involved in horizon scanning.
The EREEID framework includes risk management options for infectious diseases, which may result in changes to donor assessment, blood donor selection and eligibility or the blood screening tests used.
The Blood Service remains vigilant in maintaining the safety of the blood supply. The system place effectively minimises the risk from infectious agents to as low as possible. The Australian blood supply is one of the safest blood supplies in the world with respect to infectious diseases.
Case study: Lyme disease or Lyme-like illness in Australia
The Australian Senate has called an inquiry into the suspected presence of Lyme or Lyme-like illness in Australia.
Lyme disease is caused by a bacteria spread by ticks. To date, no evidence of this bacteria has been found in Australian ticks, despite efforts by researchers and health departments.
People often ask us if Lyme disease or lyme-like illness is transmitted unknowingly via blood transfusions. Lyme or Lyme-like illness is covered by the the Blood Service’s EREEID framework. Lyme or Lyme-like illness is not transmitted by blood transfusions and this information was included in a public submission by the Blood Service to the inquiry in a bid to explain the role that our blood safety program plays in preventing EREEIDs from entering the blood supply.
You can download and view the submission <here>.