Simian Foamy Virus Transmission by Blood and Blood Products


December 13, 2001


Presented by Kay R. Gregory, MS, MT(ASCP)SBB

Director, Regulatory Affairs


The American Association of Blood Banks (AABB) is the professional society for over 8,000 individuals involved in blood banking and transfusion medicine and represents approximately 2,000 institutional members, including blood collection centers, hospital based blood banks, and transfusion services as they collect, process, distribute, and transfuse blood and blood components and hematopoietic stem cells. Our members are responsible for virtually all of the blood collected and more than 80 percent of the blood transfused in this country. For over 50 years, the AABB's highest priority has been to maintain and enhance the safety and availability of the nation's blood supply.


Thank you for your attention to this interesting matter. Human infection with foamy viruses is not new, and was first described in a nasopharyngeal cancer derived cell line 30 years ago.1,2,3 Although there is no convincing evidence of any disease association with human infection3,4, the number of infected persons studied and the average duration of follow up are inadequate to prove they are not pathogenic under some circumstances. We would like to note that Simian Foamy Virus (SFV) is being studied as a safe, efficient alternative to current onco- and lentiviral vectors for gene transfer in cells from a broad spectrum of lineages across species boundaries.5


Foamy viruses are ubiquitous in captive primate populations, and present in many other animal genera (infections in man appear to represent rare zoonotic events3). SFV does not appear to be pathogenic. Of interest in this regard is the evidence that the putative hepatitis viruses, TT, GBV, and SEN, are either nonpathogenic or uncommonly so. Actually, GBV infection seems to have a beneficial impact on the course of HIV infection,6,7 reminding us that all viral infections may not be dangerous.


The AABB supports careful and expeditious inquiry into the prevalence of SFV infection in selected populations, including blood donors, and longitudinal analysis of the impact of such infections where identified. Epidemiological and laboratory studies of primate workers in comparison with appropriately matched controls for unique patterns of illness will provide useful information.


Newer technologies allow us to detect, with greater and greater sensitivity, more and more infectious agents. Concerns about the potential pathogenicity of these agents will challenge us repeatedly. We are ready to join the public health authorities in studies that may help clarify whether these less well known agents represent a risk for transfusion recipients. We applaud the monitoring activities that are taking place. At the same time, we would like to emphasize that available data on SFV suggest action regarding blood donors is not currently appropriate.


Thank you for the opportunity to comment.




1. Achong B, Mansell PWA, Epstein MA, et al. An unusual virus in cultures from a human nasopharyngeal carcinoma. J Natl Cancer Inst 1971;46:299-307.


2. Heneine W, Switzer WM, Sandstrom P, et al. Identification of a human population infected with simian foamy viruses. Nature Med 1998;4:403-7.


3. Meiering CD, Linial ML. Historical perspective of foamy virus epidemiology and infection. Clin Microbiol Rev 2001;14:165-76.


4. Schweizer M, Turek R, Hahn H, et al. Markers of foamy virus infections in monkeys, apes, and accidentally infected humans: appropriate testing fails to confirm suspected foamy virus prevalence in humans. AIDS Res Hum Retroviruses 1995;11:161-70.


5. Mergia A, Chari S, Kolson DL, et al. The efficiency of simian foamy virus vector type-1 (SFV-1) in nondividing cells and in human PBLs. Virology 2001;280:243-52.


6. Xiang J, Wunschmann S, Diekema DJ, et al. Effect of coinfection with GB virus C on survival among patients with HIV infection. N Engl J Med 2001;345:707-14.


7. Tillmann HL, Heiken H, Knapik-Botor A, et al. Infection with GB virus C and reduced mortality among HIV-infected patients. N Engl J Med 2001;345:715-24.