Table 3. Estimated number of hepatitis E virus RNA–positive donors not detected, according to 7-day window period risk for apheresis and whole blood donors, England, March 2016–December 2020.

Donation type, year	Donations tested	No. not detected if window period 7 days (95% CI)
Apheresis
2016	69,605	2.62 (1.68–3.90)
2017	74,422	2.19 (1.34–3.38)
2018	70,709	2.62 (1.68–3.90)
2019	68,907	1.64 (0.92–2.70)
2020	66,680	2.62 (1.68–3.90)
Total	350,323	11.70 (7.30–17.79)
Whole blood
2016	413,153	19.02 (16.30–22.06)
2017	1,256,503	28.53 (25.17–32.21)
2018	1,488,808	38.36 (34.46–42.59)
2019	1,450,628	49.73 (45.27–54.52)
2020	1,338,489	41.42 (37.36–45.81)
Total	5,947,581	177.07 (158.55–197.19)