Transfusion-transmissible infections are delayed (>24 hours), non-immunological transfusion reactions.
Several viruses are transmissible by blood transfusion.
To minimise the risk of potential blood donors transmitting infectious agents to patients, all donations are subjected to stringent screening procedures. The Australian Red Cross Blood Service mandatory testing includes the screening of donations for a number of transfusion-transmissible viruses which include;
- Human Immunodeficiency Virus (HIV) 1 and 2
- Hepatitis B Virus (HBV)
- Hepatitis C Virus (HCV)
- Human T-cell lymphotropic virus (HTLV) I and II
When required, some red cell and platelet donations undergo viral screening (non-mandatory) by the Blood Service for the presence of Cytomegalovirus (CMV) antibodies in order to provide a CMV seronegative inventory of cellular components. Leucodepletion may be equal to CMV seronegativity in the prevention of transfusion transmission of CMV. There are also some viruses for which there are no routine tests available in Australia, such as Dengue Virus (Dengue Fever) and Parvovirus B19 (B19 viral infection).
In addition, the Blood Service does not test donors for some viruses. For example, Chikungunya virus is such a low risk, that travel deferrals are an effective precaution.
The residual risk of transmission by transfusion varies according to the incidence of the infection in the donor population and the donor screening processes that are in place.
The primary cause of transfusion-transmissible viral infections is thought to be related to donations made by individuals in the window period, which is the interval between the time of infection and the appearance of detectable disease markers, such as specific antibodies or viral nucleic acid sequences.
Clinically assess patients for manifestations of specific viral infections.
Perform liver function tests and specific testing for viral markers.
What to do?
Treat the specific diagnosis, if available.