HHV-6 and HHV-7 in the Blood Supply
http://www.sigmaaldrich.com/technical-documents/articles/biology/blood-screening-for-herpesviruses-using-qpcr.html
HSV-1, HSV-2, VZV and HHV-8 were not found in any of the donations. On the other hand, EBV was found in 72%, HHV-7 in 65%, HHV-6 type B in 30%, and CMV in 1% of the samples. Most remarkably, one donor sample was found to have greater than 6.1 × 107 HHV-6 type B genome equivalents per mL of blood. This appears to be only the second report of such high levels of HHV-6 type B in an otherwise healthy adult donor. - See more at: http://www.sigmaaldrich.com/technical-documents/articles/biology/blood-screening-for-herpesviruses-using-qpcr.html#sthash.INhBld28.dpuf
HSV-1, HSV-2, VZV and HHV-8 were not found in any of the donations. On the other hand, EBV was found in 72%, HHV-7 in 65%, HHV-6 type B in 30%, and CMV in 1% of the samples. Most remarkably, one donor sample was found to have greater than 6.1 × 107 HHV-6 type B genome equivalents per mL of blood. This appears to be only the second report of such high levels of HHV-6 type B in an otherwise healthy adult donor. - See more at: http://www.sigmaaldrich.com/technical-documents/articles/biology/blood-screening-for-herpesviruses-using-qpcr.html#sthash.INhBld28.dpuf
This is why people get Chronic Fatigue Syndrome and other HHV-6-related illnesses from the blood supply.