| Infection | Residual Risk | Window Period and Comments |
|---|
| Viral Infections |
| Human immunodeficiency virus (HIV) | 1/1,860,800 | 9.1-day window |
| Hepatitis C (HCV) | 1/1,657,700 | 7.4-day window |
| Hepatitis B (HBV) | 1/366,500 | 38-day window |
| Human T-cell lymphotrophic virus (HTLV) | 1/3,394,000 | 51-day window |
| West Nile virus (WNV) | Rare | 11 cases reported from 2003–2010 |
| Cytomegalovirus (CMV)—all donors | 1%–3% | |
| 0.023% | |
| Emerging Infections | rare | Incidence is too small to estimate |
| Chagas' disease and malaria | | Donor screening limits risk in the United States |
| Creutzfeldt-Jakob (vCJD) disease | | Incubation for years |
| Dengue virus and Babesia spp. | | Transient epidemics increase risks |
| Parvovirus (B19v) | | May cause aplastic anemia in immunosuppressed patients |
| Bacterial Contamination (All Types) | 1/3,000 | |
| Packed red blood cells | 1/35,000 | Lower risk than platelet concentrates |
| Platelets | 1/15,000 | Apheresis decreases risk |