Prevalence and Residual Risk of HIV in Volunteer Blood Donors of Zhejiang Province, China, from 2018 to 2022

Table 3

HIV residual risk in blood transfusion transmission.

Donor type	Donors	Donations	Positive	Incidence^a (1/100,000)	vDWP^b	Residual risk	N^#	Overall residual risk (95% CI) (1/1000,000)
First-time donors	1545660	1545660	211	N/A	0.0219	0.444	6.863	0.266 (0.219–0.313)
Repeat donors	1830018	2349472	124	6.77	0.0219	0.148	3.477

Viraemic phase of the diagnostic window period (vDWP); confidence interval (CI); Number of vDWP blood donations. ^aN/A means no data. The positive cases of first-time blood donors can come from new cases or epidemic chronic cases, and the incidence rate cannot be obtained directly. ^bThe window period for individual NAT of HIV RNA is 8 days. The vDWP value = window period/365 = 8/365 = 0.0219. ^#Number (N) of vDWP blood donations from repeat donors = residual risk × total number of donations from repeat donors/1000000; number (N) of vDWP blood donations from first-time donors = residual risk × total number of donations from first-time donors/1 000,000.