Human herpesvirus 8 (HHV-8)

Ready to upload
Record number: 
Adverse Occurrence type: 
MPHO Type: 
Estimated frequency: 
Described in an article from 2006 (DOI: 10.1056/NEJMoa055009), transmission from seropositive donors to seronegative donors was estimated at 2.8%, indicating that transmission occurs rarely.
Time to detection: 
Seroconversion was checked 3 months post transfusion.
Alerting signals, symptoms, evidence of occurrence: 
Clinical signs and symptoms were not assessed in this study.
Demonstration of imputability or root cause: 
In the Gobbini publication, looking at the possibility of transmission in Ghana where HHV8 is endemic, one patient went from seronegative for HHV8 to seropositive for HHV8 three months after a transfusion with blood product that was HHV8 PCR positive from an HHV8 seropositive donor. A second HHV8 seronegative recipient who received blood from an HHV8 PCR positive donor did not demonstrate seroconversion. Hladik and colleagues did a similar study in Uganda where they found the risk of seroconversion was significantly higher among recipients of HHV8-seropositive blood than among recipients of seronegative blood (excess risk, 2.8%; P<0.05), and the increase in risk was seen mainly among patients in whom seroconversion occurred 3 to 10 weeks after transfusion (excess risk, 2.7%; P=0.005), a result consistent with the transmission of the virus by transfusion. Blood units stored for up to 4 days were more often associated with seroconversion than those stored for more than 4 days (excess risk, 4.2%; P<0.05).
Imputability grade: 
1 Possible
Suggest references: 
1) Human herpesvirus 8 transfusion transmission in Ghana, an endemic region of West Africa. Gobbini F et al. Transfusion. 52(11):2294-9, 2012 Nov. 2) Transmission of human herpesvirus 8 by blood transfusion. Hladik W, Dollard SC, et al. N Engl J Med. 2006 Sep 28;355(13):1331-8. 3) Vamvakas EC. Is human herpesvirus-8 transmitted by transfusion? Transfus Med Rev. 2010 Jan;24(1):1-14. doi: 10.1016/j.tmrv.2009.09.001. PMID: 19962570. 4) Cannon MJ, Operskalski EA, Mosley JW, Radford K, Dollard SC. Lack of evidence for human herpesvirus-8 transmission via blood transfusion in a historical US cohort. J Infect Dis. 2009 Jun 1;199(11):1592-8. doi: 10.1086/598859. PMID: 19385734. 3) Possible transmission of human herpesvirus-8 by blood transfusion in a historical United States cohort. Dollard SC, Nelson KE, et al. Transfusion. 2005 Apr;45(4):500-3.
MG: Here is another reference, it has a paywall so unclear if this is accessible: Vamvakas EC. Is human herpesvirus-8 transmitted by transfusion? Transfus Med Rev. 2010 Jan;24(1):1-14. doi: 10.1016/j.tmrv.2009.09.001. PMID: 19962570.
Expert comments for publication: 
In the Gobbini pubication, the recipient did not demonstrate HHV8 DNA PCR positivity, nor are symptoms reported to indicate temporal relationship with the blood transfusion. This study took place in Ghana, where prevalence of HHV8 positivity is estimated at >50%, so it is possible that transmission occurred outside of the transfusion. Similar results were obtained in Uganda, that also has high prevalence of HHV8. In US publications, verified transmission of HHV8 has not been seen and overall the literature indicates that whehter transfusion-transmission of HHV8 is a true phenomenon is unclear. It seems possible that under the right circumstances HHV8 may be transfusion-transmissible, but all available data indicate that if it occurs, it is rare and the risk seen in Africa (where the prevalence is higher) cannot be generalized to that of lower-prevalence countries.