Now that donor screening and product testing have drastically decreased the transmission of viral infections, nonviral risks of transfusion have gained emphasis and proven to be just as concerning and associated with morbidity and mortality.
- Infectious Risks of Blood Product Testing. Since the introduction of nucleic acid testing for the major transfusion transmittable viral infections (hepatitis C virus in 2000, HIV in 2003, and hepatitis B virus in 2006), the risk of infection from blood product transfusion has decreased substantially (Table 16-10: Residual Risk of Transfusion-Transmitted Infections).
- Human immunodeficiency virus (HIV). The residual risk of HIV has fallen to lower than 1 per 1.8 million blood product transfusions.
- Hepatitis C virus (HCV) is rarer than the other types of transmitted hepatitis and has a relatively benign acute phase, but it progresses to chronic carrier state in up to 85% of infections and is associated with significant risk of fulminate hepatic failure, cirrhosis, hepatocellular carcinoma, and death.
- Hepatitis B virus (low prevalence in the United States compared with the Middle East, Africa, and Asia) is asymptomatic in most patients and rarely progresses to fulminate hepatic failure.
- Human T-cell Lymphotropic Virus (HTLV) 1 and 2
- HTLV-1 causes T-cell leukemia and lymphoma or HTLV-associated myelopathy in a small percentage of infected persons.
- HTLV-2 does not have any significant consequences for immunocompetent or even HIV co-infected patients.
- CMV is the most common transfusion-transmitted disease with an incidence of 1% to 3%.
- In immune-competent recipients, the infection is often asymptomatic or mild and self-limited.
- In immunocompromised patients, particularly neonates, patients with HIV, and transplant recipients, the disease can be associated with severe multiorgan failure involving the liver, lungs, kidneys, hematologic system, gastrointestinal tract, and central nervous system.
- Bacterial contamination marks the largest risk of transfusion (two or three orders of magnitude the risk of transfusion-transmitted viral disease).
- Noninfectious Risks of Blood Product Administration. Given the extensive use of more sensitive methods for screening and controlling the infectious risks of blood product transfusion, noninfectious complications have emerged as the major source of transfusion-related morbidity and mortality (Table 16-11: Noninfectious Transfusion Reactions).