2. Frequency of infection in donated blood in high and low income countries (WHO 2015).

Transfusion transmitted infection	Frequency in high income countries	Frequency in low income countries
HIV	2 in 100,000 (IQR 0.4 in 100,000 to 20 in 100,000)	850 in 100,000 (IQR 480 in 100,000 to 2000 in 100,000)
HBV	20 in 100,000 (IQR 8 in 100,000 to 24 in 100,000)	3590 in 100,000 (IQR 2010 in 100,000 to 6080 in 100,000)
HCV	20 in 100,000 (IQR 0.4 in 100,000 to 22 in 100,000)	1070 in 100,000 (IQR 630 in 100,000 to 1690 in 100,000)

IQR=interquartile range