As in any case, the risks and benefits of the blood transfusion must be reviewed with the patient. Given this patient’s particular concerns, special attention should also be paid to the discussion of the risks of contracting transmissible diseases from the blood products she is to receive.

Risk of contracting particular infectious diseases per unit of blood product received:

• Transmission of Hepatitis B virus (1 in 250,000)
• Transmission of HTLV (1 in 3,000,000)
• Transmission of Hepatitis C virus (1 in 3,100,000)
• Transmission of HIV (1 in 4,700,000)

To better explain these numbers in real-life terms to the patient, the physician can consider comparing the above risks to those of various representative everyday hazards: Risk of death from lung cancer after smoking 1 pack/day for 30 years (1 in 10) Annual risk of being murdered in Canada (1 in 60,000) Risk of death from oral contraceptives if under 20 years of age (1 in 300,000) Annual risk of being struck by lightning in Canada (1 in 5,000,000)

The annual risk of being struck by lightning in Canada (1 in 5,000,000) is comparable to the risk of acquiring HIV infection from a unit of blood (1 in 4,700,000) ©qscalpel (illustration by Sarah Moodie)